Escherichia coli small heat‐shock protein IbpB (MW: 16 KDa) has holding chaperone activity and is present in cells at 30 °C as two large oligomers of MW 2.0–3.0 MDa and 600–700 KDa. We report here about the presence of two additional oligomers of MW around 400 and 130 KDa in cells under heat‐stress at 50 °C. These two smaller oligomers possess the most chaperone activity, as observed from the extent of inhibition of inactivation and aggregation separately, of L‐Lactate dehydrogenase in the presence of the individual oligomers at 52 and 60 °C, respectively. It is suggested here that the two larger oligomers act as poorly active storage forms, which under heat stress dissociate partially into smaller oligomers with high holdase activity.
{"title":"Two new oligomers of E. coli small heat‐shock protein IbpB identified under heat stress exhibit maximum holding chaperone activity","authors":"Md Azaharuddin, Rakhi Dasgupta, Abhijit Das, Susmita Nandi, Anabadya Pal, Soumajit Chakrabarty, Pathikrit Bandopadhyay, Sourav Ghosh, Sanchita Nandy, Upasana Sett, Tarakdas Basu","doi":"10.1002/1873-3468.15019","DOIUrl":"https://doi.org/10.1002/1873-3468.15019","url":null,"abstract":"<jats:italic>Escherichia coli</jats:italic> small heat‐shock protein IbpB (MW: 16 KDa) has holding chaperone activity and is present in cells at 30 °C as two large oligomers of MW 2.0–3.0 MDa and 600–700 KDa. We report here about the presence of two additional oligomers of MW around 400 and 130 KDa in cells under heat‐stress at 50 °C. These two smaller oligomers possess the most chaperone activity, as observed from the extent of inhibition of inactivation and aggregation separately, of L‐Lactate dehydrogenase in the presence of the individual oligomers at 52 and 60 °C, respectively. It is suggested here that the two larger oligomers act as poorly active storage forms, which under heat stress dissociate partially into smaller oligomers with high holdase activity.","PeriodicalId":12142,"journal":{"name":"FEBS Letters","volume":"14 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142250010","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Although publication in scholarly peer-reviewed journals remains the gold standard for communication of findings in the life sciences, the gold has been debased in the digital age by various impurities, including (a) reviewer fatigue, (b) fraud, paper mills, and the perils of artificial intelligence, (c) predatory journals, (d) the ongoing use of journal impact factor as a proxy for individual article quality, and (e) salami-slicing and other unethical practices. In this article, I present a detailed overview of these problems, as well as solutions proposed and implemented to counter them. Finally, I suggest that these are all symptomatic of a wider problem, namely the culture of ‘publish or perish’ and ongoing issues with how researcher performance is evaluated for grant, hiring, and promotion decisions. Only by working towards a global shift in the way scientists view the purpose of publication can we finally remove the impurities and refine the gold.
{"title":"Five problems plaguing publishing in the life sciences—and one common cause","authors":"Duncan E. Wright","doi":"10.1002/1873-3468.15018","DOIUrl":"10.1002/1873-3468.15018","url":null,"abstract":"<p>Although publication in scholarly peer-reviewed journals remains the gold standard for communication of findings in the life sciences, the gold has been debased in the digital age by various impurities, including (a) reviewer fatigue, (b) fraud, paper mills, and the perils of artificial intelligence, (c) predatory journals, (d) the ongoing use of journal impact factor as a proxy for individual article quality, and (e) salami-slicing and other unethical practices. In this article, I present a detailed overview of these problems, as well as solutions proposed and implemented to counter them. Finally, I suggest that these are all symptomatic of a wider problem, namely the culture of ‘publish or perish’ and ongoing issues with how researcher performance is evaluated for grant, hiring, and promotion decisions. Only by working towards a global shift in the way scientists view the purpose of publication can we finally remove the impurities and refine the gold.</p>","PeriodicalId":12142,"journal":{"name":"FEBS Letters","volume":"598 18","pages":"2227-2239"},"PeriodicalIF":3.5,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/1873-3468.15018","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142282616","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Drug repurposing has emerged as an effective strategy against infectious diseases such as visceral leishmaniasis. Here, we evaluated four FDA‐approved drugs–valrubicin, ciclesonide, deflazacort, and telithromycin—for their anti‐leishmanial activity on Leishmania donovani parasites, especially their ability to target the enzyme glutathione synthetase (LdGS), which enables parasite survival under oxidative stress in host macrophages. Valrubicin and ciclesonide exhibited superior inhibitory effects compared to deflazacort and telithromycin, inhibiting the promastigotes at very low concentrations, with IC50 values of 1.09 ± 0.09 μm and 2.09 ± 0.09 μm, respectively. Subsequent testing on amastigotes revealed the IC50 values of 1.74 ± 0.05 μm and 3.32 ± 0.21 μm for valrubicin and ciclesonide, respectively. Molecular and cellular level analysis further elucidated the mechanisms underlying the anti‐leishmanial activity of valrubicin and ciclesonide.
{"title":"Identification of novel anti‐leishmanials targeting glutathione synthetase of the parasite: a drug repurposing approach","authors":"Manash Sarma, Kushal Bora, Preeti Ranjan, Vikash Kumar Dubey","doi":"10.1002/1873-3468.15016","DOIUrl":"https://doi.org/10.1002/1873-3468.15016","url":null,"abstract":"Drug repurposing has emerged as an effective strategy against infectious diseases such as visceral leishmaniasis. Here, we evaluated four FDA‐approved drugs–valrubicin, ciclesonide, deflazacort, and telithromycin—for their anti‐leishmanial activity on <jats:italic>Leishmania donovani</jats:italic> parasites, especially their ability to target the enzyme glutathione synthetase (<jats:italic>Ld</jats:italic>GS), which enables parasite survival under oxidative stress in host macrophages. Valrubicin and ciclesonide exhibited superior inhibitory effects compared to deflazacort and telithromycin, inhibiting the promastigotes at very low concentrations, with IC<jats:sub>50</jats:sub> values of 1.09 ± 0.09 μ<jats:sc>m</jats:sc> and 2.09 ± 0.09 μ<jats:sc>m</jats:sc>, respectively. Subsequent testing on amastigotes revealed the IC<jats:sub>50</jats:sub> values of 1.74 ± 0.05 μ<jats:sc>m</jats:sc> and 3.32 ± 0.21 μ<jats:sc>m</jats:sc> for valrubicin and ciclesonide, respectively. Molecular and cellular level analysis further elucidated the mechanisms underlying the anti‐leishmanial activity of valrubicin and ciclesonide.","PeriodicalId":12142,"journal":{"name":"FEBS Letters","volume":"191 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142250014","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dendritic cells (DC) are professional antigen‐presenting cells involved in promoting and controlling immune responses. Different subsets of DC, named tolerogenic (tol)DC, play a critical role in the maintenance of tissue homeostasis and in fostering tolerance. These unique skills make tolDC especially attractive for strategies aimed at re‐establishing/inducing tolerance in immune‐mediated conditions. The generation of potent tolDC in vitro from peripheral blood monocytes has seen remarkable advancements. TolDC modulate T cell dynamics by favoring regulatory T cells (Tregs) and curbing effector/pathogenic T cells. Among the several methods developed for in vitro tolDC generation, IL‐10 conditioning has been proven to be the most efficient, as IL‐10‐modulated tolDC were demonstrated to promote Tregs with the strongest suppressive activities. Investigating the molecular, metabolic, and functional profiles of tolDC uncovers essential pathways that facilitate their immunoregulatory functions. This Review provides an overview of current knowledge on the role of tolDC in health and disease, focusing on IL‐10 production, functional characterization of in vitro generated tolDC, molecular and metabolic changes occurring in tolDC induced by tolerogenic agents, clinical applications of tolDC‐based therapy, and finally new perspectives in the generation of effective tolDC.
{"title":"Leveraging current insights on IL‐10‐producing dendritic cells for developing effective immunotherapeutic approaches","authors":"Konstantina Morali, Gloria Giacomello, Michela Vuono, Silvia Gregori","doi":"10.1002/1873-3468.15017","DOIUrl":"https://doi.org/10.1002/1873-3468.15017","url":null,"abstract":"Dendritic cells (DC) are professional antigen‐presenting cells involved in promoting and controlling immune responses. Different subsets of DC, named tolerogenic (tol)DC, play a critical role in the maintenance of tissue homeostasis and in fostering tolerance. These unique skills make tolDC especially attractive for strategies aimed at re‐establishing/inducing tolerance in immune‐mediated conditions. The generation of potent tolDC <jats:italic>in vitro</jats:italic> from peripheral blood monocytes has seen remarkable advancements. TolDC modulate T cell dynamics by favoring regulatory T cells (Tregs) and curbing effector/pathogenic T cells. Among the several methods developed for in vitro tolDC generation, IL‐10 conditioning has been proven to be the most efficient, as IL‐10‐modulated tolDC were demonstrated to promote Tregs with the strongest suppressive activities. Investigating the molecular, metabolic, and functional profiles of tolDC uncovers essential pathways that facilitate their immunoregulatory functions. This Review provides an overview of current knowledge on the role of tolDC in health and disease, focusing on IL‐10 production, functional characterization of <jats:italic>in vitro</jats:italic> generated tolDC, molecular and metabolic changes occurring in tolDC induced by tolerogenic agents, clinical applications of tolDC‐based therapy, and finally new perspectives in the generation of effective tolDC.","PeriodicalId":12142,"journal":{"name":"FEBS Letters","volume":"13 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142250012","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Caroline Harter, Frédéric Melin, Franziska Hoeser, Petra Hellwig, Daniel Wohlwend, Thorsten Friedrich
Respiratory complex I is a central metabolic enzyme coupling NADH oxidation and quinone reduction with proton translocation. Despite the knowledge of the structure of the complex, the coupling of both processes is not entirely understood. Here, we use a combination of site‐directed mutagenesis, biochemical assays, and redox‐induced FTIR spectroscopy to demonstrate that the quinone chemistry includes the protonation and deprotonation of a specific, conserved aspartic acid residue in the quinone binding site (D325 on subunit NuoCD in Escherichia coli). Our experimental data support a proposal derived from theoretical considerations that deprotonation of this residue is involved in triggering proton translocation in respiratory complex I.
呼吸复合体 I 是一种将 NADH 氧化和醌还原与质子转运耦合在一起的核心代谢酶。尽管我们已经知道该复合体的结构,但对这两个过程的耦合还不完全了解。在这里,我们结合使用了定点诱变、生化测定和氧化还原诱导傅立叶变换红外光谱法,证明醌的化学作用包括醌结合位点(大肠杆菌 NuoCD 亚基上的 D325)中一个特定的、保守的天冬氨酸残基的质子化和去质子化。我们的实验数据支持从理论上得出的建议,即该残基的去质子化参与触发呼吸复合体 I 中质子的易位。
{"title":"Quinone chemistry in respiratory complex I involves protonation of a conserved aspartic acid residue","authors":"Caroline Harter, Frédéric Melin, Franziska Hoeser, Petra Hellwig, Daniel Wohlwend, Thorsten Friedrich","doi":"10.1002/1873-3468.15013","DOIUrl":"https://doi.org/10.1002/1873-3468.15013","url":null,"abstract":"Respiratory complex I is a central metabolic enzyme coupling NADH oxidation and quinone reduction with proton translocation. Despite the knowledge of the structure of the complex, the coupling of both processes is not entirely understood. Here, we use a combination of site‐directed mutagenesis, biochemical assays, and redox‐induced FTIR spectroscopy to demonstrate that the quinone chemistry includes the protonation and deprotonation of a specific, conserved aspartic acid residue in the quinone binding site (D325 on subunit NuoCD in <jats:italic>Escherichia coli</jats:italic>). Our experimental data support a proposal derived from theoretical considerations that deprotonation of this residue is involved in triggering proton translocation in respiratory complex I.","PeriodicalId":12142,"journal":{"name":"FEBS Letters","volume":"44 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142197915","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Inge van der Werf, Jenna Sneifer, Catriona Jamieson
Hematopoietic system aging is characterized by both hematopoietic stem cell (HSC) and niche degeneration resulting in myeloid lineage-biased differentiation, reduced B cell and T cell lymphopoiesis, increased HSC mobilization, and fat deposition in the bone marrow. Both alterations in RNA splicing and editing during HSC aging contribute to increased myeloid lineage skewing and inflammation-responsive transcription factors, underscoring the importance of epitranscriptomic mechanisms in the acquisition of an age-related phenotype.
{"title":"RNA Modifications Shape Hematopoietic Stem Cell Aging: Beyond the Code","authors":"Inge van der Werf, Jenna Sneifer, Catriona Jamieson","doi":"10.1002/1873-3468.15014","DOIUrl":"https://doi.org/10.1002/1873-3468.15014","url":null,"abstract":"Hematopoietic system aging is characterized by both hematopoietic stem cell (HSC) and niche degeneration resulting in myeloid lineage-biased differentiation, reduced B cell and T cell lymphopoiesis, increased HSC mobilization, and fat deposition in the bone marrow. Both alterations in RNA splicing and editing during HSC aging contribute to increased myeloid lineage skewing and inflammation-responsive transcription factors, underscoring the importance of epitranscriptomic mechanisms in the acquisition of an age-related phenotype.","PeriodicalId":12142,"journal":{"name":"FEBS Letters","volume":"133 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142197916","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
<p>Biomedical research has long been dedicated to elucidating the determinants of human health and disease. The interaction between intrinsic and environmental factors that affect the metabolic, immune, nervous, and endocrine systems has been the focus of many efforts in the field. Yet, redox signaling, which involves the fine modulation of molecular pathways by free radicals and oxidants, is emerging as a unifying theme in the pathophysiology of human diseases [<span>[1, 2]</span>].</p><p>Biological oxidants are a chemically and biologically diverse group of molecules derived from molecular oxygen, nitrogen, or sulfur (although this could be extended to include other elements such as carbon, selenium, halogens, and electrophile species that undergo redox reactions) with critical signaling functions under physiological conditions, ensuring what has been coined by Helmut Sies as oxidative eustress [<span>[3]</span>]. Dysregulation of redox homeostasis results in supra-physiological concentrations of these species, which establish non-specific reactions with biomolecules and generate other, more reactive species with the ability to react indiscriminately with most biomolecules, producing what is commonly refered to as oxidative (dis)stress [<span>[4]</span>]. The transition from oxidative eustress to oxidative distress is a common observation in several pathophysiological conditions [<span>[3, 4]</span>]. As such, cells strategically employ several defense systems, including enzymes and low molecular weight antioxidants, to maintain redox homeostasis. Sensing systems detect shifts from the steady-state oxidant level and initiate appropriate defense strategies. Important redox hubs worth mentioning include NRF2, NF-κB, HIF, ERR, FOXO, PGC1α, AMPK, GAPDH, and UCP, all of which are regulated via oxidation of Cys residues either on adaptor proteins or on the transcription factor itself (reviewed in [<span>[5, 6]</span>]).</p><p>Superoxide radical (<span></span><math>