Journal of physiology and biochemistry最新文献

Exposure to hypobaric hypoxia (high altitude) diminishes systemic tissue oxygenation. Tissue hypoxia induces insulin resistance and a metabolic switch that reduces oxidative phosphorylation and glucose storage while enhancing glycolysis. Similarly to hypobaric hypoxia, insulin resistance develops in normal humans undergoing normobaric hypoxia and in patients with obstructive sleep apnea. Following acute exposure to high altitude, insulin resistance returns to baseline values upon returning to sea level or when compensatory mechanisms restore tissue oxygenation. However, insulin resistance persists in subjects unable to achieve sufficient oxygen delivery to tissues. Likewise, long-term residents at high altitude develop persistent insulin resistance when compensatory mechanisms do not attain adequate tissue oxygenation. Among these subjects, insulin resistance may cause clinical complications, such as hypertriglyceridemia, reduced HDL-c, visceral obesity, metabolic dysfunction-associated steatotic liver disease, essential hypertension, type 2 diabetes, subclinical vascular injury, cardiovascular disease, and kidney disease. Impaired tissue oxygenation allows the stabilization of hypoxia-inducible factor-1 (HIF-1), a transcription factor that modulates the transcriptional activity of a number of genes to coordinate the physiological responses to tissue hypoxia. Among them, HIF-1 downregulates PPARG, that codes peroxisome proliferator-activated receptor-gamma (PPAR-γ) and PPARGCA, that codes PPAR-γ coactivator-1α, in order to enable insulin resistance and the metabolic switch from oxidative phosphorylation toward glycolysis.

Long non-coding RNA rhabdomyosarcoma 2-associated transcript (RMST) has been found to exert effects on cardiovascular diseases. However, the research for probing its role in heart failure (HF) is limited. Our study intends to unravel the regulatory effects of RMST on HF via the microRNA (miR)-10b-5p/tumor necrosis factor receptor-associated factor 6 (TRAF6) axis. The mouse model of HF was induced by doxorubicin. The expression levels of RMST, miR-10b-5p and TRAF6 were detected. The virus carrying RMST, miR-10b-5p or TRAF6 vectors were injected into doxorubicin-induced HF mice to examine the cardiac function, inflammatory response, pathological changes and cell apoptosis in doxorubicin-induced HF mice. The target relationships among RMST, miR-10b-5p and TRAF6 were confirmed. RMST and TRAF6 were elevated and miR-10b-5p was reduced in doxorubicin-induced HF mice. RMST or TRAF6 silencing or miR-10b-5p overexpression could improve doxorubicin-induced cardiac dysfunction, and inflammatory response, and reduce cardiomyocyte apoptosis. Down-regulation of miR-10b-5p or overexpression of TRAF6 were both able to inverse the therapeutic effect of silencing RMST on doxorubicin-induced HF mice. RMST bound to miR-10b-5p that targeted TRAF6. RMST silencing could attenuate inflammatory response and cardiomyocyte apoptosis and upregulate cardiac function in mice with doxorubicin-induced HF by modulating the miR-10b-5p/TRAF6 axis. The study provides novel therapeutic targets for HF treatment.

In women the menstrual cycle influences mood and anxiety. Aim of this study was to preliminarily investigate whether different ovarian steroid hormone levels may modulate the psychophysiological responses elicited by test anxiety. Specifically, we compared the secretion of anxiety-induced salivary proteins of healthy women in the early follicular (Pre-Ov group) (low ovarian steroid hormones levels) and mid-luteal (Post-Ov group) (medium/high ovarian steroid hormones levels) phase of the menstrual cycle, during the simulation of an oral examination. Saliva samples were collected before and after a relaxation period and at two post-simulation times and analyzed by two-dimensional electrophoresis and western blot. Proteins corresponding to spots differentially expressed in the two groups across the session were identified through mass spectrometry and most of them corresponded to acute stress and/or oral mucosa immunity biomarkers. The task induced an increase in alpha-amylase, carbonic anhydrase and cystatin S, and a decrease in immunoglobulin light/J chains in both groups. Analogous changes in these proteins have previously been linked to psychological or physical stress. However, specific spots corresponding, for example, to cystatins and 14-3-3 protein, changed exclusively in the Pre-Ov group, while prolactin-inducible protein, polymeric immunoglobulin receptor, fragments of alpha-amylase and immunoglobulins only in the Post-Ov group, indicating a potential modulation of their secretion by ovarian steroid hormones. Overall, the results provide preliminary evidence that ovarian steroid hormones may be a driving factor for differences in physiological responses induced by test anxiety. The results are promising, but further validation in a larger sample is needed.

The high mortality rate of hepatocellular carcinoma (HCC) is partly due to advanced diagnosis, emphasizing the need for effective predictive tools in HCC treatment. The aim of this study is to propose a novel prognostic model for HCC based on adenosine metabolizing genes and explore the potential relationship between them. Regression analysis was performed to identify differentially expressed genes associated with adenosine metabolism in HCC patients using RNA sequencing data obtained from a public database. Adenosine metabolism-related risk score (AMrisk) was derived using the least absolute shrinkage and selection operator (LASSO) Cox regression and verified using another database. Changes in adenosine metabolism in HCC were analyzed using functional enrichment analysis and multiple immune scores. The gene expression levels in patient samples were validated using quantitative reverse transcription polymerase chain reaction. Thirty adenosine metabolism-related differentially expressed genes were identified in HCC, and six genes (ADA, P2RY4, P2RY6, RPIA, SLC6A3, and VEGFA) were used to calculate the AMrisk score; the higher the risk scores, the lower the overall survival. Moreover, immune infiltration activation and immune checkpoints were considerably higher in the high-risk group. Additional in vitro experiments validated the enhanced expression of these six genes in HCC. The established predictive model demonstrated that adenosine metabolism-related genes was significantly associated with prognosis in HCC patients.

Mutations in the CALM1-3 genes, which encode calmodulin (CaM), have been reported in clinical cases of long QT syndrome (LQTS). Specifically, the CaM mutant E141G (CaM_E141G) in the variant CALM1 gene has been identified as a causative factor in LQTS. This mutation disrupts the normal Ca²⁺-dependent inactivation (CDI) function of Ca_V1.2 channels. However, it is still unclear how CaM_E141G interferes with the regulatory role of wild-type (WT) CaM on Ca_V1.2 channels and leads to abnormal CDI. A CaM molecule contains two lobes with similar structure, the N-lobe and the C-lobe. In this study, a CaM-truncated C-lobe mutant E141G (C-lobe_E141G) was engineered to exclude the impact of the unmutated N-lobe. Our findings revealed that at low Ca²⁺ concentration ([Ca²⁺]), the binding of C-lobe_E141G to the preIQ, IQ and N-terminus (NT) of Ca_V1.2 channels has higher binding capacity (B_max: 0.17, 0.22, 0.13) compared with those of WT C-lobe (B_max: 0.04, 0.14, 0.11) in GST pull-down assay. With an increase in [Ca²⁺], the Ca²⁺-dependency for C-lobe_E141G binding to Ca_V1.2 channels was impaired. Moreover, C-lobe_E141G induced the relative channel activity to 240.58 ± 51.37% at resting [Ca²⁺], but it was unable to diminish the channel activity at high [Ca²⁺] even in the presence of WT N-lobe, which may be responsible for the abnormal CDI of Ca_V1.2 channels affected by the LQTS-related CaM mutation. Our research provides preliminary insights into the mechanism by which the CaM mutation interferes with Ca_V1.2 channels function through its C-lobe.

The increase in age-related comorbidities, such as cardiometabolic diseases, has become a global health priority. There is a growing need to find new parameters capable of improving the detection of cardiometabolic risk factors, and circulating endocannabinoids (eCBs) are a promising tool in this context. Here, we aimed to investigate the relationship between plasma levels of eCBs and their analogues with body composition and cardiometabolic risk factors in middle-aged adults. Seventy-two individuals (54% women; 53.6 ± 5.1 years old) were included in this study. Plasma levels of eCBs and analogues were determined using liquid chromatography-tandem mass spectrometry. Body composition was measured by dual-energy X-ray absorptiometry. Cardiometabolic risk factors (i.e., glucose and lipid profile, blood pressure, liver and renal parameters, and gonadal hormones) were also assessed. The plasma levels of 1- and 2-arachidonylglycerol (1-AG&2-AG) were positively correlated with adiposity (all r ≥ 0.23, P < 0.05). Interestingly, the plasma levels of 1-AG&2-AG, arachidonoylethanolamide, and palmitoyl-ethanolamide were positively correlated with the homeostatic model assessment index - Insulin Resistance (HOMA-IR) (all r ≥ 0.32, P < 0.01). Our results also showed that high levels of 1-AG&2-AG, arachidonoylethanolamide, linoleoyl ethanolamide, and palmitoleoyl ethanolamide were correlated with poorer liver (all r ≥ 0.27, P < 0.05), kidney (all r ≥ 0.24, P < 0.05), and gonadal function parameters (testosterone: all r > 0.26, P < 0.05, SHBG: 1-AG&2-AG r=-0.33, P < 0.01). The plasma levels of some eCBs and analogues are correlated with a worse cardiometabolic profile in middle-aged adults.

Exosomes are widely recognized for their roles in numerous biological processes and as intercellular communication mediators. Human cancerous and normal cells can both produce massive amounts of exosomes. They are extensively dispersed in tumor-modeling animals' pleural effusions, ascites, and plasma from people with cancer. Tumor cells interact with host cells by releasing exosomes, which allow them to interchange various biological components. Tumor growth, invasion, metastasis, and even tumorigenesis can all be facilitated by this delicate and complex system by modifying the nearby and remote surroundings. Due to the existence of significant levels of biomolecules like microRNA, exosomes can modulate the immune system's stimulation or repression, which in turn controls tumor growth. However, the role of microRNA in exosome-mediated communication between immunological and cancer cells is still poorly understood. This study aims to get the most recent information on the "yin and yang" of exosomal microRNA in the regulation of tumor immunity and immunotherapy, which will aid current cancer treatment and diagnostic techniques.

Acute kidney injury is a serious public health problem worldwide, being ischemia and reperfusion (I/R) the main lesion-aggravating factor that contributes to the evolution towards chronic kidney disease. Nonetheless, intervention approaches currently available are just considered palliative options. In order to offer an alternative treatment, it is important to understand key factors involved in the development of the disease including the rescue of the affected cells and/or the release of paracrine factors that are crucial for tissue repair. Bioactive lipids such as sphingosine 1-phosphate (S1P) have significant effects on the modulation of signaling pathways involved in tissue regeneration, such as cell survival, proliferation, differentiation, and migration. The main objective of this work was to explore the protective effect of S1P using human kidney proximal tubule cells submitted to a mimetic I/R lesion, via ATP depletion. We observed that the S1P pre-treatment increases cell survival by 50% and preserves the cell proliferation capacity of injured cells. We showed the presence of different bioactive lipids notably related to tissue repair but, more importantly, we noted that the pre-treatment with S1P attenuated the ischemia-induced effects in response to the injury, resulting in higher endogenous S1P production. All receptors but S1PR3 are present in these cells and the protective and proliferative effect of S1P/S1P receptors axis occur, at least in part, through the activation of the SAFE pathway. To our knowledge, this is the first time that S1PR4 and S1PR5 are referred in these cells and also the first indication of JAK2/STAT3 pathway involvement in S1P-mediated protection in an I/R renal model.

The gene inhibin subunit beta B (INHBB) encodes the inhibin βB subunit, which is involved in forming protein members of the transforming growth factor-β (TGF-β) superfamily. The TGF-β superfamily is extensively involved in cell proliferation, differentiation, adhesion, movement, metabolism, communication, and death. Activins and inhibins, which belong to the TGF-β superfamily, were first discovered in ovarian follicular fluid. They were initially described as regulators of pituitary follicle-stimulating hormone (FSH) secretion both in vivo and in vitro. Later studies found that INHBB is expressed not only in reproductive organs such as the ovary, uterus, and testis but also in numerous other organs, including the brain, spinal cord, liver, kidneys, and adrenal glands. This wide distribution implies its involvement in the normal physiological functions of various organs; however, the mechanisms underlying these functions have not yet been fully elucidated. Recent studies suggest that INHBB plays a significant, yet complex role in tumorigenesis. It appears to have dual effects, promoting tumor progression in some contexts while inhibiting it in others, although these roles are not yet fully understood. In this paper, we review the different expression patterns, functions, and mechanisms of INHBB in normal and tumor tissues to illustrate the research prospects of INHBB in tumor progression.

Spinal cord injury (SCI) represents a destructive pathological and neurological state. Methyltransferase-like 14 (Mettl14)-mediated m6A modification links to spinal cord injury (SCI), and we explored its mechanism. SCI mouse models were subjected to si-Mettl14 and si-negative control treatments and mouse behavior, pathological condition and apoptosis assessments. The oxygen/glucose deprivation (OGD)-induced spinal cord neuronal cell models were processed with si-Mettl14 and si-peroxisome proliferator-activated receptor γ (PPARγ) plasmids, and pcDNA3.1-YTHDF2 or synthetic dsDNA Poly(dA: dT), followed by viability and apoptosis evaluation by MTT and flow cytometry. Levels of Mettl14, PPARγ, and YTHDF2 mRNAs and proteins, AIM2 inflammasome activation-associated and pyroptosis marker proteins, PPARγ m6A methylation and pyroptosis-related inflammatory factors were determined by RT-qPCR, Western blot, Me-RIP and ELISA, with PPARγ mRNA stability and YTHDF2-PPARγ interaction assessed. Mettl14 and PPARγ m6A modification levels rose in SCI spinal cord tissues, while PPARγ levels dropped. Mettl14 knockdown dampened m6A modification, up-regulated PPARγ levels, weakened neuronal apoptosis, and ameliorated SCI in mice. OGD down-regulated PPARγ and accelerated OGD-induced neuronal apoptosis and pyroptosis via inducing Mettl14-mediated m6A modification. Mettl14 amplified PPARγ mRNA degradation and down-regulated PPARγ by mediating m6A methylation via the YTHDF2-dependent pathway. Mettl14 silencing-mediated PPARγ m6A methylation mitigated OGD-induced neuronal apoptosis and pyroptosis by inactivating AIM2 inflammasome. Mettl14 triggered activated AIM2 inflammasomes, promoted neuronal apoptosis and pyroptosis, and worsened SCI in SCI mice via mediating PPARγ m6A methylation. Mettl14 regulates AIM2 inflammasome activation, and redounds to spinal cord neuronal apoptosis and pyroptosis in SCI by mediating m6A methylation of PPARγ.