Rice Bran Phenolic Extract Confers Protective Effects against Alcoholic Liver Disease in Mice by Alleviating Mitochondrial Dysfunction via the PGC-1α-TFAM Pathway Mediated by microRNA-494-3p

5'tiRNA-33-CysACA-1 promotes septic cardiomyopathy by targeting PGC-1α-mediated mitochondrial biogenesis

BACKGROUND

We revealed for the first time that the expression of 158 tRNA-derived small RNAs (tsRNAs) was altered in septic cardiomyopathy (SCM) by microarray analysis, and we selected 5'tiRNA-33-CysACA-1, which was the most significantly up-regulated, as a representative to explore the roles and mechanisms of tsRNAs in SCM.

METHODS

We constructed a sepsis model by cecum ligation and puncture (CLP) in mice and detected the expression of 5'tiRNA-33-CysACA-1 using quantitative real-time PCR (qRT-PCR). The supernatant generated after LPS stimulation of macrophages was used as the conditional medium (CM) to stimulate H9C2 and established the injured cell model. CCK-8 and LDH release assays were used to detect cell viability and cell death. Mitochondrial membrane potential (MMP), ATP production, ROS production, and Mitotracker Red mitochondrial morphology were assayed to assess mitochondrial function. Expression of mRNA for molecules related to the mitochondrial quality control system was verified by qRT-PCR. The mechanism by which 5'tiRNA-33-CysACA-1 regulates peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) expression was examined by western blot, mRNA stability analysis, and rescue experiments.

RESULTS

Expression of 5'tiRNA-33-CysACA-1 was elevated in cardiac tissue and H9C2 cells during septic myocardial injury. Stimulation of the CM resulted in cardiomyocyte injury and impaired mitochondrial function. Transfection of 5'tiRNA-33-CysACA-1 mimic in CM further downregulated PGC-1α expression, inhibited mitochondrial biogenesis thereby impairing mitochondrial function and leading to decreased cardiomyocyte activity and increased cell death. In contrast, transfection of the inhibitor ameliorated the above biological processes. In addition, mRNA stability assay and bioinformatics analysis showed that 5'tiRNA-33-CysACA-1 led to a decrease in the stability of PGC-1α mRNA, which in turn downregulated the expression of PGC-1α and promoted the development of SCM.

CONCLUSIONS

5'tiRNA-33-CysACA-1 expression is upregulated in SCM and inhibits mitochondrial biogenesis by targeting PGC-1α and decreasing the stability of PGC-1α mRNA, leading to mitochondrial dysfunction and promoting the development of SCM.

Linoleic Acid Promotes Mitochondrial Biogenesis and Alleviates Acute Lung Injury

INTRODUCTION

Acute lung injury (ALI) is a critical and lethal medical condition. This syndrome is characterized by an imbalance in the body's oxidation stress and inflammation. Linoleic acid (LA), a polyunsaturated fatty acid, has been extensively studied for its potential health benefits, including anti-inflammatory and antioxidant activities. However, the therapeutic effects of LA on ALI remain unexplored.

METHODS

Lipopolysaccharide (LPS), found in gram-negative bacteria's outer membrane, was intraperitoneally injected to induce ALI in mice. In vitro model was established by LPS stimulation of mouse lung epithelial 12 (MLE-12) cells.

RESULTS

LA treatment demonstrated a significant amelioration in LPS-induced hypothermia, poor state, and pulmonary injury in mice. LA treatment resulted in a reduction in the concentration of bronchoalveolar lavage fluid (BALF) protein and an increase in myeloperoxidase (MPO) activity in LPS-induced mice. LA treatment reduced the generation of white blood cells. LA treatment reduced cell-free (cfDNA) release and promote adenosine triphosphate (ATP) production. LA increased the levels of superoxide dismutase (SOD) and glutathione (GSH) but decreased the production of malondialdehyde (MDA). LA treatment enhanced mitochondrial membrane potential. LA attenuated LPS-induced elevations of inflammatory cytokines in both mice and cells. Additionally, LA exerted its protective effect against LPS-induced damage through activation of the peroxisome proliferator-activated receptor γ coactivator l alpha (PGC-1α)/nuclear respiratory factor 1 (NRF1)/transcription factor A of the mitochondrion (TFAM) pathway.

CONCLUSION

LA may reduce inflammation and stimulate mitochondrial biogenesis in ALI mice and MLE-12 cells.

The Role of Oxidative Stress in Alcoholic Fatty Liver Disease: A Systematic Review and Meta-Analysis of Preclinical Studies

Alcoholic Fatty Liver Disease (AFLD) is characterized by the accumulation of lipids in liver cells owing to the metabolism of ethanol. This process leads to a decrease in the NAD+/NADH ratio and the generation of reactive oxygen species. A systematic review and meta-analysis were conducted to investigate the role of oxidative stress in AFLD. A total of 201 eligible manuscripts were included, which revealed that animals with AFLD exhibited elevated expression of CYP2E1, decreased enzymatic activity of antioxidant enzymes, and reduced levels of the transcription factor Nrf2, which plays a pivotal role in the synthesis of antioxidant enzymes. Furthermore, animals with AFLD exhibited increased levels of lipid peroxidation markers and carbonylated proteins, collectively contributing to a weakened antioxidant defense and increased oxidative damage. The liver damage in AFLD was supported by significantly higher activity of alanine and aspartate aminotransferase enzymes. Moreover, animals with AFLD had increased levels of triacylglycerol in the serum and liver, likely due to reduced fatty acid metabolism caused by decreased PPAR-α expression, which is responsible for fatty acid oxidation, and increased expression of SREBP-1c, which is involved in fatty acid synthesis. With regard to inflammation, animals with AFLD exhibited elevated levels of pro-inflammatory cytokines, including TNF-a, IL-1β, and IL-6. The heightened oxidative stress, along with inflammation, led to an upregulation of cell death markers, such as caspase-3, and an increased Bax/Bcl-2 ratio. Overall, the findings of the review and meta-analysis indicate that ethanol metabolism reduces important markers of antioxidant defense while increasing inflammatory and apoptotic markers, thereby contributing to the development of AFLD.

Dietary rice bran attenuates hepatic stellate cell activation and liver fibrosis in mice through enhancing antioxidant ability

Various endogenous and exogenous stimuli can result in an inflammatory response and collagen deposition in the liver, which affect liver function and increase the risk of developing liver cirrhosis and cancer. Rice bran, the main by-product of rice milling, contains various nutrients which possess hepatoprotective activities. In this study, we investigated the effects of rice bran on carbon tetrachloride (CCl4)-induced liver fibrosis in mice. Mice were fed a rice-bran-containing diet (10% rice bran w/w) or a standard diet with or without an injection of 20% CCl4 to induce liver fibrosis. Our results showed that feeding a rice-bran-containing diet could alleviate CCl4-induced liver damage, collagen deposition, and expressions of fibrosis-related genes, including α-smooth muscle actin (α-SMA), collagen 1a2 (COL1A2), and transforming growth factor-β (TGF-β) in liver tissues. Moreover, consumption of rice bran enhanced phase II detoxification and antioxidant gene expressions, including Gsta3, Gstp1, Catalase, SOD1, SOD2, and SOD3. Treatment with γ-oryzanol, the major bioactive compound in rice bran, decreased the sensitivity of hepatic stellate cells (HSCs) to TGF-β1-induced α-SMA, COL1A2, and phosphorylated smad2 expressions. In conclusion, a rice-bran-containing diet may have beneficial effects on liver fibrogenesis through increased antioxidant and detoxification activities. γ-Oryzanol, the major bioactive compound of rice bran, can inhibit activation of HSCs.

Structural elucidation of a highly branched α-D-glucan from Huangjiu and its hepatoprotective activity via gut microbiome regulation and intestinal barrier repairment

Polysaccharides in Huangjiu, a traditional fermented food, are expected to be potentially effective ingredients in protecting against alcoholic liver disease (ALD). Elucidating their precise structural and functional characteristics is essential for in-depth understanding of structure-activity relationships of hepatoprotective polysaccharides. Herein, a major polysaccharide component HJPS1-2 was purified from Huangjiu with an average molecular weight of 3.49 kDa. Structural analyses inferred that HJPS1-2 backbone was composed of (1 → 4)-linked α-D-Glcp and a single α(1 → 6)-D-Glcp-α(1 → 6)-D-Glcp branched unit for every three α(1 → 4)-D-Glcp. An ALD mouse model was further established to clarify the underlying effect of HJPS1-2 on ALD alleviation. Biochemical detection and histopathological assessment revealed that HJPS1-2 intervention remarkably improved ethanol-induced hepatic dysfunction and steatosis. HJPS1-2 treatment ameliorated gut microbiota dysbiosis of ALD mice in a dose-dependent manner, mainly manifested as restoration of microbial diversities, community structure and bacterial interaction patterns. Compared with ethanol group, the strikingly elevated intestinal short-chain fatty acids' levels and enhanced intestinal barrier function after HJPS1-2 intake might contribute to reduced serum and liver lipopolysaccharide levels and subsequently suppressed release of hepatic inflammatory cytokines, thus mitigating ALD. Collectively, this research supports the potential of food-derived polysaccharides to hinder the early formation and progression of ALD through maintaining intestinal homeostasis.

Nuciferine protects bovine hepatocytes against free fatty acid-induced oxidative damage by activating the transcription factor EB/peroxisome proliferator-activated receptor γ coactivator 1 alpha pathway

Excessive free fatty acid (FFA) oxidation and related metabolism are the major cause of oxidative stress and liver injury in dairy cows during the early postpartum period. In nonruminants, activation of transcription factor EB (TFEB) can improve cell damage and reduce the overproduction of mitochondrial reactive oxygen species. As a downstream target of TFEB, peroxisome proliferator-activated receptor γ coactivator 1 α (PGC-1α, gene name PPARGC1A) is a critical regulator of oxidative metabolism. Nuciferine (Nuc), a major bioactive compound isolated from the lotus leaf, has been reported to possess hepatoprotective activity. Therefore, the objective of this study was to investigate whether Nuc could protect bovine hepatocytes from FFA-induced lipotoxicity and the underlying mechanisms. A mixture of FFA was diluted in RPMI-1640 basic medium containing 2% low fatty acid bovine serum albumin to treat hepatocytes. Bovine hepatocytes were isolated from newborn calves and treated with various concentrations of FFA mixture (0, 0.3, 0.6, or 1.2 mM) or Nuc (0, 25, 50, or 100 μM), as well as co-treated with 1.2 mM FFA and different concentrations of Nuc. For the experiments of gene silencing, bovine hepatocytes were transfected with small interfering RNA targeted against TFEB or PPARGC1A for 36 h followed by treatment with 1.2 mM FFA for 12 h in presence or absence of 100 μΜ Nuc. The results revealed that FFA treatment decreased protein abundance of nuclear TFEB, cytosolic TFEB, total (t)-TFEB, lysosome-associated membrane protein 1 (LAMP1) and PGC-1α and mRNA abundance of LAMP1, but increased phosphorylated (p)-TFEB. In addition, FFA treatment increased the content of malondialdehyde (MDA) and hydrogen peroxide (H2O2) and decreased the activities of catalase (CAT) and glutathione peroxidase (GSH-Px) in bovine hepatocytes. Moreover, FFA administration enhanced the activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and lactose dehydrogenase (LDH) in the medium of FFA-treated hepatocytes, but reduced the content of urea. In FFA-treated bovine hepatocytes, Nuc administration increased TFEB nuclear localization and the protein abundance of t-TFEB, LAMP1, and PGC-1α and mRNA abundance of LAMP1, decreased the contents of MDA and H2O2 and the protein abundance of p-TFEB, and enhanced the activities of CAT and GSH-Px in a dose-dependent manner. Consistently, Nuc administration reduced the activities of ALT, AST, and LDH and increased the content of urea in the medium of FFA-treated hepatocytes. Importantly, knockdown of TFEB reduced the protein abundance of p-TFEB, t-TFEB, LAMP1, and PGC-1α and mRNA abundance of LAMP1, and impeded the beneficial effects of Nuc on FFA-induced oxidative damage in bovine hepatocytes. In addition, PPARGC1A silencing did not alter Nuc-induced nuclear translocation of TFEB, increase of the protein abundance of t-TFEB, LAMP1, and PGC-1α and mRNA abundance of LAMP1, or decrease of the protein abundance of p-TFEB, whereas it partially reduced the beneficial effects of Nuc on FFA-caused oxidative injury. Taken together, Nuc exerts protective effects against FFA-induced oxidative damage in bovine hepatocytes through activation of the TFEB/PGC-1α signaling pathway.

Rice Bran Extract Suppresses High-Fat Diet-Induced Hyperlipidemia and Hepatosteatosis through Targeting AMPK and STAT3 Signaling

Rice bran, a by-product of rice milling, is abundant in bioactive molecules and is highly recognized for its health-promoting properties, particularly in improving metabolic conditions. Building on this knowledge, we aimed to optimize the extraction conditions to maximize the functional efficacy of rice bran extract (RBE) and further validate its impact on lipid metabolism. We found that the optimized RBE (ORBE) significantly suppressed high-fat diet-induced weight gain, hyperlipidemia, and hepatosteatosis in mouse models. ORBE treatment not only suppressed lipid uptake in vivo, but also reduced lipid accumulation in HepG2 cells. Importantly, we discovered that ORBE administration resulted in activation of AMPK and inhibition of STAT3, which are both crucial players in lipid metabolism in the liver. Collectively, ORBE potentially offers promise as a dietary intervention strategy against hyperlipidemia and hepatosteatosis. This study underlines the value of optimized extraction conditions in enhancing the functional efficacy of rice bran.

Red Rice Bran Extract Alleviates High-Fat Diet-Induced Non-Alcoholic Fatty Liver Disease and Dyslipidemia in Mice

Red rice bran extract (RRBE) is rich in phytonutrients and has been shown to have anti-diabetic, anti-inflammatory, and antioxidant properties. However, its anti-hepatic steatosis and anti-dyslipidemic properties have not been thoroughly investigated. This study examined the aforementioned properties of RRBE, the underlying mechanism by which it alleviated non-alcoholic fatty liver disease in high-fat diet (HFD)-fed mice, and its major bioactive constituents. The mice were divided into four groups based on their diet: (1) low-fat diet (LFD), (2) LFD with high-dose RRBE (1 g/kg/day), (3) HFD, and (4) HFD with three different doses of RRBE (0.25, 0.5, and 1 g/kg/day). The administration of RRBE, especially at medium and high doses, significantly mitigated HFD-induced hepatosteatosis and concomitantly improved the serum lipid profile. Further, RRBE modified the level of expression of lipid metabolism-related genes (adipose triglyceride lipase (ATGL), cluster of differentiation 36 (CD36), lipoprotein lipase (LPL), liver X receptor alpha (LXRα), sterol regulatory element-binding protein-1c (SREBP-1c), SREBP-2, 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR), and carnitine palmitoyltransferase 1A (CPT1A)) in hepatic or adipose tissues and improved the expression of hepatic high-density lipoprotein cholesterol (HDL-C) cmetabolism-related genes (hepatic lipase (HL) and apolipoprotein A-ǀ (ApoA-ǀ)). RRBE also attenuated markers of liver injury, inflammation, and oxidative stress, accompanied by a modulated expression of inflammatory (nuclear factor-kappa B (NF-κB) and inducible nitric oxide synthase (iNOS)), pro-oxidant (p47^phox), and apoptotic (B-cell lymphoma protein 2 (Bcl-2)-associated X and Bcl-2) genes in the liver. High-performance liquid chromatography analyses indicated the presence of protocatechuic acid, γ-oryzanol, vitamin E, and coenzyme Q10 in RRBE. Our data indicate that RRBE alleviates HFD-induced hepatosteatosis, dyslipidemia, and their pathologic complications in part by regulating the expression of key genes involved in lipid metabolism, inflammation, oxidative stress, and apoptosis.

The Role of Gut Bacteria and Fungi in Alcohol-Associated Liver Disease

Cirrhosis and liver cancer caused by alcohol-associated liver disease (ALD) are serious threats to people's health. In addition to hepatic cell apoptosis and liver inflammation caused by oxidative stress during alcohol metabolism, intestinal microbiota disorders are also involved in the onset and development of ALD. Ethanol and its' oxidative and non-oxidative metabolites, together with dysbiosis-caused-inflammation, destroys the intestinal barrier. Changes of several microbial metabolites, such as bile acids, short-chain fatty acids, and amino acid, are closely associated with gut dysbiosis in ALD. The alcohol-caused dysbiosis can further influence intestinal barrier-related proteins, such as mucin2, bile acid-related receptors, and aryl hydrocarbon receptor (AhR), and these abnormal changes also participate in the injury of the intestinal barrier and hepatic steatosis. Gut-derived bacteria, fungi, and their toxins, such as lipopolysaccharide (LPS) and β-glucan translocate into the liver through the damaged intestinal barrier and promote the progression of inflammation and fibrosis of ALD. Thus, the prevention of alcohol-induced disruption of intestinal permeability has a beneficial effect on ALD. Currently, multiple therapeutic treatments have been applied to restore the gut microbiota of patients with ALD. Fecal microbial transplantation, probiotics, antibiotics, and many other elements has already shown their ability of restoring the gut microbiota. Targeted approaches, such as using bacteriophages to remove cytolytic Enterococcus faecalis, and supplement with Lactobacillus, Bifidobacterium, or boulardii are also powerful therapeutic options for ALD.

Diet Quality Scores Are Positively Associated with Whole Blood-Derived Mitochondrial DNA Copy Number in the Framingham Heart Study

BACKGROUND

The association between diet quality and mitochondrial DNA copy number (mtDNA-CN) remains to be examined.

OBJECTIVES

We aimed to study the relation between diet quality and mtDNA-CN.

METHODS

We analyzed data from 2931 Framingham Heart Study (FHS) participants (mean age of 57 y, 55% females). Whole-genome sequencing was used to calculate mtDNA-CN from whole-blood samples. We examined the cross-sectional associations between 3 diet quality scores, the Dietary Approaches to Stop Hypertension (DASH) score, the Alternative Healthy Eating Index (AHEI), and the Mediterranean diet score (MDS), and mtDNA-CN. Linear mixed models were used to account for maternal lineage.

RESULTS

We observed that a higher DASH score was positively associated with mtDNA-CN after adjusting for sex, age, energy intake, smoking status, alcohol intake, and physical activity level. A 1-SD increase in the DASH score was associated with a 0.042-SD greater mtDNA-CN (95% CI: 0.007, 0.077; P = 0.02). Similarly, for each SD increase in AHEI and MDS, the mtDNA-CN SD increased by 0.056 (95% CI: 0.019, 0.092; P = 0.003) and 0.047 (95% CI: 0.01, 0.083; P = 0.01), respectively. Diet quality scores were associated with neutrophil and lymphocyte counts but not platelet counts, e.g., for a 1-SD increase in the DASH, neutrophils decreased by 0.8% (95% CI: 0.5%, 1.1%; P = 4.1 × 10-6), lymphocytes increased by 0.7% (95% CI: 0.4%, 1%, P = 1.2 × 10-5), and there was no significant change in platelet number (0.1 × 1000/μL; 95% CI: -1.6, 1.9; P = 0.89). Further adjustment for neutrophil, lymphocyte, and platelet counts and the associations between diet quality scores and mtDNA-CN were completely attenuated to nonsignificant (P = 0.95, 0.54, and 0.91, respectively).

CONCLUSIONS

We observed that higher diet quality is associated with a greater whole-blood derived mtDNA-CN in middle-aged to older adult FHS participants, and that blood cell composition, particularly neutrophil counts, attenuated the association between diet quality and mtDNA-CN.

Protective Mechanism of Edible Food Plants against Alcoholic Liver Disease with Special Mention to Polyphenolic Compounds

Alcoholic liver disease (ALD) is one type of liver disease, causing a global healthcare problem and mortality. The liver undergoes tissue damage by chronic alcohol consumption because it is the main site for metabolism of ethanol. Chronic alcohol exposure progresses from alcoholic fatty liver (AFL) to alcoholic steatohepatitis (ASH), which further lead to fibrosis, cirrhosis, and even hepatocellular cancer. Therapeutic interventions to combat ALD are very limited such as use of corticosteroids. However, these therapeutic drugs are not effective for long-term usage. Therefore, additional effective and safe therapies to cope with ALD are urgently needed. Previous studies confirmed that edible food plants and their bioactive compounds exert a protective effect against ALD. In this review article, we summarized the hepatoprotective potential of edible food plants and their bioactive compounds. The underlying mechanism for the prevention of ALD by edible food plants was as follows: anti-oxidation, anti-inflammation, lipid regulation, inhibition of apoptosis, gut microbiota composition modulation, and anti-fibrosis.

Synthesis and Photoactivated Toxicity of 2-Thiophenylfuranocoumarin Induce Midgut Damage and Apoptosis in Aedes aegypti Larvae

Furanocoumarins are photoactive compounds derived from secondary plant metabolites. They possess many bioactivities, including antioxidative, anticancer, insecticidal, and bactericidal activities. Here, we designed a new scheme for synthesizing 2-arylfuranocoumarin derivatives by condensation, esterification, bromination, and Wittig reaction. We found that 2-thiophenylfuranocoumarin (Iy) had excellent photosensitive activity. Three Iy concentrations (LC₂₅, LC₅₀, and LC₇₅) were used to treat the fourth instar larvae of Aedes aegypti (A. aegypti). The photoactivated toxicity, sublethal dose, mitochondrial dysfunction, oxidative stress level, intestinal barrier dysfunction, and apoptosis were studied. The results showed that Iy induced reactive oxygen species (ROS) production in midgut cells under ultraviolet light. Ultrastructural analysis demonstrated that mitochondria were damaged, and the activities of related enzymes were inhibited. Ultimately, Iy exposure led to excessive ROS production followed by the inhibition of antioxidant enzymes, including SOD, CAT, GPx, and GR, which diminished ROS elimination and escalated oxidative stress in midgut cells, aggravating the degree of oxidative damage in these cells. Histopathological changes were observed in the midgut, which led to intestinal barrier dysfunction. When the elimination of ROS was blocked and it accumulated in cells, apoptosis-related genes, including AeDronc, AeCaspase7, and AeCaspase8, were induced and activated. In addition, Iy affected the growth and development of A. aegypti at sublethal concentrations, and there was an obvious post-lethal effect. Thus, we found that Iy caused midgut damage and apoptosis in A. aegypti larvae under ultraviolet light, which preliminarily revealed the mode of action of Iy in A. aegypti.