Pub Date : 2024-07-23DOI: 10.1101/2024.07.21.604507
Laura Elise Bruijn, Natascha Fonseca Neves, Connie M van Rhijn, Jaap Hamming, Antoon van den Bogaerdt, Johannes Lindeman
Introduction: Plaque rupture is the primary trigger of the acute clinical manifestations of atherosclerotic disease. So far, factual insight in the processes leading up to cap destabilization is largely missing. In order to overcome this knowledge gap, a pseudo-timeline of atherosclerosis progression was established in order to systematically map the qualitative changes in cap characteristics during lesion progression and destabilization. Material and Methods: A pseudo-timeline was created by randomly selecting preclassified (revised AHA classification, at least 10 per stage) left coronary artery FFPE specimens obtained during tissue donation (aortic valve procurement). Qualitative changes were visualized by (immuno)histochemistry, immunofluorescence and confocal microscopy. Scoring was performed by two observers using semiquantitative scoring estimates. Results: The median age of the donors was 56 years (IQR 51.5-59), and 67% of the patients was male. Movat staining indicated a consistent pattern of cap formation, maturation and destabilization. A distinctive cap emerged in the early fibroatheroma stage of progressive atherosclerosis. Disease progression was accompanied by profound fibrotic changes in the gap, and a progressive presence of inanotic (nutritional deprivation leading to dissolution) mesenchymal cells. Plaque rupture was preceded by thinning of the collagen fibers and accumulation of foam cells in the central portion of the thin cap. No evidence was found for a direct involvement of neovascularization in the destabilization process. Conclusion: The pseudo-time line of atherosclerotic lesion development characterizes the development of an unstable cap as a degenerative and fibrotic process with progressive exhaustion of the mesenchymal cell population. This study provides a rationale for the limited efficacy of medical strategies aimed at plaque stabilization.
{"title":"The multifaceted process of human coronary atherosclerotic cap destabilisation","authors":"Laura Elise Bruijn, Natascha Fonseca Neves, Connie M van Rhijn, Jaap Hamming, Antoon van den Bogaerdt, Johannes Lindeman","doi":"10.1101/2024.07.21.604507","DOIUrl":"https://doi.org/10.1101/2024.07.21.604507","url":null,"abstract":"Introduction: Plaque rupture is the primary trigger of the acute clinical manifestations of atherosclerotic disease. So far, factual insight in the processes leading up to cap destabilization is largely missing. In order to overcome this knowledge gap, a pseudo-timeline of atherosclerosis progression was established in order to systematically map the qualitative changes in cap characteristics during lesion progression and destabilization. Material and Methods: A pseudo-timeline was created by randomly selecting preclassified (revised AHA classification, at least 10 per stage) left coronary artery FFPE specimens obtained during tissue donation (aortic valve procurement). Qualitative changes were visualized by (immuno)histochemistry, immunofluorescence and confocal microscopy. Scoring was performed by two observers using semiquantitative scoring estimates. Results: The median age of the donors was 56 years (IQR 51.5-59), and 67% of the patients was male. Movat staining indicated a consistent pattern of cap formation, maturation and destabilization. A distinctive cap emerged in the early fibroatheroma stage of progressive atherosclerosis. Disease progression was accompanied by profound fibrotic changes in the gap, and a progressive presence of inanotic (nutritional deprivation leading to dissolution) mesenchymal cells. Plaque rupture was preceded by thinning of the collagen fibers and accumulation of foam cells in the central portion of the thin cap. No evidence was found for a direct involvement of neovascularization in the destabilization process. Conclusion: The pseudo-time line of atherosclerotic lesion development characterizes the development of an unstable cap as a degenerative and fibrotic process with progressive exhaustion of the mesenchymal cell population. This study provides a rationale for the limited efficacy of medical strategies aimed at plaque stabilization.","PeriodicalId":501471,"journal":{"name":"bioRxiv - Pathology","volume":"55 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141775403","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-23DOI: 10.1101/2024.07.22.604581
Julie Isaia, Molly Baur, Jerome Wassef, Sarah Monod, Olivier Glaizot, Philippe Christe, Romain Pigeault
Background: In vector-borne diseases, invertebrate hosts are exposed to highly variable quantities of parasites during their blood meal. This heterogeneity may partly explain the overdispersed distribution of parasites within the vector population, as well as the variability in the extrinsic incubation period (EIP) of the parasite. Indeed, the quantity of parasites ingested is often considered as a good predictor of the quantity of parasites that will develop within the vectors, as well as the speed at which they will develop (EIP). However, density-dependent processes can strongly influence the relationship between parasite burden in the vertebrate host and in vectors, making this relationship not always clear. Methods: Here, we used the avian malaria system to investigate whether the proportion of red blood cells infected by sexual and/or asexual stages of malaria parasite influences the intensity of malaria infection and the EIP of Plasmodium within the invertebrate vectors. For this purpose, we have experimentally infected twelve vertebrate hosts in order to generate a range of intensity of infection. More than a thousand mosquitoes took a blood meal on these hosts and the development of Plasmodium within the vectors was followed for more than 20 days. Results: The main finding presented in this study reveals a negative relationship between the intensity of infection in the vertebrate host and the EIP. Four days were sufficient for 10% of infected mosquitoes fed on the most infected hosts to become infectious. However, the number of transmissible stages did not significantly vary according to the vertebrate host intensity of infection. Conclusion: While the quantity of ingested parasites had no impact on the density of transmissible stages in infectious mosquitoes, the EIP was affected. Studies have demonstrated that small changes in the EIP can have a significant effect on the number of mosquitoes living long enough to transmit parasites. Here, we observed a difference of 4-6 days in the detection of the first transmissible stages, depending on the intensity of infection of the bitten vertebrate host. Considering that a gonotrophic cycle lasts 3-4 days, the shortened EIP observed here may have significant effects on Plasmodium transmission. Keywords: Avian malaria, Plasmodium, Extrinsic Incubation Period, EIP, Transmission, Overdispersion
{"title":"Impact of vertebrate host parasitaemia on Plasmodium development within mosquitoes","authors":"Julie Isaia, Molly Baur, Jerome Wassef, Sarah Monod, Olivier Glaizot, Philippe Christe, Romain Pigeault","doi":"10.1101/2024.07.22.604581","DOIUrl":"https://doi.org/10.1101/2024.07.22.604581","url":null,"abstract":"Background: In vector-borne diseases, invertebrate hosts are exposed to highly variable quantities of parasites during their blood meal. This heterogeneity may partly explain the overdispersed distribution of parasites within the vector population, as well as the variability in the extrinsic incubation period (EIP) of the parasite. Indeed, the quantity of parasites ingested is often considered as a good predictor of the quantity of parasites that will develop within the vectors, as well as the speed at which they will develop (EIP). However, density-dependent processes can strongly influence the relationship between parasite burden in the vertebrate host and in vectors, making this relationship not always clear. Methods: Here, we used the avian malaria system to investigate whether the proportion of red blood cells infected by sexual and/or asexual stages of malaria parasite influences the intensity of malaria infection and the EIP of Plasmodium within the invertebrate vectors. For this purpose, we have experimentally infected twelve vertebrate hosts in order to generate a range of intensity of infection. More than a thousand mosquitoes took a blood meal on these hosts and the development of Plasmodium within the vectors was followed for more than 20 days. Results: The main finding presented in this study reveals a negative relationship between the intensity of infection in the vertebrate host and the EIP. Four days were sufficient for 10% of infected mosquitoes fed on the most infected hosts to become infectious. However, the number of transmissible stages did not significantly vary according to the vertebrate host intensity of infection. Conclusion: While the quantity of ingested parasites had no impact on the density of transmissible stages in infectious mosquitoes, the EIP was affected. Studies have demonstrated that small changes in the EIP can have a significant effect on the number of mosquitoes living long enough to transmit parasites. Here, we observed a difference of 4-6 days in the detection of the first transmissible stages, depending on the intensity of infection of the bitten vertebrate host. Considering that a gonotrophic cycle lasts 3-4 days, the shortened EIP observed here may have significant effects on Plasmodium transmission. Keywords: Avian malaria, Plasmodium, Extrinsic Incubation Period, EIP, Transmission, Overdispersion","PeriodicalId":501471,"journal":{"name":"bioRxiv - Pathology","volume":"12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141775407","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-22DOI: 10.1101/2024.07.18.604097
Benjamin Riocreux-Verney, Marie Verneret, Remi Diesler, Christine Dolmazon, Barbara Gineys, Jean-Luc Cadore, Jocelyn Turpin, Caroline Leroux
ENTV (Enzootic Nasal Tumor Virus) and JSRV (Jaagsiekte Sheep Retrovirus) are β-retroviruses responsible for respiratory cancers in sheep and goats. In this study, we analyzed the genetic features of the sheep and goat β-retrovirus (29 JSRV and 24 ENTV strains) circulating in France to identify molecular signatures associated with disease severity in flocks. We developed a highly specific PCR to amplify and sequence exogenous targeted regions or near full length proviruses based on limited discriminating motifs along their genomes. The phylogenetic reconstructions based on the LTR and env regions suggest that one major strain is circulating on the French territory for ENTV-1 and ENTV-2 while not clustering with already published Spanish, Canadian or Chinese strains. JSRV strains circulating in French sheep flocks were distributed in 2 distinct genetic clades clustering with sequences originating from North America, Africa and United-Kingdom. JSRV clade I was found to be associated with a higher incidence of cancer in French flocks. Specific motifs spanning the entire JSRV genome particularly in the LTRs and in the intracytoplasmic domain of the envelope were detected between the two genetic subtypes. This work represents the first nationwide study describing the circulation of the three closely related β-oncogenic retrovirus JSRV, ENTV-1 and ENTV-2 in French sheep and goat flocks. Better characterization of strain genetics is a critical step in monitoring circulating β-retrovirus, especially those associated with higher cancer incidence in small ruminants.
{"title":"Association between genetic clades and cancer prevalence suggested by French-wide study of oncogenic small ruminant beta-retroviruses diversity","authors":"Benjamin Riocreux-Verney, Marie Verneret, Remi Diesler, Christine Dolmazon, Barbara Gineys, Jean-Luc Cadore, Jocelyn Turpin, Caroline Leroux","doi":"10.1101/2024.07.18.604097","DOIUrl":"https://doi.org/10.1101/2024.07.18.604097","url":null,"abstract":"ENTV (Enzootic Nasal Tumor Virus) and JSRV (Jaagsiekte Sheep Retrovirus) are β-retroviruses responsible for respiratory cancers in sheep and goats. In this study, we analyzed the genetic features of the sheep and goat β-retrovirus (29 JSRV and 24 ENTV strains) circulating in France to identify molecular signatures associated with disease severity in flocks. We developed a highly specific PCR to amplify and sequence exogenous targeted regions or near full length proviruses based on limited discriminating motifs along their genomes. The phylogenetic reconstructions based on the LTR and env regions suggest that one major strain is circulating on the French territory for ENTV-1 and ENTV-2 while not clustering with already published Spanish, Canadian or Chinese strains. JSRV strains circulating in French sheep flocks were distributed in 2 distinct genetic clades clustering with sequences originating from North America, Africa and United-Kingdom. JSRV clade I was found to be associated with a higher incidence of cancer in French flocks. Specific motifs spanning the entire JSRV genome particularly in the LTRs and in the intracytoplasmic domain of the envelope were detected between the two genetic subtypes.\u0000This work represents the first nationwide study describing the circulation of the three closely related β-oncogenic retrovirus JSRV, ENTV-1 and ENTV-2 in French sheep and goat flocks. Better characterization of strain genetics is a critical step in monitoring circulating β-retrovirus, especially those associated with higher cancer incidence in small ruminants.","PeriodicalId":501471,"journal":{"name":"bioRxiv - Pathology","volume":"74 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141775404","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-22DOI: 10.1101/2024.07.18.604201
Valentina Dargam, Anet Sanchez, Aashiya Kolengaden, Yency Perez, Rebekah Arias, Ana M Valentin Cabrera, Daniel Chaparro, Christopher Tarafa, Alexandra Coba, Nathan Yapaolo, Emily A Todd, Monique Monelle Williams, Lina A Shehadeh, Joshua D Hutcheson
BACKGROUND Chronic kidney disease (CKD) and cardiovascular disease (CVD) often co-exist and interact; however, notable sex-dependent differences are observed in how these conditions manifest and progress in parallel, despite men and women sharing similar risk factors. Identifying sex-specific diagnostic markers of cardiac structure and function throughout CKD progression could elucidate why the development and progression of these diseases differ by sex. METHODS AND RESULTS Adult, C57BL/6J male and female mice were subjected to a high-adenine (0.2%) diet throughout 12-weeks to induce CKD. Control mice were fed a normal chow diet. Every three weeks, electrocardiogram (ECG) and echocardiogram-based markers of cardiac physiology were evaluated. Adenine-induced CKD showed markers of left ventricular (LV) hypertrophy in male mice only. CKD males had markers indicative of LV systolic and diastolic dysfunction throughout regimen duration, worsening as disease progressed. Adenine males had a prolonged QTc and STc intervals when compared to Adenine females and Control males. Sex-dependent differences in the duration of the Speak-J marker, measured via ECG, was identified, with Adenine males showing increases in duration earlier than Adenine females compared to their Control counterparts. CONCLUSIONS In this study, we identified sex-dependent differences in cardiac structure, function, and electrophysiology in a mouse model of CKD-induced CVD throughout disease progression. We found that male mice are more prone to developing LV hypertrophy, systolic dysfunction, and diastolic dysfunction, with significant increases in ECG markers indicative of ventricular dysfunction observed in adenine-treated males at late stages of the disease. Additionally, we identified a new ECG parameter, Speak-J duration, that highlights sex-specific cardiac electrophysiological changes, demonstrating the model's utility in studying sex-dependent cardiac differences.
{"title":"Sex-Specific Changes in Cardiac Function and Electrophysiology During Progression of Adenine-Induced Chronic Kidney Disease in Mice","authors":"Valentina Dargam, Anet Sanchez, Aashiya Kolengaden, Yency Perez, Rebekah Arias, Ana M Valentin Cabrera, Daniel Chaparro, Christopher Tarafa, Alexandra Coba, Nathan Yapaolo, Emily A Todd, Monique Monelle Williams, Lina A Shehadeh, Joshua D Hutcheson","doi":"10.1101/2024.07.18.604201","DOIUrl":"https://doi.org/10.1101/2024.07.18.604201","url":null,"abstract":"BACKGROUND\u0000Chronic kidney disease (CKD) and cardiovascular disease (CVD) often co-exist and interact; however, notable sex-dependent differences are observed in how these conditions manifest and progress in parallel, despite men and women sharing similar risk factors. Identifying sex-specific diagnostic markers of cardiac structure and function throughout CKD progression could elucidate why the development and progression of these diseases differ by sex.\u0000METHODS AND RESULTS\u0000Adult, C57BL/6J male and female mice were subjected to a high-adenine (0.2%) diet throughout 12-weeks to induce CKD. Control mice were fed a normal chow diet. Every three weeks, electrocardiogram (ECG) and echocardiogram-based markers of cardiac physiology were evaluated. Adenine-induced CKD showed markers of left ventricular (LV) hypertrophy in male mice only. CKD males had markers indicative of LV systolic and diastolic dysfunction throughout regimen duration, worsening as disease progressed. Adenine males had a prolonged QTc and STc intervals when compared to Adenine females and Control males. Sex-dependent differences in the duration of the Speak-J marker, measured via ECG, was identified, with Adenine males showing increases in duration earlier than Adenine females compared to their Control counterparts.\u0000CONCLUSIONS\u0000In this study, we identified sex-dependent differences in cardiac structure, function, and electrophysiology in a mouse model of CKD-induced CVD throughout disease progression. We found that male mice are more prone to developing LV hypertrophy, systolic dysfunction, and diastolic dysfunction, with significant increases in ECG markers indicative of ventricular dysfunction observed in adenine-treated males at late stages of the disease. Additionally, we identified a new ECG parameter, Speak-J duration, that highlights sex-specific cardiac electrophysiological changes, demonstrating the model's utility in studying sex-dependent cardiac differences.","PeriodicalId":501471,"journal":{"name":"bioRxiv - Pathology","volume":"56 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141775405","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-22DOI: 10.1101/2024.07.18.603554
Biagio Palmisano, Chiara Tavanti, Giorgia Farinacci, Giorgio Gosti, Marco Leonetti, Samantha Donsante, Giuseppe Giannicola, Natasha Appelman-Dijkstra, Alessandro Corsi, Ernesto Ippolito, Mara Riminucci
Bone pain is a major symptom of many skeletal disorders. Fibrous dysplasia (FD) is a genetic disease with mono or polyostotic skeletal phenotype due to the post-zygotic occurrence of the causative Gsalpha mutation. Bone pain in FD often associates with skeletal deformities and fractures or nerve impingement by the pathological tissue. However, even in the absence of complications, FD patients often complain of a chronic pain that does not correlate with their disease burden. Multiple hypotheses have been made to explain this pain. However, its pathogenetic mechanisms remain, as yet, largely unexplored. In this study, we first demonstrate that the FD mouse model EF1alpha-GsalphaR201C develops a painful-like behavior and an altered response to nociceptive stimuli that, as in FD patients, do not correlate with the severity of their phenotype, thus providing a reliable model to study bone pain in FD. Then, we show that in EF1alpha-GsalphaR201C mice, the overall pattern of skeletal innervation is preserved and that within FD lesions, sensory fibers are variably and focally distributed, mainly at perivascular sites. Finally, we provide the first analysis of a series of human FD bone biopsies showing that sensory nerve fibers are rarely detected within the pathological tissue. These data confirm that bone pain is an intrinsic and reproducible feature of FD. They also show that, albeit sensory nerve fibers are found within FD lesions and may contribute to the unpleasant sensation that accompanies the disease, pathological sensory nerve sprouting or formation of neuromas are not detected in the Gsalpha-mutated skeleton.
{"title":"Bone pain in Fibrous dysplasia does not rely on aberrant sensory nerve sprouting or neuroma formation","authors":"Biagio Palmisano, Chiara Tavanti, Giorgia Farinacci, Giorgio Gosti, Marco Leonetti, Samantha Donsante, Giuseppe Giannicola, Natasha Appelman-Dijkstra, Alessandro Corsi, Ernesto Ippolito, Mara Riminucci","doi":"10.1101/2024.07.18.603554","DOIUrl":"https://doi.org/10.1101/2024.07.18.603554","url":null,"abstract":"Bone pain is a major symptom of many skeletal disorders. Fibrous dysplasia (FD) is a genetic disease with mono or polyostotic skeletal phenotype due to the post-zygotic occurrence of the causative Gsalpha mutation. Bone pain in FD often associates with skeletal deformities and fractures or nerve impingement by the pathological tissue. However, even in the absence of complications, FD patients often complain of a chronic pain that does not correlate with their disease burden. Multiple hypotheses have been made to explain this pain. However, its pathogenetic mechanisms remain, as yet, largely unexplored.\u0000In this study, we first demonstrate that the FD mouse model EF1alpha-GsalphaR201C develops a painful-like behavior and an altered response to nociceptive stimuli that, as in FD patients, do not correlate with the severity of their phenotype, thus providing a reliable model to study bone pain in FD. Then, we show that in EF1alpha-GsalphaR201C mice, the overall pattern of skeletal innervation is preserved and that within FD lesions, sensory fibers are variably and focally distributed, mainly at perivascular sites. Finally, we provide the first analysis of a series of human FD bone biopsies showing that sensory nerve fibers are rarely detected within the pathological tissue. These data confirm that bone pain is an intrinsic and reproducible feature of FD. They also show that, albeit sensory nerve fibers are found within FD lesions and may contribute to the unpleasant sensation that accompanies the disease, pathological sensory nerve sprouting or formation of neuromas are not detected in the Gsalpha-mutated skeleton.","PeriodicalId":501471,"journal":{"name":"bioRxiv - Pathology","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141775354","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-22DOI: 10.1101/2024.07.18.604040
Gemma Martinez-Rivas, Maria Victoria Ayala, Sebastien Bender, Gilles Roussine Codo, Karolina Weronika Swiderska, Alessio Lampis, Laura Pedroza, Melisa Merdanovic, Pierre Sicard, Emilie Pinault, Laurence Richard, Francesca Lavatelli, Diana Canetti, Alexia Rinsant, Kaaki Sihem, Cecile Ory, Christelle Oblet, Justine Pollet, Eyad Naser, Alexander Carpinteiro, Murielle Roussel, Vincent Javaugue, Arnaud Jaccard, Amelie Bonaud, Laurent Delpy, Michael Ehrmann, Frank Bridoux, Christophe Sirac
AL amyloidosis is one of the most common types of systemic amyloidosis, caused by the deposition in tissues of fibrillar aggregates of abnormal immunoglobulin (Ig) light chain (LC), leading to organ dysfunction. The most frequent and severe forms affect the kidneys and heart, the latter being associated with a poor prognosis. Despite extensive efforts to decipher the mechanisms of fibril formation and their toxicity, the lack of reliable in vivo models hinders the study of the disease in its physiological context. We developped a transgenic mouse model producing high amounts of a human AL light chain (LC). While mice exceptionnaly develop spontaneous AL amyloidosis and do not exhibit organ toxicity due to the circulating amyloidogenic free LC, a single injection of amyloid fibrils, made up of the variable domain (VL) of the human LC, or soluble VL led to amyloid deposits in the heart, vessels, spleen and, to a lesser extent, in the kidney and other visceral tissues. AL fibrils in mice contain both full length and fragmented LC with a fragmentation pattern highly superposable to that of human AL fibrils from the same LC subgroup (IGLV6-57). They also develop an early cardiac dysfunction closely resembling the human disease with increased NT-proBNP,and activation of pathways involved in the extracellular matrix remodeling and fibrosis. Overall, this transgenic AL model closely reproduces human cardiac AL amyloidosis and shares with humans the biochemical composition of the deposits, arguing for a conserved mechanism of amyloid fibrils formation. It also shows that a partial degradation of the LC is likely required to initiate amyloid fibril formations. This model offers a new avenue for research on AL amyloidosis and fills an important gap for the preclinical evaluation of new therapies.
AL 淀粉样变性是全身性淀粉样变性中最常见的类型之一，由异常免疫球蛋白（Ig）轻链（LC）的纤维状聚集体沉积在组织中引起，导致器官功能障碍。最常见和最严重的形式是影响肾脏和心脏，后者的预后较差。尽管人们为破译纤维的形成机制及其毒性做出了大量努力，但由于缺乏可靠的体内模型，阻碍了在生理背景下对该疾病的研究。我们开发了一种能产生大量人类 AL 轻链（LC）的转基因小鼠模型。虽然小鼠例外地发生了自发性 AL 淀粉样变性，并且不会因循环中的淀粉样蛋白游离LC而表现出器官毒性，但单次注射由人 AL 轻链的可变结构域（VL）或可溶性 VL 组成的淀粉样蛋白纤维会导致淀粉样蛋白沉积在心脏、血管和脾脏，其次是肾脏和其他内脏组织。小鼠体内的 AL 纤维既包含全长的 LC，也包含片段化的 LC，其片段化模式与来自同一 LC 亚群（IGLV6-57）的人类 AL 纤维高度重合。小鼠还出现了与人类疾病非常相似的早期心脏功能障碍，NT-proBNP 增高，细胞外基质重塑和纤维化途径被激活。总之，这种转基因 AL 模型近似再现了人类心脏 AL 淀粉样变性病，而且沉积物的生化成分与人类相同，证明淀粉样纤维形成的机制是保守的。它还表明，淀粉样纤维的形成可能需要低密度脂蛋白的部分降解。该模型为研究 AL 淀粉样变性提供了一条新途径，并填补了临床前评估新疗法的一个重要空白。
{"title":"A mouse model of cardiac AL amyloidosis unveils mechanisms of tissue accumulation and toxicity of amyloid fibrils","authors":"Gemma Martinez-Rivas, Maria Victoria Ayala, Sebastien Bender, Gilles Roussine Codo, Karolina Weronika Swiderska, Alessio Lampis, Laura Pedroza, Melisa Merdanovic, Pierre Sicard, Emilie Pinault, Laurence Richard, Francesca Lavatelli, Diana Canetti, Alexia Rinsant, Kaaki Sihem, Cecile Ory, Christelle Oblet, Justine Pollet, Eyad Naser, Alexander Carpinteiro, Murielle Roussel, Vincent Javaugue, Arnaud Jaccard, Amelie Bonaud, Laurent Delpy, Michael Ehrmann, Frank Bridoux, Christophe Sirac","doi":"10.1101/2024.07.18.604040","DOIUrl":"https://doi.org/10.1101/2024.07.18.604040","url":null,"abstract":"AL amyloidosis is one of the most common types of systemic amyloidosis, caused by the deposition in tissues of fibrillar aggregates of abnormal immunoglobulin (Ig) light chain (LC), leading to organ dysfunction. The most frequent and severe forms affect the kidneys and heart, the latter being associated with a poor prognosis. Despite extensive efforts to decipher the mechanisms of fibril formation and their toxicity, the lack of reliable in vivo models hinders the study of the disease in its physiological context. We developped a transgenic mouse model producing high amounts of a human AL light chain (LC). While mice exceptionnaly develop spontaneous AL amyloidosis and do not exhibit organ toxicity due to the circulating amyloidogenic free LC, a single injection of amyloid fibrils, made up of the variable domain (VL) of the human LC, or soluble VL led to amyloid deposits in the heart, vessels, spleen and, to a lesser extent, in the kidney and other visceral tissues. AL fibrils in mice contain both full length and fragmented LC with a fragmentation pattern highly superposable to that of human AL fibrils from the same LC subgroup (IGLV6-57). They also develop an early cardiac dysfunction closely resembling the human disease with increased NT-proBNP,and activation of pathways involved in the extracellular matrix remodeling and fibrosis. Overall, this transgenic AL model closely reproduces human cardiac AL amyloidosis and shares with humans the biochemical composition of the deposits, arguing for a conserved mechanism of amyloid fibrils formation. It also shows that a partial degradation of the LC is likely required to initiate amyloid fibril formations. This model offers a new avenue for research on AL amyloidosis and fills an important gap for the preclinical evaluation of new therapies.","PeriodicalId":501471,"journal":{"name":"bioRxiv - Pathology","volume":"60 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141775459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-19DOI: 10.1101/2024.07.16.603749
Zhengping Hu, Issahy Cano, Fengyang Lei, Jie Liu, Ramon Bossardi Ramos, Harper Gordon, Eleftherios I Paschalis, Magali Saint-Geniez, Yin Shan Eric Ng, Patricia A D'Amore
Background: Endomucin (EMCN), an endothelial-specific glycocalyx component, was found to be highly expressed by the endothelium of the renal glomerulus. We reported an anti-inflammatory role of EMCN and its involvement in the regulation of vascular endothelial growth factor (VEGF) activity through modulating VEGF receptor 2 (VEGFR2) endocytosis. The goal of this study is to investigate the phenotypic and functional effects of EMCN deficiency using the first global EMCN knockout mouse model. Methods: Global EMCN knockout mice were generated by crossing EMCN-floxed mice with ROSA26-Cre mice. Flow cytometry was employed to analyze infiltrating myeloid cells in the kidneys. The ultrastructure of the glomerular filtration barrier was examined by transmission electron microscopy, while urinary albumin, creatinine, and total protein levels were analyzed from freshly collected urine samples. Expression and localization of EMCN, EGFP, CD45, CD31, CD34, podocin, albumin, and α-smooth muscle actin were examined by immunohistochemistry. Mice were weighed regularly, and their systemic blood pressure was measured using a non-invasive tail-cuff system. Glomerular endothelial cells and podocytes were isolated by fluorescence-activated cell sorting for RNA-seq. Transcriptional profiles were analyzed to identify differentially expressed genes in both endothelium and podocytes, followed by gene ontology analysis of up- and down-regulated genes. Protein levels of EMCN, albumin, and podocin were quantified by Western blot. Results: EMCN-/- mice were viable with no gross anatomical defects in kidneys. The EMCN-/- mice exhibited increased infiltration of CD45+ cells, with an increased proportion of Ly6GhighLy6Chigh myeloid cells and higher VCAM-1 expression. EMCN-/- mice displayed albuminuria with increased albumin in the Bowman's space compared to the EMCN+/+ littermates. Glomeruli in EMCN-/- mice revealed fused and effaced podocyte foot processes and disorganized endothelial fenestrations. We found no significant difference in blood pressure between EMCN knockout mice and their wild-type littermates. RNA-seq of glomerular endothelial cells revealed downregulation of cell-cell adhesion and MAPK/ERK pathways, along with glycocalyx and extracellular matrix remodeling. In podocytes, we observed reduced VEGF signaling and alterations in cytoskeletal organization. Notably, there was a significant decrease in both mRNA and protein levels of podocin, a key component of the slit diaphragm. Conclusion: Our study demonstrates a critical role of the endothelial marker EMCN in supporting normal glomerular filtration barrier structure and function, presumably by maintaining glomerular endothelial homeostasis through modulation of VEGFR2 signaling and blocking leukocyte adhesion.
{"title":"Deletion of the endothelial glycocalyx component endomucin leads to impaired glomerular structure and function","authors":"Zhengping Hu, Issahy Cano, Fengyang Lei, Jie Liu, Ramon Bossardi Ramos, Harper Gordon, Eleftherios I Paschalis, Magali Saint-Geniez, Yin Shan Eric Ng, Patricia A D'Amore","doi":"10.1101/2024.07.16.603749","DOIUrl":"https://doi.org/10.1101/2024.07.16.603749","url":null,"abstract":"Background: Endomucin (EMCN), an endothelial-specific glycocalyx component, was found to be highly expressed by the endothelium of the renal glomerulus. We reported an anti-inflammatory role of EMCN and its involvement in the regulation of vascular endothelial growth factor (VEGF) activity through modulating VEGF receptor 2 (VEGFR2) endocytosis. The goal of this study is to investigate the phenotypic and functional effects of EMCN deficiency using the first global EMCN knockout mouse model. Methods: Global EMCN knockout mice were generated by crossing EMCN-floxed mice with ROSA26-Cre mice. Flow cytometry was employed to analyze infiltrating myeloid cells in the kidneys. The ultrastructure of the glomerular filtration barrier was examined by transmission electron microscopy, while urinary albumin, creatinine, and total protein levels were analyzed from freshly collected urine samples. Expression and localization of EMCN, EGFP, CD45, CD31, CD34, podocin, albumin, and α-smooth muscle actin were examined by immunohistochemistry. Mice were weighed regularly, and their systemic blood pressure was measured using a non-invasive tail-cuff system. Glomerular endothelial cells and podocytes were isolated by fluorescence-activated cell sorting for RNA-seq. Transcriptional profiles were analyzed to identify differentially expressed genes in both endothelium and podocytes, followed by gene ontology analysis of up- and down-regulated genes. Protein levels of EMCN, albumin, and podocin were quantified by Western blot. Results: EMCN-/- mice were viable with no gross anatomical defects in kidneys. The EMCN-/- mice exhibited increased infiltration of CD45+ cells, with an increased proportion of Ly6GhighLy6Chigh myeloid cells and higher VCAM-1 expression. EMCN-/- mice displayed albuminuria with increased albumin in the Bowman's space compared to the EMCN+/+ littermates. Glomeruli in EMCN-/- mice revealed fused and effaced podocyte foot processes and disorganized endothelial fenestrations. We found no significant difference in blood pressure between EMCN knockout mice and their wild-type littermates. RNA-seq of glomerular endothelial cells revealed downregulation of cell-cell adhesion and MAPK/ERK pathways, along with glycocalyx and extracellular matrix remodeling. In podocytes, we observed reduced VEGF signaling and alterations in cytoskeletal organization. Notably, there was a significant decrease in both mRNA and protein levels of podocin, a key component of the slit diaphragm. Conclusion: Our study demonstrates a critical role of the endothelial marker EMCN in supporting normal glomerular filtration barrier structure and function, presumably by maintaining glomerular endothelial homeostasis through modulation of VEGFR2 signaling and blocking leukocyte adhesion.","PeriodicalId":501471,"journal":{"name":"bioRxiv - Pathology","volume":"12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141741723","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-19DOI: 10.1101/2024.07.16.603729
Zhengping Hu, Issahy Cano, Anton Lennikov, Melissa Wild, Urvi Gupta, Eric Yin Shan Ng, Patricia D'Amore
Endomucin (EMCN), an endothelial-specific glycocalyx component highly expressed in capillary and venous endothelium, plays a critical role in regulating VEGF receptor 2 (VEGFR2) endocytosis and downstream VEGF signaling. Using the first global EMCN knockout mouse model, we investigated the effects of EMCN deficiency on retinal vascularization during development and pathological angiogenesis. We found relatively high expression of EMCN in choroidal capillaries and retinal vasculature. Emcn-/- mice exhibited delayed retinal vascularization at postnatal day 5, with fewer tip cells and reduced vessel density. Ultrastructural examination revealed disrupted and reduced fenestrations in choroidal capillary endothelium. In an oxygen-induced retinopathy model, while Emcn-/- mice showed no significant difference in avascular area compared to Emcn+/+ mice at postnatal day 12, there was a significant reduction in neovascular tufts in Emcn-/- mice at postnatal day 17. Similarly, in a laser-induced choroidal neovascularization model, Emcn-/- mice showed a significant reduction in vascular leakage and lesion size. These findings suggest that EMCN plays a critical role in both vascular development and pathological neovascularization, highlighting its potential as a target for anti-angiogenic therapies.
{"title":"Endomucin knockout leads to delayed retinal vascular development and reduced ocular pathological neovascularization","authors":"Zhengping Hu, Issahy Cano, Anton Lennikov, Melissa Wild, Urvi Gupta, Eric Yin Shan Ng, Patricia D'Amore","doi":"10.1101/2024.07.16.603729","DOIUrl":"https://doi.org/10.1101/2024.07.16.603729","url":null,"abstract":"Endomucin (EMCN), an endothelial-specific glycocalyx component highly expressed in capillary and venous endothelium, plays a critical role in regulating VEGF receptor 2 (VEGFR2) endocytosis and downstream VEGF signaling. Using the first global EMCN knockout mouse model, we investigated the effects of EMCN deficiency on retinal vascularization during development and pathological angiogenesis. We found relatively high expression of EMCN in choroidal capillaries and retinal vasculature. Emcn-/- mice exhibited delayed retinal vascularization at postnatal day 5, with fewer tip cells and reduced vessel density. Ultrastructural examination revealed disrupted and reduced fenestrations in choroidal capillary endothelium. In an oxygen-induced retinopathy model, while Emcn-/- mice showed no significant difference in avascular area compared to Emcn+/+ mice at postnatal day 12, there was a significant reduction in neovascular tufts in Emcn-/- mice at postnatal day 17. Similarly, in a laser-induced choroidal neovascularization model, Emcn-/- mice showed a significant reduction in vascular leakage and lesion size. These findings suggest that EMCN plays a critical role in both vascular development and pathological neovascularization, highlighting its potential as a target for anti-angiogenic therapies.","PeriodicalId":501471,"journal":{"name":"bioRxiv - Pathology","volume":"84 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141741543","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Background: In Zambia, a dog bite is the most common rabies exposure. There is limited information on rabies outbreaks in jackals in Zambia. We investigated all rabies cases in Zambia and narrowed down on jackal bites in Mungwi district to determine a temporal trend and buffer zones for rabies. Methods: The risk of exposure included all humans and animals bitten by jackals, data were collected by interviewing jackal bite victims and collecting brain specimen samples from animals. Risk of spread was determined by estimating the distance jackals strayed into human population and the Rabies Vaccination Coverage (RVC) in the district. The RVC was determined by dividing vaccinated dogs by dog population. The incidence rate (IR) and a Sen’s slope was used to determine a trend of RVC and the rabies cases in Zambia. QGIS was used to produce a heatmap and rabies risk zones. Direct Fluorescent Antibody technique was used to test for rabies. Results: Zambia had recorded a total of 224 rabies cases with a mean (SD) of 22.4 (16) rabies cases and a positivity rate of 65.4% (25.7) per year from 2013 to 2022. Lusaka and Copperbelt provinces recorded the highest rabies cases. The rabies incidence rate was 2.3 rabies cases per 10,000 dogs in Zambia. The cases had reduced from 2013 to 2021 with a Sen’s slope of -0.74 (p = 0.02). At least 227 animal bites were recorded (two jackals and 225 dog bites) in Mungwi District. 94% (213) of the victims needed Post Exposure Prophylaxis. The victim’s median age was 20 (Interquartile range=12-38) years. The accumulative RVC from 2018-2022 (611/7777), was 0.11 (95% CI: −0.4-0.7, p=0.46) annual slope increase with 1.60% mean (Standard deviation = 0.34). One rabies heatmap and three risk-level zones (low, medium and high) were produced, and two jackals and one goat specimens were positive. Conclusions: A risk-based surveillance and enhanced vaccination of dogs in high-risk areas through a one health approach is critical for rabies control in Zambia.
{"title":"An epidemiological description of rabies outbreaks in Zambia from 2013 to 2023.","authors":"wezi kachinda, Humphrey Banda, Amos Hamukale, Chitwambi Makungu, Masuzyo Ngoma, Ricky Chazya, Liywalii Mataa, Chilufya Mulenga, James Blazer Banda, Walter Muleya, Cephas Sialubanje, Dabwitso Banda, Nyambe Sinyange","doi":"10.1101/2024.07.16.603659","DOIUrl":"https://doi.org/10.1101/2024.07.16.603659","url":null,"abstract":"Background: In Zambia, a dog bite is the most common rabies exposure. There is limited information on rabies outbreaks in jackals in Zambia. We investigated all rabies cases in Zambia and narrowed down on jackal bites in Mungwi district to determine a temporal trend and buffer zones for rabies. Methods: The risk of exposure included all humans and animals bitten by jackals, data were collected by interviewing jackal bite victims and collecting brain specimen samples from animals. Risk of spread was determined by estimating the distance jackals strayed into human population and the Rabies Vaccination Coverage (RVC) in the district. The RVC was determined by dividing vaccinated dogs by dog population. The incidence rate (IR) and a Sen’s slope was used to determine a trend of RVC and the rabies cases in Zambia. QGIS was used to produce a heatmap and rabies risk zones. Direct Fluorescent Antibody technique was used to test for rabies. Results: Zambia had recorded a total of 224 rabies cases with a mean (SD) of 22.4 (16) rabies cases and a positivity rate of 65.4% (25.7) per year from 2013 to 2022. Lusaka and Copperbelt provinces recorded the highest rabies cases. The rabies incidence rate was 2.3 rabies cases per 10,000 dogs in Zambia. The cases had reduced from 2013 to 2021 with a Sen’s slope of -0.74 (p = 0.02). At least 227 animal bites were recorded (two jackals and 225 dog bites) in Mungwi District. 94% (213) of the victims needed Post Exposure Prophylaxis. The victim’s median age was 20 (Interquartile range=12-38) years. The accumulative RVC from 2018-2022 (611/7777), was 0.11 (95% CI: −0.4-0.7, p=0.46) annual slope increase with 1.60% mean (Standard deviation = 0.34). One rabies heatmap and three risk-level zones (low, medium and high) were produced, and two jackals and one goat specimens were positive. Conclusions: A risk-based surveillance and enhanced vaccination of dogs in high-risk areas through a one health approach is critical for rabies control in Zambia.","PeriodicalId":501471,"journal":{"name":"bioRxiv - Pathology","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141741544","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-17DOI: 10.1101/2024.07.13.601627
Stephanie Kourakis, Cara A. Timpani, Ryan M. Bagaric, Bo Qi, Benazir A. Ali, Rebecca Boyer, Guinevere Spiesberger, Nitika Kandhari, Amanda L. Peterson, Didier Debrincat, Thomas J. Yates, Xu Yan, Nicole Stupka, Jujiao Kuang, Brunda Nijagal, Deanna Deveson-Lucas, Dirk Fischer, Emma Rybalka
There has been a wave of new therapeutics in Duchenne muscular dystrophy (DMD) that target the genetic, (missing) protein and flow-on pathogenic mechanisms emerging recently. These medicines will be vital to extend lifespan complementary to corticosteroids, which have been used as a standard of care tool for more than 30 years. While corticosteroids significantly slow disease progression, they also impart side effects severe enough to preclude use in some patients. We have previously demonstrated that short-term treatment with dimethyl fumarate (DMF), a drug with indication and established safety data in Multiple Sclerosis, more selectively modulates Duchenne (mdx) immunology than the frequently used corticosteroid, prednisone. Here, we assess the effect of moderate-term DMF treatment over 5 weeks in exercise-aggravated mdx mice. We show that like prednisone, DMF maintains anti-inflammatory, anti-fibrotic, and anti-lipogenic activity on muscle with moderate-term use but does not reduce muscle degeneration per se. This study supports our previous work highlighting DMF as a possible repurposing candidate for DMD, especially for patients who cannot tolerate chronic corticosteroid treatment.
{"title":"Moderate-term dimethyl fumarate treatment reduces pathology of dystrophic skeletal and cardiac muscle in a mouse model","authors":"Stephanie Kourakis, Cara A. Timpani, Ryan M. Bagaric, Bo Qi, Benazir A. Ali, Rebecca Boyer, Guinevere Spiesberger, Nitika Kandhari, Amanda L. Peterson, Didier Debrincat, Thomas J. Yates, Xu Yan, Nicole Stupka, Jujiao Kuang, Brunda Nijagal, Deanna Deveson-Lucas, Dirk Fischer, Emma Rybalka","doi":"10.1101/2024.07.13.601627","DOIUrl":"https://doi.org/10.1101/2024.07.13.601627","url":null,"abstract":"There has been a wave of new therapeutics in Duchenne muscular dystrophy (DMD) that target the genetic, (missing) protein and flow-on pathogenic mechanisms emerging recently. These medicines will be vital to extend lifespan complementary to corticosteroids, which have been used as a standard of care tool for more than 30 years. While corticosteroids significantly slow disease progression, they also impart side effects severe enough to preclude use in some patients. We have previously demonstrated that short-term treatment with dimethyl fumarate (DMF), a drug with indication and established safety data in Multiple Sclerosis, more selectively modulates Duchenne (<em>mdx</em>) immunology than the frequently used corticosteroid, prednisone. Here, we assess the effect of moderate-term DMF treatment over 5 weeks in exercise-aggravated <em>mdx</em> mice. We show that like prednisone, DMF maintains anti-inflammatory, anti-fibrotic, and anti-lipogenic activity on muscle with moderate-term use but does not reduce muscle degeneration per se. This study supports our previous work highlighting DMF as a possible repurposing candidate for DMD, especially for patients who cannot tolerate chronic corticosteroid treatment.","PeriodicalId":501471,"journal":{"name":"bioRxiv - Pathology","volume":"62 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141741546","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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