Roles of Y-27632 on sheep sperm metabolism

To investigate the effect of Y-27632 on low-temperature metabolism of sheep sperm, different concentrations of Y-27632 were added to sheep semen at 4 °C in this experiment to detect indicators such as sperm motility, plasma membrane, acrosome, antioxidant performance, mitochondrial membrane potential (MMP), and metabolomics. The results showed that the addition of 20 µM Y-27632 significantly increased sperm motility, plasma membrane integrity rate, acrosome integrity rate, antioxidant capacity, MMP level, significantly increased sperm adenosine triphosphate (ATP) and total cholesterol content, and significantly reduced sperm Ca2+ content. In metabolomics analysis, compared with the control group, the 20 µM Y-27632 group screened 20 differential metabolites, mainly involved in five metabolic pathways, with the most significant difference in Histidine metabolism (P = 0.001). The results confirmed that Y-27632 significantly improved the quality of sheep sperm preservation under low-temperature conditions.

Metabolomics to Understand Alterations Induced by Physical Activity during Pregnancy

Physical activity (PA) and exercise have been associated with a reduced risk of cancer, obesity, and diabetes. In the context of pregnancy, maintaining an active lifestyle has been shown to decrease gestational weight gain (GWG) and lower the risk of gestational diabetes mellitus (GDM), hypertension, and macrosomia in offspring. The main pathways activated by PA include BCAAs, lipids, and bile acid metabolism, thereby improving insulin resistance in pregnant individuals. Despite these known benefits, the underlying metabolites and biological mechanisms affected by PA remain poorly understood, highlighting the need for further investigation. Metabolomics, a comprehensive study of metabolite classes, offers valuable insights into the widespread metabolic changes induced by PA. This narrative review focuses on PA metabolomics research using different analytical platforms to analyze pregnant individuals. Existing studies support the hypothesis that exercise behaviour can influence the metabolism of different populations, including pregnant individuals and their offspring. While PA has shown considerable promise in maintaining metabolic health in non-pregnant populations, our comprehension of metabolic changes in the context of a healthy pregnancy remains limited. As a result, further investigation is necessary to clarify the metabolic impact of PA within this unique group, often excluded from physiological research.

Metabolomics reveals the defense mechanism of histidine supplementation on high-salt exposure-induced hepatic oxidative stress

AIMS

This study mainly evaluated the protective mechanism of histidine against the hepatic oxidative stress after high-salt exposure (HSE) through combined analysis of non-targeted metabolomics and biological metabolic networks.

MATERIALS AND METHODS

Dahl salt-sensitive (SS) rats were fed with normal-salt diet or HSE ± histidine in addition to drinking water for 14 days. Gas chromatography-mass spectrometry was used to analyze the hepatic metabolites. The metabolic profile was analyzed by SIMCA-14.1, the metabolic correlation network was performed using Gephi-0.9.2, and pathway enrichment was analyzed using MetaboAnalyst 5.0 online website.

KEY FINDINGS

Results indicated that HSE disturbed the hepatic metabolic profile, generated abnormal liver metabolism and exacerbated oxidative stress. Histidine supplementation significantly reversed the hepatic metabolic profile. Of note, 14 differential metabolic pathways were enriched after histidine supplementation, most of which played an important role in ameliorating redox and nitric oxide (NO) metabolism. Histidine administration decreased the levels of hydroperoxide and malondialdehyde, and increased the activities of antioxidant enzymes (Catalase, Superoxide Dismutase, Glutathione S-transferase and Glutathione reductases). Histidine effectively enhanced the endogenous synthesis of glutathione by increasing the levels of glutamate and cysteine, thereby enhancing the antioxidant capacity of the glutathione system. After histidine administration, lysine, glutamate, and hypotaurine owned a higher metabolic centrality in the correlation network. In addition, histidine could also effectively increase the endogenous synthesis of NO by enhancing the _L-arginine/NO pathway.

SIGNIFICANCE

This study offers new insights into the metabolic mechanisms underlying the antioxidant protective effect of histidine on the liver.

Maternal Exercise Protects Male Offspring From Maternal Diet-Programmed Nonalcoholic Fatty Liver Disease Progression

Maternal obesity programs the risk for development of nonalcoholic fatty liver disease (NAFLD) in offspring. Maternal exercise is a potential intervention to prevent developmentally programmed phenotypes. We hypothesized that maternal exercise would protect from progression of NAFLD in offspring previously exposed to a maternal obesogenic diet. Female mice were fed chow (CON) or high fat, fructose, cholesterol (HFFC) and bred with lean males. A subset had an exercise wheel introduced 4 weeks after starting the diet to allow for voluntary exercise. The offspring were weaned to the HFFC diet for 7 weeks to induce NAFLD. Serum, adipose, and liver tissue were collected for metabolic, histologic, and gene expression analyses. Cecal contents were collected for 16S sequencing. Global metabolomics was performed on liver. Female mice fed the HFFC diet had increased body weight prior to adding an exercise wheel. Female mice fed the HFFC diet had an increase in exercise distance relative to CON during the preconception period. Exercise distance was similar between groups during pregnancy and lactation. CON-active and HFFC-active offspring exhibited decreased inflammation compared with offspring from sedentary dams. Fibrosis increased in offspring from HFFC-sedentary dams compared with CON-sedentary. Offspring from exercised HFFC dams exhibited less fibrosis than offspring from sedentary HFFC dams. While maternal diet significantly affected the microbiome of offspring, the effect of maternal exercise was minimal. Metabolomics analysis revealed shifts in multiple metabolites including several involved in bile acid, 1-carbon, histidine, and acylcarnitine metabolism. This study provides preclinical evidence that maternal exercise is a potential approach to prevent developmentally programmed liver disease progression in offspring.

Metabolome Genome-Wide Association Study Identifies 74 Novel Genomic Regions Influencing Plasma Metabolites Levels

Metabolites are small products of metabolism that provide a snapshot of the wellbeing of an organism and the mechanisms that control key physiological processes involved in health and disease. Here we report the results of a genome-wide association study of 722 circulating metabolite levels in 8809 subjects of European origin, providing both breadth and depth. These analyses identified 202 unique genomic regions whose variations are associated with the circulating levels of 478 different metabolites. Replication with a subset of 208 metabolites that were available in an independent dataset for a cohort of 1768 European subjects confirmed the robust associations, including 74 novel genomic regions not associated with any metabolites in previous works. This study enhances our knowledge of genetic mechanisms controlling human metabolism. Our findings have major potential for identifying novel targets and developing new therapeutic strategies.

A Cross-Platform Metabolomics Comparison Identifies Serum Metabolite Signatures of Liver Fibrosis Progression in Chronic Hepatitis C Patients

Metabolomics offers new insights into disease mechanisms that is enhanced when adopting orthogonal instrumental platforms to expand metabolome coverage, while also reducing false discoveries by independent replication. Herein, we report the first inter-method comparison when using multisegment injection-capillary electrophoresis-mass spectrometry (MSI-CE-MS) and nuclear magnetic resonance (NMR) spectroscopy for characterizing the serum metabolome of patients with liver fibrosis in chronic hepatitis C virus (HCV) infection (n = 20) and non-HCV controls (n = 14). In this study, 60 and 30 serum metabolites were detected frequently (>75%) with good technical precision (median CV < 10%) from serum filtrate samples (n = 34) when using standardized protocols for MSI-CE-MS and NMR, respectively. Also, 20 serum metabolite concentrations were consistently measured by both methods over a 500-fold concentration range with an overall mean bias of 9.5% (n = 660). Multivariate and univariate statistical analyses independently confirmed that serum choline and histidine were consistently elevated (p < 0.05) in HCV patients with late-stage (F2-F4) as compared to early-stage (F0-F1) liver fibrosis. Overall, the ratio of serum choline to uric acid provided optimal differentiation of liver disease severity (AUC = 0.848, p = 0.00766) using a receiver operating characteristic curve, which was positively correlated with liver stiffness measurements by ultrasound imaging (r = 0.606, p = 0.0047). Moreover, serum 5-oxo-proline concentrations were higher in HCV patients as compared to non-HCV controls (F = 4.29, p = 0.0240) after adjustment for covariates (age, sex, BMI), indicative of elevated oxidative stress from glutathione depletion with the onset and progression of liver fibrosis. Both instrumental techniques enable rapid yet reliable quantification of serum metabolites in large-scale metabolomic studies with good overlap for biomarker replication. Advantages of MSI-CE-MS include greater metabolome coverage, lower operating costs, and smaller sample volume requirements, whereas NMR offers a robust platform supported by automated spectral and data processing software.

Hepatoprotective effect of Saccharomyces Cervisciae Cell Wall Extract against thioacetamide-induced liver fibrosis in rats

Fibrosis represents a common outcome of almost all chronic liver diseases and leads to an impairment of liver function that requires medical intervention. The current study aimed to evaluate the potential anti-fibrotic effect of Saccharomyces cervisciae cell wall extract (SCCWE) against thioacetamide (TAA)-induced liver fibrosis in rats (200mg/kg b.w. i.p. twice weekly for 6 weeks) using Ursodeoxycholic acid (UDCA) as a reference anti-fibrotic product. SCCWE at two doses (50 and 100 mg/kg) significantly ameliorated the rise in serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), gamma glutamide transferase (GGT) activities, total bilirubin and direct bilirubin, increased total protein and albumin. SCCWE significantly reduced glutathione depletion (GSH), Nitric oxide (NOx) and malondialdehyde (MDA), thioredoxin (Trx) contents and elevated nuclear factor erythroid 2–related factor 2 (Nrf-2) content. Its anti-inflammatory effects were confirmed by observing a decrease in nuclear factor-κB (NF- κβ), interleukin-1b (IL-1β) and inducible nitric oxide synthase (iNOS) content. The anti-fibrotic effects of SCCWE were explored by assessing fibrosis related markers as it significantly reduced transform growth factor-β (TGF-β) and autotaxin (ATX) contents. Administration of SCCWE significantly decreased matrix metalloproteinase-3 and 9 (MMP-3 and -9). Furthermore, it also decreased alpha smooth muscle actin (α-SMA) and caspase-3 as assessed immunohistochemically those results were similar to that of the standard drug UDCA. This study shows that SCCWE protects against TAA-induced liver fibrosis in rats, through attenuating oxidative stress, and inflammation, ameliorating MMPs, combating apoptosis and thereby fibrotic biomarkers in addition to improving histopathological changes.

Dimethyl fumarate protects thioacetamide-induced liver damage in rats: Studies on Nrf2, NLRP3, and NF-κB

The present study was designed to investigate the hepatoprotective potential of dimethyl fumarate (DMF) against thioacetamide (TAA)-induced liver damage. Wistar rats were treated with DMF (12.5, 25, and 50 mg/kg/day, orally) and TAA (200 mg/kg intraperitoneally, every third day) for 6 consecutive weeks. TAA exposure significantly reduced body weight, increased liver weight and index, and intervention with DMF did not ameliorate these parameters. DMF treatment significantly restored TAA-induced increase in the levels of aspartate aminotransferase, alanine aminotransferase, γ-glutamyl transferase, total bilirubin, uric acid, malondialdehyde, reduced glutathione, and histopathological findings such as inflammatory cell infiltration, deposition of collagen, necrosis, and bridging fibrosis. DMF treatment significantly ameliorated TAA-induced hepatic stellate cell activation, increase in inflammatory cascade markers (NACHT, LRR, and PYD domains-containing protein 3; NLRP3, apoptosis-associated speck like protein containing a caspase recruitment domain; ASC, caspase-1, nuclear factor-kappa B; NF-κB, interleukin-6), fibrogenic makers (α-smooth muscle actin; ɑ-SMA, transforming growth factor; TGF-β1, fibronectin, collagen 1) and antioxidant markers (nuclear factor (erythroid-derived 2)-like factor 2; Nrf2, superoxide dismutase-1; SOD-1, catalase). The present findings concluded that DMF protects against TAA-induced hepatic damage mediated through the downregulation of inflammatory cascades and upregulation of antioxidant status.

Carnosine and Histidine Supplementation Blunt Lead-Induced Reproductive Toxicity through Antioxidative and Mitochondria-Dependent Mechanisms

Lead (Pb)-induced reproductive toxicity is a well-characterized adverse effect associated with this heavy metal. It has been found that Pb exposure is associated with altered spermatogenesis, increased testicular degeneration, and pathological sperm alterations. On the other hand, it has been reported that Pb-induced reproductive toxicity is associated with increased reactive oxygen species (ROS) formation and diminished antioxidant capacity in the reproductive system. Hence, administration of antioxidants as protective agents might be of value against Pb-induced reproductive toxicity. This study was designed to investigate whether carnosine (CAR) and histidine (HIS) supplementation would mitigate the Pb-induced reproductive toxicity in male rats. Animals received Pb (20 mg/kg/day, oral, 14 consecutive days) alone or in combination with CAR (250 and 500 mg/kg/day, oral, 14 consecutive days) or HIS (250 and 500 mg/kg/day, oral, 14 consecutive days). Pb toxicity was evident in the reproductive system by a significant increase in tissue markers of oxidative stress along with severe histopathological changes, seminal tubule damage, tubular desquamation, low spermatogenesis index, poor sperm parameters, and impaired sperm mitochondrial function. It was found that CAR and HIS supplementation blunted the Pb-induced oxidative stress and mitochondrial dysfunction in the rat reproductive system. Thereby, antioxidative and mitochondria-protective properties serve as primary mechanisms for CAR and HIS against Pb-induced reproductive toxicity.

Melatonin mitigates thioacetamide-induced hepatic fibrosis via antioxidant activity and modulation of proinflammatory cytokines and fibrogenic genes

AIMS

The potential antifibrotic effects of melatonin against induced hepatic fibrosis were explored.

MAIN METHODS

Rats were allocated into four groups: placebo; thioacetamide (TAA) (200mg/kg bwt, i.p twice weekly for two months); melatonin (5mg/kgbwt, i.p daily for a week before TAA and continued for an additional two months); and melatonin plus TAA. Hepatic fibrotic changes were evaluated biochemically and histopathologically. Hepatic oxidative/antioxidative indices were assessed. The expression of hepatic proinflammatory cytokines (tumor necrosis factor-α, and interleukin-1β), fibrogenic-related genes (transforming growth factor-1β, collagen I, collagen, III, laminin, and autotaxin) and an antioxidant-related gene (thioredoxin-1) were detected by qRT-PCR.

KEY FINDINGS

In fibrotic rats, melatonin lowered serum aspartate aminotransferase, alanine aminotransferase, and autotaxin activities, bilirubin, hepatic hydroxyproline and plasma ammonia levels. Melatonin displayed hepatoprotective and antifibrotic potential as indicated by mild hydropic degeneration of some hepatocytes and mild fibroplasia. In addition, TAA induced the depletion of glutathione, glutathione s-transferase, glutathione peroxidase, superoxide dismutase, catalase, and paraoxonase-1 (PON-1), while inducing the accumulation of malondialdehyde, protein carbonyl (C=O) and nitric oxide (NO), and DNA fragmentation. These effects were restored by melatonin pretreatment. Furthermore, melatonin markedly attenuated the expression of proinflammatory cytokines and fibrogenic genes via the upregulation of thioredoxin-1 mRNA transcripts.

SIGNIFICANCE

Melatonin exhibits potent anti-inflammatory, antioxidant and fibrosuppressive activities against TAA-induced hepatic fibrogenesis via the suppression of oxidative stress, DNA damage, proinflammatory cytokines and fibrogenic gene transcripts. In addition, we demonstrate that the antifibrotic activity of melatonin is mediated by the induction of thioredoxin-1 with attenuation of autotaxin expressions.

Altered lysophosphatidic acid (LPA) receptor expression during hepatic regeneration in a mouse model of partial hepatectomy

BACKGROUND

Hepatic regeneration requires coordinated signal transduction for efficient restoration of functional liver mass. This study sought to determine changes in lysophosphatidic acid (LPA) and LPA receptor (LPAR) 1-6 expression in regenerating liver following two-thirds partial hepatectomy (PHx).

METHODS

Liver tissue and blood were collected from male C57BL/6 mice following PHx. Circulating LPA was measured by enzyme-linked immunosorbent assay (ELISA) and hepatic LPAR mRNA and protein expression were determined.

RESULTS

Circulating LPA increased 72 h after PHx and remained significantly elevated for up to 7 days post-PHx. Analysis of LPAR expression after PHx demonstrated significant increases in LPAR1, LPAR3 and LPAR6 mRNA and protein in a time-dependent manner for up to 7 days post-PHx. Conversely, LPAR2, LPAR4 and LPAR5 mRNA were barely detected in normal liver and did not significantly change after PHx. Changes in LPAR1 expression were confined to non-parenchymal cells following PHx.

CONCLUSIONS

Liver regeneration following PHx is associated with significant changes in circulating LPA and hepatic LPAR1, LPAR3 and LPAR6 expression in a time- and cell-dependent manner. Furthermore, changes in LPA-LPAR post-PHx occur after the first round of hepatocyte division is complete.

Autotaxin in the crosshairs: taking aim at cancer and other inflammatory conditions

Autotaxin is a secreted enzyme that produces most of the extracellular lysophosphatidate from lysophosphatidylcholine, the most abundant phospholipid in blood plasma. Lysophosphatidate mediates many physiological and pathological processes by signaling through at least six G-protein coupled receptors to promote cell survival, proliferation and migration. The autotaxin/lysophosphatidate signaling axis is involved in wound healing and tissue remodeling, and it drives many chronic inflammatory conditions from fibrosis to colitis, asthma and cancer. In cancer, lysophosphatidate signaling promotes resistance to chemotherapy and radiotherapy, and increases both angiogenesis and metastasis. Research into autotaxin inhibitors is accelerating, both as primary and adjuvant therapy. Historically, autotaxin inhibitors had poor bioavailability profiles and thus had limited efficacy in vivo. This situation is now changing, especially since the recent crystal structure of autotaxin is now enabling rational inhibitor design. In this review, we will summarize current knowledge on autotaxin-mediated disease processes including cancer, and discuss recent advancements in the development of autotaxin-targeting strategies. We will also provide new insights into autotaxin as an inflammatory mediator in the tumor microenvironment that promotes cancer progression and therapy resistance.

Oral administration of vitamin C and histidine attenuate cyclophosphamide-induced hemorrhagic cystitis in rats

Objectives:

Cyclophosphamide (CP), a widely used antineoplastic drug causes hemorrhagic cystitis (HC) mainly via induction of oxidative stress. Both vitamin C and histidine have antioxidant properties. The present study aimed to investigate the effects of oral (p.o.) administration of vitamin C and histidine on the CP-induced HC in rats.

Materials and Methods:

The animals were divided into two major groups I and II with four subgroups (a, b, c, and d) in each. Groups I and II were treated with intraperitoneal (i.p.) injections of normal saline and CP (200 mg/kg), respectively, thereafter, normal saline, vitamin C (200 mg/kg), histidine (200 mg/kg) and vitamin C plus histidine were p.o. administered in subgroups a, b, c, and d, respectively, three times (2, 6, and 24 h) after i.p. injections of normal saline and CP. Blood samples were assayed for total antioxidant capacity (TAC) and malondialdehyde (MDA) levels. Histopathological changes of bladder wall were investigated.

Results:

The decreased TAC and increased MDA levels of plasma and the severity of hemorrhages, congestion, edema, and leukocyte infiltration of bladder induced by CP were recovered with vitamin C and histidine treatments. Combined treatment with vitamin C and histidine showed a potentiation effect.

Conclusion:

The results indicated that vitamin C and histidine attenuated the CP-induced HC by reducing of free radical-induced toxic effects.

Pro-fibrotic activity of lysophosphatidic acid in adipose tissue: in vivo and in vitro evidence

Lysophosphatidic acid (LPA) is a pro-fibrotic mediator acting via specific receptors (LPARs) and is synthesized by autotaxin, that increases with obesity. We tested whether LPA could play a role in adipose tissue (AT)-fibrosis associated with obesity. Fibrosis [type I, III, and IV collagens (COL), fibronectin (FN), TGFβ, CTGF and αSMA] and inflammation (MCP1 and F4/80) markers were quantified: (i) in vivo in inguinal (IAT) and perigonadic (PGAT) AT from obese-diabetic db/db mice treated with the LPAR antagonist Ki16425 (5mg/kg/day ip for 7 weeks); and (ii) in vitro in human AT explants in primary culture for 72h in the presence of oleoyl-LPA (10μM) and/or Ki16425 (10μM) and/or the HIF-1α inhibitor YC-1 (100μM). Treatment of db/db mice with Ki16425 reduced Col I and IV mRNAs in IAT and PGAT while Col III mRNAs were only reduced in IAT. This was associated with reduction of COL protein staining in both IAT and PGAT. AT explants showed a spontaneous and time-dependent increase in ATX expression and production of LPA in the culture medium, along with increased levels of Col I and III, TGFβ and αSMA mRNAs and of COL protein staining. In vitro fibrosis was blocked by Ki16425 and was further amplified by oleoyl-LPA. LPA-dependent in vitro fibrosis was blocked by co-treatment with YC1. Our results show that endogenous and exogenous LPA exert a pro-fibrotic activity in AT in vivo and in vitro. This activity could be mediated by an LPA1R-dependent pathway and could involve HIF-1α.

Lysophosphatidic acid receptor expression and function in human hepatocellular carcinoma

BACKGROUND

Lysophosphatidic acid (LPA) is a ubiquitously expressed phospholipid that regulates diverse cellular functions. Previously identified LPA receptor subtypes (LPAR1-5) are weakly expressed or absent in the liver. This study sought to determine LPAR expression, including the newly identified LPAR6, in normal human liver (NL), hepatocellular carcinoma (HCC), and non-tumor liver tissue (NTL), and LPAR expression and function in human hepatoma cells in vitro.

METHODS

We determined LPAR1-6 expression by quantitative reverse transcriptase polymerase chain reaction, Western blot, or immunohistochemistry in NL, NTL, and HCC, and HuH7, and HepG2 cells. Hepatoma cells were treated with LPA in the absence or presence of LPAR1-3 (Ki16425) or pan-LPAR (α-bromomethylene phosphonate) antagonists and proliferation and motility were measured.

RESULTS

We report HCC-associated changes in LPAR1, 3, and 6 mRNA and protein expression, with significantly increased LPAR6 in HCC versus NL and NTL. Analysis of human hepatoma cells demonstrated significantly higher LPAR1, 3, and 6 mRNA and protein expression in HuH7 versus HepG2 cells. Treatment with LPA (0.05-10 μg/mL) led to dose-dependent HuH7 growth and increased motility. In HepG2 cells, LPA led to moderate, although significant, increases in proliferation but not motility. Pretreatment with α-bromomethylene phosphonate inhibited LPA-dependent proliferation and motility to a greater degree than Ki16425.

CONCLUSIONS

Multiple LPAR forms are expressed in human HCC, including the recently described LPAR6. Inhibition of LPA-LPAR signaling inhibits HCC cell proliferation and motility, the extent of which depends on LPAR subtype expression.