Lactate Dehydrogenase Activity Research Articles

Fructose shields human colorectal cancer cells from hypoxia-induced necroptosis

Recent studies have shown that high dietary fructose intake enhances intestinal tumor growth in mice. Our previous work indicated that glucose enables hypoxic colorectal cancer (CRC) cells to resist receptor-interacting protein (RIP)-dependent necroptosis. Despite having the same chemical formula, glucose and fructose are absorbed through different transporters yet both can enter the glycolytic metabolic pathway. The excessive intake of dietary fructose, leading to its overflow into the colon, allows colonic cells to absorb fructose apically. This study explores the mechanisms behind apical fructose-mediated death resistance in CRC cells under hypoxic stress. Utilizing three CRC cell lines (Caco-2, HT29, and T84) under normoxic and hypoxic conditions with varying fructose concentrations, we assessed lactate dehydrogenase (LDH) activity, RIP1/3 complex formation (a necroptosis marker), and cell integrity. We investigated the role of fructose in glycolytic-mediated death resistance using glycolytic inhibitors iodoacetate (IA, a glycolytic inhibitor to glyceraldehyde 3-phosphate dehydrogenase), and UK5099 (UK, an inhibitor to mitochondrial pyruvate carrier). Our findings reveal that apical fructose prevents the hypoxia-induced RIP-dependent necroptosis in Caco-2 and HT29 cells. Fructose exposure under hypoxia also preserved epithelial integrity. IA, but not UK, blocked fructose-mediated glycolytic metabolite production and necrosis, indicating that anaerobic glycolytic metabolites facilitate death resistance. Notably, fructose treatment upregulated pyruvate kinase (PK)-M1 mRNA in hypoxic Caco-2 and HT29 cells, while PKM2 upregulation was exclusive to HT29 cells. In conclusion, apical fructose utilization through glycolysis effectively inhibits hypoxia-induced RIP-dependent necroptosis in CRC cells, shedding light on potential metabolic adaptation mechanisms in the tumor microenvironment and suggesting novel targets for therapeutic intervention.

Hypoxia-inducible factor-1α promotes ferroptosis by inducing ferritinophagy and promoting lactate production in yak longissimus thoracis et lumborum postmortem

Ferroptosis has emerged as a novel, crucial regulator of meat quality in the postmortem hypoxia environment, with its role in mediating protein oxidation and cell death. However, the interaction between ferroptosis and the hypoxia response, especially the involvement of hypoxia-inducible factor-1α (HIF-1α), remains poorly studied. This study aimed to characterize whether HIF-1α influences ferroptosis, and, if so, explore the underlying mechanisms involved. The results showed that ferroptosis mediated by HIF-1α negatively impacts meat color and water holding capacity (WHC) but improving tenderness. Inhibition of HIF-1α by 3-(5′-hydroxymethyl-2′-furyl)-1-benzyl indazole (YC-1) reduced ferroptosis, as evidenced by lower lipid ROS levels, malondialdehyde (MDA), along with higher glutathione (GSH) levels compared to the control (P < 0.05). Additionally, inhibition of HIF-1α shifted iron homeostasis towards decreased uptake via downregulation of transferrin receptor 1 (TfR1) and induced export/storage via upregulation of ferroportin (FPN) and ferritin heavy chain (FTH) (P < 0.05). The relative expression of the ferritinophagy mediator nuclear receptor coactivator 4 (NCOA4), LC3-II/LC3-I ratio, and ATG were inhibited by YC-1 (P < 0.05), these findings suggest a general decrease in ferritinophagy associated with HIF-1α inhibition. YC-1-treated samples exhibited significantly diminished lactate accumulation and lactate dehydrogenase (LDH) activity compared to the control (P < 0.05). Unexpectedly, the inhibition of ferroptosis caused by YC-1 was further amplified by lactate enhancement, suggesting that lactate can exert its suppressive effects on ferroptosis independently of HIF-1α. Collectively, these findings demonstrate that HIF-1α drives ferroptosis by regulating iron metabolism, while lactate inhibits ferroptosis in a HIF-1α-independent manner. Overall, the HIF-1α mediated ferroptosis of postmortem yak muscle had a negative impact on WHC and color, while as a contributing factor of tenderness.

Sevoflurane Activates PI3K/AKT Signaling Pathway by Upregulating GDF11 Expression to Attenuate Ischemia/Reperfusion Injury in Cardiomyocytes.

Myocardial ischemia/reperfusion (I/R) injury stands as a primary contributor to ischemic heart disease. Sevoflurane (SEVO), a commonly used inhalation anesthetic, has been shown to exert a direct protective effect on ischemic heart injury. However, the specific mechanism by which it exerts the protective effect remains unclear. This study was designed to investigate the role of SEVO in myocardial I/R injury and its potential molecular mechanisms. Blood samples were collected from patients with acute myocardial infarction (AMI) (n = 20) and healthy volunteers (n = 20). The human cardiomyocytes AC16 models of I/R injury were induced by hypoxia/reoxygenation. The mRNA expression levels of growth differentiation factor 11 (GDF11) in the cells and blood were determined by reverse transcription quantitative real-time PCR (RT-qPCR). The cell proliferation was detected by Cell Counting Kit-8 (CCK-8). Enzyme-Linked Immunosorbent Assay (ELISA) was utilized to detect the levels of inflammatory factors interleukin (IL)-8, IL-1β and IL-6 in the cells. And biochemical assay kits were applied for the measurement of the activity of lactate dehydrogenase (LDH) and superoxide dismutase (SOD) as well as the malondialdehyde (MDA) level in the cells. Moreover, western blot was employed to evaluate the levels of the p-serine-threonine protein kinase (AKT), AKT, and phosphatidylinositol 3-kinase (PI3K), protein expression in the cells. The GDF11 expression was decreased in the blood of AMI patients and cardiomyocytes induced by I/R (p < 0.01). Besides, 1% SEVO was presented to promote cardiomyocyte proliferation, inhibit apoptosis, oxidative stress and inflammation, and activate the PI3K/AKT signaling pathway through up-regulation of GDF11 expression (p < 0.01). SEVO promotes proliferation and inhibits inflammatory response, apoptosis, and oxidative stress of I/R-treated cardiomyocytes by elevating GDF11 expression, thereby reducing myocardial I/R injury. Notably, the mechanism underlying the alleviation of the I/R injury may involve the activation of PI3K/AKT signaling pathway.

Pre-implantation embryo metabolism identified by PEMA reveals endogenous lactate insufficiency contributes to pre-implantation development arrest

Metabolism is a major regulator of pre-implantation embryonic development, but pre-implantation development arrest (PIDA) due to abnormal metabolisms remains ambiguous. By estimating a weight for each metabolic reaction using the translatome data, we developed a computational tool to perform pre-implantation embryos metabolic analysis (PEMA), and uncovered that the embryos exist in high activities of lactate dehydrogenase (LDH) and lactate synthesis when major zygotic genome activation (ZGA) occurs in humans and mice. The insufficiency of endogenous lactate was predicted by PEMA in human 8-cell PIDA and corrected human tripronuclear (ch3PN) embryos, which was coordinated with failed H3K18lac and major ZGA. In transcriptomes, the human PIDA embryos resembled endogenous lactate-deprived mouse embryos. Lac-CoA addition could promote H3K18lac, major ZGA, and ch3PN pre-implantation development. Collectively, our study decodes the metabolic abnormalities in human PIDA embryos. The experimental validation suggests that PEMA offers an opportunity to study metabolic heterogeneity in early embryos.

Aqueous Extract of Rhubarb Promotes Hepatotoxicity via Facilitating PKM2-Mediated Aerobic Glycolysis in a Rat Model of Diethylnitrosamine-Induced Liver Cancer.

To identify the polar parts in Rhubarb that cause hepatotoxicity and explore the underlying mechanisms. The rat model of liver cancer was established by gavage of diethylnitrosamine (DEN; 0.002 g/rat) for 14weeks. Starting from the 11th week, Rhubarb granule (4 g/kg), aqueous, ethyl acetate and n-butanol extract of Rhubarb or Rhein equivalent to a dose of 4 g/kg Rhubarb granule were administered intragastrically for 4 consecutive weeks. Liver tissues from rats treated with DEN and Rhubarb granules were used for non-targeted metabolomics analysis. The correlation between pyruvate kinase isozyme type M2 (PKM2) expression level and the progress and prognosis of hepatocellular carcinoma (HCC) was evaluated through bioinformatics analysis based on TCGA database. Liver tissues and blood samples from rats treated with DEN and aqueous, ethyl acetate and n-butanol extract of Rhubarb were used for the screening of hepatotoxic polar parts of Rhubarb. The liver injuries were evaluated by the changes in pathology, liver function, and the expression levels of proliferating cell nuclear antigen (PCNA) and transforming growth factor beta1 (TGF-β1). The mechanism studies focus on PKM2 expression, and the metabolic reprogramming via detecting the activities of lactate dehydrogenase A (LDHA) and isocitrate dehydrogenase (ICDH). Furthermore, molecular docking analysis was performed to validate the target interaction between Rhein and PKM2, and the hepatotoxicity of Rhein was evaluated by testing liver function in the DEN-induced liver cancer model. The non-targeted metabolomics analysis revealed that Rhubarb promoted aerobic glycolysis in the rat model of DEN-induced liver cancer. And bioinformatics analysis revealed that high PKM2 expression was closely related to the progression and poor prognosis of HCC. In vivo studies indicated that the aqueous extract of Rhubarb, but not ethyl acetate and n-butanol extract, promoted the liver injuries induced by DEN. The mechanism study showed that the aqueous extract of Rhubarb increased the expression of PKM2 and promoted aerobic glycolysis. Moreover, Rhein had a strong binding affinity for PKM2 and aggravated liver injury in the DEN-induced liver cancer model. Aqueous extract of Rhubarb promoted hepatotoxicity via facilitating PKM2-mediated aerobic glycolysis in the rat model of DEN-induced liver cancer.

Reproductive effort affects cellular response in the mantle of Nodipecten subnodosus scallops exposed to acute hyperthermia

In marine ecosystems, temperature regulates the energy metabolism of animals. In the last decades, the temperature increase was related to mass mortality events of marine ectotherms, particularly during high-energy investment for reproduction. In scallops, the mantle has been poorly investigated while this tissue covers more than 40 % of the body mass, contributing to the perception of surrounding environmental stimuli. Our aim was to assess the cellular and molecular responses linked to energy metabolism in the mantle of adult N. subnodosus facing acute hyperthermia during reproductive effort. Scallops collected in spring (late gametogenesis) and summer (ripe gonads) were exposed to a control temperature (22 °C) or acute hyperthermia (30 °C) for 24 h. In spring, increased arginine kinase (AK) activity together with increased pyruvate kinase/citrate synthase ratio (PK/CS) suggested an enhanced carbohydrate, pyruvate, and arginine metabolism to maintain the adenylate energy charge (AEC) in the mantle of scallops coping with acute thermal increase. In summer, animals decreased their AEC (5 %) and arginine phosphate pool (40 %) and increased their anaerobic metabolism as shown by enhanced activities of lactate-dehydrogenase (LDH) and octopine dehydrogenase (ODH), respectively. The abundance of twenty proteins involved in energy metabolism (isocitrate dehydrogenase, ATP synthase subunit β), protein protection (cognates heat shock protein 70), and cytoskeleton (actins and tubulins) were affected only by season. These results underlie the role of the mantle of N. subnodosus in the seasonal responses of this tissue to thermal fluctuations during reproductive effort with possible implications for the physiological performance of scallops under heat waves in wild or harvest conditions.

Bioaccumulation, transformation and toxicity of imidacloprid and dinotefuran in Eisenia fetida under single and binary exposure scenarios

Earthworms (Eisenia fetida) were exposed to individual and binary mixture of imidacloprid (IMI) and dinotefuran (DIN) at 0.05 and 0.5 mg/kg for 28 days to investigate their bioaccumulation, transformation and toxicity. IMI was more easily absorbed by earthworms than DIN, and worms didn’t accumulate or generate toxic metabolites. The obvious accumulation of neonicotinoids during later period caused significant neural dysfunction, especially when exposed to high-concentration IMI. Meanwhile, oxidative stress indicated by decreased SOD/CAT activity (33.2 %-68.1 %) and increased MDA (38.4 %-55.0 %) was induced by binary exposure with high-concentration IMI. By contrast, coelomocytes responded earlier and more strongly than oxidative responses. Coelomocytes’ viability and mitochondrial membrane potential were inhibited (23.6 %-91.7 %) mainly by IMI and binary exposure. Coelomocytes’ lactate dehydrogenase activity exerted a fluctuating pattern, suggesting irregular disturbance on cellular functions. This study highlights the role of coelomocytes and the need to consider binary/multiple scenarios and transformation of neonicotinoids in their risk assessment to earthworms.

Adaptive capability of slow-growing backyard poultry as indicated by physiological and molecular responses in a hot and humid coastal climate

Assessing the adaptability of slow-growing rural chickens for improving thermotolerance to suit the global climate change is a major research need. This work was aimed to evaluate the adaptability of CARI-Debendra chickens and to identify the polymorphism as well as expression profiling of thermotolerant genes (HSP70 and GRP78) under prevailing temperature-humidity indices and thermal stress in a coastal environment. One hundred sixty straight run chicks were reared at THI≥75 (control) and THI>80 under coastal climate till 12 weeks. Polymorphism of HSP70 and GRP78 candidate genes were explored using restriction enzymes TaqI and HaeIII to identify possible thermotolerance markers. Expression profiling of both the genes in liver, intestine and pectoralis muscle was determined through quantitative real-time PCR. Rectal and body surface temperature recorded in the neck and back showed significant differences (P < 0.01) with higher temperature in THI>80 group. Comparatively lower live weights (P < 0.05) and poor FCR were recorded in THI>80 group. The villi height in all intestinal segments was significantly lower (P < 0.01), but deeper crypt depth was observed in THI>80 than control group. A lowest thymus weight (P < 0.05) was noted with no significant differences in immune response in treatment group. Serum levels of cholesterol, activities of lactate dehydrogenase, creatinine kinase and concentration of potassium, sodium and thyroxine hormone were not different between the 2 groups. The concentration of triiodothyronine and chloride ion was lower in THI>80 group indicating adaptive changes for thermoregulation. HSP70 gene expressions in the three tissues were differentially increased (P < 0.01) by temperature-humidity indices, but the expression of GRP78 was not different between the 2 groups. The results concluded that the environmental factors interact with genetics on adaptability towards thermotolerance in slow-growing chickens.

Chemotherapy-induced peripheral neuropathy in the neuronal cells model

This research aims to investigate the impacts of quercetin and low-level laser therapy (LLLT) on undifferentiated and nerve growth factor-differentiated PC12 cells experiencing cisplatin-induced peripheral neuropathy. PC12 cells treated with cisplatin were simultaneously exposed to quercetin and LLLT. We evaluated the effects of quercetin and LLLT on the expression of GAP-43 and Synapsin I genes through real-time PCR, cell viability using MTT assay, apoptosis induction via Annexin and dead assay, mitochondrial potential alterations using a mitopotential assay, and lactate dehydrogenase activity analysis in cells. Our findings revealed that cisplatin led to increased apoptosis, mitochondrial dysfunction, and LDH activity, while reducing cell viability and inhibiting the expression of GAP-43 and Synapsin I genes in both undifferentiated and differentiated PC12 cells. However, the application of quercetin and LLLT resulted in decreased apoptosis, mitochondrial potential alterations, and lactate dehydrogenase activity. We propose further investigation into the in vivo effects of quercetin and low-level laser therapy on cisplatin-induced peripheral neuropathy, as well as exploring the molecular relationship between quercetin and low-level laser therapy.

Comparative Study of the Protective Effects of Citral, Thymoquinone, and Silymarin on Methotrexate-induced Cardiotoxicity in Rats.

Methotrexate (MTX), an immunosuppressant and anti-cancer medication, can harm the heart. The goal of the current investigation was to assess the cardiotoxicity caused by MTX and the potential cardioprotective properties of silymarin, citral, and thymoquinone as antioxidants. Forty-eight rats were divided into six groups, which included control, MTX, cosolvent, citral, thymoquinone, and silymarin groups. At the end of the study, the rats were anesthetized (ketamine and xylazine) and killed using CO2. Their blood samples were collected to measure the enzymatic activities of creatine kinase-myoglobin binding (CK-MB), creatine phosphokinase (CPK), and lactate dehydrogenase (LDH). Also, the heart tissue was sampled to determine the antioxidant capacity and examine the histopathology. The findings revealed that the activity of CPK, CK-MB, and LDH enzymes significantly reduced in the thymoquinone treatment group compared to the MTX group (p < 0.05). On the other hand, total antioxidant capacity was significantly increased in the thymoquinone group compared to the MTX group (p < 0.05). The pathological modifications (i.e. severe congestion, edema fluid, the presence of inflammatory cells around the blood vessels, mild to moderate hemorrhaging between cardiac muscle fibers) were seen in the MTX group. The treatment groups, particularly thymoquinone, did not experience any appreciable pathological changes. The thymoquinone was found to have the strongest protective effect against the heart damage caused by MTX.

Effects of season on metabolic profile of Holstein Friesian cows in postpartum period

The aim of the present study was to determine the metabolic profile of Holstein-Friesian cows in the postpartum period, as well as the effect of season on metabolic profile. The postpartum period is essential in the reproductive life of high yielding dairy cows because of its impact on future gravidity. This study included 60 cows up to 15 days after parturition, aged 2-8 years (the largest number of cows was between 3 and 5 years old) with no apparent clinical problems. Cows were sampled in summer season (n=30) and winter season (n=30). Parameters of metabolic profile were determined as follows: glucose, albumin, total protein, cholesterol, bilirubin, alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), urea, calcium, phosphorus and magnesium. Statistical differences were considered significant at the p&lt;0.05. Present research showed that all investigated parameters were within a reference range for cattle. Impact of season sampling was determined for glucose, albumin, total protein, cholesterol and phosphorus, while bilirubin, calcium, magnesium, urea as well as activities of ALT, AST and LDH were unaffected by the season of sampling. In conclusion, metabolic status is affected by the season and examination during the postpartum period can provide valuable information of cows' health status, in order to diagnose and moreover prevent postpartum diseases.

TRIM27 revealing by tumor educated platelet RNA-sequencing, as a potential biomarker for malignant ground-glass opacities diagnosis mediates glycolysis of non-small cell lung cancer cells partially through HOXM1.

Efficient ground-glass opacities (GGOs) diagnosis is challenging. A diagnostic method distinguishing malignant from benign GGOs is warranted. In this study, we sought to construct a noninvasive method based on tumor educated platelet (TEP) RNA profiles for malignant GGOs diagnosis and explore the molecular mechanism of the potential biomarker for the first time. Based on TEP RNA-sequencing (TEP RNA-seq) in benign and malignant GGOs, a classification model was constructed using differentially expressed genes (DEGs) and was used to evaluate diagnostic performance. High-throughput quantitative polymerase chain reaction (HT-qPCR) verified 23 genes selected from the top 60 DEGs between benign and malignant GGOs. The correlation between 17 verified DEGs and 22 key glycolytic genes was analyzed. Tripartite motif-containing 27 (TRIM27) overexpressing and knockdown (KD) cell models were constructed using A549 and PC-9 cells, respectively in which cell growth, apoptosis, migration and invasion were evaluated. The protein levels of HK-1/2, PKM1/2, LDHA and GLUT1 were evaluated by western blot. Glycolysis was evaluated through adenosine triphosphate (ATP), reactive oxygen species (ROS), lactate acid (LD) production, glucose uptake, and lactate dehydrogenase (LDH) activity assays. RNA-seq was performed in loss-of TRIM27-KD PC-9 cells to clarify the downstream factors of TRIM27 which was verified using western blot and immunofluorescence double staining. In 81 samples, the 1,647-DEG-based classification model exhibited area under the curve (AUC), sensitivity, and specificity values of 0.99 [95% confidence interval (CI): 0.972-1.000], 100%, and 91%, respectively, while the top 60-DEG-based classification model exhibited AUC, sensitivity, and specificity values of 0.986 (95% CI: 0.962-1.000), 98%, and 91%, respectively. TRIM27 achieved AUC of 0.87 in the diagnosis of malignant GGOs, with 83.93% sensitivity, 78.79% specificity, 81.15% accuracy, 77.05% positive predictive value (PPV) and 85.25% negative predictive value (NPV). TRIM27 was highly expressed in non-small cell lung cancer (NSCLC) cells, and accelerated cell migration and invasion. In addition, TRIM27 was found to promote glycolysis in NSCLC cells partially through HMOX1 which was negatively correlated with TRIM27. We constructed a novel TEP RNA-seq based classifier for malignant GGOs diagnosis. TRIM27, an important target discovered, could accelerate migration, invasion and regulate glycolysis partially through HMOX1 in NSCLC cells, thus providing scientific support for TRIM27 as a diagnostic biomarker for malignant GGO diagnosis.

The Antioxidant and Anti-Fatigue Effects of Rare Ginsenosides and γ-Aminobutyric Acid in Fermented Ginseng and Germinated Brown Rice Puree.

γ-aminobutyric acid (GABA) and rare ginsenosides are good antioxidant and anti-fatigue active components that can be enriched via probiotic fermentation. In this study, ginseng and germinated brown rice were used as raw materials to produce six fermented purees using fermentation and non-fermentation technology. We tested the chemical composition of the purees and found that the content of GABA and rare ginsenoside (Rh4, Rg3, and CK) in the puree made of ginseng and germinated brown rice (FGB) increased significantly after fermentation. The antioxidant activity of the six purees was determined using cell-free experiments, and it was found that FGB had better ferric-ion-reducing antioxidant power (FRAP) and 1,1-diphenyl-2-picryl-hydrazyl (DPPH) free radical scavenging rates, exhibiting better antioxidant effects. We then evaluated the antioxidant effect of FGB in HepG2 cells induced by H2O2 and found that FGB can reduce the generation of reactive oxygen species (ROS) in HepG2 cells and increase the membrane potential level, thereby improving oxidative damage in these cells. In vivo experiments also showed that FGB has good antioxidant and anti-fatigue activities, which can prolong the exhaustive swimming time of mice and reduce the accumulation of metabolites, and is accompanied by a corresponding increase in liver glycogen and muscle glycogen levels as well as superoxide dismutase and lactate dehydrogenase activities. Finally, we believe that the substances with good antioxidant and anti-fatigue activity found in FGB are derived from co-fermented enriched GABA and rare ginsenosides.

Study on sperm cryopreservation of hybrid fish derived from Carassius cuvieri (♀) × Carassius auratus red var (♂)

Cryopreservation of sperm is an effective method for conserving germplasm resources in fish genetic breeding. The high-quality hybrid fish (WR) derived from white crucian carp (Carassius cuvieri, WCC, ♀) and red crucian carp (C. auratus red var., RCC, ♂), possesses valuable traits such as high survival rates, strong resistance, and rapid growth, representing an important germplasm resources of crucian carp. This study compared the effects of different antifreeze solutions on sperm viability among three varieties (WR, WCC, and RCC) and examined changes in enzyme activity, fertilization rates, and hatching rates after cryopreservation, aiming to enhance the cryogenic sperm cryopreservation technique in hybrid fish and investigate the mechanisms underlying spermatozoa damage caused by cryopreservation. The results showed that the antifreeze combination of D14 with 15 % dimethyl sulfoxide (DMSO) had the best effect in preserving the sperm of WR and WCC, while D20 with 10 % DMSO was the optimal combination for RCC sperm. After ultra-low temperature preservation, the longevity, fertilization, and hatching rates of frozen sperm were significantly lower (P < 0.05) compared to fresh sperm. The enzyme activities of superoxide dismutase (SOD), lactate dehydrogenase (LDH), and creatine kinase (CK) were significantly decreased (P < 0.05) in spermatozoa, whereas they showed a significant increase (P < 0.05) in sperm plasma. Succinate dehydrogenase (SDH) activity was significantly reduced (P < 0.05) in frozen spermatozoa of RCC compared to fresh spermatozoa, and exhibited lower activity in frozen spermatozoa of WCC and WR. Additionally, SDH activity was significantly elevated (P < 0.05) in frozen sperm plasma, and glutathione reductase (GR) activity was significantly lower (P < 0.05) in both frozen sperm plasma and spermatozoa across all three species. The study demonstrated that cryopreservation had a significant effect on the enzyme activities of spermatozoa and sperm plasma in all three species. These findings provide important technical support for the conservation of high-quality fish germplasm resources, particularly for novel varieties resulting from distant hybridization in fish.

Dynamic changes of protein lactylation and their correlations with the glycolytic process during the postmortem acidification of broiler breast

This experiment aimed to reveal the dynamic changes of protein post-translational lactylation modifications and their correlations with the glycolytic process in broiler breast muscle within 48 h of postmortem acidification. The experiment involved 12 male AA broilers, 42 days old, with similar body weights (2.8 ± 0.05 kg). The breast fillets (Pectoralis major) were collected after slaughter, and samples were taken at various time points: 0, 15 min, 30 min, 45 min, 60 min, 2 h, 4 h, 6 h, 8 h, 12 h, 18 h, 24 h, 36 h, and 48 h postmortem. The results showed that the rate of glycogen decline in the muscle was highest at 45 min postmortem, and glycogen levels tended to stabilize at 8 h postmortem. The lactate content in the breast reached its highest level at 4 h postmortem and began to decrease, stabilizing at 24 h postmortem. Additionally, the glycolytic potential increased gradually in the first 4 h postmortem, decreased rapidly from 4 to 8 h. Similarly, lactylation modification levels were highest at 8 h postmortem, but stabilized at 12 h postmortem. During this process, the protein expression of the enzymatic lactylation modifier p300 showed no significant difference, while the content of the nonenzymatic lactylation substrate lactoylglutathione significantly decreased at 8 h and 24 h postmortem. Correlation analysis found that lactylation levels were negatively correlated with glycogen content, glucose content, glycolytic potential, and pH value, while positively correlated with lactate content. Besides, there was a positive correlation between lactylation levels and the protein expression of hexokinase, phosphoglycerate kinase 2, phosphoglucomutase 1, and triosephosphate isomerase. Additionally, lactylation levels were positively correlated with the activities of lactate dehydrogenase and phosphofructokinase. In summary, our experiment elucidated the dynamic changes in the entire glycolytic pathway in broiler pectoral muscle during acidification. During this process, lactylation modifications may participate in the glycolysis process by regulating the protein expression and activity of glycolytic enzymes.

Cinnamaldehyde Alleviates Alveolar Epithelial Cell Injury in ALI by Inhibiting the CaMKII Pathway.

Alveolar epithelial cell injury plays a key role in acute lung injury (ALI) and is a vital determinant of its severity. Here, we aimed to assess the protective effects of cinnamaldehyde (CA) on lipopolysaccharide (LPS)-induced A549 cells and elucidate the underlying mechanisms. A549 cells were stimulated with 1 μg/mL LPS for 24 h to establish an alveolar epithelial cell injury model and subsequently treated with CA or Ca2+/calmodulin-dependent protein kinase II (CaMKII) inhibitor KN93. Flow cytometry, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, and lactate dehydrogenase release assays were used to evaluate apoptosis, cell viability, and lactate dehydrogenase activity, respectively. Levels of inflammatory cytokines (interleukin-6, interleukin-1β, tumor necrosis tactor-α, and interferon-γ) and oxidative stress markers (reactive oxygen species, superoxide dismutase, catalase, and malondialdehyde) were determined using enzyme-linked immunosorbent assay and specific assay kits, respectively. Furthermore, levels of apoptosis-related proteins (cleaved caspase-3, Bcl-2-associated X, and Bcl-2) and CaMKII were assessed via western blotting. CA did not exhibit significant cytotoxicity in A549 cells. It dose-dependently improved the cell viability, suppressed apoptosis, decreased cleaved caspase-3 and Bcl-2-associated X levels, and increased Bcl-2 levels in LPS-treated A549 cells. It also inhibited inflammatory factor release and oxidative stress in LPS-induced A549 cells. Similar results were observed in the KN93- and CA-treated groups. Western blotting assay revealed that CA and KN93 inhibited CaMKII pathway activation, as indicated by the reduced p-CaMKII and p-phospholamban (PLN) levels and p-CaMKII/CaMKII and p-PLN/PLN ratios. Overall, CA alleviated alveolar epithelial cell injury by inhibiting the inflammatory response and oxidative stress and inducing cell apoptosis in LPS-induced A549 cells by regulating the CaMKII pathway, serving as a potential candidate for ALI prevention and treatment.

Sex-specific decline in prefrontal cortex mitochondrial bioenergetics in aging baboons correlates with walking speed.

Mitochondria play a crucial role in brain aging due to their involvement in bioenergetics, neuroinflammation and brain steroid synthesis. Mitochondrial dysfunction is linked to age-related neurodegenerative diseases, including Alzheimer's disease and Parkinson's disease. We investigated changes in the activities of the electron transport chain (ETC) complexes in normally aging baboon brains and determined how these changes relate to donor sex, morning cortisol levels, and walking speed. Using a novel approach, we assessed mitochondrial bioenergetics from frozen prefrontal cortex (PFC) tissues from a large cohort (60 individuals) of well-characterized aging baboons (6.6-22.8 years, approximately equivalent to 26.4-91.2 human years). Aging was associated with a decline in mitochondrial ETC complexes in the PFC, which was more pronounced when activities were normalized for citrate synthase activity, suggesting that the decline in respiration is predominantly driven by changes in the specific activity of individual complexes rather than changes in mitochondrial number. Moreover, when donor sex was used as a covariate, we found that mitochondrial respiration was preserved with age in females, whereas males showed significant loss of ETC activity with age. Males had higher activities of each individual ETC complex and greater lactate dehydrogenase activity relative to females. Circulating cortisol levels correlated only with complex II-linked respiration in males. We also observed a robust positive predictive relationship between walking speed and respiration linked to complexes I, III, and IV in males but not in females. This data reveals a previously unknown link between aging and bioenergetics across multiple tissues linking frailty and bioenergetic function. This study highlights a potential molecular mechanism for sexual dimorphism in brain resilience and suggests that in males changes in PFC bioenergetics contribute to reduced motor function with age.

Influence of Starvation on Biochemical, Physiological, Morphological, and Transcriptional Responses Associated with Glucose and Lipid Metabolism in the Liver of Javelin Goby (Synechogobius hasta).

In this study, the influence of fasting on hepatic glucose and lipid metabolism was explored by examining biochemical, antioxidative, and morphological indicators and transcriptional expression in the liver of javelin goby (Synechogobius hasta) after 0, 3, 7, or 14 days of starvation. Marked reductions in hepatic glycogen and triglycerides occurred from the seventh day of starvation until the end of the trial (p < 0.05). However, no alterations in hepatic cholesterol or protein were detected throughout the entire experiment (p > 0.05). During fasting, the activities of pyruvate kinase, lactate dehydrogenase, and glycogen phosphorylase a all rose firstly and then fell (p < 0.05). The activities of hepatic fatty acid synthase and acetyl-CoA carboxylase were minimized to their lowest levels at the end of food deprivation (p < 0.05), while lipase was elevated after 7-14 days of fasting (p < 0.05). Catalase, glutathione, and the total antioxidative capacity were increased and maintained their higher values in the later stage of fasting (p < 0.05), whereas malondialdehyde was not significantly changed (p > 0.05). Hepatic vein congestion, remarkable cytoplasmic vacuoles, and irregular cell shape were present in S. hasta which endured 3-7 days of fasting and were less pronounced when food shortage was prolonged. In terms of genes associated with glucose and lipid metabolism, the hepatic phosphofructokinase gene was constantly up-regulated during fasting (p < 0.05). However, the mRNA levels of glycogen synthase and glucose-6-phosphatase were obviously lower when the food scarcity extended to 7 days or more (p < 0.05). Fatty acid synthase, stearoyl-CoA desaturase 1, and peroxisome proliferator-activated receptor γ were substantially down-regulated in S. hasta livers after 7-14 days of food deprivation (p < 0.05). However, genes involved in lipolysis and fatty acid transport were transcriptionally enhanced to varying extents and peaked at the end of fasting (p < 0.05). Overall, starvation lasting 7 days or more could concurrently mobilize hepatic carbohydrates and fat as energy resources and diminished their hepatic accumulation by suppressing biosynthesis and enhancing catabolism and transport, ultimately metabolically and structurally perturbing the liver in S. hasta. This work presents preliminary data on the dynamic characteristics of hepatic glucose and lipid metabolism in S. hasta in response to starvation, which may shed light on the sophisticated mechanisms of energetic homeostasis in fish facing nutrient unavailability and may benefit the utilization/conservation of S. hasta.

Angiotensin 1–7 restrains vascular injury of extracorporeal membrane oxygenation by inhibiting ferroptosis

BackgroundAngiotensin 1–7 (Ang1-7) is the classical end product of angiotensin II, which has the effects of dilating blood vessels, protecting endothelial cells, anti-hypertension, improving cardiac function, and inhibiting atherosclerosis. We hypothesize that Ang1-7 inhibits human umbilical vein endothelial cells (HUVEC) ferroptosis through NF-κB/P53 signal pathway, and reduces extracorporeal membrane oxygenation (ECMO) vascular injury. MethodsCultured HUVEC were seeded into 15 wells and randomly divided into five groups: the control group and four experimental groups (erastin, erastin + Ang1-7, erastin + Ang1-7 + Betulinic acid, erastin + Betulinic acid). After stimulation, cell viability, lactate dehydrogenase (LDH), malondialdehyde (MDA), and superoxide dismutase (SOD) activity were measured. The effects of Ang1-7 on HUVEC microstructure, antioxidant enzymes (ferritin heavy chain 1 (FTH1), cystine/glutamic acid reverse transport solute carrier family 7 members 11 (SLC7A11 or XCT), superoxide dismutase-2 (SOD-2) and glutathione peroxidase 4 (GPX4)), NF-κB, P-NF-κB, P53, and P-P53). ResultsErastin stimulation promoted HUVEC lipid peroxidation, decreased antioxidant enzyme expression, increased P-NF-κB, P53, and P-P53 expressions, and damaged HUVEC mitochondrial structure. Ang1-7 alleviated the effect of erastin on HUVEC, which was destroyed by Betulinic acid. ConclusionAngiotensin1-7 pretreatment inhibited vascular endothelial cells’ ferroptosis and alleviated ECMO vessel injury through NF-κB /P53 signal pathway.

Understanding the mechanisms behind the antibacterial activity of magnesium hydroxide nanoparticles against sulfate-reducing bacteria in sediments

Nanomaterials, with their small size, surface characteristics, and antibacterial properties, are extensively employed across environmental, energy, biomedical, agricultural, and other industries. This study examined the antibacterial efficacy of magnesium hydroxide (Mg(OH)2) nanoparticles (NPs) against sulfate-reducing bacteria (SRB) within sediments. The inhibitory effects of two types of Mg(OH)2 NPs with distinct particle sizes (20.3 and 29.6 nm) and concentrations (0–10.0 mg/mL) were examined under optimal treatment conditions. The antibacterial mechanisms of Mg(OH)2 NPs through direct contact and dissolution effects were determined. The results revealed a correlation between the concentration, particle size, and inhibitory activity, with the smallest NPs (20.3 nm) at the highest concentration (10.0 mg/mL) substantially reducing SRB counts from 8.77 ± 0.18 to 6.48 ± 0.13 log10 colony forming units/mL after 6 h treatment. Treatment with high concentrations of Mg(OH)2 NPs induced cellular damage, reduced intracellular lactate dehydrogenase activity, and elevated intracellular catalase activity and H2O2 content, suggesting that the contact effect of NPs stimulated SRB. This leads to oxidative stress response and structural damage to the cell membrane, which has emerged as the primary driver of the antibacterial action of Mg(OH)2 NPs. This study presents a novel nanomaterial that can inhibit and control SRB in natural sedimentary environments.