Melissa A Luse, Luke S Dunaway, Shruthi Nyshadham, Alicia Carvalho, Meghan W Sedovy, Claire A Ruddiman, Rachel Tessema, Karen Hirschi, Scott R Johnstone, Brant E Isakson
{"title":"Endothelial-adipocyte Cx43 Mediated Gap Junctions Can Regulate Adiposity.","authors":"Melissa A Luse, Luke S Dunaway, Shruthi Nyshadham, Alicia Carvalho, Meghan W Sedovy, Claire A Ruddiman, Rachel Tessema, Karen Hirschi, Scott R Johnstone, Brant E Isakson","doi":"10.1093/function/zqae029","DOIUrl":"10.1093/function/zqae029","url":null,"abstract":"<p><p>Obesity is a multifactorial metabolic disorder associated with endothelial dysfunction and increased risk of cardiovascular disease. Adipose capillary adipose endothelial cells (CaECs) plays a crucial role in lipid transport and storage. Here, we investigated the mechanisms underlying CaEC-adipocyte interaction and its impact on metabolic function. Single-cell RNA sequencing (scRNAseq) revealed an enrichment of fatty acid handling machinery in CaECs from high fat diet (HFD) mice, suggesting their specialized role in lipid metabolism. Transmission electron microscopy (TEM) confirmed direct heterocellular contact between CaECs and adipocytes. To model this, we created an in vitro co-culture transwell system to model the heterocellular contact observed with TEM. Contact between ECs and adipocytes in vitro led to upregulation of fatty acid binding protein 4 in response to lipid stimulation, hinting intercellular signaling may be important between ECs and adipocytes. We mined our and others scRNAseq datasets to examine which connexins may be present in adipose capillaries and adipocytes and consistently identified connexin 43 (Cx43) in mouse and humans. Genetic deletion of endothelial Cx43 resulted in increased epididymal fat pad (eWAT) adiposity and dyslipidemia in HFD mice. Consistent with this observation, phosphorylation of Cx43 at serine 368, which closes gap junctions, was increased in HFD mice and lipid-treated ECs. Mice resistant to this post-translational modification, Cx43S368A, were placed on an HFD and were found to have reduced eWAT adiposity and improved lipid profiles. These findings suggest Cx43-mediated heterocellular communication as a possible regulatory mechanism of adipose tissue function.</p>","PeriodicalId":73119,"journal":{"name":"Function (Oxford, England)","volume":" ","pages":""},"PeriodicalIF":5.1,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11384900/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141565330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rebekah J Nicholson, Nirupama Ramkumar, Aylin R Rodan
{"title":"Megalin as a Metabolic Modulator in the Kidney and Beyond.","authors":"Rebekah J Nicholson, Nirupama Ramkumar, Aylin R Rodan","doi":"10.1093/function/zqae032","DOIUrl":"10.1093/function/zqae032","url":null,"abstract":"","PeriodicalId":73119,"journal":{"name":"Function (Oxford, England)","volume":" ","pages":""},"PeriodicalIF":5.1,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11384898/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141565331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Alex Hanson, Conor McClenaghan, Kuo-Chan Weng, Sarah Colijn, Amber N Stratman, Carmen M Halabi, Dorothy K Grange, Jonathan R Silva, Colin G Nichols
{"title":"Electrophysiology of Human iPSC-derived Vascular Smooth Muscle Cells and Cell-autonomous Consequences of Cantú Syndrome Mutations.","authors":"Alex Hanson, Conor McClenaghan, Kuo-Chan Weng, Sarah Colijn, Amber N Stratman, Carmen M Halabi, Dorothy K Grange, Jonathan R Silva, Colin G Nichols","doi":"10.1093/function/zqae027","DOIUrl":"10.1093/function/zqae027","url":null,"abstract":"<p><p>Cantú syndrome (CS), a multisystem disease with a complex cardiovascular phenotype, is caused by gain-of-function (GoF) variants in the Kir6.1/SUR2 subunits of ATP-sensitive potassium (KATP) channels and is characterized by low systemic vascular resistance, as well as tortuous, dilated, vessels, and decreased pulse-wave velocity. Thus, CS vascular dysfunction is multifactorial, with both hypomyotonic and hyperelastic components. To dissect whether such complexities arise cell autonomously within vascular smooth muscle cells (VSMCs) or as secondary responses to the pathophysiological milieu, we assessed electrical properties and gene expression in human induced pluripotent stem cell-derived VSMCs (hiPSC-VSMCs), differentiated from control and CS patient-derived hiPSCs, and in native mouse control and CS VSMCs. Whole-cell voltage clamp of isolated aortic and mesenteric arterial VSMCs isolated from wild-type (WT) and Kir6.1[V65M] (CS) mice revealed no clear differences in voltage-gated K+ (Kv) or Ca2+ currents. Kv and Ca2+ currents were also not different between validated hiPSC-VSMCs differentiated from control and CS patient-derived hiPSCs. While pinacidil-sensitive KATP currents in control hiPSC-VSMCs were similar to those in WT mouse VSMCs, they were considerably larger in CS hiPSC-VSMCs. Under current-clamp conditions, CS hiPSC-VSMCs were also hyperpolarized, consistent with increased basal K conductance and providing an explanation for decreased tone and decreased vascular resistance in CS. Increased compliance was observed in isolated CS mouse aortae and was associated with increased elastin mRNA expression. This was consistent with higher levels of elastin mRNA in CS hiPSC-VSMCs and suggesting that the hyperelastic component of CS vasculopathy is a cell-autonomous consequence of vascular KATP GoF. The results show that hiPSC-VSMCs reiterate expression of the same major ion currents as primary VSMCs, validating the use of these cells to study vascular disease. Results in hiPSC-VSMCs derived from CS patient cells suggest that both the hypomyotonic and hyperelastic components of CS vasculopathy are cell-autonomous phenomena driven by KATP overactivity within VSMCs .</p>","PeriodicalId":73119,"journal":{"name":"Function (Oxford, England)","volume":" ","pages":""},"PeriodicalIF":5.1,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11388097/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141565329","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Candee T Barris, Emily Burns-Ray, Jennifer C Sullivan
{"title":"Managing Sex as a Biological Variable in Physiological Research: Best Practices.","authors":"Candee T Barris, Emily Burns-Ray, Jennifer C Sullivan","doi":"10.1093/function/zqae034","DOIUrl":"10.1093/function/zqae034","url":null,"abstract":"","PeriodicalId":73119,"journal":{"name":"Function (Oxford, England)","volume":" ","pages":""},"PeriodicalIF":5.1,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11384905/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141894942","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Robert T Mankowski, Raymond Jones, Thomas W Buford
{"title":"MoTrPAC Animal Aerobic Exercise Protocol and Biorepository: A Novel Resource for Uncovering Systemic Adaptations to Aerobic Exercise and Extending Healthspan.","authors":"Robert T Mankowski, Raymond Jones, Thomas W Buford","doi":"10.1093/function/zqae040","DOIUrl":"10.1093/function/zqae040","url":null,"abstract":"","PeriodicalId":73119,"journal":{"name":"Function (Oxford, England)","volume":" ","pages":""},"PeriodicalIF":5.1,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11420664/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142302565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Defining Cytokine Responsive and Non-responsive Human β-cells.","authors":"Samuel B Stephens","doi":"10.1093/function/zqae039","DOIUrl":"https://doi.org/10.1093/function/zqae039","url":null,"abstract":"","PeriodicalId":73119,"journal":{"name":"Function (Oxford, England)","volume":"5 5","pages":""},"PeriodicalIF":5.1,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11406544/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142302569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Simonetta Falzoni, Valentina Vultaggio-Poma, Paola Chiozzi, Mario Tarantini, Elena Adinolfi, Paola Boldrini, Anna Lisa Giuliani, Giampaolo Morciano, Yong Tang, Dariusz C Gorecki, Francesco Di Virgilio
{"title":"The P2X7 Receptor is a Master Regulator of Microparticle and Mitochondria Exchange in Mouse Microglia.","authors":"Simonetta Falzoni, Valentina Vultaggio-Poma, Paola Chiozzi, Mario Tarantini, Elena Adinolfi, Paola Boldrini, Anna Lisa Giuliani, Giampaolo Morciano, Yong Tang, Dariusz C Gorecki, Francesco Di Virgilio","doi":"10.1093/function/zqae019","DOIUrl":"10.1093/function/zqae019","url":null,"abstract":"<p><p>Microparticles (MPs) are secreted by all cells, where they play a key role in intercellular communication, differentiation, inflammation, and cell energy transfer. P2X7 receptor (P2X7R) activation by extracellular ATP (eATP) causes a large MP release and affects their contents in a cell-specific fashion. We investigated MP release and functional impact in microglial cells from P2X7R-WT or P2X7R-KO mice, as well as mouse microglial cell lines characterized for high (N13-P2X7RHigh) or low (N13-P2X7RLow) P2X7R expression. P2X7R stimulation promoted release of a mixed MP population enriched with naked mitochondria. Released mitochondria were taken up and incorporated into the mitochondrial network of the recipient cells in a P2X7R-dependent fashion. NLRP3 and the P2X7R itself were also delivered to the recipient cells. Microparticle transfer increased the energy level of the recipient cells and conferred a pro-inflammatory phenotype. These data show that the P2X7R is a master regulator of intercellular organelle and MP trafficking in immune cells.</p>","PeriodicalId":73119,"journal":{"name":"Function (Oxford, England)","volume":" ","pages":""},"PeriodicalIF":5.1,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11237899/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141565335","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Elynna B Youm, Katherine E Shipman, Wafaa N Albalawy, Amber M Vandevender, Ian J Sipula, Youssef Rbaibi, Allison E Marciszyn, Jared A Lashway, Emma E Brown, Corry B Bondi, Cary R Boyd-Shiwarski, Roderick J Tan, Michael J Jurczak, Ora A Weisz
{"title":"Megalin Knockout Reduces SGLT2 Expression and Sensitizes to Western Diet-induced Kidney Injury.","authors":"Elynna B Youm, Katherine E Shipman, Wafaa N Albalawy, Amber M Vandevender, Ian J Sipula, Youssef Rbaibi, Allison E Marciszyn, Jared A Lashway, Emma E Brown, Corry B Bondi, Cary R Boyd-Shiwarski, Roderick J Tan, Michael J Jurczak, Ora A Weisz","doi":"10.1093/function/zqae026","DOIUrl":"10.1093/function/zqae026","url":null,"abstract":"<p><p>Megalin (Lrp2) is a multiligand receptor that drives endocytic flux in the kidney proximal tubule (PT) and is necessary for the recovery of albumin and other filtered proteins that escape the glomerular filtration barrier. Studies in our lab have shown that knockout (KO) of Lrp2 in opossum PT cells leads to a dramatic reduction in sodium-glucose co-transporter 2 (SGLT2) transcript and protein levels, as well as differential expression of genes involved in mitochondrial and metabolic function. SGLT2 transcript levels are reduced more modestly in Lrp2 KO mice. Here, we investigated the effects of Lrp2 KO on kidney function and health in mice fed regular chow (RC) or a Western-style diet (WD) high in fat and refined sugar. Despite a modest reduction in SGLT2 expression, Lrp2 KO mice on either diet showed increased glucose tolerance compared to control mice. Moreover, Lrp2 KO mice were protected against WD-induced fat gain. Surprisingly, renal function in male Lrp2 KO mice on WD was compromised, and the mice exhibited significant kidney injury compared with control mice on WD. Female Lrp2 KO mice were less susceptible to WD-induced kidney injury than male Lrp2 KO. Together, our findings reveal both positive and negative contributions of megalin expression to metabolic health, and highlight a megalin-mediated sex-dependent response to injury following WD.</p>","PeriodicalId":73119,"journal":{"name":"Function (Oxford, England)","volume":" ","pages":""},"PeriodicalIF":5.1,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11237895/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141565332","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C M Lazaro, I N Freitas, V S Nunes, D M Guizoni, J A Victorio, H C F Oliveira, A P Davel
{"title":"Sex-Specific Effects of Cholesteryl Ester Transfer Protein (CETP) on the Perivascular Adipose Tissue.","authors":"C M Lazaro, I N Freitas, V S Nunes, D M Guizoni, J A Victorio, H C F Oliveira, A P Davel","doi":"10.1093/function/zqae024","DOIUrl":"10.1093/function/zqae024","url":null,"abstract":"<p><p>Cholesteryl ester transfer protein (CETP) increases the atherosclerosis risk by lowering HDL-cholesterol levels. It also exhibits tissue-specific effects independent of HDL. However, sexual dimorphism of CETP effects remains largely unexplored. Here, we hypothesized that CETP impacts the perivascular adipose tissue (PVAT) phenotype and function in a sex-specific manner. PVAT function, gene and protein expression, and morphology were examined in male and female transgenic mice expressing human or simian CETP and their non-transgenic counterparts (NTg). PVAT exerted its anticontractile effect in aortas from NTg males, NTg females, and CETP females, but not in CETP males. CETP male PVAT had reduced NO levels, decreased eNOS and phospho-eNOS levels, oxidative stress, increased NOX1 and 2, and decreased SOD2 and 3 expressions. In contrast, CETP-expressing female PVAT displayed increased NO and phospho-eNOS levels with unchanged NOX expression. NOX inhibition and the antioxidant tempol restored PVAT anticontractile function in CETP males. Ex vivo estrogen treatment also restored PVAT function in CETP males. Moreover, CETP males, but not female PVAT, show increased inflammatory markers. PVAT lipid content increased in CETP males but decreased in CETP females, while PVAT cholesterol content increased in CETP females. CETP male PVAT exhibited elevated leptin and reduced Prdm16 (brown adipocyte marker) expression. These findings highlight CETP sex-specific impact on PVAT. In males, CETP impaired PVAT anticontractile function, accompanied by oxidative stress, inflammation, and whitening. Conversely, in females, CETP expression increased NO levels, induced an anti-inflammatory phenotype, and preserved the anticontractile function. This study reveals sex-specific vascular dysfunction mediated by CETP.</p>","PeriodicalId":73119,"journal":{"name":"Function (Oxford, England)","volume":" ","pages":""},"PeriodicalIF":5.1,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11237897/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141565333","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jennifer S Stancill, Moujtaba Y Kasmani, Weiguo Cui, John A Corbett
{"title":"Single Cell RNAseq Analysis of Cytokine-Treated Human Islets: Association of Cellular Stress with Impaired Cytokine Responsiveness.","authors":"Jennifer S Stancill, Moujtaba Y Kasmani, Weiguo Cui, John A Corbett","doi":"10.1093/function/zqae015","DOIUrl":"10.1093/function/zqae015","url":null,"abstract":"<p><p>Pancreatic β-cells are essential for survival, being the only cell type capable of insulin secretion. While they are believed to be vulnerable to damage by inflammatory cytokines such as interleukin-1 beta (IL-1β) and interferon-gamma, we have recently identified physiological roles for cytokine signaling in rodent β-cells that include the stimulation of antiviral and antimicrobial gene expression and the inhibition of viral replication. In this study, we examine cytokine-stimulated changes in gene expression in human islets using single-cell RNA sequencing. Surprisingly, the global responses of human islets to cytokine exposure were remarkably blunted compared to our previous observations in the mouse. The small population of human islet cells that were cytokine responsive exhibited increased expression of IL-1β-stimulated antiviral guanylate-binding proteins, just like in the mouse. Most human islet cells were not responsive to cytokines, and this lack of responsiveness was associated with high expression of genes encoding ribosomal proteins. We further correlated the expression levels of RPL5 with stress response genes, and when expressed at high levels, RPL5 is predictive of failure to respond to cytokines in all endocrine cells. We postulate that donor causes of death and isolation methodologies may contribute to stress of the islet preparation. Our findings indicate that activation of stress responses in human islets limits cytokine-stimulated gene expression, and we urge caution in the evaluation of studies that have examined cytokine-stimulated gene expression in human islets without evaluation of stress-related gene expression.</p>","PeriodicalId":73119,"journal":{"name":"Function (Oxford, England)","volume":" ","pages":""},"PeriodicalIF":5.1,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11237896/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141565334","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}