bluuebunny/crossref_metadata_2025_split huggingface dataset:
Histopathological and Molecular Characteristics of Breast Cancer Patients in Northern Egypt
Authors: Talaat Iman , Soliman Nada , Elnahas Salwa , Elemam Noha 
Published: May 2023

Background: In 2020, breast cancer (BC) became the most common cancer worldwide, including Egypt. Despite the extensive research throughout the past years, a detailed analysis of the patients, including the molecular and histopathological characteristics, is needed in order to tailor effective screening and treatment strategies for a particular population of BC patients. In this study, we aimed to explore the various characteristics and survival of a large cohort of BC patients in Northern Egypt. Materials and Methods: The recruited cohort in this study was composed of more than 4,000 BC patients who were managed in different centers across Northern Egypt for 10 years. Various clinical, demographic, and histopathological parameters were retrieved from the records. This included tumor size, grade, and stage, as well as the histological and molecular subtypes. Also, therapeutic modalities and responses, as well as disease-free survival (DFS, no recurrence or metastasis) and overall survival rates (OS, alive/dead), were collected. The SPSS 26.0 software was used for statistical analysis, and p<0.05 was considered statistically significant. Results: Invasive ductal carcinoma was found to be the most common histological type in the recruited cohort (94%). Interestingly, the median age of the patients’ cohort was 50 years, with most of the cohort presenting before the age of 55 years. Around 50% of the patients presented with advanced stage III. Further, the classification of the BC patients according to the Nottingham grading system revealed that the majority were graded as well and moderately differentiated BC (grades 1 and 2). Moreover, 77% of the patients belonged to the hormonal subtypes with positive estrogen (ER) and/or progesterone (PR) receptors. Intriguingly, 45.5% of BC patients were classified as luminal B subtype, 31.8% as luminal A group, 7.6% of BC patients as HER2-enriched subtype, and around 15% were triple-negative subtype. Such stratification by molecular subtyping of BC patients showed a significant difference in both the DFS and OS of the patients. Conclusion: Our findings highlight the different clinical, demographic, and histopathological characteristics of BC patients in Northern Egypt that might be different from other populations. Further studies are needed to identify early detection programs and management strategies for each population in order to improve BC patients’ clinical outcomes. No funding. 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.
Cardiomyocyte beta2AR mediates cardiac fibrosis via maintaining Ca2+ homeostasis in the heart
Authors: Zhu Chaoqun , Zhao Meimi , Xu Bing , Xiang Yang 
Published: May 2023

Objective: Cardiac beta2-adrenoceptor (β2AR) has been suggested functions a protective role in defending myocyte apoptosis and cardiac damage induced by various stress. Our recent studies indicate divergent roles of cardiac β2AR in cardiomyocytes and myofibroblasts in regulating high fat diet (HFD) induced cardiac remodeling and dysfunction. While β2AR in cardiomyocytes attenuates HFD-induced cardiac fibrosis, myofibroblast β2AR facilitates cardiac fibrosis. Cell-specific actions of β2AR has been suggested in mediating cardiac fibrosis in the heart. This study is aimed to further determine the role of cardiomyocyte-specific β2AR in cardiac function and cardiac fibrosis. Hypothesis: Cardiomyocyte-specific β2AR regulates cardiac fibrosis via maintaining Ca2+ homeostasis in the heart. Results and Methods: 2-3-month-old mice with cardiomyocyte-specific deletion of β2AR (β2AR-cKO) and β2AR-flox mice were used. While echocardiography showed a comparable cardiac function between cKO and flox mice, the expression of both inflammatory and fibrotic marker proteins, NLR family pyrin domain containing 3 (NLRP3) and connective tissue growth factor (CTGF), was elevated in cKO hearts. As β2AR has been suggested to restrict excessive adrenergic insults, the activities of major molecules in β-adrenergic signaling were examined. Notably, western blot showed the phosphorylation level of Calcium/calmodulin-dependent kinase II (CaMKII) was significantly upregulated in cKO heart which implies a higher level of cytosolic Ca2+. Consequently, the CaMKII phosphorylation site (serine 1700) on L-type Ca2+ channel (LTCC) was also upregulated. To further examine the LTCC activity, whole cell currents (ICa) were recorded from freshly isolated ventricular myocytes, which indicated a higher LTCC activity after isoproterenol stimulation (peak ICa: cKO, -12.87 vs. flox, -10.40, p<0.05). Moreover, cKO and flox were subjected to LTCC blocker (nifedipine,10mg/kg/day) treatment to confirm the effect of Ca2+ activity on cardiac inflammatory and fibrotic response. Two weeks of nifedipine injection completely attenuated over-elevated CaMKII activity and NLRP3 and CTGF expression in cKO hearts. Overall, these results indicate that deletion of β2AR in cardiomyocytes facilitates cardiac fibrosis by altering cytosolic Ca2+ homeostasis via LTCC activity. Conclusion: This study elucidates that cardiomyocyte β2AR is essential to maintain normal cardiac function and plays a protective role against the development of cardiac fibrosis. National Institutes of Health grants R01-HL147263, Veteran Affair Merit grant 01BX002900, American Heart Association postdoctoral fellowship 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.
Small molecule activator of Serca2a improves myocardial bioenergetics and lipid metabolism in diabetic mice
Authors: Majid Abdul , Kang Soojeong , Hammoudi Nadjib , Lebeche Djamel 
Published: May 2023

Background: Altered calcium homeostasis, insulin resistance, and dysregulated energy metabolism are major causes of diabetic cardiomyopathy. The expression and activity of Sarco/endoplasmic reticulum Ca2+-ATPase 2a (SERCA2a) are decreased in the diabetic heart failure. Increasing SERCA2a function reverses both systolic and diastolic dysfunction. However, the mechanisms and consequences underlying the role of SERCA2a in the diabetic failing heart are not clear yet. Objective: To examine the effect of pharmacological activation of SERCA2a on the diabetic heart. Methods and Results: To restore calcium abnormality in leptin-deficient (ob/ob) diabetic mice, we employed and contrasted two different models to elevate the restoration of SERCA2a function: 1) activation of SERCA2 with a novel allosteric agonist, CDN1163 or 2) overexpression of SERCA2a using cardiac-specific AAV9-mediated gene transfer. We demonstrate that SERCA2a activation with CDN1163 or AAV9 repressed the expression of genes involved in lipid synthesis and fatty acid oxidation in obese mice, leading to improved lipid homeostasis. Increased SERCA2a function improved mitochondrial function through elevation of mitochondrial biogenesis, mitochondrial DNA content, oxidative phosphorylation, and ATPase activity in the heart of obese mice. SERCA2a also restored mitochondrial membrane potential to normal levels in cultured H9C2 myocytes in the presence of high glucose and H2O2. SERCA2a ameliorated intracellular lipid toxicity and cell damage, possibly through the upregulation of the gene expression of antioxidant enzymes, and attenuated ROS generation by repression of NADPH oxidase in the obese heart. Furthermore, these molecular changes were paralleled by improvement in diabetes-induced diastolic dysfunction following CDN1163 activation of SERCA2a or AAV9-SERCA2a overexpression in the obese mice. Conclusion: These results suggest that calcium resolving diabetes-induced calcium dyshomeostasis by pharmacological activation of SERCA2a in obese individuals may be a highly effective therapeutic modality for treating obesity-induced diabetes. 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.
Colonic butyrate lowers hepatic glucose production via FFAR2-dependant GLP-1 receptor neuronal signaling
Authors: Wachsmuth Hallie , Lane Adelina , Meyer Rachel , Weninger Savanna , Duca Frank 
Published: May 2023

Hyperglycemia is a hallmark characteristic of type II diabetes, due in part to increased hepatic glucose production (HGP). The gut microbiota is now recognized as an important contributor to host energy and glucose homeostasis, and our lab has demonstrated that the gut microbiota can impact HGP. One mechanism that the gut microbiome may be impact HGP is through alterations in gut-derived metabolites from breakdown of ingested foodstuff. Specifically, short chain fatty acids (SCFAs) are bacterial metabolites produced primarily in the distal intestine from dietary fibers, and when administered exogenously, SCFAs improve glucose tolerance. However, the mechanisms underlying the effects of SCFAs on glucose tolerance are not fully understood. Given that SCFAs bind to free fatty acid receptors (FFARs) 2 and 3 localized on enteroendocrine cells to induce gut peptide release, and gut peptides regulate HGP via a gut-brain-liver neuronal axis, we propose colonic SCFAs activate a neuronal signaling mechanism to lower HGP mediated via gut peptide signaling. We infused SCFAs into the colon (50min at 0.01mL/min) during a basal insulin euglycemic clamp in rats. Compared with saline infusion, colonic administration of 10mM butyrate increased the glucose infusion rate needed to maintain glycemia due to a reduction in HGP. This was associated with increased portal concentrations of GLP-1 following butyrate infusion compared to saline. We investigated the role of colonic FFAR2 signaling, which is known to induce release of GLP-1, through either co-administration of a FFAR2 antagonist with butyrate or by colon-specific FFAR2 lentiviral knockdown; both abolished the HGP-lowering effect. Next, co-administering a GLP-1 receptor antagonist with 10mM butyrate during a clamp abolished the butyrate-induced reduction of HGP. Additionally, hepatic or celiac branch vagotomy abolished the HGP-lowering effect of colonic butyrate, suggesting a celiac afferent and hepatic efferent neuronal signaling pathway. Together, these studies uncover a FFAR2, GLP-1 receptor, vagal-dependent signaling mechanism by which colonic butyrate lowers HGP. Research presented was supported under NIH award R01DK121804. 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.
High-phosphate diet disrupts ACE/ACE2 balance in mouse kidney
Authors: Elased Dalia , Branch Daniel , Oh Jooho , Pepperney Luke , Elased Khalid , Baskin Kedryn 
Published: May 2023

Phosphate binders are a common treatment in dialysis patients and people with chronic kidney disease (CKD) to prevent phosphorous accumulation in the blood. The physiological mechanism behind the relation between excess phosphate and renal damage is largely unknown. The renin-angiotensin-aldosterone system (RAAS) is a hormone regulating system that controls blood pressure and electrolyte balance in cardiovascular organs and dysregulation of RAAS is often an indicator of organ damage. Angiotensin-converting enzyme 2 (ACE2) and Neprilysin (NEP) are both key players in the RAAS due to their role in producing the renoprotective peptide Angiotensin-(1-7). Ang-(1-7) plays a pivotal role in kidney protection due to its anti-inflammatory and vasodilatory effects on various cardiovascular organs including the kidney. Angiotensin-converting enzyme (ACE) is another key enzyme in RAAS which produces opposite effects to those of ACE2. ACE induces the formation of the vasoconstrictor Angiotensin II which causes hypertension and renal fibrosis. To test the hypothesis that a high phosphate diet affects ACE2, NEP, and ACE levels in kidneys, we fed mice high-Pi diet (HP) or normal-Pi diet (NP) for 22 weeks. Serum phosphate levels were increased by the HP diet while body weight and body composition were unaffected. Fluorogenic substrate-based assay and western blot analysis were used to evaluate enzyme activity and protein expression. In mice fed the HP diet, there was a significant downregulation of renal ACE2 activity and expression ( p<0.01), and upregulation of renal ACE expression (p<0.01). NEP activity and protein expression were unchanged. Our data demonstrates that the link between excess dietary Pi and kidney damage could be due to an increased ACE/ACE2 ratio. Future studies will investigate the effect of a high phosphate diet on other key players in the RAAS including Angiotensin II and Angiotensin-(1-7). 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.
Meso- and nanoscale structural changes in the hippocampus of control and transgenic Alzheimer's mice exposed to Intermittent Hypoxia
Authors: Sampathkumar Vandana , Polo Ashleigh , Piao Lin , Crowley Lorenzo , Gan Haotian , Dodiya Hemraj , Sisodia Sangram , Sharp Willard , Garcia Alfredo , Kasthuri Narayanan 
Published: May 2023

Sleep apnea, a clinical condition characterized by repetitive pauses in breathing that cause intermittent hypoxia (IH), affects a billion people worldwide, increases the risk for mild cognitive impairment, and is estimated to occur in up to 50% of individuals with Alzheimer’s Disease (AD). Previous work in wildtype mice has shown that IH impairs spatial memory that is associated with deficits in NMDAr-dependent synaptic physiology. However, a significant knowledge gap remains in understanding how IH may impact ultrastructural properties in the brain. Using large volume serial electron microscopy (EM), we studied mitochondrial abnormalities and synaptic density changes in the area CA1 of hippocampus of non-transgenic mice and CeAPP/PS1 mice, a mouse model of Aß amyloidosis, exposed to ten days of IH. Immediately after IH, mitochondria became elongated and appeared to undergo fusion (becoming 4x to 8x longer) in pyramidal CA1 neurons. This change in mitochondrial morphology reversed, e.g. mitochondrial length normalized relative to controls, when the IH-exposed mice were allowed to recover in room air for 10 days post-IH. We also found a 20-40% increase in synaptic density in proximal and distal dendrites of IH-exposed pyramidal CA1 neurons, yet the ratio of multi-synaptic boutons to single synaptic boutons in area CA1 did not appear to change. These observations indicate that changes in synaptic density occur without producing significant changes in axonal innervation patterns. Finally, using synchrotron source X-ray microscopy, and automated serial EM in IH-exposed brain tissue from CeAPP/PS1 transgenic mice, we documented an increased amyloid plaque number in both cortex (two-fold increase) and hippocampus (ten-fold increase). Large volume EM showed similarly elongated mitochondrial morphology changes in hippocampal neurons in CeAPP/PS1 mice when exposed to IH. These findings suggest that IH, such as that experienced with untreated sleep apnea, may drive ultrastructural changes that both contribute to mild cognitive impairment and promote the progression of AD and related dementias. NIH: R01NS107421; R01HL163965; R01DA057767. 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.
Characterization of Mitochondria from Primary Isolated Mouse Aortic Smooth Muscle Cells
Authors: Sakamuri Anil , Ogola Benard 
Published: May 2023

Sexual dimorphism is demonstrated in cardiovascular disease (CVD). Vascular dysfunction is a critical player in CVD involving mitochondrial respiration in aortic smooth muscle cells. In this study, we characterized contractile and synthetic gene expression, and mitochondrial respiration by sex in aortic smooth muscle cells (ASMC). We hypothesize that female than male ASMC have increased contractile genes and better mitochondrial energetics. Adult male and female C57BL6J mice were euthanized, and thoracic aorta excised. Aortic tissue sections were subject to enzymatic digestion and cultured for subsequent experiments. The 2-delta delta CT method using beta actin as housekeeping gene was used for analysis. For mitochondrial respiration, confluent (70%) cells were trypsinized, enumerated, and seeded in Seahorse mini-culture plates (20,000 cells/well). After overnight incubation mitochondrial stress test was performed to measure basal respiration, maximal respiration, spare capacity, ATP production, proton leak, and non-mitochondrial respiration. All mitochondrial respiratory parameters were expressed as oxygen consumption rate normalized with protein levels (OCR, picomoles/L of O2 per microgram protein, n=8-10 wells/group). Unpaired t-test was used for statistical analysis and P<0.05 was considered significant. To characterize the sex of isolated cells (n=6-8/group), we used sex specific primers that showed significantly higher Sry (P<0.001) and Xist (P<0.001) gene expression of male and female ASMC, respectively. Next, we assessed contractile and synthetic genes including myocardin, alpha actin, and myosin heavy chain 11 that were higher in female than male ASMC (P<0.05). However, myosin heavy chain 10 was higher (P=0.002) in male than female cells. The basal respiration and ATP production were significantly high in female ASMC by 79% and 77%, respectively, when compared with male ASMC (2.48 ± 0.13 vs. 1.38 ± 0.15, P= 0.0001; 2.11 ± 0.11 vs. 1.19 ± 0.11, P= 0.0001). Female cells indicated increased spare respiratory capacity compared to male ASMC (1.67 ± 0.31 vs. 1.1 ± 0.23, p= 0.01). The maximal respiration and proton leak were significantly higher in female than male cells by 69% and 109% (4.21 ± 0.33 vs. 2.49 ± 0.31, P= 0.001: 0.42 ± 0.02 vs. 0.2 ± 0.04, P= 0.001). Female and male cells did not show any significant difference in non-mitochondrial respiration. Based on these results, female than male ASMC exhibit increased contractile gene expression and better mitochondrial energetics at basal and stressed conditions. The sex-specific differences in mitochondrial function may attribute to sex bias in CVD. R00HL155841 and R25HL105400 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 clock gene Bmal1 inhibits kidney expression of SGLT2 and glucose reabsorption via the NR1d1/NRF1 pathway
Authors: Pan Xiaoyue , Mowdawalla Cyrus , Mota Samantha , Hussain M. Mahmood , Pessin Jeffrey , Vallon Volker 
Published: May 2023

Background & Aims: The nuclear receptor subfamily 1, group D, member 1 (Nr1d1, also called Rev-erbα) is highly expressed in the kidney, and its transcriptional activity is increased by the clock gene Bmal1 (ARNTL or MOP3). Here we studied the roles and functional interactions of Bmal1 and Nr1d1 in mouse kidney, particularly in regulating the expression of the glucose transporter SGLT2 (SLC5A2) and glucose reabsorption. Methods: We performed histologic and biochemical analyses of kidney tissues from male C57BL/6 and Bmal1-knockout mice and performed gene expression analyses to identify genes regulated by Bmal1. The effects of fasting and refeeding on renal expression of Sglt2 was examined in male C57BL/6, Bmal1-knockout, and Nr1d1-knockout mice. Some mice were given hemin to stimulate Nr1d1 gene expression (daily for 1 week) at 12:00 with 100 μg/kg/day; renal glucose reabsorption, and glucose and fatty acid levels were measured. Renal proximal tubule epithelial cells (RPTECs) were generated from C57BL/6 and Bmal1-knockout mice and glucose uptake determined. Luciferase reporter assays were performed using HK2 cell. Results: We found that kidney SGLT2 mRNA and protein expression and glucose absorption were increased in Bmal1-knockout mice compared with C57BL/6 mice. Expression of SGLT2 was affected by fasting and refeeding in C57BL/6 mice, but not in Bmal1-knockout or Nr1d1-knockout mice. Bmal1-knockout mice also presented with higher levels of renal fatty acids compared with C57BL/6 mice. Hemin injection reduced expression of SGLT2, decreased glucose re-absorption in RPTECs, and increased levels of fatty acid in kidney; these changes were not observed in Bmal1-knockout mice. Nuclear respiratory factor 1 (NRF1), which regulates glucose, activated transcription of Sglt2. Fasting caused MAPK signing pathway to phosphorylate Bmal1, which activated NR1d1 and inhibited NRF1 activity and thereby reduced Sglt2 expression. Conclusions: The data indicate that fasting activates Bmal1 and Nr1d1, which inhibits NRF1 and leads to repression of renal SGLT2 expression and glucose reabsorption. This is the first study that mechanistically links food intake to the regulation of kidney glucose transport through a circadian clock gene. NIH National Heart, Lung, and Blood Institute grant R56 HL137912-01, and American Heart Association grant-in-aid 16GRNT30960027 to PX; NIH R01DK112042 to VV 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.