Journal of physiology and biochemistry最新文献

Our aim was to study the metabolic effects of eight weeks of high-intensity interval training (HIIT) on the liver of rats with type 2 diabetes (T2D) using untargeted metabolomics. Twenty male Wistar rats, were divided into four groups (n = 5 per group): control (CTL), type 2 diabetes (DB), HIIT (EX), and type 2 diabetes + HIIT (DTX). A two months of a high-fat diet followed by a single dose of streptozotocin (35 mg/kg body weight) was used to induce T2D. Animals in the EX and DTX groups were trained for eight weeks (5 times per week, 4-10 running intervals at 80-100% of their maximum velocity). Metabolomic data were collected using proton nuclear magnetic resonance (¹H-NMR) to assess metabolic changes in the liver after training. Data were then pre-processed using ProMetab (MATLAB) for baseline correction, normalisation and binning. Fasting blood glucose (FBG) levels were analysed using a repeated-measures mixed ANOVA [i.e., time as the within-subject factor (Baseline - Month 0, Post-induction - Month 2, and Post-intervention - Month 4) and gruop (CTL, DB, HIIT, DTX) as the between-subject factor]. A one-way ANOVA with Tukey's post hoc test (p < 0.05) was applied to assess differences in Homeostatic Model Assessment for Insulin Resistance (HOMA-IR). Multivariate analysis - using sparse partial least squares discriminant analysis (sPLS-DA) - was performed to identify key metabolites, followed by pathway analysis (MetaboAnalyst) to determine significantly affected metabolic pathways. DB group showed higher HOMA-IR than CTL and DTX groups (p < 0.05). Furthermore, distinct clustering patterns was shown for metabolites by multivariate analysis. Key altered metabolic pathways included valine, leucine, and isoleucine biosynthesis; glutathione metabolism; pantothenate and coenzyme A biosynthesis; fructose and mannose metabolism; glycine, serine, and threonine metabolism; cysteine and methionine metabolism; arginine biosynthesis; tyrosine metabolism; histidine metabolism; beta-alanine metabolism; propanoate metabolism; glycolysis/gluconeogenesis; phenylalanine, tyrosine, and tryptophan biosynthesis; arginine and proline metabolism; and thiamine metabolism. These results suggest that eight weeks of HIIT may reverse metabolic changes induced by T2D in the rat liver, potentially contributing to reduced FBG and HOMA-IR levels. Clinical trial number: Not applicable.

Exercise has been proved to be effective in ameliorating diabetes but the underlying mechanisms remain obscure. It has been recently demonstrated that overactivation of the nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasome led to hepatic insulin resistance. Therefore, we aimed to explore the role and underlying mechanism of NLRP3 inflammasome in exercise-mediated hepatic insulin resistance. Wild type and db/db mice were sedentary or subjected to 8-week moderate intensity exercise, liver tissues and primary hepatic macrophages were isolated. Exercise mitigated hepatic steatosis and enhanced the hepatic insulin sensitivity of db/db mice. More importantly, exercise reduced the protein expression of two-pore domain weak inwardly rectifying K⁺ channel 2 (TWIK2) to suppress cellular K⁺ efflux, blunted the generation of mitochondrial ROS (mROS) and the release of oxidized mitochondrial DNA (ox-mtDNA) into cytosol, leading to the inhibition of NLRP3 inflammasome in hepatic macrophages of db/db mice. Accordingly, the hepatic macrophages switched from pro-inflammatory phenotype to anti-inflammatory phenotype and the infiltration of macrophages into liver was decreased in response to exercise. Moreover, inhibition of TWIK2 expression with TWIK2 inhibitor or shRNA interference in hepatic macrophages blunted the TWIK2-mtDNA-NLRP3 inflammasome signaling. The macrophages switched to anti-inflammatory phenotype upon TWIK2 deficiency. Additionally, the insulin sensitivity was elevated in primary hepatocytes which were exposed to culture medium from hepatic macrophages with TWIK2 deficiency, suggesting that inhibition of TWIK2-mtDNA-NLRP3 inflammasome signaling in hepatic macrophages could attenuate hepatic insulin resistance Taken together, we first observed the inhibition of TWIK2-mtDNA-NLRP3 inflammasome signaling in hepatic macrophages of diabetic mice in response to exercise intervention, implying a probable role for TWIK2-mtDNA-NLRP3 inflammasome signaling in exercise-mediated alleviation of hepatic inflammation and insulin resistance, hoping to provide theoretical basis and new target for the prevention and treatment of metabolic diseases.

Since its introduction in 2012, ferroptosis has garnered significant attention from researchers over the past decade. Unlike autophagy and apoptosis, ferroptosis is an atypical iron-dependent programmed cell death that falls under necrosis. It is regulated by various cellular metabolic and signaling processes, which encompass amino acid, lipid, iron, and mitochondrial metabolism. The initiation of ferroptosis occurs through iron-dependent phospholipid peroxidation. Notably, ferroptosis exhibits a dual effect and is associated with various diseases. A significant challenge lies in managing autoimmune disorders with unknown origins that stem from the reactivation of the immune system. Two contributing factors to autoimmunity are the aberrant stimulation of cell death and the inadequate clearance of dead cells, which can expose or release intracellular components that activate the immune response. Ferroptosis is distinct from other forms of cell death, such as apoptosis, necroptosis, autophagy, and pyroptosis, due to its unique morphological, biochemical, and genetic characteristics and specific relationship with cellular iron levels. Recent studies indicate that immune cells can both induce and undergo ferroptosis. To better understand how ferroptosis influences immune responses and its imbalance in disease, a molecular understanding of the relationship between ferroptosis and immunity is essential. Consequently, further research is needed to develop immunotherapeutics that target ferroptosis. This review primarily focuses on the role of ferroptosis in immune-related disorders.

Obesity constitutes a global health epidemic which worsens the main leading death causes such as type 2 diabetes, cardiovascular diseases, and cancer. Changes in the metabolism in patients with obesity frequently lead to insulin resistance, along with hyperglycemia, dyslipidemia and low-grade inflammation, favoring a more aggressive tumor microenvironment. One of the hallmarks of cancer is the reprogramming of the energy metabolism, in which tumor cells change oxidative phosphorylation to aerobic glycolysis or "Warburg effect". Aerobic glycolysis is faster than oxidative phosphorylation, but less efficient in terms of ATP production. To obtain sufficient ATP, tumor cells increase glucose uptake by the glucose transporters of the GLUT/SLC2 family. The human glucose transporter GLUT12 was isolated from the breast cancer cell line MCF7. It is expressed in adipose tissue, skeletal muscle and small intestine, where insulin promotes its translocation to the plasma membrane. Moreover, GLUT12 over-expression in mice increases the whole-body insulin sensitivity. Thus, GLUT12 has been proposed as a second insulin-responsive glucose transporter. In obesity, GLUT12 is downregulated and does not respond to insulin. In contrast, GLUT12 is overexpressed in human solid tumors such as breast, prostate, gastric, liver and colon. High glucose concentration, insulin, and hypoxia upregulate GLUT12 both in adipocytes and tumor cells. Inhibition of GLUT12 mediated Warburg effect suppresses proliferation, migration, and invasion of cancer cells and xenografted tumors. This review summarizes the up-to-date information about GLUT12 physiological role and its implication in obesity and cancer, opening new perspectives to consider this transporter as a therapeutic target.

Scientific evidence demonstrates that a very low-calorie ketogenic diet (VLCKD) is effective and beneficial in the treatment of obesity, capable of reversing the methylome associated with obesity and has immunomodulatory capacity. This effect is in part promoted by nutritional ketosis and could be involved in counteracting obesity-related cancer. The aim of this study was to evaluate the effect of nutritional ketosis on the methylation of genes related to tumor processes in patients with obesity and in breast cancer cells. Based on methylome data (Infinium MethylationEPIC BeadChip, Illumina) from patients with obesity treated with a VLCKD for weight loss (n = 10; n = 5 women, age = 48.8 ± 9.20 years, BMI = 32.9 ± 1.4 kg/m2), genes belonging to cancer-related pathways were specifically evaluated and further validated in vitro in MDA-MB-231 (triple negative) and MCF7 (RE positive) breast tumor cells pretreated for 72 h with βOHB, the main ketone body, secretome from visceral (VATs) or subcutaneous (SATs) adipose tissue of patients with obesity. The cell tumoral phenotype was evaluated by proliferation assay and expression of cancer-related genes. VLCKD-induced nutritional ketosis promoted changes in the methylation of 18 genes (20 CpGs; 17 hypomethylated, 3 hypermethylated) belonged to cancer-related pathways with MAPK10, CCN1, CTNNA2, LAMC3 and GLI2 being the most representative genes. A similar pattern was observed in the MDA-MB-231 cells treated with β-OHB, without changes in MCF7. These epigenetic changes paralleled the tumoral phenotype modulated by the treatments. Taking together these results highlight the potential role of VLCKD as an adjuvant to anticancer treatment in groups more susceptible to the development of cancer such as patients with obesity, exerting epigenetic regulation through nutritional ketosis and weight loss.

Conflicting evidence exists regarding the superiority of Polarized Training (POL) vs other training intensity distribution models. Compare POL vs threshold (THR) training on V̇O₂max, endurance capacity (EC) and mitochondrial function. Fifteen male Wistar rats (336.1 ± 30.4 g) were divided in: POL (n = 5), THR (n = 5) or control (CON; n = 5) groups. V̇O₂max (indirect calorimetry) and EC (treadmill exhaustion test) were determined at baseline four and eight-weeks of training. POL consisted of 80% running volume at 60%V̇O₂max and 20% at 90%V̇O₂max while THR trained only at 75%V̇O₂max. Both protocols were isocaloric and performed 5d/week. All animals were housed in cages with access to running wheel to allow ad libitum activity. After training, animals were sacrificed and left ventricle (LV) myocardium, diaphragm, tibialis anterior and soleus muscles were collected for high-resolution respirometry, biochemical and histological analysis. There were no baseline differences between groups. After training V̇O₂max and EC were similar between POL and THR even though THR V̇O₂max was higher compared to CON. After training, there were also no significant differences in OXPHOS or any of the other major mitochondrial function markers assessed between POL and THR in any of the tissues analyzed. The expression of MFN1, MFN2, PGC-1α, TFAM, DRP1, OPA1 and TOM20 as well as the activity of citrate synthase were also similar between POL and THR in all tissues. There were no significant differences in endurance performance or markers of bioenergetic function between POL and THR after eight-weeks of training.

Excess adiposity contributes to the development of colon carcinoma (CC). Interleukin (IL)-1β is a pro-inflammatory cytokine relevant in obesity-associated chronic inflammation and tumorigenic processes. We herein aimed to study how obesity and CC affects the expression of IL1B, and to determine the impact of IL-1β on the regulation of metabolic inflammation and gut barrier function in the context of obesity and CC. Samples from 71 volunteers were used in a case-control study and a rat model of diet-induced obesity (DIO). Furthermore, bariatric surgery was used to determine the effect of weight loss on the intestinal gene expression levels of Il1b. To evaluate the effect of IL-1β and obesity in CC, we treated the adenocarcinoma cell line HT-29 with IL-1β and the adipocyte-conditioned medium (ACM) from patients with obesity. We showed that obesity (P < 0.05) and CC (P < 0.01) upregulated the transcript levels of IL1B in visceral adipose tissue as well as in the colon from patients with CC (P < 0.01). The increased expression of Il1b in the ileum and colon in DIO rats decreased after weight loss achieved by either sleeve gastrectomy or caloric restriction (both P < 0.05). ACM treatment on HT-29 cells upregulated (P < 0.05) the transcripts of IL1B and CCL2, while reducing (P < 0.05) the expression of the anti-inflammatory ADIPOQ and MUC2 genes. Additionally, IL-1β upregulated (P < 0.01) the expression of CCL2 and TNF whilst downregulating (P < 0.01) the transcript levels of IL4, ADIPOQ and TJP1 in HT-29 cells. We provide evidence of the important role of IL-1β in obesity-associated CC by directly promoting inflammation.

Recent studies have focused on genetic polymorphisms that may influence athlete status. This meta-analysis aimed to investigate the association between athlete status and specific candidate genetic polymorphisms (AGTR2 rs11091046, FTO rs9939609, GALNTL6 rs558129, GNB3 rs5443, MCT1 rs1049434, NOS3 rs2070744). Only case-control studies collected from PubMed and Web of Science databases, published between 2009 and 2022, were included. A total of 23 studies were included in the meta-analysis according to the criteria of the research, and analyses were performed using random or fixed effects models. Effect size, odds ratio, or risk ratio were evaluated with a suitable 95% confidence interval. The results showed that the GALNTL6 rs558129 T/T genotype, MCT1 rs1049434 T/T genotype, and NOS3 rs2070744 T allele and T/T genotype were more prevalent in power athletes than in controls (p < 0.05). Conversely, the GALNTL6 rs558129 C allele, C/C genotype, and AGTR2 rs11091046 C allele and C/C genotype were more common in the control group. These findings indicate that some genetic polymorphisms may be important markers in athlete status and should be supported by future studies.

Cardiovascular diseases (CVDs) constitute a major global health problem, being the leading cause of death. Several risk factors for CVDs have been identified, including tobacco use, unhealthy diet, and physical inactivity. However, the role of genetic factors in CVDs remains unclear. Recent studies suggest that vitamin D deficiency is associated with an increased risk of CVDs. Therefore, the aim of this study is to assess the impact of 13 single nucleotide polymorphisms (SNPs) located in genes involved in vitamin D metabolism (VDR, GC, CYP27B1, CYP2R1, and CYP24A1) on the risk of developing CVDs. A retrospective case-control study was conducted in 766 Caucasian individuals from southern Spain: 383 diagnosed with CVDs and 383 without cardiovascular complications, matched based on age and sex. The 13 SNPs were identified by real-time PCR using TaqMan™ probes at the Virgen de las Nieves University Hospital and the University of Granada. According to statistical analysis the allele G and genotype GG of the SNP CYP2R1 rs10741657 and the allele C and CC genotype of the SNP CYP27B1 rs3782130 are associated with a decreased risk of CVDs and diabetes in three of the five heritage models studied. Thus, it can be concluded that CYP2R1 rs10741657 and CYP27B1 rs3782130 could be used as risk biomarkers for CVDs in the future, although studies with a larger number of participants are needed.

Mitochondrial dysfunction plays an important role in the pathogenesis of metabolic dysfunction-associated steatotic liver disease (MASLD). Transient receptor potential ankyrin-1 (TRPA1) activation improves mitochondrial dysfunction in a variety of cells. The present study tested the effects of Trpa1 knockout and activation in diet-induced MASLD in mice and palmitate-induced lipid deposition in HepG2 cells. Mice were fed with a high-fat diet (HFD) for 24 weeks to establish the animal model of MASLD. TRPA1 was downregulated in the liver of mice with MASLD and in HepG2 cells with palmitate-treated steatosis. Compared with HFD-fed wild-type mice, Trpa1^-/- mice on HFD demonstrated exacerbated lipid deposition and mitochondrial damage in hepatocytes. AMP-activated protein kinase (AMPK) and carnitine palmitoyl transferase 1 A (CPT1A) in the liver were downregulated by HFD and to a greater extent in Trpa1^-/- mice. Similarly, knockdown of Trpa1 worsened palmitate-induced lipid accumulation, mitochondrial morphological damage, mitochondrial ATP reduction and dysfunction, and downregulation of AMPK and CPT1A in HepG2 cells. Oral administration of cinnamaldehyde significantly reduced lipid deposition and improved mitochondrial damage in hepatocytes, which were abolished by HC030031, a TRPA1 antagonist. In HepG2 cells, cinnamaldehyde remarkably attenuated palmitate-induced lipid accumulation, mitochondrial damage, ATP reduction, and mitochondrial dysfunction, which were blunted by HC030031. Cinnamaldehyde reversed downregulation of AMPK and CPT1A in the liver of HFD-fed mice and palmitate-treated HepG2 cells through activating TRPA1. In conclusion, these findings suggest that the downregulation of TRPA1 may be involved in the pathogenesis of MASLD and activation of TRPA1 holds potential in the prevention and treatment of MASLD.