Physiology最新文献

{"title":"Effects of Electronic vs. Tobacco Cigarettes on Cardiovascular Health in Male and Female Mice","authors":"Candice J. Lao, Maria C. Jordan, Theodore C. Friedman, Yin Tintut, Xuesi M. Shao, Kenneth P. Roos","doi":"10.1152/physiol.2024.39.s1.1235","DOIUrl":"https://doi.org/10.1152/physiol.2024.39.s1.1235","url":null,"abstract":"Objective: Smoking electronic cigarettes (E-cig) has been promoted as a safer alternative to conventional tobacco cigarettes (CIG) and thus become popular, especially among younger generations. However, one mode of smoking nicotine containing products vs. another on the effects on health and gender are largely unknown. Hypothesis: Both E-cig and CIG have adverse effects on body weight as well as cardiovascular health. Methods: To closely mimic the Western population, we investigated the effects of two insults (diet and/or nicotine exposure) in mice. Nine-week old male and female Apoe−/− mice (C57BL/6 background) were placed on normal chow or high-fat diet (Western diet, WD) and/or exposed to air, E-cig, or CIG for 12 weeks. The E-cig and Cig exposures used a chronic-intermittent puff protocol for 10 hours a day, seven days a week during their active (dark) circadian cycle. Changes in body weight, cardiac structure, function, and atherosclerotic lesions were assessed and compared. Results: In males, body weight was significantly reduced by CIG exposure with both the normal diet or WD, while in females, only on WD. This suggests that CIG exposure had gender-dependent effects on the body weight. E-cig exposure, however, did not affect the body weight in both males and females on either diet compared with the controls. Echocardiographic analysis showed that left ventricular mass was increased while ejection fraction was reduced by both e-cigarette and CIG-exposure. These data suggest that both modes of nicotine delivery had gender-independent adverse effects on cardiac structure and function. En face analysis of the aorta in both genders showed that two insults (CIG and WD) are necessary to induce significantly greater lesions. There were no significant increases in lesions with E-Cigs. This suggests that CIG exposure had insult-dependent but gender-independent effects on atherosclerotic lesion development. Summary: These findings suggest that both electronic cigarettes and conventional tobacco cigarettes impose adverse effects on the body weight and cardiovascular health in modes of nicotine- and gender-dependent manners. Funding: Department of Defense CDMRP Grant PR 190942 (TCF) and DODCDMRP Grant PR190942-P1 (KPR). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.","PeriodicalId":49694,"journal":{"name":"Physiology","volume":null,"pages":null},"PeriodicalIF":8.4,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141141284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Intact DNA Repair in Differentiated Cardiomyocytes Is Essential for Maintaining Cardiac Function in Response to Pressure Overload in Mice","authors":"Martine de Boer, J. H. Hoeijmakers, D. J. Duncker","doi":"10.1152/physiol.2024.39.s1.398","DOIUrl":"https://doi.org/10.1152/physiol.2024.39.s1.398","url":null,"abstract":"Introduction: DNA in every cell is continuously damaged and DNA repair mechanisms are essential for protection against DNA damage-induced aging-related diseases. For example, deficient repair of endogenously generated DNA damage in mice with cardiomyocyte-restricted inactivation of Xpg, is associated with progressive heart failure (de Boer et al. Aging Cell 2023). Here we tested the hypothesis that unrepaired DNA damage in differentiated cardiomyocytes increases cardiac vulnerability in response to hemodynamic overload. Methods: At 8 weeks of age, αMHC-Xpgc/- and control (Ctrl) mice were subjected to pressure overload by mild transverse aortic constriction (TAC). Eight weeks after TAC, left ventricular (LV) function was assessed using echocardiography and hemodynamic measurements, followed by histological and molecular analyses. Results: Cardiomyocyte-restricted inactivation of Xpg resulted in systolic as well as diastolic LV dysfunction. TAC-induced LV hypertrophy was similar in both groups (Ctrl 38%; αMHC-Xpgc/- 34%). In Ctrl mice, LV hypertrophy was accompanied by minimal LV dilation and only modest changes in systolic and diastolic LV function. Conversely, TAC in αMHC-Xpgc/- produced severe LV dilation and dysfunction and resulted in overt backward failure, demonstrated by marked increases in LV end-diastolic pressure, left atrial weight and lung fluid weight. These changes were accompanied by further increases in the expression levels of the hypertrophic marker genes atrial natriuretic peptide and beta-myosin heavy chain. Moreover, lectin staining revealed a decrease in capillary density and TUNEL staining revealed further elevated levels of myocardial apoptosis in αMHC-Xpgc/--TAC mice as compared to Ctrl-TAC mice. In addition, a significant increase of myocardial collagen content was observed in αMHC-Xpgc/--TAC but not in Ctrl-TAC mice. Conclusion: Cardiomyocyte-restricted loss of DNA repair protein Xpg increases cardiac vulnerability to develop heart failure in response to pressure-overload. These findings underscore the importance of genomic stability for maintenance of cardiac function, not only under basal conditions, but also during increased cardiac loading conditions. Supported by the Dutch Heart Foundation [Grants 2017B018-ARENA-PRIME; 2021B008-RECONNEXT]. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.","PeriodicalId":49694,"journal":{"name":"Physiology","volume":null,"pages":null},"PeriodicalIF":8.4,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141143438","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Placental programming mediates the vicious cycle between maternal gestational diabetes and offspring type 2 diabetes in a novel mouse model","authors":"Qun Gao, Albert Gao, Fuller Gao, Sarah Kim, Natasha Driver, Haijun Gao","doi":"10.1152/physiol.2024.39.s1.2181","DOIUrl":"https://doi.org/10.1152/physiol.2024.39.s1.2181","url":null,"abstract":"Accumulating evidence from human epidemiological studies indicates that there is a vicious cycle between maternal gestational diabetes (GDM) and offspring type 2 diabetes (T2D). However, the underlying mechanisms remain unclear. A handful of studies found that mitochondrial defects occur in the GDM placenta, including excess accumulation of destroyed mitochondria, reduced ATP and enhanced ROS production, which indicates that mitophagy, a specific process to remove destroyed mitochondria, may be impaired in the GDM placenta. Our recent study suggested that BNIP3 plays a critical role in maintaining mitochondria homeostasis in human trophoblast cells. Therefore, in this study, we hypothesized that conditional knockout of BNIP3 specifically in mouse trophoblast cells will recapitulate the typical symptoms of GDM in maternal pregnancy and T2D in offspring. First, we made male mice with double homozygous Cre and LoxP by breeding Cyp19-Cre and Bnip3-LoxP mice, which was used to mate females with homozygous LoxP, forming a cKO group. On the other hand, wild-type female mice were bred by males with homozygous Cre, forming a control group (CT). Second, offspring from cKO and CT mothers were allowed to grow up. On Day 18 of pregnancy, glucose tolerance test was conducted in pregnant cKO or CT mice. The placental tissues were collected and mRNA and protein levels of BNIP3 were measured by qPCR and Western blotting, respectively. In male offspring at the age of eight months, glucose tolerance test was conducted, and metabolic rate was measured by CaloBox Indirect Calorimetry. All numerical parameters between the cKO and CT pregnant mice, and between their male offspring were analyzed by ANOVA (n=5). The main findings include: 1) On Day 18 of pregnancy, BNIP3 mRNA and protein levels in the placental tissue were reduced by 47% and by 40% in cKO compared to CT mice (p<0.05), respectively (p<0.05); 2) Pregnant cKO mice demonstrated enhanced glucose intolerance compared to those control mice; 3) At the age of 8 months, the body weight of male offspring from cKO mothers was increased by 1.16-fold (p<0.05) compared to those from CT mothers; 4) Male offspring from cKO mothers demonstrated enhanced glucose intolerance compared to those from CT mothers; 5) The metabolic rates was lower in male offspring from cKO mothers compared to those from CT mothers, with decreased oxygen consumption and carbon dioxide production by 1.18- and 1.19-fold, respectively (p<0.05). These results suggest that placental programming possibly via the disrupted functions of BNIP3 in trophoblast cells mediates the occurrence of maternal GDM and offspring T2D, therefore, placental BNIP3 may play a critical role in the vicious cycle of maternal GDM and offspring T2D and thus, being a potential target in treatment of GDM and prevention of T2D. NIH research grants R03HD095417, U54MD007597. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in ","PeriodicalId":49694,"journal":{"name":"Physiology","volume":null,"pages":null},"PeriodicalIF":8.4,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141143689","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Novel Role of YAP1 in Regulating Blood Pressure and Vascular Tone","authors":"Sanjana Kumariya, Arturo Grano de Oro, Islam Osman","doi":"10.1152/physiol.2024.39.s1.1243","DOIUrl":"https://doi.org/10.1152/physiol.2024.39.s1.1243","url":null,"abstract":"Introduction: Hypertension is a major risk factor for occlusive vascular diseases, myocardial infarction, heart failure, stroke, and chronic kidney disease. In the U.S., ~30% of adults suffer from hypertension. Merely half of the individuals with hypertension have their blood pressure under control, despite the wide range of antihypertensive medications available, indicating an urgent need for a better understanding of the underlying causes of hypertension to identify novel therapeutic strategies for its treatment and prevention. Recent genome-wide association study (GWAS) has identified an unexpected association between a loss-of-function SNP in the YAP1 gene locus and decreased blood pressure (BP). Moreover, de novo analysis of publicly available RNAseq data revealed that the vascular tissues of hypertensive mice treated with Ang-II exhibit increased YAP1 expression. Suggesting a novel role of YAP1 in blood pressure regulation. However, whether Vascular smooth muscle cell (VSMC) expressed YAP1 has a specific role in VSMC contraction and BP regulation remains completely unknown. Therefore, we hypothesized that YAP1 could play a key role in regulating blood pressure. Methodology: We have generated a novel inducible SM-specific- Yap1 Knockout ( YAP1 iKO) mouse model and employed a pharmacological inhibitor of YAP1, Verteporfin, to delineate the functional role of VSMC-expressed YAP1 in hypertension in regulating vascular tone and BP. Vascular reactivity experiments were performed using wire myography. BP was measured in ambulant mice via radiotelemetry. In vitro gain- and loss-of-function studies utilizing human coronary artery SMCs were conducted to examine the impact of YAP1 on contractility signaling components using western blotting. Results: Consistent with GWAS and RNAseq data, we found that YAP1 is upregulated in vascular tissues of spontaneously hypertensive rats (SHRs). Using aortic rings from WT mice, we discovered that Verteporfin significantly reduced vasoconstrictive responses to Phenylephrine or Serotonin but did not alter endothelium-dependent vasorelaxant responses to Acetylcholine, suggesting a specific role of YAP1 in VSMCs. Consistently, YAP1 iKO exhibited attenuated responses to vasoconstrictors in isolated conduit and resistance vessels. Importantly, radiotelemetry studies demonstrated for the first time that YAP1 iKO mice exhibit a hypotensive phenotype. Mechanistically, YAP1 gain- and loss-of-function studies in human VSMCs showed that YAP1 activates multiple signaling pathways that play a key role in VSMC contractility including RhoA/ROCK1/actin polymerization and PKC/ERK signaling pathways. Summary/Conclusion: This is the first study to demonstrate that inhibition of SM-specific-Yap1 expression regulates BP and vascular tone, likely via the regulation of contractile machinery components. Together, our data suggest that YAP1 is a promising novel therapeutic target for ameliorating hypertension. This work is supported by a g","PeriodicalId":49694,"journal":{"name":"Physiology","volume":null,"pages":null},"PeriodicalIF":8.4,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141143938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Glucose-Induced Cellular Morphological Changes Across Mammalian Species","authors":"Cassandra Burke, Michael Blackwell, Carla Madelaire, Allyson G Hindle","doi":"10.1152/physiol.2024.39.s1.2098","DOIUrl":"https://doi.org/10.1152/physiol.2024.39.s1.2098","url":null,"abstract":"All organisms encounter environmental fluctuations and must contend with these changes to maintain homeostasis. Some mammals tolerate a wide range of intracellular conditions while others do not. Altered glucose levels are an example of a physiological challenge that can be encountered by cells. We studied responses of dermal fibroblasts obtained from skin biopsies to altered glucose treatments in culture using a comparative approach. Specifically, we investigated responses of mammals known to tolerate a range of blood glucose levels (fruit-eating geladas and Egyptian rousettes) as well as a hibernator (ground squirrel), which exhibits a marked winter decrease in glucose metabolism. As a comparison, we investigated species that maintain fairly stable blood glucose (human and rat). Fibroblasts were cultured at baseline (8mM glucose), then subjected to hypoglycemic (2.5mM) and hyperglycemic (30mM) treatment over 24h. We assayed glycolytic rate in human and rat fibroblasts using a Seahorse XFp analyzer, and found no significance between oxygen consumption or glycolysis across glucose treatments (all p>0.05). To investigate underlying cell phenotypes, we used Cell Painting, employing fluorescent stains to mark organelles. Hoechst 34580 stained DNA, to quantify number and size of nuclei, offering insights into proliferation. MitoTracker Deep Red visualized mitochondria, providing information about energy generation. Alexa Fluor 488 Concanavalin A conjugate marked endoplasmic reticulum. F-actin was stained with Alexa Fluor 555 Phalloidin conjugate, detecting cytoskeletal organization and overall cell structure. Images were analyzed with CellProfiler software, which extracts ~1400 morphological cell features, including area, compactness, fluorescence intensity, and cell connectivity to quantify subtle changes in phenotype. Each extracted feature will be compared across treatments and within a comparative context. We predict that fibroblasts exposed to hyperglycemia exhibit mitochondrial fragmentation and redistribution (MitoTracker) and increased production of reactive oxygen species (assessed with MitoSOX), which is linked to the opening of mitochondrial permeability transition pores. Cell Profiler analysis will identify structural changes that could indicate negative outcomes, such as mitophagy. Hyperglycemia may also induce endoplasmic stress, increasing lipid droplets and altering shape and size of the endoplasmic reticulum. In contrast, hypoglycemia will cause mitochondrial degradation. In both hyper- and hypoglycemia, proliferation rates are predicted to decrease, resulting in fewer nuclei and reduced cell connectivity. Phenotypic differences across species, evaluated in the context of their organismal phenotype, will help explain the mechanisms of cell function in mammals under environmental stress. Funding by NSF #2022046. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. The","PeriodicalId":49694,"journal":{"name":"Physiology","volume":null,"pages":null},"PeriodicalIF":8.4,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141144460","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Role of Leptin in Regulating Renal Phosphate Transport","authors":"Linto Thomas, Sima Al-Masri, Jessica A Dominguez Rieg, Timo Rieg","doi":"10.1152/physiol.2024.39.s1.1308","DOIUrl":"https://doi.org/10.1152/physiol.2024.39.s1.1308","url":null,"abstract":"Elevated plasma phosphate (Pi) levels, known as hyperphosphatemia, are associated with an increased risk of cardiovascular complications and mortality. Although studies have suggested a correlation between obesity and hyperphosphatemia/phosphate toxicity, the root cause of this observation has not been established. Since hyperleptinemia was also found to be associated with abnormalities in bone structure, we hypothesized that effects on renal Pi transport are responsible for this observation. To address this question, we studied hyperleptinemic mice (db/db, n=14) and compared them to wild-type mice (WT, n=10). Blood and urine samples, as well as kidney tissues, were collected and analyzed. Body weight was approximately twice as high in db/db compared to WT mice (59±3 vs. 30±2 g, P<0.05). Plasma Pi levels in db/db mice were significantly greater (~1.5-fold) compared to WT mice (2.6±0.1 vs. 1.7±0.1 mmol/L, P<0.05). However, urinary Pi /creatinine ratios were similar between genotypes. Plasma Ca2+ levels in db/db mice were significantly higher compared to WT mice (2.68±0.03 vs. 2.48±0.03 mmol/L, P<0.05) alongside urinary Ca2+/creatinine ratios being significantly higher in db/db mice compared to WT mice (1.6±0.4 vs. 0.3±0.1 mmol/mmol, P<0.05). Plasma parathyroid hormone (PTH, regulating Pi and Ca2+) levels were similar in both genotypes. The phosphaturic hormone fibroblast growth factor 23 (FGF23), which is produced and released from bone, was slightly but significantly elevated in db/db compared to WT mice (254±12 vs. 227±18 pg/mL, P<0.05). Bone formation markers (osteocalcin and procollagen type I N-propeptide) and bone resorption markers (tartrate-resistant acid phosphatase 5b and C-terminal telopeptide of type I collagen) were similar between genotypes, indicating that Pi and Ca2+ release from bone may not be causing these mineral differences. To determine the role of the kidney for the development of hyperphosphatemia, we performed 32P radiotracer studies in acutely isolated renal brush border membrane vesicles. Sodium-dependent 32P transport was not significantly different between genotypes. To determine the ambient in vivo contribution of the Na+-Pi cotransporter Npt2a, we employed acute pharmacological inhibition with PF-06869206 (Npt2a inhibitor, 30 mg/kg b.w, n=7) or vehicle (n=11) and compared plasma Pi before and 2 hours after administration in db/db mice. Vehicle treatment slightly increased plasma Pi levels compared to baseline (2.6±0.1 vs. 2.1±0.1 mmol/L, P<0.05); in contrast, the Npt2a inhibitor significantly reduced (~50%) plasma Pi levels compared to baseline (1.3±0.1 vs. 2.5±0.1 mmol/L, P<0.05). In summary, our study demonstrates that hyperphosphatemia in db/db mice is not caused by changes in renal Pi transport or bone turnover, suggesting that possibly intestinal mechanisms are responsible for increased Pi, and possibly Ca2+, absorption. Of note, Npt2a inhibition was effective in reducing hyperphosphatemia in db/db mice, indicat","PeriodicalId":49694,"journal":{"name":"Physiology","volume":null,"pages":null},"PeriodicalIF":8.4,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141144517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of Diabetic Intramuscular Adipose Tissue and its Impact on Skeletal Muscle","authors":"Chang Gui, Kathryn Bohnert, Jeremy McCormick, Jonathon Bakus, Jeffrey Johnson, Sandra Klein, Gretchen Meyer","doi":"10.1152/physiol.2024.39.s1.1393","DOIUrl":"https://doi.org/10.1152/physiol.2024.39.s1.1393","url":null,"abstract":"Obesity and type 2 Diabetes exhibit a muscle pathology called fatty infiltration where adipocytes develop between muscle fibers in the intramuscular space. This is associated with reduced contractile strength and physical function in these populations. However, the mechanisms governing this phenomenon are not well understood. In this study, we aim to characterize intramuscular adipose tissue (IMAT) in both healthy and diabetic patients and explore its impact on muscle regeneration. We hypothesized that diabetes would alter the secretory profile of IMAT and hinder muscle regeneration. Finally, we treated IMAT-derived progenitor cells with a browning agent to determine whether this intervention could modulate IMAT-muscle cross-talk. We collected human IMAT from the abductor hallucis muscle and subcutaneous fat from patients during elective below-knee amputation, both with and without type 2 Diabetes. All participants gave informed consent to participate in this study. Samples were divided and processed for RNA sequencing and adipose progenitor cell (APC) isolation. Following sequencing, we identified top differentially expressed genes (DEGs) encoding secretory proteins that differed between IMAT and subcutaneous fat across participants, including WNT2, BMP5, OSTN. Additionally, IPA analysis revealed that the Wound Healing Signaling pathway is more activated in IMAT under diabetic conditions. We then screened these target genes using a co-culture system in vitro. In this system, APCs were cultured under different conditions and then used to condition media which was applied to separate cultures of isolated human muscle myoblasts. Cultured ASCs were additionally collected for qPCR analysis and a sample of the media was collected for screening. The impact of the conditioned media on myogenesis was assayed by Myosin Heavy Chain (MHC) immunostaining. Myogenesis was not affected by treatment with any conditioned media, including that from Diabetic IMAT. Furthermore, no improvement of myogenesis was observed by treating the APCs with a browning agent. We were able to confirm that WNT2 is differentially expressed in IMAT APCs treated with a browning agent, compared with SQ (p=0.0406, n=4, FC=0.47) and diabetic conditions (p=0.1581, n=5), in line with our intact tissue RNAseq. This study highlights the distinct transcriptional profile of IMAT compared to subcutaneous fat, with WNT2 identified as a potential mediator between adipose tissue and skeletal muscle. The failure to observe decreased myogenesis implies the crosstalk between muscle and muscle-associated fat might involve a more complex cell-cell network than a simple ASC-myoblast interaction. 1R01AR075773-01. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.","PeriodicalId":49694,"journal":{"name":"Physiology","volume":null,"pages":null},"PeriodicalIF":8.4,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141144530","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Erbb3 regulation of secretory differentiation in the intestinal epithelium","authors":"Ashley Lehr, Stephanie King, Jonathan J. Hsieh, Kelsey Finnigan, Alisella Hernandez, D. Almohazey, Michael Schumacher","doi":"10.1152/physiol.2024.39.s1.1581","DOIUrl":"https://doi.org/10.1152/physiol.2024.39.s1.1581","url":null,"abstract":"Background: Previous work by our lab showed that intestinal-specific deletion of the ErbB3 receptor tyrosine kinase results in increased ileal Paneth cell numbers. These cells produce host defense peptides and support stem cells with growth factors. The mechanisms by which ErbB3 regulates Paneth cells are not well understood, but a candidate mediator is the polycomb repressor complex 1 component BMI1, which marks secretory progenitor cells. Furthermore, while there are no Paneth cells in the mouse colon, deep crypt secretory (DCS) cells are a distinct Reg4+ population that have some functional overlap with both Paneth and goblet cells; we will also test whether ErbB3 regulates DCS differentiation. Overall we are testing the hypothesis that ErbB3 regulates secretory cell numbers through BMI1. Methods: We bred Villin-Cre;ErbB3flox/flox mice (ErbB3ΔIE) to delete ErbB3 from the intestinal epithelium. Colonic sections from ErbB3ΔIE and ErbB3flox/flox littermates were subjected to RNAscope in situ hybridization for Reg4. RNA from mucosal scrapings (both ileum and colon) was assessed by qPCR for Reg4, Bmi1, and Lgr5. To test signaling mechanisms, we treated HT-29 cells with NRG-1β to activate ErbB3, +/- inhibitors to PI3K (LY294002), MEK/MAPK (U0126), or BMI1 (PTC-209). Colonoids and enteroids from ErbB3ΔIE and ErbB3flox/flox mice were used to confirm responses in a non-transformed system. Results: In ErbB3ΔIE mice, the colonic epithelium showed increased Reg4 levels and more Reg4+ cells compared to littermate controls, similar to our published data for the Paneth cell marker Lyz1 in ileum. BMI1 RNA and protein levels were also increased in both small and large intestinal mucosal scrapings from ErbB3ΔIE mice vs. littermates. ErbB3ΔIE colonoids had increased Reg4 versus control colonoids, and NRG-1β reduced levels in control but not ErbB3ΔIE cultures. Ileal enteroids showed a decrease in Lyz1 expression with Bmi1 inhibition and an increase in Bmi1 expression with PI3K and MAPK blockade. In HT-29 cells, NRG-1β treatment reduced Reg4 and Bmi1 expression. Conversely, Reg4 and Bmi1 were induced by PI3K inhibition with LY294002 (p<0.03) (p<0.0005) or MEK/MAPK inhibition with U0126 (p<0.05) (p<0.0001). Conclusions: NRG1-ErbB3 signaling restricts both ileal Paneth ( Lyz1+) and colonic DCS ( Reg4+) cell numbers. Furthermore, ErbB3 regulates Bmi1 expression through PI3K/Akt and MAPK signaling and BMI1 activity promotes secretory cell development. Since loss of DCS or Paneth cells has been shown to disrupt the intestinal stem cell niche and secretory cell markers are altered in several intestinal disease states, these results may point to potential future therapeutic avenues targeting this regulatory mechanism. NIH/NIDDK award R01DK095004. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not invo","PeriodicalId":49694,"journal":{"name":"Physiology","volume":null,"pages":null},"PeriodicalIF":8.4,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141144591","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Role of GLP-1 Affects Fate of Astrocytes Following Ischemic Stroke in Mice","authors":"Hsuan-Yu Lu, Su-Ying Li, Jenq-Lin Yang","doi":"10.1152/physiol.2024.39.s1.508","DOIUrl":"https://doi.org/10.1152/physiol.2024.39.s1.508","url":null,"abstract":"Stroke is one of the leading causes of physical and intellectual disability and mortality in adults of most of the developed countries. The most of studies in ischemic stroke focus on neuronal pathological mechanisms and neuronal death trying to rescue neurons via stopping the detrimental pathological processes or enhancing neuronal viability. Although astrocytes are the most abundant cells and in mammal central nervous system (CNS), they were ignored for period of time but are return to spotlight in recent years. Astrocyte play multiple roles in maintain normal function of central nervous system and respond to all kinds of CNS injury and disease. Responses of astrocytes to CNS damage lead to both detrimental and beneficial consequences. Previous studies have reported that astrocyte inflammatory responses to ischemic stroke may devastate the ischemic lesion, but other astrocytic responses lead to anti-excitotoxicity, secreting neurotrophic factors, neurogenesis, synaptogenesis, axonal remodeling, and angiogenesis promoting neuroprotective effects. Glucagon-like peptide-1 (GLP-1) have been intensively studied on beneficial effects of neurons, but not many studies work on effects of GLP-1 to astrocytes. Our early study has found that activation of GLP-1 receptors prevented ischemia-induced brain cell death and observed newly neuronal progenitor cells were from astrocyte-lineage in penumbral area of 3-day post-ischemic mouse brains by immunohistochemistry (IHC). RT-PCR, immunoblotting, and immunofluorescent results also clearly indicated the astrocytes expressed GLP-1 receptors. Furthermore, Western blotting results showed administration of GLP-1 analogue, exendin-4 (EX-4), suppressed expression of pro-inflammatory proteins in oxygen-glucose deprivation (OGD) treated mouse primary astrocytes. Interestingly, we also observed that infarct site obtained sever DNA damage and less GFAP positive astrocytes, on contrary, the penumbral area had more GFAP positive astrocytes and less DNA damage in IHC images of stroke brains. The results implied that A1 and A2 astrocytes play certain roles in ischemic brains and recovery. The goal of this study is to determine the mechanisms of GLP-1 involving in astrocytic fate decision and approach on minimizing detrimental effects and amplifying the beneficial effects, which possibly develop innovative therapies for ischemic stroke. The study is supported by 108-2320-B-182A-005-MY3 and 112-2320-B-182A-003- from Taiwan National Science and Technology Council. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.","PeriodicalId":49694,"journal":{"name":"Physiology","volume":null,"pages":null},"PeriodicalIF":8.4,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141145379","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Selective Timing of Maternal Immune Activation Alters Developmental Milestones, Behavior, and Blood-Brain Barrier Integrity","authors":"Julietta A. Sheng, S. Tobet","doi":"10.1152/physiol.2024.39.s1.851","DOIUrl":"https://doi.org/10.1152/physiol.2024.39.s1.851","url":null,"abstract":"Background and Hypothesis: Maternal immune activation (MIA) has been associated with increased risk for neuropsychiatric disease. Fetal exposure to maternal infection activates different toll-like receptors (TLRs) to initiate innate inflammatory responses in mother and fetus. The goal of the current study is to determine sex-dependent aspects of MIA during mid-gestation on neurodevelopment. Methods: Timed-pregnant female mice were administered RQ (TLR7 agonist) or vehicle saline on embryonic day (E) 12.5. Maternal and fetal cytokines were measured to ensure infection of pregnant dam (E15). Offspring were assessed postnatally for developmental milestones and behavior. Adult offspring were perfused with fluorescein isothiocyanate (FITC; 100mg/mL) to visualize blood vessel integrity (FITC leakage; Frahm & Tobet, 2015). To determine neural molecular mechanisms for behavioral changes, sections through the paraventricular nucleus of the hypothalamus (PVN) of offspring were immunolabeled for Glial Fibrillary Acidic Protein (GFAP; astrocytic end feet), Desmin (pericytes) and IBA-1 (microglia). Results: Maternal cytokines IL-6 (p<0.05) and IL-10 (p<0.01) were higher while TNFα (p<0.01) and IL-17 were lower 3 days after RQ-exposure. In fetuses (E15), IL-6 (p<0.05) and IL-17 (p<0.0001) were greater, while IL-10 was higher only in males (p<0.001) exposed to maternal infection. RQ-exposed males also had reduced TNFα (p<0.05). Additionally, RQ-exposed offspring had lower body weights at birth and delayed eye openings. Females exposed to maternal RQ exhibited slower onset of puberty with delayed vaginal openings. On the behavioral side, juvenile and adult offspring of RQ injected moms exhibited less social-like behavior (p<0.001 for all groups) with lower hedonic-like behavior selectively in females (p<0.001). RQ-offspring further showed greater leakage in the PVN indicated by more FITC in the extravascular space (males p<0.001, females p<0.01). GFAP + (astrocytic end feet) coverage of FITC-labeled vessels was higher in the PVN selectively in RQ males (p<0.001). Desmin+ (pericyte) coverage was greater in the PVN of RQ males (p<0.01) and females (p<0.001). Finally, there was greater number of IBA-1+ cells in the adult offspring PVN of both sexes (p<0.01) after maternal injection of RQ. Conclusions: This study provides support for sex-dependent influences of fetal antecedents for altered brain development and behavioral outputs that could be indicative of increased susceptibility for adult disorders through immune mechanisms. Future studies will examine how timing of infection during gestation (mid vs. late) changes neurodevelopmental outputs in offspring. Supported by ORWH-NIMH U54 SCORE-MH118919. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.","PeriodicalId":49694,"journal":{"name":"Physiology","volume":null,"pages":null},"PeriodicalIF":8.4,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141135512","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}