Targeting peroxisomal fatty acid oxidation improves hepatic steatosis and insulin resistance in obese mice

Dendrobium officinale leaf phenolic extracts alleviate diabetes mellitus in mice via modulating metabolism and reshaping gut microbiota

BACKGROUND

Diabetes mellitus is a chronic metabolic disorder posing a significant public health challenge. Dendrobium officinale is a valuable edible-medicinal homologous plant. Phenolic extracts from fermented D. officinale leaves (DOLP) demonstrate a hypoglycemic effect. However, the effects of DOLP on physiological metabolism and gut microbiota under diabetic conditions remain unknown.

RESULTS

Untargeted metabolomics analysis revealed that DOLP reversed 98 significantly differential metabolites (SDMs) in diabetic mice. Indoxyl sulfate and palmitoyl sphingomyelin were identified as the primary candidate biomarkers associated with the hypoglycemic effect. KEGG pathway enrichment analysis underscored the significance of arginine and proline metabolism, ascorbate and aldarate metabolism, and fatty acid metabolism in the regulatory effects of DOLP. Furthermore, DOLP reversed the dysbiosis of the gut microbiota in diabetic mice, significantly influencing the relative abundance of the genera Intestinimonas, GCA_900066575, Muribaculum, and Enterorhabdus. These differential genera exhibited various correlations with SDMs, including l-hydroxyarginine, γ-guanidinobutyrate, l-threonate, d-galactarate, l-ascorbic acid, palmitic acid, cis-9-palmitoleic acid, octadecanoic acid, and oleic acid.

CONCLUSION

The protective effect of DOLP against diabetes mellitus is closely linked to its regulation of physiological metabolism and gut microbiota. DOLP may serve as a promising agent for the prevention and treatment of diabetes mellitus. © 2025 Society of Chemical Industry.

A comprehensive approach, based on the use of Caenorhabditis elegans, mouse, and human models, elucidates the impact of Lactiplantibacillus plantarum TWK10 on exercise performance and longevity

The functionality of probiotics is highly influenced by culture and processing conditions, making batch stability validation through human or mouse trials impractical. Here, we employed a comprehensive approach using Caenorhabditis elegans, mouse and human models to elucidate the beneficial effects of Lactiplantibacillus plantarum TWK10 (TWK10). In C. elegans, TWK10 administration significantly prolonged lifespan by 26.1 ± 11.9 % (p < 0.05), enhanced locomotion (p < 0.01) and muscle mass (p < 0.001), elevated glycogen storage (p < 0.05), and reduced lipid accumulation (p < 0.001), outperforming Lacticaseibacillus rhamnosus GG and L. plantarum type strain ATCC 14917T. We also confirmed the equivalence of laboratory-prepared and mass-produced TWK10 in ergogenic efficacy using C. elegans assay. In mice, oral administration of mass-produced TWK10 significantly enhanced exercise performance and glycogen storage in muscle and liver in a dose-dependent manner. In a clinical study involving healthy male adults, significant improvements in grip strength (1.1-fold, p < 0.01) and exhaustion time (1.27-fold, p < 0.01), and significant reductions in circulating lactate and ammonia levels were observed in the TWK10 group (1 × 1010 colony-forming unit/day) compared to the control group. Both humans and mice receiving mass-produced TWK10 showed improved body composition with increased muscle mass and reduced fat mass. In conclusion, TWK10 demonstrates superior longevous and ergogenic effects in C. elegans compared to reference strains. The consistent ergogenic efficacy of mass-produced TWK10 across C. elegans, mice, and humans, highlights the utility of C. elegans as a reliable model for probiotic research and industrial application.

Targeting ABCD1-ACOX1-MET/IGF1R axis suppresses multiple myeloma

Multiple myeloma (MM) remains an incurable hematological malignancy that necessitates the identification of novel therapeutic strategies. Here, we report that intracellular levels of very long chain fatty acids (VLCFAs) control the cytotoxicity of MM chemotherapeutic agents. Inhibition of VLCFA biosynthesis reduced cell death in MM cells caused by the proteasome inhibitor, bortezomib. Conversely, inhibition of VLCFA degradation via suppression of peroxisomal acyl-CoA oxidase 1 (ACOX1) increased the cytotoxicity of bortezomib, its next-generation analog, carfilzomib, and the immunomodulatory agent lenalidomide. Furthermore, treatment with an orally available ACOX1 inhibitor cooperated with bortezomib in suppressing the growth of bortezomib-resistant MM xenografts in mice. Increased VLCFA levels caused by genetic or pharmacological inhibition of VLCFA degradation reduced the activity of two major kinases involved in MM pathogenesis, MET proto-oncogene (MET) and insulin-like growth factor 1 receptor (IGF1R). Mechanistically, inhibition of ACOX1 promoted the accumulation of VLCFA-containing cerebrosides, altered MET and IGF1R interaction with a cerebroside analog, and selectively inhibited the association of these kinases with the plasma membrane signaling platforms, importantly, without disrupting the platforms' integrity. Our study revealed a specific metabolic vulnerability of MM cells and identified a targetable axis linking VLCFA metabolism to the regulation of MET and IGF1R activity.

Polysaccharide extracted from Phellinus igniarius attenuated hyperuricemia by modulating bile acid metabolism and inhibiting uric acid synthesis in adenine/potassium oxonate-treated mice

ETHNOPHARMACOLOGICAL RELEVANCE

Phellinus igniarius (Linnearus: Fries) Quelet (Phellinus igniarius) is an edible and medicinal fungi and has been used in China for centuries. It is found to improve organs function and metabolic homeostasis including ameliorating hyperuricemia (HUA). Polysaccharide is a predominant component in P. igniarius.

AIMS OF THIS STUDY

This study aimed to investigate the anti-HUA effects and underlying mechanism of the polysaccharide extracted from P. igniarius (PPI).

MATERIALS AND METHODS

PPI was extracted and characterized by molecular weight, monosaccharide composition and FT-IR spectroscopy. HUA was induced in C57BL/6 male mice by gavage of adenine/potassium oxonate for 14 days. PPI (2.2, 4.4 or 8.8 mg/kg) was orally given to HUA mice and its effects on HUA were determined.

RESULTS

Compared to HUA group, PPI significantly reduced the serum levels of uric acid (UA), creatinine, blood urea nitrogen (BUN), AST, ALT, and total cholesterol. In the liver of HUA mice, PPI notably inhibited the activity of xanthine oxidase (XOD) and its expression mediated by peroxisome proliferator-activated receptor α (PPARα), suggesting a decrease in UA synthesis. Furthermore, PPI was found to modulate enterohepatic bile acid (BA) metabolism. The profile of BAs showed that PPI significantly elevated the TUDCA + THDCA levels in the liver of HUA mice. In the hepatocytes HepG2, TUDCA decreased the expression of PPARα/XOD and reduced UA production, whereas THDCA did not present similar effects. The anti-HUA effects of TUDCA was further confirmed in HUA mice, where it lowered serum UA level and inhibited XOD expression and activity.

CONCLUSION

This study demonstrates that PPI ameliorates HUA in vivo, and this effect may be mediated by the regulation of bile acid metabolism, particularly through the function of TUDCA in suppressing UA production in the liver.

Loss of long-chain acyl-CoA dehydrogenase protects against acute kidney injury

The renal tubular epithelial cells (RTECs) are particularly vulnerable to acute kidney injury (AKI). While fatty acids are the preferred energy source for RTECs via fatty acid oxidation (FAO), FAO-mediated H2O2 production in mitochondria has been shown to be a major source of oxidative stress. We have previously shown that a mitochondrial flavoprotein, long-chain acyl-CoA dehydrogenase (LCAD), which catalyzes a key step in mitochondrial FAO, directly produces H2O2 in vitro. Furthermore, we showed that renal LCAD becomes hyposuccinylated during AKI. Here, we demonstrated that succinylation of recombinant LCAD protein suppresses the production of H2O2. Following 2 distinct models of AKI, cisplatin treatment or renal ischemia/reperfusion injury (IRI), LCAD-/- mice demonstrated renoprotection. Specifically, LCAD-/- kidneys displayed mitigated renal tubular injury, decreased oxidative stress, preserved mitochondrial function, enhanced peroxisomal FAO, and decreased ferroptotic cell death. LCAD deficiency confers protection against 2 distinct models of AKI. This suggests a therapeutically attractive mechanism whereby preserved mitochondrial respiration as well as enhanced peroxisomal FAO by loss of LCAD mediates renoprotection against AKI.

Adipose Tissues Have Been Overlooked as Players in Prostate Cancer Progression

Obesity is a common risk factor in multiple tumor types, including prostate cancer. Obesity has been associated with driving metastasis, therapeutic resistance, and increased mortality. The effect of adipose tissue on the tumor microenvironment is still poorly understood. This review aims to highlight the work conducted in the field of obesity and prostate cancer and bring attention to areas where more research is needed. In this review, we have described key differences between healthy adipose tissues and obese adipose tissues, as they relate to the tumor microenvironment, focusing on mechanisms related to metabolic changes, abnormal adipokine secretion, altered immune cell presence, and heightened oxidative stress as drivers of prostate cancer formation and progression. Interestingly, common treatment options for prostate cancer ignore the adipose tissue located near the site of the tumor. Because of this, we have outlined how excess adipose tissue potentially affects therapeutics' efficacy, such as androgen deprivation, chemotherapy, and radiation treatment, and identified possible drug targets to increase prostate cancer responsiveness to clinical treatments. Understanding how obesity affects the tumor microenvironment will pave the way for understanding why some prostate cancers become metastatic or treatment-resistant, and why patients experience recurrence.

Loss of long-chain acyl-CoA dehydrogenase protects against acute kidney injury

Proximal tubular epithelial cells (PTECs) are particularly vulnerable to acute kidney injury (AKI). While fatty acids are the preferred energy source for PTECs via fatty acid oxidation (FAO), FAO-mediated H 2 O 2 production in mitochondria has been shown to be a major source of oxidative stress. We have previously shown that a mitochondrial flavoprotein, long-chain acyl-CoA dehydrogenase (LCAD), which catalyzes a key step in mitochondrial FAO, directly produces H 2 O 2 in vitro . Further we have established that loss of a lysine deacylase, Sirtuin 5 ( Sirt5 -/- ), induces hypersuccinylation and inhibition of mitochondrial FAO genes to stimulate peroxisomal FAO and to protect against AKI. However, the role of LCAD has yet to be determined. Mass spectrometry data acquisition revealed that LCAD is hypersuccinylated in Sirt5 -/- kidneys after AKI. Following two distinct models of AKI, cisplatin treatment or renal ischemia/reperfusion (IRI), LCAD knockout mice ( LCAD -/- ) demonstrated renoprotection against AKI. Specifically, LCAD -/- kidneys displayed mitigated renal tubular injury, decreased oxidative stress, preserved mitochondrial function, enhanced peroxisomal FAO, and decreased ferroptotic cell death. LCAD deficiency confers protection against two distinct models of AKI. This suggests a therapeutically attractive mechanism whereby preserved mitochondrial respiration as well as enhanced peroxisomal FAO by loss of LCAD mediates renoprotection against AKI.

Electrochemical and Fluorescence MnO2-Polymer Dot Electrode Sensor for Osteoarthritis-Based Peroxisomal β-Oxidation Knockout Model

A coenzyme A (CoA-SH)-responsive dual electrochemical and fluorescence-based sensor was designed utilizing an MnO2-immobilized-polymer-dot (MnO2@D-PD)-coated electrode for the sensitive detection of osteoarthritis (OA) in a peroxisomal β-oxidation knockout model. The CoA-SH-responsive MnO2@D-PD-coated electrode interacted sensitively with CoA-SH in OA chondrocytes, triggering electroconductivity and fluorescence changes due to cleavage of the MnO2 nanosheet on the electrode. The MnO2@D-PD-coated electrode can detect CoA-SH in immature articular chondrocyte primary cells, as indicated by the significant increase in resistance in the control medium (R24h = 2.17 MΩ). This sensor also sensitively monitored the increase in resistance in chondrocyte cells in the presence of acetyl-CoA inducers, such as phytol (Phy) and sodium acetate (SA), in the medium (R24h = 2.67, 3.08 MΩ, respectively), compared to that in the control medium, demonstrating the detection efficiency of the sensor towards the increase in the CoA-SH concentration. Furthermore, fluorescence recovery was observed owing to MnO2 cleavage, particularly in the Phy- and SA-supplemented media. The transcription levels of OA-related anabolic (Acan) and catabolic factors (Adamts5) in chondrocytes also confirmed the interaction between CoA-SH and the MnO2@D-PD-coated electrode. Additionally, electrode integration with a wireless sensing system provides inline monitoring via a smartphone, which can potentially be used for rapid and sensitive OA diagnosis.

Investigating the physicochemical characteristics and importance of insoluble dietary fiber extracted from legumes: An in-depth study on its biological functions

Legumes are widely appreciated for their abundant reserves of insoluble dietary fiber, which are characterized by their high fiber content and diverse bioactive compounds. Insoluble dietary fiber in leguminous crops is primarily localized in the structural cell walls and outer integument and exhibits strong hydrophilic properties that enable water absorption and volumetric expansion, resulting in increased food bulk and viscosity. This contributes to enhanced satiety and accelerated gastrointestinal transit. The benefits of legume insoluble dietary fiber extend to its notable antioxidant, anti-inflammatory, and anti-cancer properties, as well as its ability to modulate the composition of the intestinal microbiota, promoting the growth of beneficial bacteria while suppressing the proliferation of harmful pathogens, thereby promoting optimal intestinal health. It is highly valued as a valuable thickening agent, stabilizer, and emulsifier, contributing to the texture and stability of a wide range of food products.

Mid-Long Chain Dicarboxylic Acid Production via Systems Metabolic Engineering: Progress and Prospects

Mid-to-long-chain dicarboxylic acids (DCAi, i ≥ 6) are organic compounds in which two carboxylic acid functional groups are present at the terminal position of the carbon chain. These acids find important applications as structural components and intermediates across various industrial sectors, including organic compound synthesis, food production, pharmaceutical development, and agricultural manufacturing. However, conventional petroleum-based DCA production methods cause environmental pollution, making sustainable development challenging. Hence, the demand for eco-friendly processes and renewable raw materials for DCA production is rising. Owing to advances in systems metabolic engineering, new tools from systems biology, synthetic biology, and evolutionary engineering can now be used for the sustainable production of energy-dense biofuels. Here, we explore systems metabolic engineering strategies for DCA synthesis in various chassis via the conversion of different raw materials into mid-to-long-chain DCAs. Subsequently, we discuss the future challenges in this field and propose synthetic biology approaches for the efficient production and successful commercialization of these acids.

Nuclear Receptor PPARα as a Therapeutic Target in Diseases Associated with Lipid Metabolism Disorders

Lipid metabolic diseases have substantial morbidity and mortality rates, posing a significant threat to human health. PPARα, a member of the peroxisome proliferator-activated receptors (PPARs), plays a crucial role in lipid metabolism and immune regulation. Recent studies have increasingly recognized the pivotal involvement of PPARα in diverse pathological conditions. This comprehensive review aims to elucidate the multifaceted role of PPARα in metabolic diseases including liver diseases, diabetes-related diseases, age-related diseases, and cancers, shedding light on the underlying molecular mechanisms and some regulatory effects of natural/synthetic ligands of PPARα. By summarizing the latest research findings on PPARα, we aim to provide a foundation for the possible therapeutic exploitation of PPARα in lipid metabolic diseases.

Effects of a High-Fat Diet and Docosahexaenoic Acid during Pregnancy on Fatty Acid Composition in the Fetal Livers of Mice

A high-fat diet (HFD) during pregnancy promotes fat accumulation and reduces docosahexaenoic acid (DHA) levels in the liver of the offspring at postnatal ages, which can depend on fetal sex. However, the prenatal mechanisms behind these associations are still unclear. Thus, we analyzed if an HFD alters DHA content and the expression of molecules related to fatty acid (FA) metabolism in the fetal liver. Female C57BL/6 mice were fed a control diet or HFD for 4-6 weeks before pregnancy until the gestational day (GD) 17.5. A subgroup of each diet received DHA (100 mg/Kg) orally from GD 6.5 until 16.5. On GD 17.5, maternal livers, placentas, and livers from male and female fetuses were collected for FA profiling with gas-chromatography and gene expression of molecules related to FA metabolism using qPCR. PPAR-α protein expression was evaluated using Western blot. The gene expression of placental FA transporters was also assessed. An HFD increased eicosapentaenoic acid (EPA) and decreased DHA levels and protein expression of PPAR-α in the fetal livers of both sexes. DHA increased the gene expression of Ppara, Cpt1, and Acsl1 in the livers of female fetuses. Therefore, an HFD reduces DHA levels and PPAR-α, a master regulator of gene expression, in the fetal liver. In turn, the livers of female fetuses seem to be more sensitive to DHA action.

Long-chain dicarboxylic acids play a critical role in inducing peroxisomal β-oxidation and hepatic triacylglycerol accumulation

Recent studies provide evidence that peroxisomal β-oxidation negatively regulates mitochondrial fatty acid oxidation, and induction of peroxisomal β-oxidation causes hepatic lipid accumulation. However, whether there exists a triggering mechanism inducing peroxisomal β-oxidation is not clear. Long-chain dicarboxylic acids (LCDAs) are the product of mono fatty acids subjected to ω-oxidation, and both fatty acid ω-oxidation and peroxisomal β-oxidation are induced under ketogenic conditions, indicating there might be a crosstalk between. Here, we revealed that administration of LCDAs strongly induces peroxisomal fatty acid β-oxidation and causes hepatic steatosis in mice through the metabolites acetyl-CoA and hydrogen peroxide. Under ketogenic conditions, upregulation of fatty acid ω-oxidation resulted in increased generation of LCDAs and induction of peroxisomal β-oxidation, which causes hepatic accumulation of lipid droplets in animals. Inhibition of fatty acid ω-oxidation reduced LCDA formation and significantly lowered peroxisomal β-oxidation and improved hepatic steatosis. Our results suggest that endogenous LCDAs act as triggering molecules inducing peroxisomal β-oxidation and hepatic triacylglycerol deposition. Targeting fatty acid ω-oxidation might be an effective pathway in treating fatty liver and related metabolic diseases through regulating peroxisomal β-oxidation.

Insoluble Dietary Fiber from Soybean Residue (Okara) Exerts Anti-Obesity Effects by Promoting Hepatic Mitochondrial Fatty Acid Oxidation

Numerous investigations have shown that insoluble dietary fiber (IDF) has a potentially positive effect on obesity due to a high-fat diet (HFD). Our previous findings based on proteomic data revealed that high-purity IDF from soybean residue (okara) (HPSIDF) prevented obesity by regulating hepatic fatty acid synthesis and degradation pathways, while its intervention mechanism is uncharted. Consequently, the goal of this work is to find out the potential regulatory mechanisms of HPSIDF on hepatic fatty acid oxidation by determining changes in fatty acid oxidation-related enzymes in mitochondria and peroxisomes, the production of oxidation intermediates and final products, the composition and content of fatty acids, and the expression levels of fatty acid oxidation-related proteins in mice fed with HFD. We found that supplementation with HPSIDF significantly ameliorated body weight gain, fat accumulation, dyslipidemia, and hepatic steatosis caused by HFD. Importantly, HPSIDF intervention promotes medium- and long-chain fatty acid oxidation in hepatic mitochondria by improving the contents of acyl-coenzyme A oxidase 1 (ACOX1), malonyl coenzyme A (Malonyl CoA), acetyl coenzyme A synthase (ACS), acetyl coenzyme A carboxylase (ACC), and carnitine palmitoyl transferase-1 (CPT-1). Moreover, HPSIDF effectively regulated the expression levels of proteins involved with hepatic fatty acid β-oxidation. Our study indicated that HPSIDF treatment prevents obesity by promoting hepatic mitochondrial fatty acid oxidation.