bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cardiac Na/K-ATPase alpha1 isoform-specific role in hypertrophic response: role of metabolic and oxidative signaling
Authors: Pessoa Marco , Marck Pauline , Perdoncin Maddie , Collins Dominic , Cai Liquan , Tian Jiang , Artigas Pablo , Blanco Gustavo , Xie Zijian , Pierre Sandrine 
Published: May 2023

Cardiac Na/K-ATPase (NKA) inhibition by cardiotonic steroids (CTS) modulates intracellular Na+ and Ca2+, leading to increased force of contraction. In contrast, hypertrophy of cardiomyocytes (CM) is triggered by CTS through stimulation of reactive oxygen species (ROS) and fetal gene re-expression independently of changes in intracellular Na+ or Ca2+. Based on recent evidence that NKAα1 serves an isoform-specific function in the regulation of oxidative metabolism and ROS generation, we used a genetic approach in the mouse and in human cardiac cells (AC16) to test the hypothesis that NKAα1 is required for cardiac hypertrophy. Cardio α1-/- mice, a conditional KO of NKAα1 in the heart, were viable without overt abnormality of cardiac structure or function. NKAα1 was undetectable in heart lysates or isolated CM of adult cardio α1-/- mice. Despite a compensatory upregulation of NKAα2, Na/K-ATPase activity in crude heart homogenates and NKA currents in CM were reduced by about 60%. Decreased ROS (assessed by total protein carbonylation) and reduced fatty acid oxidation (FAO) and oxidative phosphorylation pathways (revealed by RNA-seq analysis) were noted at baseline. RT-qPCR revealed downregulated genes involved with FAO and the electron transport chain (such as, Acadl and Ndufa9, about 20% decrease, n=6) in cardio α1-/- hearts. The activity of the electron transport chain complex I was decreased in cardio α1-/- hearts (0.3354 vs 0.2732 mOD/min/mg of protein, p<0.05). When 3-month-old male mice were challenged with angiotensin II (1.5 mg.kg-1.day-1 for 1 week, n=6-15), cardio α1-/- mice did not develop cardiac hypertrophy, as assessed by heart weight to tibia length ratio, but displayed exacerbated cardiac fibrosis, revealed by Trichrome staining, consistent with the postulated role of CM NKAα1 isoform-specific function in cardiac hypertrophy in vivo. In vitro, CRISPR-Cas9-mediated KO of NKAα1 in AC16 cells led to a drastic downregulation of NKAα1 compared to WT AC16 cells. In contrast to WT AC16 cells, NKAα1 KO cells did not respond to the α-adrenergic agonist phenylephrine (50 μM for 24h) with the expected increase in cell area (2243 vs 3520 μm2 for WT, p<0.05; 2454 vs 2563 μm2 for KO, p>0.05). These data suggest that NKAα1 isoform-specific function is required for cardiac hypertrophy. Mechanistically, our data support an isoform-specific regulatory function of NKAα1 in normal FAO, electron transport chain activity, and ROS generation, which are critical for CM hypertrophy. Supported by NIH Grant R15 HL145666 and American Heart Association Grant 22POST917776 (Marco T. Pessoa) This is the full abstract presented at the American Physiology Summit 2023 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.
Acetaminophen causes mitochondrial dysfunction in heart cardiomyocytes
Authors: Rivera Gabriela , Sule Rasheed , Gomes Aldrin 
Published: May 2023

Acetaminophen (APAP) is a common over-the-counter medication used to treat pain and fever. It can be taken orally, topically, or intravenously and is considered a safe and effective drug when taken at therapeutic doses. However, recent research suggests that taking APAP regularly can result in increased blood pressure and cardiovascular risk. Previous publications found that Non-Steroidal-Anti-Inflammatory-Drugs (NSAIDs) increased Reactive Oxygen Species (ROS) in cardiomyocytes, resulting in cardiac dysfunction. Although APAP is not a NSAID, APAP likely has similar effects. We hypothesized that regular APAP usage resulted in increased ROS levels, leading to potential dysfunction in hearts and other organs. We used the embryonic rat heart cell line H9C2 to test our hypothesis. We conducted a ROS Assay using H9C2 cells treated with dichlorodihydrofluorescein diacetate (DFCDA). The cells were then treated with vehicle, various concentrations of APAP (25μM, 50μM, 100μM, and 200μM), or 100μM hydrogen peroxide for 1.5 hours before measuring the ROS levels of the cells. We also measured the cell viability of H9C2 cells. Cells were treated with 10μM Alamar Blue, then treated with vehicle, various concentrations of APAP (25μM, 50μM, 100μM, and 200μM), or 100μM or 200μM hydrogen peroxide for 48 hours before detecting the percentage of viable cells. The mitochondrial membrane potential (MMP) of cells treated with APAP was also measured. Cells were treated with vehicle, various concentrations of APAP (25μM, 50μM, 100μM, and 200μM), or 250μM p-triflouromethoxyphenylhydrazone (FCCP) for 24 hours before being incubated with JC-10 for one hour. The cells were measured using a fluorescent reader at excitation/emission 490/525 nm and 540/590 nm. For the ROS assay, the cells treated with 100μM APAP, 200μM APAP, and 100μM Hydrogen Peroxide significantly increased total ROS compared to the control. The cell viability assay resulted in a significant decrease in percent viability in cells treated with 200μM APAP, 100μM hydrogen peroxide, and 200μM hydrogen peroxide compared to the control. The MMP Assay resulted in a significant decrease in MMP at all concentrations of APAP and 250μM FCCP compared to the control. These results suggest that treatment of H9C2 cardiac cells with physiological concentrations of APAP causes an increase in intracellular ROS levels, decreased cell viability, and decreased MMP. Overall, APAP causes mitochondrial dysfunction, which is likely to cause cardiomyocyte dysfunction. This research is funded by the NIEHS/Superfund Research Program (P42 ES004699). This is the full abstract presented at the American Physiology Summit 2023 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.
Increased renal dysfunction and neutrophil infiltration in a mouse model of psoriasis
Authors: Chen Ziche , Meyer Jason , Ward Nicole , Alexander Matthew 
Published: May 2023

Psoriasis is a chronic inflammatory skin disease affecting 2-5% of the global population. As an autoimmune disease, psoriasis is characterized by T cell-mediated hyperproliferation of epidermal keratinocytes. Interestingly, most of the morbidity and mortality from psoriasis is related to increased risk of cardiovascular and renal disease. For example, moderate to severe psoriasis is associated with an approximately 1.5-fold increased risk of chronic kidney disease. Neutrophils are increased in the skin and circulation of patients with psoriasis, and markers of neutrophil activation are associated with extra-cutaneous manifestations of psoriasis including vascular inflammation. However, the molecular mechanisms linking psoriasis and kidney disease remain unclear. We hypothesized that increased neutrophil infiltration of the kidney through enhanced granulopoiesis promotes renal dysfunction in psoriasis. Using a KC-Tie2 mouse model of psoriasis with keratinocyte-specific overexpression of the angiopoietin receptor Tie2, we found that KC-Tie2 mice compared to littermate controls exhibit significantly increased urine albumin, suggestive of renal dysfunction. KC-Tie2 mice also exhibit significantly increased kidney/body weight and heart/body weight ratios compared to littermate controls. To determine a mechanism for the increased renal dysfunction in these mice, we assessed skin and renal immune cell content using flow cytometry. KC-Tie2 mice had increased neutrophils in the skin, as well as an approximately 10-fold increase in neutrophils in the kidneys. This increase in renal neutrophils in KC-Tie2 mice was relatively selective as there were no differences in the number of renal dendritic cells, lymphocytes, or monocytes and a modest but significant increase in macrophages. We also observed a selective increase in neutrophils in the spleen of KC-Tie2 mice. Given these findings and prior reports of increased circulating neutrophils in KC-Tie2 mice, we assessed mediators of granulopoiesis in the serum and found a significant increase in granulocyte colony stimulating factor (GCSF) in KC-Tie2 mice. Taken together, these results provide evidence for increased renal dysfunction in a mouse model of psoriasis coincident with marked increases in renal neutrophils that may represent a novel mechanism linking skin inflammation to renal dysfunction through enhanced granulopoiesis. MRA is funded by NIH K08HL153786-01. JM is funded by 2T32GM007569. NW is funded by NIH R01 AR075777, NIH R01 AR073196, NIH P50 CORT AR070590, and National Psoriasis Foundation. This is the full abstract presented at the American Physiology Summit 2023 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.
Impact of intranasal insulin on cerebral blood flow and cerebrovascular reactivity in healthy young adults
Authors: Shariffi Brian , McMillan Neil , Jacob Dain , Harper Jennifer , Manrique-Acevedo Camila , Padilla Jaume , Limberg Jacqueline 
Published: May 2023

Objective: Adults with obesity and insulin resistance exhibit impaired cerebrovascular reactivity and endothelial dysfunction, which increases the risk of dementia and Alzheimer’s disease. Impairments in cerebrovascular health have been attributed to vascular insulin resistance and emerging data support the use of intranasal insulin as a potential therapeutic intervention. Although mechanisms are unclear, the benefits of intranasal insulin may in part be mediated by changes in cerebral blood flow and/or cerebrovascular reactivity. Using intranasal administration of insulin, we examined the acute effect of central insulin on resting cerebral blood flow as well as reactivity to inhaled carbon dioxide. We hypothesized intranasal insulin would increase indices of cerebral blood flow and cerebrovascular reactivity in healthy young adults. Methods: Nineteen healthy young adults were randomized into time control [n=12 (5F/7M), 27±1 yrs, 25±3 kg/m2] or 160 IU of intranasal insulin administered over 5 min [n=7 (0F/7M), 27±3 yrs, 25±3 kg/m2]. Carotid artery blood flow (CBF, Doppler ultrasound) and middle cerebral artery blood velocity (MCAv, transcranial Doppler ultrasound) were measured prior to and 60 min following insulin administration and/or time control. In a subset of participants (time control, n=10; insulin, n=5), cerebrovascular reactivity was assessed as the relative (%) increase in MCAv and CBF from baseline during 3 min of carbon dioxide air breathing (+7.5±0.5 mmHg). Results: Blood glucose and plasma insulin remained unchanged throughout the protocol (both, p>0.05). CBF (712±39 to 727±40 mL/min, p=0.45) and MCAv (50±3 to 52±3 cm/s, p=0.50) remained at baseline levels following the 60-min time control condition. Similarly, resting CBF (901±60 to 908±58 mL/min, p=0.78) and MCAv (54±5 to 52±5 cm/s, p=0.41) did not differ from baseline following intranasal insulin administration. Carbon dioxide breathing led to an elevation in CBF and MCAv, and their respective increases were unaffected by time control (33±5 to 37±7%, p=0.58; 49±6 to 58±9%, p=0.32) or intranasal insulin (25±3 to 24±5%, p=0.93; 39±6 to 46±6%, p=0.49). Conclusions: Contrary to our hypothesis, acute intranasal insulin administration had no effect on indices of cerebral blood flow and/or cerebrovascular reactivity in healthy young adults. Future studies should examine the cerebrovascular effects of intranasal administration in disease states ( e.g., obesity, insulin resistance, Alzheimer’s disease). CAFNR Joy of Discovery (JKL, JP) This is the full abstract presented at the American Physiology Summit 2023 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.
Neonatal Enteric Glia Enhance Intestinal Epithelial Restitution in vitro Following Exposure to Sterile Colonic Luminal Content of Mature but not Neonatal Pigs
Authors: Caldwell Madison , Van Landeghem Laurianne , Blikslager Anthony , Ziegler Amanda 
Published: May 2023

Neonates exhibit significantly poorer outcomes from damage to the intestinal epithelium following ischemia for unknown reasons. In our pig model, we recently discovered an age-dependent epithelial restitution defect in ischemia-injured neonatal intestine that is rescued by application of homogenized juvenile mucosa, but the mechanism remains unknown. Enteric glial cells (EGC) have been shown to promote epithelial restitution following injury via paracrine signaling and are abundant in the intestinal mucosa of juvenile but not neonatal pigs. Co-culture studies have shown that pig EGC enhance restitution in epithelial monolayers following scratch wounding. In mice, postnatal maturation and maintenance of the EGC network is purportedly driven by colonization of gut microbiota. Furthermore, weaning of neonates leads to drastic shifts in the dynamics and populations of these gut microbiota. Therefore, we believe that changes to pig intestinal microbiota during weaning may play a key role in EGC maturation required for proper epithelial restitution. We hypothesized that treatment with mature (>6 weeks of age), but not neonatal (2 weeks of age), luminal content would improve restitution of neonatal epithelial monolayers co-cultured with neonatal EGC. We compared the effect of sterile-filtered neonatal or mature luminal content addition to the apical chamber on scratch wound restitution in neonatal porcine IPEC-J2 monolayers in monoculture or co-culture with primary porcine neonatal submucosal EGC using a transwell system (n = 9). Our results support a significant effect of luminal content treatment in the presence of EGC (P=0.0085). Specifically, mature luminal content treatment enhanced IPEC-J2 wound closure in co-culture with EGC but not in IPEC-J2 monoculture (P=0.0156). EGC co-culture alone or treated with neonatal lumen content did not affect restitution. Both neonatal and mature luminal content treatment decreased restitution in monoculture, but this effect was not significant. These data suggest that EGC provide secretory signals to the intestinal epithelium that promote repair in response to a component of mature luminal content, which we believe to be microbial products. Future work aims to determine what is driving these differences in restitution by analyzing neonatal and mature luminal secretomes. NIH 5 T35 OD 11070-12; NIH K01 OD 028207; NIH P30 DK 034987; NIH-NICHD R01 HD095876; USDA-NIFA VMCG-0065. This is the full abstract presented at the American Physiology Summit 2023 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.
Interleukin-12 alpha deficiency attenuates pressure overload-induced cardiac inflammation, hypertrophy, dysfunction, and heart failure progression
Authors: Bhattarai Umesh , He Xiaochen , Xu Rui , Liu Xiaoguang , Pan Lihong , Sun Yuxiang , Chen Jian-Xiong , Chen Yingjie 
Published: May 2023

IL-12α plays an important role in modulating inflammatory response, fibroblast proliferation and angiogenesis through modulating macrophage polarization or T cell function, but its effect on cardiorespiratory fitness is not clear. Here, we studied the effect of IL-12α on cardiac inflammation, hypertrophy, dysfunction, and lung remodeling in IL-12α gene knockout (KO) mice in response to chronic pressure-overload produced by transverse aortic constriction (TAC). Our results showed that IL-12α KO significantly ameliorated TAC-induced left ventricular (LV) failure, as evidenced by a smaller decrease of LV ejection fraction and fractional shortening. IL-12α KO also significantly attenuated TAC-induced increase of LV weight, left atrial weight, lung weight, right ventricular weight, and their ratios to body weight or tibial length. In addition, IL-12α KO significantly attenuated TAC-induced LV leukocyte infiltration, fibrosis, cardiomyocyte hypertrophy, and lung inflammation and remodeling (such as lung fibrosis and vessel muscularization). Moreover, IL-12α KO significantly attenuated TAC-induced activation of CD4+ T cells and CD8+ T cells in the lung. Furthermore, IL-12α KO significantly suppressed accumulation and activation of pulmonary macrophages and dendritic cells. Taken together, these findings indicate that inhibition of IL-12α is effective in attenuating pressure overload-induced cardiac inflammation, heart failure development, promoting transition from LV failure to lung remodeling and right ventricular hypertrophy. This work was supported by research grants R01HL161085, R01HL139797, P20GM104357, and P01HL51971 from NIH. This is the full abstract presented at the American Physiology Summit 2023 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.
The regulatory role of Sirtuin 6 in coronary endothelial dysfunction in HFpEF
Authors: Wang Yang , Enrick Molly , Gadd James , Yin Liya 
Published: May 2023

Sirtuin 6 (Sirt6) has been implicated in obesity, insulin resistance, type 2 diabetes mellitus, and cardiovascular diseases. Sirt6 protects EC from premature senescence, oxidative stress, and atherosclerosis by sustaining high eNOS levels and preserving cell replication. A recent publication showed that overexpressed Sirt 6 in EC mitigated heart failure with preserved ejection fraction (HFpEF) in diabetes. We hypothesize Sirt 6 regulates coronary microvascular dysfunction (CMD) in HFpEF associated with diabetic cardiomyopathy. CMD is characterized by impaired endothelial-dependent vasodilation, but detailed mechanisms have yet to be elucidated. How Sirt6 regulates coronary microvascular function remains to be determined. Inducible Sirt6 endothelial-specific knockout and wild-type (WT) mice were fed a chow or high fat and sugar (HFHS) diet. Coronary arterioles were isolated, and endothelial-dependent vasodilation (EDD) was assessed using myography (DMT). Echocardiography and treadmill exercise exertion tests were performed to evaluate cardiac function. Myocardial blood flow (MBF) was measured by doppler. Cardiac fibrosis was detected using trichrome staining, and molecular pathways were elucidated via gene and protein analysis. Our preliminary data show that the EDD of coronary arterioles of Sirt6 endothelial-specific knockout treated with HFHS was impaired, and the mediator of coronary vasodilation switched from NO to H2O2 in the Sirt6 knockout mice. Compared to the WT mice, myocardial blood flow and cardiac function were changed in Sirt6 knockout mice. Our data suggest that Sirt6 regulated coronary microvascular function through endothelial cells, and ablation of Sirt6 in endothelial cells caused CMD and diastolic dysfunction, eventually HFpEF. Further genetic profiling will elucidate the pathways and mechanisms converging with Sirt6 to regulate microvascular function in HFpEF. This is the full abstract presented at the American Physiology Summit 2023 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.
Rhabdomyolysis-induced renal ion accumulation promotes early acute kidney injury in sickle cell mice
Authors: Williams Jada , Kumar Ravi , Afolabi Jeremiah , Park Frank , Adebiyi Adebowale 
Published: May 2023

Individuals with sickle cell disease (SCD) are at greater risk for developing rhabdomyolysis, a potentially life-threatening syndrome resulting from the breakdown of skeletal muscle fibers. Acute kidney injury (AKI) is one of the most severe complications of rhabdomyolysis. Chronic kidney and cardiovascular disease, which account for SCD mortality, are long-term consequences of AKI. Although SCD elevates the risks of rhabdomyolysis-induced sudden death, the mechanisms that underlie rhabdomyolysis-induced AKI in SCD are unclear. Here, we examined the effects of glycerol-induced rhabdomyolysis on kidney health in transgenic humanized mice that express human sickle hemoglobin (HbSS-Townes model). Unlike the control mice (AA), homozygous SCD mice (SS) exhibited 100% mortality 8-24 h after intramuscular glycerol injection. Five hours of glycerol-induced rhabdomyolysis caused a more significant increase in myoglobinuria and plasma creatine kinase levels in SS compared to AA mice. Since SS mice experience chronic hemolysis, releasing free heme and iron into the bloodstream, and the induction of rhabdomyolysis releases myoglobin, we examined heme and renal iron parameters in these mice. Basal plasma heme, iron accumulation, and kidney tissue ferric iron levels were significantly higher in SS than in AA control mice. In contrast to AA, rhabdomyolysis aggravated these parameters in SS mice. Rhabdomyolysis also amplified renal oxidative stress in SS compared to AA mice. SS mice exhibited worse renal function, exemplified by a significant decrease in GFR, increased plasma and urinary biomarkers of early AKI, and more significant renal tubular injury. The free radical scavenger TEMPOL ameliorated rhabdomyolysis-induced AKI in the SS mice. These findings suggest that rhabdomyolysis and subsequent AKI are heightened in SCD mice. It can also be inferred that oxidative stress driven by renal iron accumulation may underlie rhabdomyolysis-induced early AKI in SCD. NHLBI: R01 HL151735-01 and R01HL151735-S This is the full abstract presented at the American Physiology Summit 2023 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.