Endothelial Notch1 signaling in white adipose tissue promotes cancer cachexia.

Cachexia is a major cause of morbidity and mortality in individuals with cancer and is characterized by weight loss due to adipose and muscle tissue wasting. Hallmarks of white adipose tissue (WAT) remodeling, which often precedes weight loss, are impaired lipid storage, inflammation and eventually fibrosis. Tissue wasting occurs in response to tumor-secreted factors. Considering that the continuous endothelium in WAT is the first line of contact with circulating factors, we postulated whether the endothelium itself may orchestrate tissue remodeling. Here, we show using human and mouse cancer models that during precachexia, tumors overactivate Notch1 signaling in distant WAT endothelium. Sustained endothelial Notch1 signaling induces a WAT wasting phenotype in male mice through excessive retinoic acid production. Pharmacological blockade of retinoic acid signaling was sufficient to inhibit WAT wasting in a mouse cancer cachexia model. This demonstrates that cancer manipulates the endothelium at distant sites to mediate WAT wasting by altering angiocrine signals.

Semaphorin 3C exacerbates liver fibrosis.

BACKGROUND AND AIMS: Chronic liver disease is a growing epidemic, leading to fibrosis and cirrhosis. TGF-ß is the pivotal profibrogenic cytokine that activates HSC, yet other molecules can modulate TGF-ß signaling during liver fibrosis. Expression of the axon guidance molecules semaphorins (SEMAs), which signal through plexins and neuropilins (NRPs), have been associated with liver fibrosis in HBV-induced chronic hepatitis. This study aims at determining their function in the regulation of HSCs. APPROACH AND RESULTS: We analyzed publicly available patient databases and liver biopsies. We used transgenic mice, in which genes are deleted only in activated HSCs to perform ex vivo analysis and animal models. SEMA3C is the most enriched member of the semaphorin family in liver samples from patients with cirrhosis. Higher expression of SEMA3C in patients with NASH, alcoholic hepatitis, or HBV-induced hepatitis discriminates those with a more profibrotic transcriptomic profile. SEMA3C expression is also elevated in different mouse models of liver fibrosis and in isolated HSCs on activation. In keeping with this, deletion of SEMA3C in activated HSCs reduces myofibroblast marker expression. Conversely, SEMA3C overexpression exacerbates TGF-ß-mediated myofibroblast activation, as shown by increased SMAD2 phosphorylation and target gene expression. Among SEMA3C receptors, only NRP2 expression is maintained on activation of isolated HSCs. Interestingly, lack of NRP2 in those cells reduces myofibroblast marker expression. Finally, deletion of either SEMA3C or NRP2, specifically in activated HSCs, reduces liver fibrosis in mice. CONCLUSION: SEMA3C is a novel marker for activated HSCs that plays a fundamental role in the acquisition of the myofibroblastic phenotype and liver fibrosis.

Temporally and regionally distinct morphogenetic processes govern zebrafish caudal fin blood vessel network expansion.

Blood vessels form elaborate networks that depend on tissue-specific signalling pathways and anatomical structures to guide their growth. However, it is not clear which morphogenetic principles organize the stepwise assembly of the vasculature. We therefore performed a longitudinal analysis of zebrafish caudal fin vascular assembly, revealing the existence of temporally and spatially distinct morphogenetic processes. Initially, vein-derived endothelial cells (ECs) generated arteries in a reiterative process requiring vascular endothelial growth factor (Vegf), Notch and cxcr4a signalling. Subsequently, veins produced veins in more proximal fin regions, transforming pre-existing artery-vein loops into a three-vessel pattern consisting of an artery and two veins. A distinct set of vascular plexuses formed at the base of the fin. They differed in their diameter, flow magnitude and marker gene expression. At later stages, intussusceptive angiogenesis occurred from veins in distal fin regions. In proximal fin regions, we observed new vein sprouts crossing the inter-ray tissue through sprouting angiogenesis. Together, our results reveal a surprising diversity among the mechanisms generating the mature fin vasculature and suggest that these might be driven by separate local cues.

Notch Signaling in the Vasculature: Angiogenesis and Angiocrine Functions.

Formation of a functional blood vessel network is a complex process tightly controlled by pro- and antiangiogenic signals released within the local microenvironment or delivered through the bloodstream. Endothelial cells precisely integrate such temporal and spatial changes in extracellular signals and generate an orchestrated response by modulating signaling transduction, gene expression, and metabolism. A key regulator in vessel formation is Notch signaling, which controls endothelial cell specification, proliferation, migration, adhesion, and arteriovenous differentiation. This review summarizes the molecular biology of endothelial Notch signaling and how it controls angiogenesis and maintenance of the established, quiescent vasculature. In addition, recent progress in the understanding of Notch signaling in endothelial cells for controlling organ homeostasis by transcriptional regulation of angiocrine factors and its relevance to disease will be discussed.

Imperceptible learners: Students' reasons for keeping webcams off and strategies to address students' challenges.

BACKGROUND: "Should students keep their webcams on or off during synchronous online classes?" is an unanswered question with educators' opinions divided on this aspect. Along with educators' perspectives, it is also important to unfold students' perspectives on this question. The objectives of this study were to determine the routine and opinion of students' regarding webcam usage and identification of students' reasons for not using webcams during online learning. MATERIALS AND METHODS: A cross-sectional study was carried out at Margalla Institute of Health Sciences, Rawalpindi, Pakistan. Census was done for data collection by including all dental students (n = 180) enrolled at the institute attending synchronous online preclinical and clinical operative dentistry classes. Data collection was carried out using a self-administrated questionnaire. Descriptive analysis was used to describe survey item responses. Pair-wise differences between demographic categories (female vs. male, and preclinical vs. clinical) were analyzed using the Pearson Chi-Square test. Correlation of routine and opinion with students' reasons were done using Spearman correlation. Ordinal regression analysis was done to associate routine and opinion with reasons. The level of significance (P value) was set at 0.05. RESULTS: Out of 180 students, 141 submitted the survey form, with a response rate of 77.47%. The majority of the students (n = 117, 83%) used to keep their webcams off during online classes and were (n = 69, 48.9%) of the opinion that webcams should be kept off during online classes. The most common reasons for keeping the webcam off during online classes were "comfort" (n = 87, 61.7%) and "distractions" (n = 84, 59.6%). A statistically significant association of gender was obtained, with females more likely than males due to distraction, self-consciousness, and appearance (P = 0.000, 0.003, and 0.016, respectively). The odds of gender highly influenced routine use of cameras, and this was statistically significant (OR: 3.478, P = 0.011). Students tended to keep their webcam off when they were inattentative during online classes (OR; 3.743, P < 0.001). CONCLUSION: The majority of the students did not agree to keep the webcam on during online synchronous learning. The main reasons for students' reluctance to keep the webcam on were self-consciousness, surrounding consciousness, distractions, and technological issues. Students can be encouraged to turn the webcam on by framing strategies according to students' concerns.

Incivility in online learning environment: Perception of dental students and faculty.

OBJECTIVES: The objectives of this study were to assess the extent of incivility and perception of dental students and faculty regarding uncivil behaviors in the online learning environment. METHODS: Incivility in online environment (IOLE) survey was used to collect data from dental students (n = 232) and faculty (n = 35) at Margalla Institute of Health Sciences, Rawalpindi, Pakistan from September to December 2021. A 4- point Likert scale was used for respondents to indicate their perceptions regarding incivility in IOLE, and a list of students' and faculty's uncivil behaviors. Descriptive analysis, chi-square test, and Spearman's correlation coefficient were used for data analysis. The level of significance was kept at ≤0.05. RESULTS: The majority of the students reported online incivility as either "a moderate or serious problem" (n = 103, 72.0%), and the majority of faculty (n = 12, 56%) reported incivility as "no to a mild problem" (p = 0.018). Both students and faculty agreed that students are more likely to engage in uncivil behavior in OLE as compared to faculty. Various forms of rude/threatening comments and posting ambiguous or vague responses that do not add meaning to the online discussion were considered uncivil student behaviors by both students and faculty (p ≤ 0.05). Assigning grades without providing useful feedback and threatening to fail students for not complying with faculty's demands were perceived as uncivil faculty behaviors (p ≤ 0.05). Female students and students with less self-reported expertise in online learning had greater mean scores for faculty uncivil behaviors (p ≤ 0.05). CONCLUSION: Incivility exists in OLE in dentistry with the more likely engagement of students in uncivil behaviors. With the increasing use of online platforms for education in dentistry, there is a need for further research and training courses for both students and faculty to reduce the extent of incivility and create a healthy and conducive learning environment.

The effect of cystic fibrosis transmembrane conductance regulator modulators on impaired glucose tolerance and cystic fibrosis related diabetes.

Cystic fibrosis (CF) is an autosomal recessive disorder, with a prevalence of 1 in 2,500 live births. It is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. With the significant advancement in CFTR-directed therapies, life expectancy of CF patients has steadily increased. With improved survival, CF related co-morbidities have become more apparent. The most common endocrine complication includes Cystic fibrosis related diabetes (CFRD). Impaired glucose tolerance and insulin deficiency in CFRD leads to a decline in pulmonary function in CF patients. Here we review the underlying mechanisms involved in the pathogenesis of CFRD, focusing on the role of CFTR in the regulation of insulin secretion from the ß-cell. We then discuss CFTR modulators and their effect on impaired glucose tolerance and CFRD.

Ketone body oxidation increases cardiac endothelial cell proliferation.

Blood vessel formation is dependent on metabolic adaption in endothelial cells. Glucose and fatty acids are essential substrates for ATP and biomass production; however, the metabolism of other substrates remains poorly understood. Ketone bodies are important nutrients for cardiomyocytes during starvation or consumption of carbohydrate-restrictive diets. This raises the question whether cardiac endothelial cells would not only transport ketone bodies but also consume some of these to achieve their metabolic needs. Here, we report that cardiac endothelial cells are able to oxidize ketone bodies and that this enhances cell proliferation, migration, and vessel sprouting. Mechanistically, this requires succinyl-CoA:3-oxoacid-CoA transferase, a key enzyme of ketone body oxidation. Targeted metabolite profiling revealed that carbon from ketone bodies got incorporated into tricarboxylic acid cycle intermediates as well as other metabolites fueling biomass production. Elevation of ketone body levels by a high-fat, low-carbohydrate ketogenic diet transiently increased endothelial cell proliferation in mouse hearts. Notably, in a mouse model of heart hypertrophy, ketogenic diet prevented blood vessel rarefication. This suggests a potential beneficial role of dietary intervention in heart diseases.

The role of genetic modifiers, inflammation and CFTR in the pathogenesis of Cystic fibrosis related diabetes.

Cystic fibrosis related diabetes (CFRD) generally reflects insufficient and/or delayed production of insulin, developing slowly over years to decades. Multiple mechanisms have been implicated in the pathogenesis of CFRD. CFTR function itself is a strong determinant of CFRD risk. Variants in CFTR that result in residual CFTR function and exocrine pancreatic sufficiency reduce the risk of CFRD by ten to twenty fold. Two groups of hypotheses have been proposed for the mechanism of CFTR impairing insulin secretion in CFRD: (1) ß-cell dysfunction results from ß cell intrinsic CFTR-dependent mechanisms of insulin secretion. (2) ß-cell dysfunction results from factors outside the ß cell. Genome-wide association studies have identified multiple susceptibility genes for type 2 diabetes, including TCF7L2, CDKN2A/B, CDKAL1, and IGF2BP2, as containing genetic modifiers of CFRD. These findings support the presence of intrinsic ß cell defects playing a role in CFRD pathogenesis. Oxidative stress and inflammation are ß cell-extrinsic mechanisms involved with CFRD. CFTR mutations render ß cells more susceptible to oxidative stress and also leads to defects in α-cell function, resulting in reduced suppression of glucagon secretion. Furthermore, CFRD is characterized by ß cell loss secondary to intra-islet inflammation. Recent studies have demonstrated the presence of multiple inflammatory mediators within the human CF islet. This review presents a concise overview of the current understanding of genetic modifiers of CFRD, oxidative stress, islet inflammation, and the controversies about the role of CFTR in the islet.

The role of modulators in cystic fibrosis related diabetes.

The development and introduction of modulator therapies have completely shifted the paradigm for the treatment of cystic fibrosis (CF). Highly effective modulator therapies have driven marked improvements in lung function, exacerbation rate, weight and quality of life in CF patients. However, their effect on CF related diabetes (CFRD) is not well delineated. The role of CF transmembrane conductance regulator (CFTR) in CFRD pathogenesis is inadequately understood and research aimed at deciphering the underlying mechanisms of CFRD continues to evolve. In this review, we summarize what is known regarding the effect of CFTR modulators on CFRD. Small studies using ivacaftor monotherapy in gating mutations have revealed improvement in insulin secretion, glucose tolerance and/or decrease in insulin requirement. However, lumacaftor/ivacaftor studies (primarily in delta F 508 homozygous) have not revealed significant improvement in CFRD or glucose tolerance. No studies are yet available regarding the effect of the highly effective triple therapy (elexacaftor/tezacaftor/ivacaftor) on CFRD or insulin secretion. CFTR modulators might affect development or progression of CFRD through many mechanisms including improving insulin secretion by correcting the CFTR defect directly, improving ductal function, reducing islet inflammation, and improving incretin secretion or by enhancing insulin sensitivity via reduced systemic inflammation and increased physical activity driven by improved lung function and quality of life. On the other hand, they can stimulate appetite and improve gastrointestinal function resulting in increased caloric intake and absorption, driving excessive weight gain and potentially increased insulin resistance. If the defect in insulin secretion is reversible then it is possible that initiation of CFTR modulators at a younger age might help prevent CFRD. Despite the advances in CF management, CFRD remains a challenge and knowledge continues to evolve. Future studies will drive better understanding of the role of highly effective CFTR modulators in CFRD.

COVID-19: Pathophysiology and implications for cystic fibrosis, diabetes and cystic fibrosis-related diabetes.

The novel SARS-CoV-2 coronavirus (COVID-19) has become a global health crisis since its initial outbreak in Wuhan, China in December 2019. On January 30, 2020, the WHO recognized the COVID-19 outbreak as a Public Health Emergency, and on March 11, 2020, it was declared a pandemic. Although all age groups have been affected, patients with cystic fibrosis (CF) and patients with type 1 or type 2 diabeteshave been categorized as highly vulnerable to SARS-CoV-2 infection. Thus far, studies have found that the incidence of SARS-CoV-2 in the CF population is lower than the general population. We review the underlying protective mechanisms which may reduce inflammation and lung damage in CF patients, thus decreasing their risk of severe COVID-19. While the effect of SARS-CoV-2 in those with diabetes related to CF is unknown, other forms of diabetes have been associated with more severe disease. To further understand the potential impact of SARS-CoV-2 in cystic fibrosis-related diabetes, we provide a comprehensive overview of the potential factors contributing to COVID-19 severity in other forms of diabetes, including direct viral effect on the pancreas and indirect effects related to hyperglycemia and immune dysregulation.

A Clinician's guide to vitamin D supplementation for patients with cystic fibrosis.

Vitamin D deficiency is common in the general population, and even more so in patients with cystic fibrosis. Deficiency is exacerbated in cystic fibrosis patients because of a myriad of causes including malabsorption, decreased fat mass, reduced 25-hydroxylation of vitamin D, reduced exposure to sunlight, decreased vitamin D binding protein, and exposure to drugs that increase catabolism. In turn, vitamin D deficiency can contribute to poor bone health. Additionally, it may contribute to pulmonary decline in the form of worsening pulmonary function, increased colonization with pathogens, and increased pulmonary exacerbation. Because vitamin D deficiency is correlated with negative clinical effects in multiple organ systems of patients with cystic fibrosis, it is important to screen for and treat deficiency in these patients. The Cystic Fibrosis Foundation has issued guidelines for the treatment of vitamin D deficiency, targeting serum levels of 25-hydroxyvitamin D of at least 30 ng/ml. The guidelines offer age-specific escalating dose regimens depending on serum vitamin D levels, with monitoring at 12- week intervals after changing therapy. They address the literature on alternative vitamin D sources, such as UV lamps, ideal formulations (cholecalciferol in preference to ergocalciferol), and optimal vehicles of administration. Despite these detailed recommendations, most centers are still unable to achieve in-target serum vitamin D levels for many of their patients. Future research examining ideal treatment regimens to achieve serum targets and maximize clinical effects are needed. Moreover, it is unknown whether vitamin D sufficiency will be easier to achieve on new triple therapy cystic fibrosis drug combinations, and how these drugs will contribute to vitamin D-related clinical outcomes.

Prognostic Significance of Substance P/Neurokinin 1 Receptor and Its Association with Hormonal Receptors in Breast Carcinoma.

Expression and immunolocalization of Substance P (SP)/Neurokinin-1 Receptor (NK-1R) in breast carcinoma (BC) patients and its association with routine proliferative markers (ER, PR, HER2/neu, and Ki-67) were evaluated. A cross-sectional study was performed on 34 cases of BC. There were 23 cases of group A (grade III), 8 of group B (grade II), and only 3 cases of group C (grade I). All samples were then processed for SP and NK-1R immunohistochemistry for few cases. 14/23 cases (61%) of group A, 7/8 cases (88%) of group B, and 2/3 (67%) cases of group C were SP positive. Overall, strong staining (≥10% tumor cells), labeled as "+3," was observed in 9/14 (64.2%) cases of group A and 1/8 (12.5%) cases of group B. Moderate staining labelled as "+2" (in ≥10% tumor cells) was observed in 3/14 (21.4%) cases of group A and 4/8 (50%) cases of group B. Weak positive staining "+1" was observed in only 2/14 (14.28%) cases of group A, 2/8 (25%) cases of group B, and all 2/2 (100%) cases of group C. SP and NK-1R are overexpressed in breast carcinomas, and there is significant association between the grade of tumor and their overexpression.

Managing Cystic Fibrosis related diabetes via telehealth during COVID-19 pandemic.

Coronavirus disease 2019 (COVID-19) was declared a pandemic on March 11, 2020. In efforts to reduce the risk of transmission, telehealth visits for routine care has significantly increased in the United States. Cystic fibrosis patients have been categorized as a highly vulnerable population to COVID-19 infection. Cystic Fibrosis centers are rapidly assessing and responding to the pandemic to ensure the safety of CF patients. At our Cleveland Clinic Cystic Fibrosis center, we transitioned outpatient clinics to a virtual care model in March 2020. Here, we report the changes that were implemented to optimize diabetes management in CF patients through telehealth during the COVID-19 crisis.

The importance of implementing inpatient virtual coverage in an endocrinology practice: lessons learned thus far from the COVID-19 pandemic.

The COVID-19 pandemic has rapidly changed the landscape of medical care and the healthcare system needs to quickly adapt in order to continue providing optimal medical care to hospitalized patients in an efficient, effective, and safe manner. Endocrinology diseases are commonly present in patients with COVID-19 and often are major risk factors for development of severe disease. The use of electronic consultation and telemedicine have already been well-established in the outpatient setting but yet not commonly implemented in the inpatient arena. This type of remote medical care has the potential to provide a reliable delivery of endocrine care while protecting providers and patients from spreading infection. This short review intends to provide the initial steps for the development of an inpatient telemedicine endocrine service to patients with endocrine diseases. Telehealth will become part of our daily practices and has a potential to provide a safe and efficient method of consultative service.

The Endothelium: An Active Regulator of Lipid and Glucose Homeostasis.

The vascular endothelium serves as a dynamic barrier that separates blood from interstitia. Endothelial cells (ECs) respond rapidly to changes in the circulation and actively regulate vessel tone, permeability, and platelet functions. ECs also secrete angiocrine factors that dictate the function of adjacent parenchymal cells in an organ-specific manner. Endothelial dysfunction is considered as a hallmark of metabolic diseases. However, there is emerging evidence that ECs modulate the transfer of nutrients and hormones to parenchymal cells in response to alterations in metabolic profile. As such, a causal role for ECs in systemic metabolic dysregulation can be envisaged. This review summarizes recent progress in the understanding of regulated fatty acid, glucose, and insulin transport across the endothelium and discusses its pathophysiological implications.

Notch Signaling in Familial Cerebral Cavernous Malformations and Immunohistochemical Detection of Cleaved Notch1 Intracellular Domain.

Cerebral cavernous malformations (CCM) or cavernomas are slow-flow capillary vascular malformations with a mulberry-like appearance, which are predominantly located in the central nervous system. CCM can occur in a sporadic or a familial form. The latter is inherited in an autosomal dominant manner, and in the majority of the fragile lesions, mutations in the genes CCM1 (KRIT1), CCM2 (OSM), or CCM3 (PDCD10) can be detected. Loss of these genes leads to numerous alterations in endothelial cell signaling resulting in a disturbed vessel architecture and function. Lower activity of Notch signaling occurs upon loss of CCM1, CCM3, or the CCM1-interacting protein ICAP1 in cell culture and animal models. Notch signaling in endothelial cells is an essential regulator of angiogenesis, arterial-venous differentiation, vascular permeability and stability, mural cell recruitment, and flux of metabolites across the vessel wall. The purpose of this chapter is to briefly summarize the current understanding of Notch signaling in familial CCM and to provide a protocol for detecting cleaved Notch1 receptor proteins on paraformaldehyde-fixed paraffin-embedded mouse tissue.

Comparison of Epidemiological Variations in COVID-19 Patients Inside and Outside of China-A Meta-Analysis.

The objective of this study is to compare the epidemiological variations in COVID-19 patients reported in studies from inside and outside of China. We selected COVID-19 observational studies from eight countries, including, China, Italy, Australia, Canada, Korea, Taiwan, Singapore, and the USA, comprising a total of 13 studies and performed a meta-analysis for age, gender, fatality rate, and clinical symptoms of fever, cough, shortness of breath, and diarrhea. The meta-analysis shows that there are differences in symptoms and other characteristics reported by the patients of COVID-19 inside and outside China. Patients in China have a higher proportion of fever, cough, and shortness of breath as compared to patients outside of China. However, we found the opposite results for the gastrointestinal symptoms such as Diarrhea. Patients outside of China have a significantly higher proportion of Diarrhea as compared to patients within China. We also observed gender disparity among our studies, with the male population being more susceptible than the female population. Moreover, the analysis suggests that the fatality rate in China is relatively lower as compared to the fatality rate in other countries. These findings also suggest that the clinical symptoms of COVID-19 should not be generalized to fever, shortness of breath, and cough only but other symptoms such as diarrhea are also prevalent in patients with COVID-19.

Endothelial Notch signaling controls insulin transport in muscle.

The role of the endothelium is not just limited to acting as an inert barrier for facilitating blood transport. Endothelial cells (ECs), through expression of a repertoire of angiocrine molecules, regulate metabolic demands in an organ-specific manner. Insulin flux across the endothelium to muscle cells is a rate-limiting process influencing insulin-mediated lowering of blood glucose. Here, we demonstrate that Notch signaling in ECs regulates insulin transport to muscle. Notch signaling activity was higher in ECs isolated from obese mice compared to non-obese. Sustained Notch signaling in ECs lowered insulin sensitivity and increased blood glucose levels. On the contrary, EC-specific inhibition of Notch signaling increased insulin sensitivity and improved glucose tolerance and glucose uptake in muscle in a high-fat diet-induced insulin resistance model. This was associated with increased transcription of Cav1, Cav2, and Cavin1, higher number of caveolae in ECs, and insulin uptake rates, as well as increased microvessel density. These data imply that Notch signaling in the endothelium actively controls insulin sensitivity and glucose homeostasis and may therefore represent a therapeutic target for diabetes.

Managing Postural Hypotension in Diabetic Autonomic Dysfunction When Adrenergic Drugs are Contraindicated: Case Report and Review of Literature.

Postural hypotension, as a manifestation of autonomic neuropathy is a very sinister long-term debilitating complication of diabetes, is usually irreversible and tough to manage with medications. The treatment of this condition following the standard treatment protocols can be contraindicated in the patients with underlying heart conditions. We report the case of a patient at our hospital who presented with full-blown symptomatic dysautonomia secondary to long-standing diabetes, with bedside testing positive for autonomic dysfunction. Treating this patient with the standard protocol of adrenergic agonist could have worsened his underlying coronary artery disease. So, we moved a step aside to go out of the box and we have a trial of the ß1-selective beta-blocker, with astonishing results and significant improvement in the quality of life and symptoms of postural hypotension. We report here the use of alternative treatment option in managing a patient with severe postural hypotension secondary to diabetes-related autonomic neuropathy when adrenergic drugs are contraindicated.