Chronic Elevation Research Articles

Tangzhiqing-mediated NRF2 reduces autophagy-dependent ferroptosis to mitigate diabetes-related cognitive impairment neuronal damage.

Diabetes is a chronic condition defined by the body's inability to process glucose. The most common form, diabetes mellitus, reflects the body's insulin resistance, which leads to long-term raised glucose blood levels. These levels can cause oxidative damage, cell stress, and excessive autophagy throughout the body, including the nervous system. Diabetes-related cognitive impairment (DCI) results from chronic elevation of blood glucose, and as diabetes cases continue to rise, so too do comorbidities such as DCI. Although there are medications to address high blood glucose, there are few that can inhibit excessive autophagy and cell death. Therefore, we investigated if the Traditional Chinese Medicine, Tangzhiqing (TZQ), can reduce the impact of DCI in a high-glucose cell model. We used commercially available kits to evaluate cell viability, mitochondrial activity, and oxidative stress. We found that TZQ treatment increased cell viability, ensured continued mitochondrial activity, and reduced reactive oxygen species. We also found that TZQ functions by increasing NRF2 activity, which decreases the ferroptotic-associated pathways that involve p62, HO-1, and GPX4. Therefore, TZQ should be further investigated for its role in reducing DCI.

Physical Activity and Cardiac Morphologic Adaptations.

Chronic and intense exercise programs lead to cardiac adaptations, followed by increased left ventricular wall thickness and cavity diameter, at times meeting the criteria for left ventricular hypertrophy (LVH), commonly referred to as "athlete's heart". Recent studies have also reported that extremely vigorous exercise practices have been associated with heightened left ventricular trabeculation extent, fulfilling noncompaction cardiomyopathy criteria, as part of exercise-induced structural adaptation. These changes are specific to the exercise type, intensity, duration, and volume and workload demands imposed on the myocardium. They are considered physiologic adaptations not associated with a negative prognosis. Conversely, hypertrophic cardiac adaptations resulting from chronic elevations in blood pressure (BP) or chronic volume overload due to valvular regurgitation, lead to compromised cardiac function, increased cardiovascular events, and even death. In younger athletes, hypertrophic cardiomyopathy (HCM) is the usual cause of non-traumatic, exercise-triggered sudden cardiac death. Thus, an extended cardiac examination should be performed, to differentiate between HCM and non-pathological exercise-related LVH or athlete's heart. The exercise-related cardiac structural and functional adaptations are normal physiologic responses designed to accommodate the increased workload imposed by exercise. Thus, we propose that such adaptations are defined as "eutrophic" hypertrophy and that LVH is reserved for pathologic cardiac adaptations. Systolic BP during daily activities may be the strongest predictor of cardiac adaptations. The metabolic demand of most daily activities is approximately 3-5 metabolic equivalents (METs) (1 MET = 3.5 mL of kg of body weight per minute). This is similar to the metabolic demand of treadmill exercise at the first stage of the Bruce protocol. Some evidence supports that an exercise systolic BP response 150 mmHg at the end of that stage is a strong predictor of left ventricular hypertrophy, as this BP reflects the hemodynamic burden of most daily physical tasks. Aerobic training of moderate intensity lowers resting and exercise systolic BP at absolute workloads, leading to a lower hemodynamic burden during daily activities, and ultimately reducing the stimulus for LVH. This mechanism explains the significant LVH regression addressed by aerobic exercise intervention clinical studies.

Abstract #1413021: Teprotumumab Induced Type 1 Diabetes Mellitus

Thyroid Eye disease is a potentially vison impairing condition for which Teprotumumab has emerged as a premier option in managing disease activity. The primary mechanism of action is monoclonal antibody against the insulin-like growth factor-I receptor but a large portion remains unknown. In the original trial for Teprotumumab about 10% of patients developed hyperglycemia which was described as self limited and mild. Since commercial release there has been great heterogeneity of hyperglycemia shown with case reports of HHS and DKA despite a third of trial patients returning to baseline after completion of therapy. We present a case of type 1 diabetes after starting Teprotumumab which may help advise decisions for therapy, monitoring, and surveillance. A 52-year-old female with prediabetes (A1C 6.1%), mild hypothyroidism and tobacco use who presents with diplopia, proptosis, palpitations in January of 2022 to PCP. She had lab work performed in March 2022 with TSH 0.007, FT4 2.45, TPO antibodies 219 positive. Last normal TFTs in Feb of 2020. Her levothyroxine was stopped by PCP and she was started on methimazole 10 mg tid and propranolol ER 60 mg daily. April 2022 referred to Endocrinology, Labs: TSI index of 2.9, TSH now of 13, Free T4 of 0.56 (0.93 - 1.7) while on methimazole 10 mg tid. She was reduced to 10 mg bid and referred to Ophthalmology for co-management of thyroid eye disease with plan for Teprotumumab for moderate to severe disease. Subsequent follow up in June 2022, she had been tapered down to 5 mg bid between visits and labs showed: TSH 0.074, FT4 1.08, FT3 3.8. Methimazole was further reduced to 5 mg daily. She was started on metformin XR 500 mg bid given her diagnosis of prediabetes and plan for Teprotumumab therapy. She achieved smoking cessation with varenicline. CBC and LFT monitoring were remarkable for chronic mild ALP elevation. Teprotumumab was started and her eye symptoms improved significantly by the second infusion. Hyperglycemia worsened and A1C increased to 7.5%.TSH was 6.32 and Free T4 1.1 on 5 mg of methimazole. Subsequently methimazole was decreased to 2.5 mg daily and Metformin increased to 1g bid and addition of glimepiride 2mg daily. She had continued hyperglycemia. Subsequent labs we obtained GAD antibodies with continued hyperglycemia and monitoring labs for remission. GAD antibodies >125 exceeding beyond the upper limit of normal for the assay and subsequent thyroid tests with c-peptide are pending at this time. Teprotumumab has revolutionized thyroid eye disease treatment. This case demonstrates there are multiple modalities of hyperglycemia that may be non-reversible after completion of Teprotumumab. The importance of monitoring and perhaps a role in evaluating antibodies and insulin reserve in Teprotumumab induced hyperglycemia surveillance. This case supports that this group is heterogenous and needs further studies. Further evaluation for this patient is still pending with initiation of insulin therapy. We hope that this case can help guide research, safety protocols, and awareness in the management of thyroid eye disease.

CD38-cADPR axis mediated chronic Ca 2+signaling promotes the differentiation of TCF1 loterminal exhausted CD8 +T cells in tumor

Abstract Preponderance of terminally exhausted CD8 +T cells (Tex term) at the tumor site is the major impediment for successful immunotherapy of cancer. Despite the recent understanding in epigenetic, transcriptomic and metabolic features of Tex term, the cellular pathway underpinning the differentiation of Tex termremains elusive. Upon assessing intratumoral CD8 +T cells from both clinical samples and pre-clinical mouse models, we observed that CD8 +T cells co-expressing CD38 and PD1 displayed the characteristic features of Tex term. Single cell RNA sequencing analysis from both murine tumor infiltrating CD8 +T cells and in vitrochronically stimulated human CD8 +T cells revealed that clusters co-expressing Cd38and Pdcd1diplayed the transcriptomic signature of Tex term. Most importantly, clusters expressing Cd38and Tcf7were found to be mutually exclusive. Further studies to decipher the role of CD38 showed that both pharmacological and genetic knockdown of CD38 maintained TCF1 expression in chronically exhausted CD8 +T cells and significantly improved their ability to control tumor growth upon adoptive transfer in B16–F10 melanoma bearing mice. Mechanistic studies revealed that CD38 expression on Tex termled to chronic elevation of intracellular Ca 2+levels through cADPR-RyR2 axis, which activated Akt signalling. Activation of Akt restrained the nuclear localization of Ezh2, which was found to be pivotal in maintaining TCF1 expression in Tex termand inhibition of which in CD8 +T cells resulted in poor anti-tumor response. Thus, our data suggests that CD38 could be a drugable target to improve the immunotherapeutic efficacy of CD8 +T cells in cancer. Supported by grants from IA/I/19/1/504277/WTDBT_/DBT-Wellcome Trust India Alliance/India CRG/2019/001334 SERB Extramural Fund CSIR Intramural Fund

Cardiac biomarkers and their clinical relevance

Cardiac biomarkers are an integral, guideline-recommended part of the diagnosis and follow-up of heart diseases. High sensitivity tests for troponin I or T allow for the early diagnosis of myocardial infarction. Rule-in and rule-out algorithms based on the dynamic of plasma concentrations in the first hour after admission improve safe, evidence-based decision making for patients with acute chest pain. Low concentrations of brain natriuretic peptides (BNP or NT-proBNP) reliably exclude heart failure. Elevated BNP/NT-proBNP concentrations are part of the definition of all types of heart failure but require additional tests to diagnose heart failure. Chronic elevations of troponins and BNP/NT-proBNP identify subpopulations at increased risk of cardiovascular events even in the absence of manifest cardiac disease. Whether and how this risk can be reduced requires further evaluation. Several novel biomarkers were recently discovered and characterised. Their place in cardiovascular medicine has yet to be defined.

Chronic troponin elevation assessed by myocardial T1 mapping in patients with stable coronary artery disease.

Cardiac troponin detected with sensitive assays can be chronically elevated, in the absence of unstable coronary syndromes. In patients with chronic coronary artery disease, clinically silent ischemic episodes may cause chronic troponin release. T1 mapping is a cardiovascular magnetic resonance technique useful in quantitative cardiac tissue characterization. We selected patients with anatomically and functionally normal hearts to investigate associations between chronic troponin release and myocardial tissue characteristics assessed by T1 mapping. We investigated the relationship between cardiac troponin I concentrations and cardiovascular magnetic resonance T1 mapping parameters in patients with stable coronary artery disease enrolled in MASS V study before elective revascularization. Participants had no previous myocardial infarction, negative late gadolinium enhancement, normal left ventricular function, chamber dimensions and wall thickness. A total of 56 patients were analyzed in troponin tertiles: nativeT1 and extracellular volume (ECV) values (expressed as means ± standard deviations) increased across tertiles: nativeT1 (1006 ± 27 ms vs 1016 ± 27 ms vs 1034 ± 37 ms, ptrend = 0.006) and ECV (22 ± 3% vs 23 ± 1.9% vs 25 ± 3%, ptrend = 0.007). Cardiac troponin I concentrations correlated with native T1(R = 0.33, P = .012) and ECV (R = 0.3, P = .025), and were independently associated with nativeT1 (P = .049) and ventricular mass index (P = .041) in multivariable analysis. In patients with chronic coronary artery disease and structurally normal hearts, troponin I concentrations correlated with T1 mapping parameters, suggesting that diffuse edema or fibrosis scattered in normal myocardium might be associated with chronic troponin release.

Unpredictable fasting transiently alters corticosterone and feeding behavior but not body mass or later HPA axis function in zebra finches (Taeniopygia guttata)

The hypothalamic-pituitary-adrenal (HPA) axis is commonly activated in response to unpredictable conditions, including unstable or inadequate food supply. Extended exposure to unpredictable food resources can alter HPA axis function, with the potential for negative fitness consequences. We addressed the interrelationships of unpredictable food resources, HPA axis activity, and food intake in adult and juvenile zebra finches (Taeniopygia guttata). Finches exposed to prolonged periods of unpredictable food elevate corticosterone (the primary avian glucocorticoid) when food is unavailable; however, whether they experience chronic elevation in baseline corticosterone during periods of unpredictability, even when food is available, is unclear. We subjected adults and juveniles to an extended period of temporally unpredictable food (consisting of a random daily fast) or predictable food supply. We investigated baseline corticosterone under fed conditions and in response to an acute fast (mimicking the daily fasting periods in the unpredictable treatment), and assessed differences in body mass, food intake, and corticosterone responses to restraint. Regardless of sex and age, individuals in both treatment groups elevated corticosterone when fasted, and baseline corticosterone under fed conditions was indistinguishable between groups. Thus, corticosterone levels were not persistently elevated in the unpredictably fed group. Treatment groups did not differ in body mass or corticosterone responses to restraint, but unpredictably fed birds consumed food more rapidly when food was available. Our findings suggest that the unpredictably fed birds experienced repeated, moderate elevations in corticosterone. Such elevations may aid birds in coping with unpredictable food sources, in part by activating compensatory changes in foraging behavior.

Ormdl3 regulation of specific ceramides is dispensable for mouse β-cell function and glucose homeostasis under obesogenic conditions.

Chronic elevation of sphingolipids contributes to β-cell failure. ORMDL3 has been identified as a key regulator of sphingolipid homeostasis, however, its function in pancreatic β-cell pathophysiology remains unclear. Here, we generated a mouse model lacking Ormdl3 within pancreatic β-cells (Ormdl3 β-/-). We show that loss of β-cell Ormdl3 does not alter glucose tolerance, insulin sensitivity, insulin secretion, islet morphology, or cellular ceramide levels on standard chow diet. When challenged with a high fat diet, while Ormdl3 β-/- mice did not exhibit any alteration in metabolic parameters or islet architecture, lipidomics analysis revealed significantly higher levels of very long chain ceramides in their islets. Taken together, our results reveal that loss of Ormdl3 alone is not sufficient to impinge upon β-cell function or whole-body glucose and insulin homeostasis, however, β-cell-specific loss of Ormdl3 does significantly alter levels of specific sphingolipid species in islets upon high fat feeding.

Age-related alterations in meningeal immunity drive impaired CNS lymphatic drainage.

The meningeal lymphatic network enables the drainage of cerebrospinal fluid (CSF) and facilitates the removal of central nervous system (CNS) waste. During aging and in Alzheimer's disease, impaired meningeal lymphatic drainage promotes the buildup of toxic misfolded proteins in the CNS. Reversing this age-related dysfunction represents a promising strategy to augment CNS waste clearance; however, the mechanisms underlying this decline remain elusive. Here, we demonstrate that age-related alterations in meningeal immunity underlie this lymphatic impairment. Single-cell RNA sequencing of meningeal lymphatic endothelial cells from aged mice revealed their response to IFNγ, which was increased in the aged meninges due to T cell accumulation. Chronic elevation of meningeal IFNγ in young mice via AAV-mediated overexpression attenuated CSF drainage-comparable to the deficits observed in aged mice. Therapeutically, IFNγ neutralization alleviated age-related impairments in meningeal lymphatic function. These data suggest manipulation of meningeal immunity as a viable approach to normalize CSF drainage and alleviate the neurological deficits associated with impaired waste removal.

72 Establishing a histologically defined NAFLD cohort in the Million Veteran Program for further genetic analyses

OBJECTIVES/GOALS: Research in Non Alcoholic Fatty Liver Disease Genetics is ongoing. In this project, we aim to: 1.Identify and describe a histological NAFLD Cohort in the MVP Biobank by extracting liver biopsy proven NAFLD patients using natural language processing (NLP) 2.Confirm previously defined NALFD genetic loci (via look up-GWAS) in the histological NLP cohort METHODS/STUDY POPULATION: We will utilize the Million Veteran Program Biobank where a total of 10,959 subjects have been identified using liver biopsy reports in the EMR via CPT codes. Cases will be based on i) steatosis, steatohepatitis, inflammation or fibrosis in liver biopsy reports with ii) exclusion of other causes of liver disease. Controls will be comprised of the general VA population. In collaboration with the Applied NLP and Precision Medicine groups at the VA Informatics and Computing Infrastructure(VINCI); we will attempt to create and validate a histological cohort of NAFLD in the MVP database by: 1)Annotation of biopsy reports for the NLP algorithm 2)Automation/training of the NLP algorithm We will then perform a multi-ancestry genetic lookup of previously established genetic loci among the cases identified. RESULTS/ANTICIPATED RESULTS: Recently published data: the MVP NAFLD research led by Dr. Chang and Dr. Vujkovic had first validated a proxy NAFLD phenotype based on chronic alanine aminotransferase elevation (cALT). A GWAS was then performed using this phenotype which revealed 77 loci of genome-wide significance including 10 established NAFLD- and 52 ALT-associated SNPs were identified. Replication in external Liver Biopsy and Imaging Cohorts validated 17 SNPs of which 9 were novel. Preliminary data on Liver Biopsy reports: Using CPT codes for Liver Biopsy we estimated a total of 10,959 unique patients and 18,812 notes in the MVP biobank. We anticipate 2,000-3,000 NAFLD cases (based on the prevalence of NAFLD in the general population). Initial review reveals 90% concordance between analysts for the purposes of developing an NLP. DISCUSSION/SIGNIFICANCE: NAFLD is a major cause for morbidity and mortality in liver disease. Gold standard for diagnosis is based on biopsy. GWAS studies with biopsy proven phenotypes are limited. The study will aim to isolate a histologically defined NAFLD cohort in MVP to conduct further GWAS that can provide new clinically relevant knowledge for future research.Contemporary Research Challenges

ASSOCIATIONS BETWEEN STRUCTURAL AND FUNCTIONAL STATUS OF MYOCARDIUM AND SERUM LEVELS OF NT-proBNP AND ST2 IN PATIENTS WITH COMBINED CARDIAC PATHOLOGY

Damage to the heart under essential hypertension manifests a combination of changes in the left ventricle, left atrium, and coronary arteries resulted from a chronic elevation in blood pressure. Hypertension increases the load on the heart, causing structural and functional changes in the myocardium. Associations between clinical, laboratory and instrumental indicators and the levels of various biomarkers, which characterize the specificity and severity of systemic processes occurring in the cardiovascular system and can also be used for predicting the prognosis of diseases, are of undoubted practical interest.
 The aim of this study was to research the associations between the structural and functional state of the myocardium and the levels of serum NT-proBNP and ST2 in hypertensive patients with / without chronic coronary disease.
 Materials and methods. 118 patients with stage II hypertension with / without chronic coronary disease were included in the study. For all patients, both the main indicators of the structural and functional state of the myocardium according to echocardiography and serum levels of NT-proBNP and ST2 were additionally measured on the 2-3rd day of hospital stay when optimal therapy was being selected.
 Results. The obtained data indicate that a relatively low level of NT-proBNP is associated with a significant increase in the size of the right atrium and the right atrial index and the frequency of cases with concentric hypertrophy of the left ventricle compared to intermediate and relatively high levels of the neurohormone. The patients with relatively low neurohormone level demonstrate a significant increase in end-diastolic size and left atrial size compared with only intermediate levels. The results of the analysis of changes in echocardiogram indicators depending on the level of ST2 in plasma demonstrate the complete absence of any reliable changes between the selected groups.

Vitamin D as a Shield against Aging

Aging can be seen as a physiological progression of biomolecular damage and the accumulation of defective cellular components, which trigger and amplify the process, toward whole-body function weakening. Senescence initiates at the cellular level and consists in an inability to maintain homeostasis, characterized by the overexpression/aberrant expression of inflammatory/immune/stress responses. Aging is associated with significant modifications in immune system cells, toward a decline in immunosurveillance, which, in turn, leads to chronic elevation of inflammation/oxidative stress, increasing the risk of (co)morbidities. Albeit aging is a natural and unavoidable process, it can be regulated by some factors, like lifestyle and diet. Nutrition, indeed, tackles the mechanisms underlying molecular/cellular aging. Many micronutrients, i.e., vitamins and elements, can impact cell function. This review focuses on the role exerted by vitamin D in geroprotection, based on its ability to shape cellular/intracellular processes and drive the immune response toward immune protection against infections and age-related diseases. To this aim, the main biomolecular paths underlying immunosenescence and inflammaging are identified as biotargets of vitamin D. Topics such as heart and skeletal muscle cell function/dysfunction, depending on vitamin D status, are addressed, with comments on hypovitaminosis D correction by food and supplementation. Albeit research has progressed, still limitations exist in translating knowledge into clinical practice, making it necessary to focus attention on the role of vitamin D in aging, especially considering the growing number of older individuals.

Gut microbiome composition associates with corticosteroid treatment, morbidity, and senescence in Chinook salmon (Oncorhynchus tshawytscha)

Pacific salmon experience prolonged elevation in corticosteroid hormones during important life history events including migration, reproduction, and senescence. These periods of elevated corticosteroids correspond with changes to immunity and energy metabolism; therefore, fish may be particularly vulnerable to mortality at these times. Recent studies found that stress-induced cortisol release associated with microbial community shifts in salmonids, raising the question of how longer-term corticosteroid dynamics that accompany life history transitions affect salmonid microbiomes. In this work, we experimentally evaluated the relationships between gut microbiome composition, chronically elevated corticosteroids, and mortality in juvenile Chinook salmon (Oncorhynchus tshawytscha). We found that treatment with slow-release implants of the corticosteroids cortisol or dexamethasone resulted in changes to the gut microbiome. Morbidity was also associated with microbiome composition, suggesting that the gut microbiome reflects individual differences in susceptibility to opportunistic pathogens. Additionally, we analyzed a small number of samples from adult fish at various stages of senescence. Results from these samples suggest that microbiome composition associated with gut integrity, and that the microbial communities of corticosteroid treated juveniles shift in composition toward those of senescent adults. Overall, findings from this work indicate that the gut microbiome correlates with mortality risk during periods of chronic corticosteroid elevation.

Chronic cortisol elevation restricts glucose uptake but not insulin responsiveness in zebrafish skeletal muscle

Although teleosts show an elevated insulin response to hyperglycemia, the circulating glucose levels are not normalized as rapidly as in mammals. While this may suggest a lack of target tissue insulin responsiveness, the underlying mechanisms are unclear. We investigated whether changes in skeletal muscle insulin sensitivity and glucose uptake underlie the cortisol-mediated elevated blood glucose levels. Adult zebrafish (Danio rerio) were exposed to water-borne cortisol for 3 days followed by an intraperitoneal injection of glucose with or without insulin. Cortisol treatment resulted in a temporal delay in the reduction in blood glucose levels, and this corresponded with a reduced glucose uptake capacity and lower glycogen content in the skeletal muscle. The transcript abundance of slc2a1b (which encodes for GLUT1b) and a suite of genes encoding enzymes involved in muscle glycogenesis and glycolysis were upregulated in the cortisol group. Both the control and cortisol groups showed higher whole body insulin expression in response to blood glucose elevation, which also resulted in enhanced insulin-stimulated phosphorylation of AKT in the skeletal muscle. The insulin-mediated phosphorylation of S6 kinase was lower in the cortisol group. Altogether, chronic cortisol stimulation restricts glucose uptake and enhances the glycolytic capacity without affecting insulin responsiveness in zebrafish skeletal muscle.

Nrf2 and Antioxidant Response in Animal Models of Type 2 Diabetes.

This perspective examines the proposition that chronically elevated blood glucose levels caused by type 2 diabetes (T2D) harm body tissues by locally generating reactive oxygen species (ROS). A feed-forward scenario is described in which the initial onset of defective beta cell function T2D becomes sustained and causes chronic elevations in blood glucose, which flood metabolic pathways throughout the body, giving rise to abnormally high local levels of ROS. Most cells can defend themselves via a full complement of antioxidant enzymes that are activated by ROS. However, the beta cell itself does not contain catalase or glutathione peroxidases and thereby runs a greater risk of ROS-induced damage. In this review, previously published experiments are revisited to examine the concept that chronic hyperglycemia can lead to oxidative stress in the beta cell, how this relates to the absence of beta cell glutathione peroxidase (GPx) activity, and whether this deficiency might be ameliorated by genetic enrichment of beta cell GPx and by oral antioxidants, including ebselen, a GPx mimetic.

Chronic angiotensin II signaling drives sustained PIP2 deficits and altered sarcolemmal Cav1.2 expression and function in cardiomyocytes.

Contractile dysfunction, hypertrophy, and cell death during heart failure are linked to altered Ca2+ handling and elevated levels of angiotensin II (AngII). This hormone signals through Gq-coupled AT1 receptors, initiating hydrolysis of phosphatidylinositol 4,5-bisphosphate (PIP2). Previous work revealed acute AngII signaling and PIP2 depletion destabilizes CaV1.2 clusters in cardiomyocytes, triggering their internalization, and subsequent reduction of whole-cell Ca2+ current (ICa) and contractility. However, the effects of chronically elevated AngII on the phospholipid landscape and associated effects on ICa remain unknown. We subjected mice to sustained delivery of AngII to test the impact on phosphoinositides, ICa, and excitation-contraction coupling. We hypothesized that chronic AngII signaling leads to sustained PIP2 and CaV1.2 deficits, contributing to the diminished functional output associated with disease development. Phospholipid mass spectrometry revealed extensive alteration of phosphoinositide species, including a ∼44% reduction in PIP2 and ∼37% reduction in cardioprotective PIP3 in AngII-infused hearts compared to controls. To study the effects of this phospholipid imbalance on CaV1.2, we examined ICa, finding similar current density in both groups. However, super-resolution imaging revealed a ∼54% reduction in t-tubular CaV1.2 expression and a ∼23% reduction in cluster area. Conserved ICa density despite reduced t-tubular CaV1.2 suggests that either the channels have relocated to the sarcolemmal crest, or their Po has increased. We examined crest CaV1.2 and observed no change with AngII, thus the Po of the remaining channels must increase to maintain ICa. Western blots revealed enhanced phosphorylation of CaV1.2, phosphorylation of RyR2, and an increased expression of the catalytic subunit of PKA, suggesting a compensatory sympathetic activation underlying conserved ICa. These findings support a model wherein chronic elevation of AngII disrupts phosphoinositide and CaV1.2 levels, elucidating the role of chronic AngII in disease progression.

Muscle calcium stress cleaves junctophilin1, unleashing a gene regulatory program predicted to correct glucose dysregulation.

Calcium ion movements between cellular stores and the cytosol govern muscle contraction, the most energy-consuming function in mammals, which confers skeletal myofibers a pivotal role in glycemia regulation. Chronic myoplasmic calcium elevation ("calcium stress"), found in malignant hyperthermia-susceptible (MHS) patients and multiple myopathies, has been suggested to underlie the progression from hyperglycemia to insulin resistance. What drives such progression remains elusive. We find that muscle cells derived from MHS patients have increased content of an activated fragment of GSK3β - a specialized kinase that inhibits glycogen synthase, impairing glucose utilization and delineating a path to hyperglycemia. We also find decreased content of junctophilin1, an essential structural protein that colocalizes in the couplon with the voltage-sensing CaV1.1, the calcium channel RyR1 and calpain1, accompanied by an increase in a 44 kDa junctophilin1 fragment (JPh44) that moves into nuclei. We trace these changes to activated proteolysis by calpain1, secondary to increased myoplasmic calcium. We demonstrate that a JPh44-like construct induces transcriptional changes predictive of increased glucose utilization in myoblasts, including less transcription and translation of GSK3β and decreased transcription of proteins that reduce utilization of glucose. These effects reveal a stress-adaptive response, mediated by the novel regulator of transcription JPh44.

Upacicalcet, a positive allosteric modulator of the calcium-sensing receptor, prevents vascular calcification and bone disorder in a rat adenine-induced secondary hyperparathyroidism model.

Secondary hyperparathyroidism (SHPT) is a major comorbidity of chronic kidney disease (CKD). Chronic elevation of PTH levels is associated with cortical bone deterioration and increase in the risk of fractures in CKD patients. Here, we evaluated the effect of repeated administration of upacicalcet, a novel positive allosteric modulator of the calcium-sensing receptor, in a rat model of adenine-induced renal failure, by determining serum levels of intact PTH (iPTH), calcium, phosphorus, creatinine, and urea nitrogen. Furthermore, parathyroid hyperplasia (parathyroid gland weight and Ki-67-positive cell density), ectopic calcification (calcium content in the thoracic aorta, kidney and heart and positive von Kossa staining in the thoracic aorta), and bone morphometry parameters (cortical porosity and fibrosis volume) were evaluated. Rats treated with either 0.2mg/kg or 1mg/kg upacicalcet exhibited significantly lower serum iPTH levels than CKD-control rats, as early as 7days after the first dose. Repeated administration of upacicalcet reduced serum iPTH levels and inhibited parathyroid hyperplasia in rats with adenine-induced severe renal failure. Moreover, it suppressed ectopic calcification and cortical pore formation. In contrast, serum calcium and phosphorus levels were not significantly affected, suggesting a low risk of hypocalcemia, which often occurs with SHPT treatment. In conclusion, repeated administration of upacicalcet decreased serum iPTH levels and suppressed parathyroid hyperplasia in the adenine-induced CKD rat model of SHPT. Furthermore, ectopic calcification and cortical pore formation were suppressed without significant changes in blood mineral parameters. Upacicalcet safely inhibited the progression of SHPT in an adenine-induced CKD rat model.

A meta-analysis investigating the relationship between inflammation in autoimmune disease, elevated CRP, and the risk of dementia.

Alzheimer's Disease (AD) represents the most common type of dementia and is becoming a steadily increasing challenge for health systems globally. Inflammation is developing as the main focus of research into Alzheimer's disease and has been demonstrated to be a major driver of the pathologies associated with AD. This evidence introduces an interesting research question, whether chronic inflammation due to pathologies such as inflammatory bowel disease (IBD) and rheumatoid arthritis (RA) could lead to a higher risk of developing dementia. In both IBD and RA, increased levels of the inflammatory biomarker C-reactive protein (CRP) can be highlighted, the latter being directly implicated in neuroinflammation and AD. In this meta-analysis both the association between chronic inflammatory diseases and elevated levels of CRP during midlife were investigated to examine if they correlated with an augmented risk of dementia. Moreover, the association between increased CRP and modifications in the permeability of the Blood Brain Barrier (BBB) in the presence of CRP is explored. The results displayed that the odds ratio for IBD and dementia was 1.91 [1.15-3.15], for RA it was 1.90 [1.09-3.32] following sensitivity analysis and for CRP it was 1.62 [1.22-2.15]. These results demonstrate a higher risk of dementia in patients presenting chronic inflammation and that exists an independent association with high CRP in midlife. This paper builds on published research that suggest a critical role for CRP both in stroke and AD and provides an analysis on currently published research on multiple diseases (IBD and RA) in which CRP is raised as well as chronically elevated. CRP and the associated risk of dementia and further research indicated that the monomeric form of CRP can infiltrate the BBB/be released from damaged micro-vessels to access the brain. This meta-analysis provides first-time evidence that chronic elevation of CRP in autoimmune diseases is directly associated with an increased risk of later development of Alzheimer's disease. Therefore, greater priority should be provided to the effective control of inflammation in patients with chronic inflammatory or autoimmune conditions and further long-term assessment of circulating CRP might inform of an individual's relative risk of developing dementia.

Association Between Arterial Stiffness and Measures of Autonomic Dysfunction in People With Chronic Kidney Disease.

Autonomic nervous system (ANS) dysfunction and vascular stiffness increase cardiovascular risk in people with chronic kidney disease (CKD). Chronic elevations in sympathetic activity can lead to increased arterial stiffness; however, the relationship between these variables is unknown in CKD. To explore the association between measures of autonomic function and arterial stiffness in patients with moderate-to-severe CKD. This study was a prespecified secondary analysis of a randomized controlled trial. This included the following measures: 24-hour ambulatory blood pressure (BP), carotid-femoral and carotid-radial pulse wave velocity (PWV), and postexercise heart rate recovery (HRR). We used mixed effect linear regression models with Bayesian information criteria (BIC) to assess the contribution of ANS measurements. Forty-four patients were included in the analysis. Mean carotid-femoral and carotid-radial PWV were 7.12 m/s (95% CI 6.13, 8.12) and 8.51 m/s (7.90, 9.11), respectively. Mean systolic dipping, calculated as percentage change in mean systolic readings from day to night, was 10.0% (95% CI 7.79, 12.18). Systolic dipping was independently associated with carotid-radial PWV, MD -0.09 m/s (95% CI -0.15, -0.02) and had the lowest BIC. Systolic dipping was associated with carotid-radial PWV in people with moderate-to-severe CKD; however, there was no association with carotid-femoral PWV. Systolic dipping may be a feasible surrogate of ANS function, as the association with carotid-radial PWV was consistent with the minimal clinically important difference (MCID). Future studies are needed to define the relationship between ANS function, arterial stiffness, and CV events over time in people with CKD.