Pub Date : 2024-08-23eCollection Date: 2024-08-01DOI: 10.1371/journal.pbio.3002756
Rose M Doss, Martin W Breuss
The endosymbiosis of mitochondrial ancestors resulted in the transfer of genetic material on an evolutionary scale for eukaryotic species. A new study in PLOS Biology expands this to the genome of somatic cells within individuals and highlights its correlation with aging and disease.
{"title":"A somatic view of the genomic impact of mitochondrial endosymbiosis.","authors":"Rose M Doss, Martin W Breuss","doi":"10.1371/journal.pbio.3002756","DOIUrl":"10.1371/journal.pbio.3002756","url":null,"abstract":"<p><p>The endosymbiosis of mitochondrial ancestors resulted in the transfer of genetic material on an evolutionary scale for eukaryotic species. A new study in PLOS Biology expands this to the genome of somatic cells within individuals and highlights its correlation with aging and disease.</p>","PeriodicalId":49001,"journal":{"name":"PLoS Biology","volume":null,"pages":null},"PeriodicalIF":9.8,"publicationDate":"2024-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11343374/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142044242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-23eCollection Date: 2024-08-01DOI: 10.1371/journal.pbio.3002781
Bjarke Haldrup Pedersen, Filipa Bica Simões, Ivan Pogrebnyakov, Martin Welch, Helle Krogh Johansen, Søren Molin, Ruggero La Rosa
Metabolism provides the foundation for all cellular functions. During persistent infections, in adapted pathogenic bacteria metabolism functions radically differently compared with more naïve strains. Whether this is simply a necessary accommodation to the persistence phenotype or if metabolism plays a direct role in achieving persistence in the host is still unclear. Here, we characterize a convergent shift in metabolic function(s) linked with the persistence phenotype during Pseudomonas aeruginosa colonization in the airways of people with cystic fibrosis. We show that clinically relevant mutations in the key metabolic enzyme, pyruvate dehydrogenase, lead to a host-specialized metabolism together with a lower virulence and immune response recruitment. These changes in infection phenotype are mediated by impaired type III secretion system activity and by secretion of the antioxidant metabolite, pyruvate, respectively. Our results show how metabolic adaptations directly impinge on persistence and pathogenicity in this organism.
新陈代谢是所有细胞功能的基础。在持续感染过程中,适应病原菌的新陈代谢功能与较幼稚的菌株截然不同。这究竟是对持久性表型的必要适应,还是新陈代谢在实现宿主持久性感染中发挥了直接作用,目前尚不清楚。在这里,我们描述了铜绿假单胞菌在囊性纤维化患者气道中定植期间与持久性表型相关的代谢功能的趋同性转变。我们的研究表明,关键代谢酶丙酮酸脱氢酶的临床相关突变会导致宿主特化代谢,同时降低毒力和免疫反应招募。感染表型的这些变化分别是由 III 型分泌系统活性受损和抗氧化代谢产物丙酮酸的分泌介导的。我们的研究结果表明,新陈代谢的适应性如何直接影响到这种生物的持久性和致病性。
{"title":"Metabolic specialization drives reduced pathogenicity in Pseudomonas aeruginosa isolates from cystic fibrosis patients.","authors":"Bjarke Haldrup Pedersen, Filipa Bica Simões, Ivan Pogrebnyakov, Martin Welch, Helle Krogh Johansen, Søren Molin, Ruggero La Rosa","doi":"10.1371/journal.pbio.3002781","DOIUrl":"10.1371/journal.pbio.3002781","url":null,"abstract":"<p><p>Metabolism provides the foundation for all cellular functions. During persistent infections, in adapted pathogenic bacteria metabolism functions radically differently compared with more naïve strains. Whether this is simply a necessary accommodation to the persistence phenotype or if metabolism plays a direct role in achieving persistence in the host is still unclear. Here, we characterize a convergent shift in metabolic function(s) linked with the persistence phenotype during Pseudomonas aeruginosa colonization in the airways of people with cystic fibrosis. We show that clinically relevant mutations in the key metabolic enzyme, pyruvate dehydrogenase, lead to a host-specialized metabolism together with a lower virulence and immune response recruitment. These changes in infection phenotype are mediated by impaired type III secretion system activity and by secretion of the antioxidant metabolite, pyruvate, respectively. Our results show how metabolic adaptations directly impinge on persistence and pathogenicity in this organism.</p>","PeriodicalId":49001,"journal":{"name":"PLoS Biology","volume":null,"pages":null},"PeriodicalIF":9.8,"publicationDate":"2024-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11376529/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142044245","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-22eCollection Date: 2024-08-01DOI: 10.1371/journal.pbio.3002762
Zonglai Liang, Daniel Christiaan Dondorp, Marios Chatzigeorgiou
During embryonic development, tissues and organs are gradually shaped into their functional morphologies through a series of spatiotemporally tightly orchestrated cell behaviors. A highly conserved organ shape across metazoans is the epithelial tube. Tube morphogenesis is a complex multistep process of carefully choreographed cell behaviors such as convergent extension, cell elongation, and lumen formation. The identity of the signaling molecules that coordinate these intricate morphogenetic steps remains elusive. The notochord is an essential tubular organ present in the embryonic midline region of all members of the chordate phylum. Here, using genome editing, pharmacology and quantitative imaging in the early chordate Ciona intestinalis we show that Ano10/Tmem16k, a member of the evolutionarily ancient family of transmembrane proteins called Anoctamin/TMEM16 is essential for convergent extension, lumen expansion, and connection during notochord morphogenesis. We find that Ano10/Tmem16k works in concert with the plasma membrane (PM) localized Na+/Ca2+ exchanger (NCX) and the endoplasmic reticulum (ER) residing SERCA, RyR, and IP3R proteins to establish developmental stage specific Ca2+ signaling molecular modules that regulate notochord morphogenesis and Ca2+ dynamics. In addition, we find that the highly conserved Ca2+ sensors calmodulin (CaM) and Ca2+/calmodulin-dependent protein kinase (CaMK) show an Ano10/Tmem16k-dependent subcellular localization. Their pharmacological inhibition leads to convergent extension, tubulogenesis defects, and deranged Ca2+ dynamics, suggesting that Ano10/Tmem16k is involved in both the "encoding" and "decoding" of developmental Ca2+ signals. Furthermore, Ano10/Tmem16k mediates cytoskeletal reorganization during notochord morphogenesis, likely by altering the localization of 2 important cytoskeletal regulators, the small GTPase Ras homolog family member A (RhoA) and the actin binding protein Cofilin. Finally, we use electrophysiological recordings and a scramblase assay in tissue culture to demonstrate that Ano10/Tmem16k likely acts as an ion channel but not as a phospholipid scramblase. Our results establish Ano10/Tmem16k as a novel player in the prevertebrate molecular toolkit that controls organ morphogenesis across scales.
{"title":"The ion channel Anoctamin 10/TMEM16K coordinates organ morphogenesis across scales in the urochordate notochord.","authors":"Zonglai Liang, Daniel Christiaan Dondorp, Marios Chatzigeorgiou","doi":"10.1371/journal.pbio.3002762","DOIUrl":"10.1371/journal.pbio.3002762","url":null,"abstract":"<p><p>During embryonic development, tissues and organs are gradually shaped into their functional morphologies through a series of spatiotemporally tightly orchestrated cell behaviors. A highly conserved organ shape across metazoans is the epithelial tube. Tube morphogenesis is a complex multistep process of carefully choreographed cell behaviors such as convergent extension, cell elongation, and lumen formation. The identity of the signaling molecules that coordinate these intricate morphogenetic steps remains elusive. The notochord is an essential tubular organ present in the embryonic midline region of all members of the chordate phylum. Here, using genome editing, pharmacology and quantitative imaging in the early chordate Ciona intestinalis we show that Ano10/Tmem16k, a member of the evolutionarily ancient family of transmembrane proteins called Anoctamin/TMEM16 is essential for convergent extension, lumen expansion, and connection during notochord morphogenesis. We find that Ano10/Tmem16k works in concert with the plasma membrane (PM) localized Na+/Ca2+ exchanger (NCX) and the endoplasmic reticulum (ER) residing SERCA, RyR, and IP3R proteins to establish developmental stage specific Ca2+ signaling molecular modules that regulate notochord morphogenesis and Ca2+ dynamics. In addition, we find that the highly conserved Ca2+ sensors calmodulin (CaM) and Ca2+/calmodulin-dependent protein kinase (CaMK) show an Ano10/Tmem16k-dependent subcellular localization. Their pharmacological inhibition leads to convergent extension, tubulogenesis defects, and deranged Ca2+ dynamics, suggesting that Ano10/Tmem16k is involved in both the \"encoding\" and \"decoding\" of developmental Ca2+ signals. Furthermore, Ano10/Tmem16k mediates cytoskeletal reorganization during notochord morphogenesis, likely by altering the localization of 2 important cytoskeletal regulators, the small GTPase Ras homolog family member A (RhoA) and the actin binding protein Cofilin. Finally, we use electrophysiological recordings and a scramblase assay in tissue culture to demonstrate that Ano10/Tmem16k likely acts as an ion channel but not as a phospholipid scramblase. Our results establish Ano10/Tmem16k as a novel player in the prevertebrate molecular toolkit that controls organ morphogenesis across scales.</p>","PeriodicalId":49001,"journal":{"name":"PLoS Biology","volume":null,"pages":null},"PeriodicalIF":9.8,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11341064/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142037455","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-22eCollection Date: 2024-08-01DOI: 10.1371/journal.pbio.3002723
Weichen Zhou, Kalpita R Karan, Wenjin Gu, Hans-Ulrich Klein, Gabriel Sturm, Philip L De Jager, David A Bennett, Michio Hirano, Martin Picard, Ryan E Mills
The transfer of mitochondrial DNA into the nuclear genomes of eukaryotes (Numts) has been linked to lifespan in nonhuman species and recently demonstrated to occur in rare instances from one human generation to the next. Here, we investigated numtogenesis dynamics in humans in 2 ways. First, we quantified Numts in 1,187 postmortem brain and blood samples from different individuals. Compared to circulating immune cells (n = 389), postmitotic brain tissue (n = 798) contained more Numts, consistent with their potential somatic accumulation. Within brain samples, we observed a 5.5-fold enrichment of somatic Numt insertions in the dorsolateral prefrontal cortex (DLPFC) compared to cerebellum samples, suggesting that brain Numts arose spontaneously during development or across the lifespan. Moreover, an increase in the number of brain Numts was linked to earlier mortality. The brains of individuals with no cognitive impairment (NCI) who died at younger ages carried approximately 2 more Numts per decade of life lost than those who lived longer. Second, we tested the dynamic transfer of Numts using a repeated-measures whole-genome sequencing design in a human fibroblast model that recapitulates several molecular hallmarks of aging. These longitudinal experiments revealed a gradual accumulation of 1 Numt every ~13 days. Numtogenesis was independent of large-scale genomic instability and unlikely driven by cell clonality. Targeted pharmacological perturbations including chronic glucocorticoid signaling or impairing mitochondrial oxidative phosphorylation (OxPhos) only modestly increased the rate of numtogenesis, whereas patient-derived SURF1-mutant cells exhibiting mtDNA instability accumulated Numts 4.7-fold faster than healthy donors. Combined, our data document spontaneous numtogenesis in human cells and demonstrate an association between brain cortical somatic Numts and human lifespan. These findings open the possibility that mito-nuclear horizontal gene transfer among human postmitotic tissues produces functionally relevant human Numts over timescales shorter than previously assumed.
{"title":"Somatic nuclear mitochondrial DNA insertions are prevalent in the human brain and accumulate over time in fibroblasts.","authors":"Weichen Zhou, Kalpita R Karan, Wenjin Gu, Hans-Ulrich Klein, Gabriel Sturm, Philip L De Jager, David A Bennett, Michio Hirano, Martin Picard, Ryan E Mills","doi":"10.1371/journal.pbio.3002723","DOIUrl":"10.1371/journal.pbio.3002723","url":null,"abstract":"<p><p>The transfer of mitochondrial DNA into the nuclear genomes of eukaryotes (Numts) has been linked to lifespan in nonhuman species and recently demonstrated to occur in rare instances from one human generation to the next. Here, we investigated numtogenesis dynamics in humans in 2 ways. First, we quantified Numts in 1,187 postmortem brain and blood samples from different individuals. Compared to circulating immune cells (n = 389), postmitotic brain tissue (n = 798) contained more Numts, consistent with their potential somatic accumulation. Within brain samples, we observed a 5.5-fold enrichment of somatic Numt insertions in the dorsolateral prefrontal cortex (DLPFC) compared to cerebellum samples, suggesting that brain Numts arose spontaneously during development or across the lifespan. Moreover, an increase in the number of brain Numts was linked to earlier mortality. The brains of individuals with no cognitive impairment (NCI) who died at younger ages carried approximately 2 more Numts per decade of life lost than those who lived longer. Second, we tested the dynamic transfer of Numts using a repeated-measures whole-genome sequencing design in a human fibroblast model that recapitulates several molecular hallmarks of aging. These longitudinal experiments revealed a gradual accumulation of 1 Numt every ~13 days. Numtogenesis was independent of large-scale genomic instability and unlikely driven by cell clonality. Targeted pharmacological perturbations including chronic glucocorticoid signaling or impairing mitochondrial oxidative phosphorylation (OxPhos) only modestly increased the rate of numtogenesis, whereas patient-derived SURF1-mutant cells exhibiting mtDNA instability accumulated Numts 4.7-fold faster than healthy donors. Combined, our data document spontaneous numtogenesis in human cells and demonstrate an association between brain cortical somatic Numts and human lifespan. These findings open the possibility that mito-nuclear horizontal gene transfer among human postmitotic tissues produces functionally relevant human Numts over timescales shorter than previously assumed.</p>","PeriodicalId":49001,"journal":{"name":"PLoS Biology","volume":null,"pages":null},"PeriodicalIF":9.8,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11340991/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142037454","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-22eCollection Date: 2024-08-01DOI: 10.1371/journal.pbio.3002645
Tom E Hardwicke, Sarah R Schiavone, Beth Clarke, Simine Vazire
Research articles published by the journal eLife are accompanied by short evaluation statements that use phrases from a prescribed vocabulary to evaluate research on 2 dimensions: importance and strength of support. Intuitively, the prescribed phrases appear to be highly synonymous (e.g., important/valuable, compelling/convincing) and the vocabulary's ordinal structure may not be obvious to readers. We conducted an online repeated-measures experiment to gauge whether the phrases were interpreted as intended. We also tested an alternative vocabulary with (in our view) a less ambiguous structure. A total of 301 participants with a doctoral or graduate degree used a 0% to 100% scale to rate the importance and strength of support of hypothetical studies described using phrases from both vocabularies. For the eLife vocabulary, most participants' implied ranking did not match the intended ranking on both the importance (n = 59, 20% matched, 95% confidence interval [15% to 24%]) and strength of support dimensions (n = 45, 15% matched [11% to 20%]). By contrast, for the alternative vocabulary, most participants' implied ranking did match the intended ranking on both the importance (n = 188, 62% matched [57% to 68%]) and strength of support dimensions (n = 201, 67% matched [62% to 72%]). eLife's vocabulary tended to produce less consistent between-person interpretations, though the alternative vocabulary still elicited some overlapping interpretations away from the middle of the scale. We speculate that explicit presentation of a vocabulary's intended ordinal structure could improve interpretation. Overall, these findings suggest that more structured and less ambiguous language can improve communication of research evaluations.
{"title":"An empirical appraisal of eLife's assessment vocabulary.","authors":"Tom E Hardwicke, Sarah R Schiavone, Beth Clarke, Simine Vazire","doi":"10.1371/journal.pbio.3002645","DOIUrl":"10.1371/journal.pbio.3002645","url":null,"abstract":"<p><p>Research articles published by the journal eLife are accompanied by short evaluation statements that use phrases from a prescribed vocabulary to evaluate research on 2 dimensions: importance and strength of support. Intuitively, the prescribed phrases appear to be highly synonymous (e.g., important/valuable, compelling/convincing) and the vocabulary's ordinal structure may not be obvious to readers. We conducted an online repeated-measures experiment to gauge whether the phrases were interpreted as intended. We also tested an alternative vocabulary with (in our view) a less ambiguous structure. A total of 301 participants with a doctoral or graduate degree used a 0% to 100% scale to rate the importance and strength of support of hypothetical studies described using phrases from both vocabularies. For the eLife vocabulary, most participants' implied ranking did not match the intended ranking on both the importance (n = 59, 20% matched, 95% confidence interval [15% to 24%]) and strength of support dimensions (n = 45, 15% matched [11% to 20%]). By contrast, for the alternative vocabulary, most participants' implied ranking did match the intended ranking on both the importance (n = 188, 62% matched [57% to 68%]) and strength of support dimensions (n = 201, 67% matched [62% to 72%]). eLife's vocabulary tended to produce less consistent between-person interpretations, though the alternative vocabulary still elicited some overlapping interpretations away from the middle of the scale. We speculate that explicit presentation of a vocabulary's intended ordinal structure could improve interpretation. Overall, these findings suggest that more structured and less ambiguous language can improve communication of research evaluations.</p>","PeriodicalId":49001,"journal":{"name":"PLoS Biology","volume":null,"pages":null},"PeriodicalIF":9.8,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11340897/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142037453","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-21eCollection Date: 2024-08-01DOI: 10.1371/journal.pbio.3002719
Chih-Chia Su, Zhemin Zhang, Meinan Lyu, Meng Cui, Edward W Yu
The band 3 transporter is a critical integral membrane protein of the red blood cell (RBC), as it is responsible for catalyzing the exchange of bicarbonate and chloride anions across the plasma membrane. To elucidate the structural mechanism of the band 3 transporter, detergent solubilized human ghost membrane reconstituted in nanodiscs was applied to a cryo-EM holey carbon grid to define its composition. With this approach, we identified and determined structural information of the human band 3 transporter. Here, we present 5 different cryo-EM structures of the transmembrane domain of dimeric band 3, either alone or bound with chloride or bicarbonate. Interestingly, we observed that human band 3 can form both symmetric and asymmetric dimers with a different combination of outward-facing (OF) and inward-facing (IF) states. These structures also allow us to obtain the first model of a human band 3 molecule at the IF conformation. Based on the structural data of these dimers, we propose a model of ion transport that is in favor of the elevator-type mechanism.
带3转运体是红细胞(RBC)的一种重要的整体膜蛋白,它负责催化碳酸氢盐和氯离子在质膜上的交换。为了阐明带3转运体的结构机制,我们将去垢溶解的人鬼膜重组在纳米盘中,并将其应用于低温电子显微镜孔状碳网格,以确定其组成。通过这种方法,我们识别并确定了人类带3转运体的结构信息。在这里,我们展示了二聚体 band 3 跨膜结构域的 5 种不同的低温电子显微镜结构,有的单独存在,有的与氯化物或碳酸氢盐结合。有趣的是,我们观察到人类 band 3 可以形成对称和不对称的二聚体,并具有不同的外向(OF)和内向(IF)状态组合。通过这些结构,我们还首次获得了人类 band 3 分子的 IF 构象模型。根据这些二聚体的结构数据,我们提出了一个有利于电梯型机制的离子传输模型。
{"title":"Cryo-EM structures of the human band 3 transporter indicate a transport mechanism involving the coupled movement of chloride and bicarbonate ions.","authors":"Chih-Chia Su, Zhemin Zhang, Meinan Lyu, Meng Cui, Edward W Yu","doi":"10.1371/journal.pbio.3002719","DOIUrl":"10.1371/journal.pbio.3002719","url":null,"abstract":"<p><p>The band 3 transporter is a critical integral membrane protein of the red blood cell (RBC), as it is responsible for catalyzing the exchange of bicarbonate and chloride anions across the plasma membrane. To elucidate the structural mechanism of the band 3 transporter, detergent solubilized human ghost membrane reconstituted in nanodiscs was applied to a cryo-EM holey carbon grid to define its composition. With this approach, we identified and determined structural information of the human band 3 transporter. Here, we present 5 different cryo-EM structures of the transmembrane domain of dimeric band 3, either alone or bound with chloride or bicarbonate. Interestingly, we observed that human band 3 can form both symmetric and asymmetric dimers with a different combination of outward-facing (OF) and inward-facing (IF) states. These structures also allow us to obtain the first model of a human band 3 molecule at the IF conformation. Based on the structural data of these dimers, we propose a model of ion transport that is in favor of the elevator-type mechanism.</p>","PeriodicalId":49001,"journal":{"name":"PLoS Biology","volume":null,"pages":null},"PeriodicalIF":9.8,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11338459/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142019219","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-20eCollection Date: 2024-08-01DOI: 10.1371/journal.pbio.3002768
Jianfeng Liu, Niels Niethard, Yu Lun, Stoyan Dimitrov, Ingrid Ehrlich, Jan Born, Manfred Hallschmid
According to the synaptic homeostasis hypothesis (SHY), sleep serves to renormalize synaptic connections that have been potentiated during the prior wake phase due to ongoing encoding of information. SHY focuses on glutamatergic synaptic strength and has been supported by numerous studies examining synaptic structure and function in neocortical and hippocampal networks. However, it is unknown whether synaptic down-regulation during sleep occurs in the hypothalamus, i.e., a pivotal center of homeostatic regulation of bodily functions including sleep itself. We show that sleep, in parallel with the synaptic down-regulation in neocortical networks, down-regulates the levels of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) in the hypothalamus of rats. Most robust decreases after sleep were observed at both sites for AMPARs containing the GluA1 subunit. Comparing the effects of selective rapid eye movement (REM) sleep and total sleep deprivation, we moreover provide experimental evidence that slow-wave sleep (SWS) is the driving force of the down-regulation of AMPARs in hypothalamus and neocortex, with no additional contributions of REM sleep or the circadian rhythm. SWS-dependent synaptic down-regulation was not linked to EEG slow-wave activity. However, spindle density during SWS predicted relatively increased GluA1 subunit levels in hypothalamic synapses, which is consistent with the role of spindles in the consolidation of memory. Our findings identify SWS as the main driver of the renormalization of synaptic strength during sleep and suggest that SWS-dependent synaptic renormalization is also implicated in homeostatic control processes in the hypothalamus.
{"title":"Slow-wave sleep drives sleep-dependent renormalization of synaptic AMPA receptor levels in the hypothalamus.","authors":"Jianfeng Liu, Niels Niethard, Yu Lun, Stoyan Dimitrov, Ingrid Ehrlich, Jan Born, Manfred Hallschmid","doi":"10.1371/journal.pbio.3002768","DOIUrl":"10.1371/journal.pbio.3002768","url":null,"abstract":"<p><p>According to the synaptic homeostasis hypothesis (SHY), sleep serves to renormalize synaptic connections that have been potentiated during the prior wake phase due to ongoing encoding of information. SHY focuses on glutamatergic synaptic strength and has been supported by numerous studies examining synaptic structure and function in neocortical and hippocampal networks. However, it is unknown whether synaptic down-regulation during sleep occurs in the hypothalamus, i.e., a pivotal center of homeostatic regulation of bodily functions including sleep itself. We show that sleep, in parallel with the synaptic down-regulation in neocortical networks, down-regulates the levels of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) in the hypothalamus of rats. Most robust decreases after sleep were observed at both sites for AMPARs containing the GluA1 subunit. Comparing the effects of selective rapid eye movement (REM) sleep and total sleep deprivation, we moreover provide experimental evidence that slow-wave sleep (SWS) is the driving force of the down-regulation of AMPARs in hypothalamus and neocortex, with no additional contributions of REM sleep or the circadian rhythm. SWS-dependent synaptic down-regulation was not linked to EEG slow-wave activity. However, spindle density during SWS predicted relatively increased GluA1 subunit levels in hypothalamic synapses, which is consistent with the role of spindles in the consolidation of memory. Our findings identify SWS as the main driver of the renormalization of synaptic strength during sleep and suggest that SWS-dependent synaptic renormalization is also implicated in homeostatic control processes in the hypothalamus.</p>","PeriodicalId":49001,"journal":{"name":"PLoS Biology","volume":null,"pages":null},"PeriodicalIF":9.8,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11364421/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142009777","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Cell-to-cell mitochondrial transfer has recently been shown to play a role in maintaining physiological functions of cell. We previously illustrated that mitochondrial transfer within osteocyte dendritic network regulates bone tissue homeostasis. However, the mechanism of triggering this process has not been explored. Here, we showed that stressed osteocytes in mice release adenosine diphosphate (ADP), resulting in triggering mitochondrial transfer from healthy osteocytes to restore the oxygen consumption rate (OCR) and to alleviate reactive oxygen species accumulation. Furthermore, we identified that P2Y2 and P2Y6 transduced the ADP signal to regulate osteocyte mitochondrial transfer. We showed that mitochondrial metabolism is impaired in aged osteocytes, and there were more extracellular nucleotides release into the matrix in aged cortical bone due to compromised membrane integrity. Conditioned medium from aged osteocytes triggered mitochondrial transfer between osteocytes to enhance the energy metabolism. Together, using osteocyte as an example, this study showed new insights into how extracellular ADP triggers healthy cells to rescue energy metabolism crisis in stressed cells via mitochondrial transfer in tissue homeostasis.
{"title":"Adenosine diphosphate released from stressed cells triggers mitochondrial transfer to achieve tissue homeostasis.","authors":"Hao Li, Hongping Yu, Delin Liu, Peng Liao, Chuan Gao, Jian Zhou, Jialun Mei, Yao Zong, Peng Ding, Meng Yao, Bingqi Wang, Yafei Lu, Yigang Huang, Youshui Gao, Changqing Zhang, Minghao Zheng, Junjie Gao","doi":"10.1371/journal.pbio.3002753","DOIUrl":"10.1371/journal.pbio.3002753","url":null,"abstract":"<p><p>Cell-to-cell mitochondrial transfer has recently been shown to play a role in maintaining physiological functions of cell. We previously illustrated that mitochondrial transfer within osteocyte dendritic network regulates bone tissue homeostasis. However, the mechanism of triggering this process has not been explored. Here, we showed that stressed osteocytes in mice release adenosine diphosphate (ADP), resulting in triggering mitochondrial transfer from healthy osteocytes to restore the oxygen consumption rate (OCR) and to alleviate reactive oxygen species accumulation. Furthermore, we identified that P2Y2 and P2Y6 transduced the ADP signal to regulate osteocyte mitochondrial transfer. We showed that mitochondrial metabolism is impaired in aged osteocytes, and there were more extracellular nucleotides release into the matrix in aged cortical bone due to compromised membrane integrity. Conditioned medium from aged osteocytes triggered mitochondrial transfer between osteocytes to enhance the energy metabolism. Together, using osteocyte as an example, this study showed new insights into how extracellular ADP triggers healthy cells to rescue energy metabolism crisis in stressed cells via mitochondrial transfer in tissue homeostasis.</p>","PeriodicalId":49001,"journal":{"name":"PLoS Biology","volume":null,"pages":null},"PeriodicalIF":9.8,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11335167/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142009775","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-20eCollection Date: 2024-08-01DOI: 10.1371/journal.pbio.3002776
Ayush Aggarwal, Ayesha Nasreen, Babita Sharma, Sarthak Sahoo, Keerthic Aswin, Mohammed Faruq, Rajesh Pandey, Mohit K Jolly, Abhyudai Singh, Rajesh S Gokhale, Vivek T Natarajan
The ultraviolet (UV) radiation triggers a pigmentation response in human skin, wherein, melanocytes rapidly activate divergent maturation and proliferation programs. Using single-cell sequencing, we demonstrate that these 2 programs are segregated in distinct subpopulations in melanocytes of human and zebrafish skin. The coexistence of these 2 cell states in cultured melanocytes suggests possible cell autonomy. Luria-Delbrück fluctuation test reveals that the initial establishment of these states is stochastic. Tracking of pigmenting cells ascertains that the stochastically acquired state is faithfully propagated in the progeny. A systemic approach combining single-cell multi-omics (RNA+ATAC) coupled to enhancer mapping with H3K27 acetylation successfully identified state-specific transcriptional networks. This comprehensive analysis led to the construction of a gene regulatory network (GRN) that under the influence of noise, establishes a bistable system of pigmentation and proliferation at the population level. This GRN recapitulates melanocyte behaviour in response to external cues that reinforce either of the states. Our work highlights that inherent stochasticity within melanocytes establishes dedicated states, and the mature state is sustained by selective enhancers mark through histone acetylation. While the initial cue triggers a proliferation response, the continued signal activates and maintains the pigmenting subpopulation via epigenetic imprinting. Thereby our study provides the basis of coexistence of distinct populations which ensures effective pigmentation response while preserving the self-renewal capacity.
{"title":"Distinct melanocyte subpopulations defined by stochastic expression of proliferation or maturation programs enable a rapid and sustainable pigmentation response.","authors":"Ayush Aggarwal, Ayesha Nasreen, Babita Sharma, Sarthak Sahoo, Keerthic Aswin, Mohammed Faruq, Rajesh Pandey, Mohit K Jolly, Abhyudai Singh, Rajesh S Gokhale, Vivek T Natarajan","doi":"10.1371/journal.pbio.3002776","DOIUrl":"10.1371/journal.pbio.3002776","url":null,"abstract":"<p><p>The ultraviolet (UV) radiation triggers a pigmentation response in human skin, wherein, melanocytes rapidly activate divergent maturation and proliferation programs. Using single-cell sequencing, we demonstrate that these 2 programs are segregated in distinct subpopulations in melanocytes of human and zebrafish skin. The coexistence of these 2 cell states in cultured melanocytes suggests possible cell autonomy. Luria-Delbrück fluctuation test reveals that the initial establishment of these states is stochastic. Tracking of pigmenting cells ascertains that the stochastically acquired state is faithfully propagated in the progeny. A systemic approach combining single-cell multi-omics (RNA+ATAC) coupled to enhancer mapping with H3K27 acetylation successfully identified state-specific transcriptional networks. This comprehensive analysis led to the construction of a gene regulatory network (GRN) that under the influence of noise, establishes a bistable system of pigmentation and proliferation at the population level. This GRN recapitulates melanocyte behaviour in response to external cues that reinforce either of the states. Our work highlights that inherent stochasticity within melanocytes establishes dedicated states, and the mature state is sustained by selective enhancers mark through histone acetylation. While the initial cue triggers a proliferation response, the continued signal activates and maintains the pigmenting subpopulation via epigenetic imprinting. Thereby our study provides the basis of coexistence of distinct populations which ensures effective pigmentation response while preserving the self-renewal capacity.</p>","PeriodicalId":49001,"journal":{"name":"PLoS Biology","volume":null,"pages":null},"PeriodicalIF":9.8,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11364419/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142009776","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dynamic properties are essential for microtubule (MT) physiology. Current techniques for in vivo imaging of MTs present intrinsic limitations in elucidating the isotype-specific nuances of tubulins, which contribute to their versatile functions. Harnessing the power of the AlphaFold2 pipeline, we engineered a strategy for the minimally invasive fluorescence labeling of endogenous tubulin isotypes or those harboring missense mutations. We demonstrated that a specifically designed 16-amino acid linker, coupled with sfGFP11 from the split-sfGFP system and integration into the H1-S2 loop of tubulin, facilitated tubulin labeling without compromising MT dynamics, embryonic development, or ciliogenesis in Caenorhabditis elegans. Extending this technique to human cells and murine oocytes, we visualized MTs with the minimal background fluorescence and a pathogenic tubulin isoform with fidelity. The utility of our approach across biological contexts and species set an additional paradigm for studying tubulin dynamics and functional specificity, with implications for understanding tubulin-related diseases known as tubulinopathies.
{"title":"AlphaFold2-guided engineering of split-GFP technology enables labeling of endogenous tubulins across species while preserving function.","authors":"Kaiming Xu, Zhiyuan Li, Linfan Mao, Zhengyang Guo, Zhe Chen, Yongping Chai, Chao Xie, Xuerui Yang, Jie Na, Wei Li, Guangshuo Ou","doi":"10.1371/journal.pbio.3002615","DOIUrl":"10.1371/journal.pbio.3002615","url":null,"abstract":"<p><p>Dynamic properties are essential for microtubule (MT) physiology. Current techniques for in vivo imaging of MTs present intrinsic limitations in elucidating the isotype-specific nuances of tubulins, which contribute to their versatile functions. Harnessing the power of the AlphaFold2 pipeline, we engineered a strategy for the minimally invasive fluorescence labeling of endogenous tubulin isotypes or those harboring missense mutations. We demonstrated that a specifically designed 16-amino acid linker, coupled with sfGFP11 from the split-sfGFP system and integration into the H1-S2 loop of tubulin, facilitated tubulin labeling without compromising MT dynamics, embryonic development, or ciliogenesis in Caenorhabditis elegans. Extending this technique to human cells and murine oocytes, we visualized MTs with the minimal background fluorescence and a pathogenic tubulin isoform with fidelity. The utility of our approach across biological contexts and species set an additional paradigm for studying tubulin dynamics and functional specificity, with implications for understanding tubulin-related diseases known as tubulinopathies.</p>","PeriodicalId":49001,"journal":{"name":"PLoS Biology","volume":null,"pages":null},"PeriodicalIF":9.8,"publicationDate":"2024-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11361732/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142005613","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}