Efficacy of a cysteine protease inhibitor compared with enalapril in murine heart failure models.

Cysteine proteases calpains contribute to heart failure (HF), but it remains unknown whether their inhibition provides any benefit compared to standard pharmacological treatment for HF. Here, we characterize the pharmacological properties of NPO-2270 (NPO) as a potent inhibitor of cysteine proteases. Then, we describe that acute administration of NPO in rodent models of transient ischemia at the time of reperfusion reduces myocardial infarction, while its chronic oral administration attenuates adverse remodeling and cardiac dysfunction induced by ischemic and non-ischemic pathological stimuli more effectively than enalapril when given at the same dose. Finally, we provide evidence showing that the effects of NPO correlate with calpain inhibition and the preservation of the T-tubule morphology, due at least in part to reduced cleavage of the calpain substrate junctophilin-2. Together, our data highlight the potential of cysteine protease inhibition with NPO as a therapeutic strategy for the treatment of heart failure.

Ambient Air Pollution and Hospitalizations for Schizophrenia in China.

Importance: Schizophrenia episodes may be triggered by short-term environmental stimuli. Short-term increases in ambient air pollution levels may elevate the risk of schizophrenia episodes, yet few epidemiologic studies have examined this association. Objective: To investigate whether short-term increases in air pollution levels are associated with an additional risk of schizophrenia episodes, independent of absolute air pollution concentrations, and whether sustained increases in air pollution levels for several days are associated with more pronounced risks of schizophrenia episodes. Design, Setting, and Participants: This nationwide, population-based, time-stratified case-crossover study was performed based on hospitalization records for schizophrenia across 295 administrative divisions of prefecture-level or above cities in China. Records were extracted from 2 major health insurance systems from January 1, 2013, to December 31, 2017. Thirty-six cities with a small number of schizophrenia hospitalizations (n < 50) were excluded. Data analysis for this study was performed from January to March 2024. Exposure: Daily absolute concentrations of fine particulate matter (PM2.5), inhalable particulate matter (PM10), nitrogen dioxide, sulfur dioxide, ozone, and carbon monoxide were collected. Air pollution increases between neighboring days (APINs) were generated as the differences in absolute air pollution concentrations on the current day minus that on the previous day. Sustained increases (APIN ≥5 µg/m3 for PM2.5 and PM10, APIN ≥1 µg/m3 for nitrogen dioxide and sulfur dioxide, and APIN ≥0.05 mg/m3 for carbon monoxide) lasting for 1 or more to 4 or more days were defined for different air pollutants. Main Outcome and Measure: Patients with schizophrenia episodes were identified by principal discharge diagnoses of schizophrenia. A conditional logistic regression model was used to capture the associations of absolute concentrations, APINs, and sustained increase events for different air pollutants with risks of schizophrenia hospitalizations. Results: The study included 817 296 hospitalization records for schizophrenia across 259 Chinese cities (30.6% aged 0-39 years, 56.4% aged 40-64 years, and 13.0% aged ≥65 years; 55.04% male). After adjusting for the absolute concentrations of respective air pollutants, per-IQR increases in 6-day moving average (lag0-5) APINs of PM2.5, PM10, nitrogen dioxide, sulfur dioxide, and carbon monoxide were associated with increases of 2.37% (95% CI, 0.88%-3.88%), 2.95% (95% CI, 1.46%-4.47%), 4.61% (95% CI, 2.93%-6.32%), 2.16% (95% CI, 0.59%-3.76%), and 2.02% (95% CI, 0.39%-3.68%) in schizophrenia hospitalizations, respectively. Greater risks of schizophrenia hospitalizations were associated with sustained increases in air pollutants lasting for longer durations up to 4 or more days. Conclusions and Relevance: This case-crossover study of the association between ambient air pollution increases and schizophrenia hospitalizations provides novel evidence that short-term increases in ambient air pollution levels were positively associated with an elevated risk of schizophrenia episodes. Future schizophrenia prevention practices should pay additional attention to APINs, especially sustained increases in air pollution levels for longer durations, besides the absolute air pollution concentrations.

IRS2 Signaling Protects Against Stress-Induced Arrhythmia by Maintaining Ca2+ Homeostasis.

BACKGROUND: The docking protein IRS2 (insulin receptor substrate protein-2) is an important mediator of insulin signaling and may also regulate other signaling pathways. Murine hearts with cardiomyocyte-restricted deletion of IRS2 (cIRS2-KO) are more susceptible to pressure overload-induced cardiac dysfunction, implying a critical protective role of IRS2 in cardiac adaptation to stress through mechanisms that are not fully understood. There is limited evidence regarding the function of IRS2 beyond metabolic homeostasis regulation, particularly in the context of cardiac disease. METHODS: A retrospective analysis of an electronic medical record database was conducted to identify patients with IRS2 variants and assess their risk of cardiac arrhythmias. Arrhythmia susceptibility was examined in cIRS2-KO mice. The underlying mechanisms were investigated using confocal calcium imaging of ex vivo whole hearts and isolated cardiomyocytes to assess calcium handling, Western blotting to analyze the involved signaling pathways, and pharmacological and genetic interventions to rescue arrhythmias in cIRS2-KO mice. RESULTS: The retrospective analysis identified patients with IRS2 variants of uncertain significance with a potential association to an increased risk of cardiac arrhythmias compared with matched controls. cIRS2-KO hearts were found to be prone to catecholamine-sensitive ventricular tachycardia and reperfusion ventricular tachycardia. Confocal calcium imaging of ex vivo whole hearts and single isolated cardiomyocytes from cIRS2-KO hearts revealed decreased Ca²+ transient amplitudes, increased spontaneous Ca²+ sparks, and reduced sarcoplasmic reticulum Ca²+ content during sympathetic stress, indicating sarcoplasmic reticulum dysfunction. We identified that overactivation of the AKT1/NOS3 (nitric oxide synthase 3)/CaMKII (Ca2+/calmodulin-dependent protein kinase II)/RyR2 (type 2 ryanodine receptor) signaling pathway led to calcium mishandling and catecholamine-sensitive ventricular tachycardia in cIRS2-KO hearts. Pharmacological AKT inhibition or genetic stabilization of RyR2 rescued catecholamine-sensitive ventricular tachycardia in cIRS2-KO mice. CONCLUSIONS: Cardiac IRS2 inhibits sympathetic stress-induced AKT/NOS3/CaMKII/RyR2 overactivation and calcium-dependent arrhythmogenesis. This novel IRS2 signaling axis, essential for maintaining cardiac calcium homeostasis under stress, presents a promising target for developing new antiarrhythmic therapies.

Preventing Site-Specific Calpain Proteolysis of Junctophilin-2 Protects Against Stress-Induced Excitation-Contraction Uncoupling and Heart Failure Development.

BACKGROUND: Excitation-contraction (E-C) coupling processes become disrupted in heart failure (HF), resulting in abnormal Ca2+ homeostasis, maladaptive structural and transcriptional remodeling, and cardiac dysfunction. Junctophilin-2 (JP2) is an essential component of the E-C coupling apparatus but becomes site-specifically cleaved by calpain, leading to disruption of E-C coupling, plasmalemmal transverse tubule degeneration, abnormal Ca2+ homeostasis, and HF. However, it is not clear whether preventing site-specific calpain cleavage of JP2 is sufficient to protect the heart against stress-induced pathological cardiac remodeling in vivo. METHODS: Calpain-resistant JP2 knock-in mice (JP2CR) were generated by deleting the primary JP2 calpain cleavage site. Stress-dependent JP2 cleavage was assessed through in vitro cleavage assays and in isolated cardiomyocytes treated with 1 µmol/L isoproterenol by immunofluorescence. Cardiac outcomes were assessed in wild-type and JP2CR mice 5 weeks after transverse aortic constriction compared with sham surgery using echocardiography, histology, and RNA-sequencing methods. E-C coupling efficiency was measured by in situ confocal microscopy. E-C coupling proteins were evaluated by calpain assays and Western blotting. The effectiveness of adeno-associated virus gene therapy with JP2CR, JP2, or green fluorescent protein to slow HF progression was evaluated in mice with established cardiac dysfunction. RESULTS: JP2 proteolysis by calpain and in response to transverse aortic constriction and isoproterenol was blocked in JP2CR cardiomyocytes. JP2CR hearts are more resistant to pressure-overload stress, having significantly improved Ca2+ homeostasis and transverse tubule organization with significantly attenuated cardiac dysfunction, hypertrophy, lung edema, fibrosis, and gene expression changes relative to wild-type mice. JP2CR preserves the integrity of calpain-sensitive E-C coupling-related proteins, including ryanodine receptor 2, CaV1.2, and sarcoplasmic reticulum calcium ATPase 2a, by attenuating transverse aortic constriction-induced increases in calpain activity. Furthermore, JP2CR gene therapy after the onset of cardiac dysfunction was found to be effective at slowing the progression of HF and superior to wild-type JP2. CONCLUSIONS: The data presented here demonstrate that preserving JP2-dependent E-C coupling by prohibiting the site-specific calpain cleavage of JP2 offers multifaceted beneficial effects, conferring cardiac protection against stress-induced proteolysis, hypertrophy, and HF. Our data also indicate that specifically targeting the primary calpain cleavage site of JP2 by gene therapy approaches holds great therapeutic potential as a novel precision medicine for treating HF.

Variation in worldwide incidence of Guillain-Barré syndrome: a population-based study in urban China and existing global evidence.

Background and objectives: Geographical variation existed in the incidences of Guillain-Barré syndrome (GBS), but no national population-based study has evaluated the incidences of GBS in China. This study aimed to estimate the incidence of GBS in urban China and evaluate the worldwide variation in the incidence of GBS. Methods: Firstly, we did a population-based study to calculate the incidence of GBS in urban China based on the National Urban Medical Insurance database from 2013 to 2017. To identify GBS cases, natural language processing was used first for handling the lengthy and unstructured diagnostic information and then checked by prestigious neurologists. Secondly, a systematic review and meta-analysis were performed to analyze the incidence of GBS worldwide. Up to July 4, 2022, Medline, Embase, and Web of Science were retrieved to identify the population-based studies regarding the incidence of GBS. The basic information and the statistics regarding incidence were extracted. Quality assessment considered sample representativeness, condition assessment, and statistical methods. Results: A total of 1.44 billion person-years in insurance data was covered, with 3,534 GBS cases identified. The annual incidences of GBS in urban China between 2013 and 2017 ranged from 0.41 (95% CI: 0.27 to 0.58) to 0.58 (95% CI: 0.38 to 0.82) per 100,000 person-years. The incidence was the highest in Northwest China and the lowest in Northeast China. The meta-analysis included 122 articles. The quality assessment showed that the quality scores of 43.3% of studies were ≥ 0.75 (the total score is 1). The global incidence of GBS was 1.12 (95% CI: 0.98 to 1.27) per 100,000 person-years. The incidences in West Europe, South Asia, and North Europe were higher, while the incidences in Australia and New Zealand, Southeast Asia, and North Africa were lower. The incidence of enteric infections was positively associated with the incidence of GBS (coefficient=0.0000185, P=0.007). The incidence in Europe, Australia, and America rose significantly from 1960 to 2020 (coefficient=0.01, t=2.52, P=0.015). Discussion: There is a clear regional variation of the GBS incidence at both national and global levels. Careful control of enteric infections should be conducted to reduce the disease burden.

Global prevalence of diet low in calcium and the disease burden: results from the Global Burden of Disease Study 2019.

BACKGROUND: Due to the essential role of calcium in vital biological functions, diet low in calcium (DLC) is associated with various diseases. However, there is a lack of study about the current prevalence and health burden due to DLC using reliable data sources. METHODS: We used data from the Global Burden of Disease study 2019 (GBD 2019) to estimate the prevalence and health burden of DLC in 204 countries from 1990 to 2019, by age, sex, and sociodemographic index (SDI). The estimates were produced in DisMod-MR 2.1, a Bayesian meta-regression tool. Summary exposure value (SEV) was used to show the prevalence of DLC, while diseases adjusted life year (DALY) was used to represent the disease burden. The disease burden was estimated for DLC-induced colorectal cancer. Spearman Rank Order correlation was used for correlation analysis, and estimated annual percentage (EAPC) was used to reflect the temporal trends. RESULTS: From 1990 to 2019, the global prevalence of DLC decreased (EAPC of SEV, -0.47; 95% CI, -0.5 to -0.43), but have increased in Oceania region and in many countries, such as United Arab Emirates, New Zealand, Japan, and France. The global DALYs associated with low in calcium were estimated to be 3.14 million (95% uncertainty interval (UI), 2.25-4.26 million) in 2019, with an age standardized rate of 38.2 (95% UI, 27.2-51.8) per 100,000. Unlike the prevalence, the global age standardized DALY rates has remained unchanged (EAPC, -0.03; 95% CI, -0.12 to 0.07), but has increased in over 80 of the 204 countries, located mainly in Asia, Africa, and South America. In all years and regions, the age standardized SEV and DALY rates were higher in male people than that in female people. The prevalence (rho = -0.823; P < 0.001) and disease burden (rho = -0.433; P < 0.001) associated with diet in low calcium were strongly correlated to SDI. The prevalence decreased with age, but the DALY rates increased with age and peaked at about 90 years. The prevalence of DLC has decreased worldwide and in most countries, but the disease burden of DLC induced colorectal cancer has increased in over 40% of countries worldwide. CONCLUSION: Countries with low sociodemographic level and male people are more likely to experience the risk of DLC and related disease burden. Related measures in improve dietary calcium intake are in need to address diet in low calcium related health problems.

Incidence and prevalence of systemic lupus erythematosus in urban China, 2013-2017: A nationwide population-based study.

Systemic lupus erythematosus (SLE) is becoming a growing public health concern due to increasing disease and economic burdens. Epidemiological information about SLE, especially its incidence rate, is limited in developing countries. In the current study, we sought to investigate the incidence, prevalence, and economic burdens of SLE in urban China. We conducted a nationwide population-based cohort study using databases from Urban Employee Basic Medical Insurance and Urban Resident Basic Medical Insurance between 2013 and 2017, covering approximately 300 million residents in 23 provincial regions in China. Incidence rate and prevalence were standardized by age and gender to China's 2010 national census data. Additionally, we calculated the average annual costs and hospital visit rates. A total of 132,258 SLE patients were identified during the study period, with a mean age of 43.03 years (standard deviation: 15.29 years). Of these patients, 81.33% were women. In 2017, the standardized incidence rate of SLE in China was 14.09 (95% confidence interval (CI), 11.95-16.41) per 100,000 person-years, with a higher incidence in women than in men (26.41 vs. 5.92 per 100,000 person-years). Standardized prevalence in 2017 was 47.61 (41.77-53.83), 94.16 (80.67-108.69), and 17.86 (13.84-22.38) per 100,000 people in the overall, female, and male populations, respectively. The average annual rates of increase in prevalence were 21.50%, 19.72%, and 25.67% from 2013 to 2017 in the overall, female, and male populations, respectively. The age-specific incidence rates peaked at 30-49 years old in women and 40-59 years old in men. SLE incident and prevalent cases were most common in North-West China and less common in southern and eastern China. Distinct variations in incidence rates across different regions are also consistent with the varying levels of ultraviolet radiation exposure in China. Additionally, the average estimated annual per-capita cost was 1599.34 US dollars in SLE patients, with the highest costs observed in adolescent and young adult patients among different age groups. The SLE population in China is rapidly expanding, and younger at onset, especially in women, which has placed significant burdens on China's healthcare system.

Learning Implicit Fields for Point Cloud Filtering.

Since point clouds acquired by scanners inevitably contain noise, recovering a clean version from a noisy point cloud is essential for further 3D geometry processing applications. Several data-driven approaches have been recently introduced to overcome the drawbacks of traditional filtering algorithms, such as less robust preservation of sharp features and tedious tuning for multiple parameters. Most of these methods achieve filtering by directly regressing the position/displacement of each point, which may blur detailed features and is prone to uneven distribution. In this paper, we propose a novel data-driven method that explores the implicit fields. Our assumption is that the given noisy points implicitly define a surface, and we attempt to obtain a point's movement direction and distance separately based on the predicted signed distance fields (SDFs). Taking a noisy point cloud as input, we first obtain a consistent alignment by incorporating the global points into local patches. We then feed them into an encoder-decoder structure and predict a 7D vector consisting of SDFs. Subsequently, the distance can be obtained directly from the first element in the vector, and the movement direction can be obtained by computing the gradient descent from the last six elements (i.e., six surrounding SDFs). We finally obtain the filtered results by moving each point with its predicted distance along its movement direction. Our method can produce feature-preserving results without requiring explicit normals. Experiments demonstrate that our method visually outperforms state-of-the-art methods and generally produces better quantitative results than position-based methods (both learning and non-learning).

A real-world observational study on the effect of Qingre Lishi decoction on glycemic profile using continuous glucose monitoring in obese type 2 diabetes adults.

Objective: To observe the clinical efficacy and safety of the Qingre Lishi decoction in treating of newly diagnosed overweight and obese patients with type 2 diabetes mellitus (T2DM) from an evidence-based medical perspective. Methods: 70 cases of overweight and obese patients with newly diagnosed T2DM treated in the outpatient clinic of the Department of Endocrinology of the Affiliated Hospital of Liaoning University of Traditional Chinese Medicine from December 2021 to November 2022 were selected, of which 35 cases were in the observation group and 35 cases were in the control group. The observation group was treated with the Qingre Lishi decoction add lifestyle intervention, and the control group was treated with lifestyle intervention only. We compared and analyzed the fasting blood glucose (FPG), 2-hour postprandial glucose (2hPG), the occurrence of adverse reactions, and the related indexes provided by wearing the CGM device during the observation period of the patients in the two groups. Results: 53 participants completed the clinical trial. In relation of glycemic control, a decreasing trend has shown in both groups, with the decreases in FPG, 2hPG, eHbA1c, and MG in the observation group being higher than those in the control group (P<0.05). In regard to blood glucose attainment, at the 28d, the attainment rate of patients in the observation group with TIR>80% was 87.10%, and the magnitude of changes in the rise of TIR and the fall of TAR was significantly better than that in the control group (P<0.01). In terms of blood glucose fluctuation, CV and SD of the patients in the observation group decreased compared with the 0d; the magnitude of daytime blood glucose fluctuation was significantly alleviated compared with that of the control group. The degree of decrease in LAGE, MAGE, and MODD was significantly lower than that of the control group (P<0.01). Conclusion: The Qingre Lishi decoction can effectively improve the hyperglycemic condition of overweight and obese patients with newly diagnosed T2DM. It can reduce blood glucose, alleviate blood glucose fluctuations, reduce the incidence of hypoglycemia, and improve patients' adherence and self-confidence in controlling blood glucose. Clinical Trial Registration: https://itmctr.ccebtcm.org.cn/, identifier ITMCTR2024000006.

Epigenetic silencing of miR-125a-3p promotes the progress of human cholangiocarcinoma via increasing CAC1 expression.

We aimed to investigate the dysregulation of the microRNAs(miRNAs) in cholangiocarcinoma (CCA), including its impact on the homeostasis of the transcriptome and cellular behavior. MiRNAs serve as potent epigenetic regulators of transcriptional output, targeting various signaling pathways. This study aimed to investigate the expression level, epigenetic mechanism and function of miR-125a-3 in CCA. The study data showed that the expression level of miR125a-3p was decreased in CCA tissue samples and cell lines, and it was closely related to lymph node metastasis, tissue differentiation and TNM stage. The data demonstrate a strong association between decreased miR-125a-3p expression and poorer prognosis in cholangiocarcinoma patients. miR-125a-3p acts as a tumor suppressor by inhibiting the viability, migration and invasion of CCA cells. There are CpG islands in the promoter region of miR-125a-3p gene, and the methylation of the promoter region of miR-125a-3p gene leads to the transcriptional repression of miR-125a-3p. In addition, miR125a-3p can target and regulate CAC1 mRNA and protein expression in the downstream mechanism, and the high expression of CAC1 can promote the proliferation, migration and invasion of cholangiocarcinoma cells. These data demonstrate that miR-125a-3p promoter methylation leads to silencing of its expression. Mechanically, miR-125a-3p acts as a tumor suppressor and participates in the occurrence and development of CCA through targeting CAC1 gene expression. Therefore, miR-125a-3p may serve as a new target for the diagnosis, prognostic assessment or molecular therapy of CCA.

Glutamine Protects against Mouse Abdominal Aortic Aneurysm through Modulating VSMC Apoptosis and M1 Macrophage Activation.

Glutamine (Gln), known as the most abundant free amino acid, is widely spread in human body. In this study, we demonstrated the protective effects of glutamine against mouse abdominal aortic aneurysm (AAA) induced by both angiotensin II (AngII) and calcium phosphate (Ca3(PO4)2) in vivo, which was characterized with lower incidence of mouse AAA. Moreover, histomorphological staining visually presented more intact elastic fiber and less collagen deposition in abdominal aortas of mice treated by glutamine. Further, we found glutamine inhibited the excessive production of reactive oxide species (ROS), activity of matrix metalloproteinase (MMP), M1 macrophage activation, and apoptosis of vascular smooth muscle cells (VSMCs) in suprarenal abdominal aortas of mice, what's more, the high expressions of MMP-2 protein, MMP-9 protein, pro-apoptotic proteins, and IL-6 as well as TNF-α in protein and mRNA levels in cells treated by AngII were down-regulated by glutamine. Collectively, these results revealed that glutamine protected against mouse AAA through inhibiting apoptosis of VSMCs, M1 macrophage activation, oxidative stress, and extracellular matrix degradation.

A study on the mechanism of Beclin-1 m6A modification mediated by catalpol in protection against neuronal injury and autophagy following cerebral ischemia.

OBJECTIVE: Catalpol (CAT) has various pharmacological activities and plays a protective role in cerebral ischemia. It has been reported that CAT played a protective role in cerebral ischemia by upregulaing NRF1 expression. Bioinformatics analysis reveals that NRF1 can be used as a transcription factor to bind to the histone acetyltransferase KAT2A. However, the role of KAT2A in cerebral ischemia remains to be studied. Therefore, we aimed to investigate the role of CAT in cerebral ischemia and its related mechanism. METHODS: In vitro, a cell model of oxygen and glucose deprivation/reperfusion (OGD/R) was constructed, followed by evaluation of neuronal injury and the expression of METTL3, Beclin-1, NRF1, and KAT2A. In vivo, a MCAO rat model was prepared by means of focal cerebral ischemia, followed by assessment of neurological deficit and brain injury in MCAO rats. Neuronal autophagy was evaluated by observation of autophagosomes in neurons or brain tissues by TEM and detection of the expression of LC3 and p62. RESULTS: In vivo, CAT reduced the neurological function deficit and infarct volume, inhibited neuronal apoptosis in the cerebral cortex, and significantly improved neuronal injury and excessive autophagy in MCAO rats. In vitro, CAT restored OGD/R-inhibited cell viability, inhibited cell apoptosis, LDH release, and neuronal autophagy. Mechanistically, CAT upregulated NRF1, NRF1 activated METTL3 via KAT2A transcription, and METTL3 inhibited Beclin-1 via m6A modification. CONCLUSION: CAT activated the NRF1/KAT2A/METTL3 axis and downregulated Beclin-1 expression, thus relieving neuronal injury and excessive autophagy after cerebral ischemia.

Management of hypertrophic cardiomyopathy.

Hypertrophic cardiomyopathy is an important cause of heart failure and arrhythmias, including sudden death, with a major impact on the healthcare system. Genetic causes and different phenotypes are now increasingly being identified for this condition. In addition, specific medications, such as myosin inhibitors, have been recently shown as potentially able to modify its symptoms, hemodynamic abnormalities and clinical course. Our article aims to provide a comprehensive outline of the epidemiology, diagnosis and treatment of hypertrophic cardiomyopathy in the current era.

The Sympatric Coexistence Mechanism: A Case Study of Two Penahia Species in the Beibu Gulf, South China Sea.

The study of trophic relationships among closely related species plays an important role in deepening our understanding of the resource utilization characteristics, differentiation patterns, and population dynamics of co-occurring species in the same habitat. This research uses two congeneric fish species, Pennahia pawak and Pennahia anea, as examples. Based on a stomach content analysis and a carbon-nitrogen stable isotope analysis, a comparative analysis of their feeding habits and trophic niches is conducted. Additionally, a spatial niche analysis is employed to explore the coexistence and competitive mechanisms between these two closely related fish species. The results show that specialized feeding habits mitigate intraspecific competition as the population densities increase. The carbon and nitrogen stable isotope analysis reveals variations in the feeding habits and trophic levels with body length, indicating adaptive shifts in prey selection. Despite similar food resources, niche differentiation arises due to differences in dominant prey, facilitating coexistence. Differences in spatial niche further contribute to niche separation and coexistence. In resource-limited environments, species such as Pennahia utilize trophic and spatial niche differentiation to collectively exploit resources and achieve coexistence, with implications for fishery management favoring Pennahia resource occupancy capabilities.

Calpain inhibition protects against atrial fibrillation by mitigating diabetes-associated atrial fibrosis and calcium handling dysfunction in type 2 diabetes mice.

BACKGROUND: Diabetes mellitus (DM) is a major risk factor for atrial structural remodeling and atrial fibrillation (AF). Calpain activity is hypothesized to promote atrial remodeling and AF. OBJECTIVE: The purpose of this study was to investigate the role of calpain in diabetes-associated AF, fibrosis, and calcium handling dysfunction. METHODS: DM-associated AF was induced in wild-type (WT) mice and in mice overexpressing the calpain inhibitor calpastatin (CAST-OE) using high-fat diet feeding followed by low-dose streptozotocin injection (75 mg/kg). DM and AF outcomes were assessed by measuring blood glucose levels, fibrosis, and AF susceptibility during transesophageal atrial pacing. Intracellular Ca2+ transients, spontaneous Ca2+ release events, and intracellular T-tubule membranes were measured by in situ confocal microscopy. RESULTS: WT mice with DM had significant hyperglycemia, atrial fibrosis, and AF susceptibility with increased atrial myocyte calpain activity and Ca2+ handling dysfunction relative to control treated animals. CAST-OE mice with DM had a similar level of hyperglycemia as diabetic WT littermates but lacked significant atrial fibrosis and AF susceptibility. DM-induced atrial calpain activity and downregulation of the calpain substrate junctophilin-2 were prevented by CAST-OE. Atrial myocytes of diabetic CAST-OE mice exhibited improved T-tubule membrane organization, Ca2+ handling, and reduced spontaneous Ca2+ release events compared to littermate controls. CONCLUSION: This study confirmed that DM promotes calpain activation, atrial fibrosis, and AF in mice. CAST-OE effectively inhibits DM-induced calpain activation and reduces atrial remodeling and AF incidence through improved intracellular Ca2+ homeostasis. Our results support calpain inhibition as a potential therapy for preventing and treating AF in DM patients.

[Effect of Zuogui Jiangtang Jieyu Formula on intestinal flora and short-chain fatty acid metabolism in rats with diabetes mellitus complicated with depression].

This study aimed to investigate the regulatory effects of Zuogui Jiangtang Jieyu Formula(ZJJ) on the intestinal flora, short chain fatty acids(SCFAs), and neuroinflammation in rats with diabetes mellitus complicated depression(DD). The DD model was established in rats and model rats were randomly divided into a model group, a positive drug(metformin + fluoxetine) group, a ZJJ low-dose group, and a ZJJ high-dose group, with eight rats in each group. Another eight rats were assigned to the blank group. Subsequently, depressive-like behavior test was conducted on the rats, and cerebrospinal fluid samples were collected to measure pro-inflammatory cytokines [interleukin-1ß(IL-1ß), interleukin-6(IL-6), and tumor necrosis factor-α(TNF-α)]. Blood serum samples were collected to measure proteins related to the hypothalamic-pituitary-adrenal axis(HPA axis), including corticotropin-releasing hormone(CRH), adrenocorticotropic hormone(ACTH), and cortisol(CORT), as well as glucose metabolism. Gut contents were collected from each group for 16S rRNA sequencing analysis of intestinal flora and SCFAs sequencing. The results indicated that ZJJ not only improved glucose metabolism in DD rats(P<0.01) but also alleviated depressive-like behavior(P<0.05) and HPA axis hyperactivity(P<0.05 or P<0.01). Besides, it also improved the neuroinflammatory response in the brain, as evidenced by a significant reduction in pro-inflammatory cytokines in cerebrospinal fluid(P<0.05 or P<0.01). Additionally, ZJJ improved the intestinal flora, causing the intestinal flora in DD rats to resemble that of the blank group, characterized by an increased Firmicutes abundance. ZJJ significantly increased the levels of SCFAs(acetic acid, butyric acid, valeric acid, and isovaleric acid)(P<0.01). Therefore, it is deduced that ZJJ can effectively ameliorate intestinal flora dysbiosis, regulate SCFAs, and thereby improve both glucose metabolism disturbances and depressive-like behavior in DD.

A novel Kit mutant rat enables hematopoietic stem cell engraftment without irradiation.

Hematopoietic stem cell (HSC) transplantation is extensively studied in mouse models, but their limited scale presents challenges for effective engraftment and comprehensive evaluations. Rats, owing to their larger size and anatomical similarity to humans, offer a promising alternative. In this study, we establish a rat model with the KitV834M mutation, mirroring KitW41 mice often used in KIT signaling and HSC research. KitV834M rats are viable and fertile, displaying anemia and mast cell depletion similar to KitW41 mice. The colony-forming unit assay revealed that the KitV834M mutation leads to reduced proliferation and loss of or decreased pluripotency of hematopoietic stem and progenitor cells (HSPCs), resulting in diminished competitive repopulating capacity of KitV834M HSPCs in competitive transplantation assays. Importantly, KitV834M rats support donor rat-HSC engraftment without irradiation. Leveraging the larger scale of this rat model enhances our understanding of HSC biology and transplantation dynamics, potentially advancing our knowledge in this field.

Cardiac monoamine oxidase-A inhibition protects against catecholamine-induced ventricular arrhythmias via enhanced diastolic calcium control.

AIMS: A mechanistic link between depression and risk of arrhythmias could be attributed to altered catecholamine metabolism in the heart. Monoamine oxidase-A (MAO-A), a key enzyme involved in catecholamine metabolism and longstanding antidepressant target, is highly expressed in the myocardium. The present study aimed to elucidate the functional significance and underlying mechanisms of cardiac MAO-A in arrhythmogenesis. METHODS AND RESULTS: Analysis of the TriNetX database revealed that depressed patients treated with MAO inhibitors had a lower risk of arrhythmias compared with those treated with selective serotonin reuptake inhibitors. This effect was phenocopied in mice with cardiomyocyte-specific MAO-A deficiency (cMAO-Adef), which showed a significant reduction in both incidence and duration of catecholamine stress-induced ventricular tachycardia compared with wild-type mice. Additionally, cMAO-Adef cardiomyocytes exhibited altered Ca2+ handling under catecholamine stimulation, with increased diastolic Ca2+ reuptake, reduced diastolic Ca2+ leak, and diminished systolic Ca2+ release. Mechanistically, cMAO-Adef hearts had reduced catecholamine levels under sympathetic stress, along with reduced levels of reactive oxygen species and protein carbonylation, leading to decreased oxidation of Type II PKA and CaMKII. These changes potentiated phospholamban (PLB) phosphorylation, thereby enhancing diastolic Ca2+ reuptake, while reducing ryanodine receptor 2 (RyR2) phosphorylation to decrease diastolic Ca2+ leak. Consequently, cMAO-Adef hearts exhibited lower diastolic Ca2+ levels and fewer arrhythmogenic Ca2+ waves during sympathetic overstimulation. CONCLUSION: Cardiac MAO-A inhibition exerts an anti-arrhythmic effect by enhancing diastolic Ca2+ handling under catecholamine stress.

Ptpn23 Controls Cardiac T-Tubule Patterning by Promoting the Assembly of Dystrophin-Glycoprotein Complex.

BACKGROUND: Cardiac transverse tubules (T-tubules) are anchored to sarcomeric Z-discs by costameres to establish a regular spaced pattern. One of the major components of costameres is the dystrophin-glycoprotein complex (DGC). Nevertheless, how the assembly of the DGC coordinates with the formation and maintenance of T-tubules under physiological and pathological conditions remains unclear. METHODS: Given the known role of Ptpn23 (protein tyrosine phosphatase, nonreceptor type 23) in regulating membrane deformation, its expression in patients with dilated cardiomyopathy was determined. Taking advantage of Cre/Loxp, CRISPR/Cas9, and adeno-associated virus 9 (AAV9)-mediated in vivo gene editing, we generated cardiomyocyte-specific Ptpn23 and Actn2 (α-actinin-2, a major component of Z-discs) knockout mice. We also perturbed the DGC by using dystrophin global knockout mice (DmdE4*). MM 4-64 and Di-8-ANEPPS staining, Cav3 immunofluorescence, and transmission electron microscopy were performed to determine T-tubule structure in isolated cells and intact hearts. In addition, the assembly of the DGC with Ptpn23 and dystrophin loss of function was determined by glycerol-gradient fractionation and SDS-PAGE analysis. RESULTS: The expression level of Ptpn23 was reduced in failing hearts from dilated cardiomyopathy patients and mice. Genetic deletion of Ptpn23 resulted in disorganized T-tubules with enlarged diameters and progressive dilated cardiomyopathy without affecting sarcomere organization. AAV9-mediated mosaic somatic mutagenesis further indicated a cell-autonomous role of Ptpn23 in regulating T-tubule formation. Genetic and biochemical analyses showed that Ptpn23 was essential for the integrity of costameres, which anchor the T-tubule membrane to Z-discs, through interactions with α-actinin and dystrophin. Deletion of α-actinin altered the subcellular localization of Ptpn23 and DGCs. In addition, genetic inactivation of dystrophin caused similar T-tubule defects to Ptpn23 loss-of-function without affecting Ptpn23 localization at Z-discs. Last, inducible Ptpn23 knockout at 1 month of age showed Ptpn23 is also required for the maintenance of T-tubules in adult cardiomyocytes. CONCLUSIONS: Ptpn23 is essential for cardiac T-tubule formation and maintenance along Z-discs. During postnatal heart development, Ptpn23 interacts with sarcomeric α-actinin and coordinates the assembly of the DGC at costameres to sculpt T-tubule spatial patterning and morphology.

Association between red blood cell distribution width-to-albumin ratio and prognosis in non-ischaemic heart failure.

AIMS: Red blood cell distribution width-to-albumin ratio (RAR), an innovate biomarker of inflammation, can independently predict adverse cardiovascular outcomes. However, the association between RAR and prognosis in patients with non-ischaemic heart failure (NIHF) remains unclear. METHODS AND RESULTS: A total of 2077 NIHF patients admitted to the Heart Failure Care Unit, Fuwai Hospital, were consecutively enrolled from December 2006 to October 2017 in this retrospective study. The primary endpoint was a composite outcome of all-cause mortality and heart transplantation. The correlation between RAR and the composite outcome was assessed by the Kaplan-Meier survival analysis and the Cox regression analysis. Incremental predictive values and the clinical performance of RAR for all-cause mortality or heart transplantation were also assessed based on a 12-variable traditional risk model. The median follow-up time in this study was 1433 (1341, 1525) days. As the gender no longer satisfied the Cox proportional risk assumption after 1150 days, we set 1095 days as the follow-up time for analysis. A total of 500 patients reached the composite outcome. Multivariable Cox regression showed that per log2 increase of RAR was significantly associated with a 132.9% [hazard ratio 2.329, 95% confidence interval (CI) 1.677-3.237, P < 0.001] increased risk of all-cause mortality or heart transplantation. Better model discrimination [concordance index: 0.766 (95% CI 0.754-0.778) vs. 0.758 (95% CI 0.746-0.770), P < 0.001], calibration (Akaike information criterion: 1487.3 vs. 1495.74; Bayesian information criterion: 1566.25 vs. 1569.43; Brier score: 1569.43 vs. 1569.43; likelihood ratio test P < 0.001), and reclassification (integrated discrimination improvement: 1.35%, 95% CI 0.63-2.07%, P < 0.001; net reclassification improvement: 13.73%, 95% CI 2.05-27.18%, P = 0.034) were improved after adding RAR to the traditional model (P < 0.001 for all). A higher overall net benefit was also obtained in the threshold risk probability of 20-55%. CONCLUSIONS: High level of RAR was an independent risk factor of poor outcome in NIHF.