Omega-3 Fatty Acids Attenuate Renal Fibrosis via AMPK-Mediated Autophagy Flux Activation

Spatially Resolved Metabolomics and Network Pharmacology Reveal Extract D Nephrotoxicity Mechanisms in Pleuropterus multiflorus Thunb

As a traditional Chinese medicine, the adverse hepatotoxicity effects of Pleuropterus multiflorus (Thunb.) Nakai (PM) have been documented. However, nephrotoxicity has been neglected as studies related to kidney toxicity mechanisms are limited. Our previous research reported that extract D [95% ethanol (EtOH) elution, PM-D] in a 70% EtOH PM extract showed more significant hepatotoxicity than other extracts. In the current study, PM-D was continuously administered to mice for 7 days at a dose of 2 g/kg (equivalent to a human dose of 219.8 mg/kg), which increased renal biochemical indexes and caused pathological kidney injury, suggesting renal toxicity. Therefore, network pharmacology and spatially resolved metabolomics were conducted to explore nephrotoxicity mechanisms underpinning PM-D. Network pharmacology indicated that BCL2, HSP90, ESR1, and CTNNB1 genes were core targets, while the phosphoinositide 3-kinase (PI3K)/protein kinase B(AKT)/signaling pathway was significantly enriched. Spatially resolved metabolomics indicated heterogeneous metabolite distribution in the kidney, further indicating that PM-D nephrotoxic metabolic pathways were enriched for α-linolenic acid and linoleic acid metabolism, pyrimidine metabolism, carnitine synthesis, and branched-chain fatty acid oxidation. Our comprehensive analyses highlighted that nephrotoxicity mechanisms were related to oxidative stress and apoptosis induced by disordered energy metabolism, lipid metabolism issues, and imbalanced nucleotide metabolism, which provide a platform for further research into PM nephrotoxicity mechanisms.

Development of a fish oil-nanoemulsion gel as a drug-delivery system to prevent capsular contracture

Capsular contracture, a significant complication of breast-implant surgery, causes pain and deformation following the formation of a tight capsule around an implant. Current surgical and non-surgical treatment options are invasive, expensive, and typically administered for prolonged periods, potentially leading to side effects. To address these challenges, we developed a novel fish oil-encapsulated, poloxamer-based nanoemulsion gel with omega-3 (ω3) as the primary active component (NE-ω3 gel; N3G). This formulation can be injected during surgery, reducing the need for prolonged administration of medications and minimizing associated side effects. N3G was prepared through a two-step process involving the emulsification of fish oil followed by gelation with poloxamer to create a thermoreversible gel. Dynamic light-scattering analysis confirmed a uniform distribution of nanoemulsion particles, which had a mean diameter of 287 ± 8.599 nm and a PDI of 0.29 ± 0.047. FTIR and DSC analyses validated the encapsulation of fish oil within poloxamer micelles. Drug-release analysis demonstrated that more than 96% of fish oil was released within 10 h. In in vivo experiments, rats (n = 30) were divided into three groups: a negative control group (G1), a positive control group receiving fish oil (G2), and an experimental group with implants coated with N3G (G3). G3 exhibited a 21.2% reduction in capsular thickness compared to G1 and a 5.6% reduction compared to G2. In addition, significant decreases in fibrosis and myofibroblast counts were observed in G3. These results, supported by histological and gene expression analyses, highlight the effectiveness of N3G in reducing inflammation and fibrosis. This study underscores the therapeutic potential of N3G for capsular contracture, based on its persistence, thermoreversibility, and improved dosing and storage characteristics.

Autophagy and autophagic cell death in sepsis: friend or foe?

In sepsis, inflammation, and nutrient deficiencies endanger cellular homeostasis and survival. Autophagy is primarily a mechanism of cellular survival under fasting conditions. However, autophagy-dependent cell death, known as autophagic cell death, is proinflammatory and can exacerbate sepsis. Autophagy also regulates various types of non-inflammatory and inflammatory cell deaths. Non-inflammatory apoptosis tends to suppress inflammation, however, inflammatory necroptosis, pyroptosis, ferroptosis, and autophagic cell death lead to the release of inflammatory cytokines and damage-associated molecular patterns (DAMPs) and amplify inflammation. The selection of cell death mechanisms is complex and often involves a mixture of various styles. Similarly, protective autophagy and lethal autophagy may be triggered simultaneously in cells. How cells balance the regulatory mechanisms of these processes is an area of interest that is still under investigation. Therapies aimed at modulating autophagy are considered promising. Enhancing autophagy helps clear and recycle damaged organelles and reduce the burden of inflammatory processes while inhibiting excessive autophagy, which could prevent autophagic cell death. In this review, we introduce recent advances in research and the complex regulatory system of autophagy in sepsis.

Protective effect of long-chain polyunsaturated fatty acids on hepatorenal syndrome in rats

BACKGROUND

Hepatorenal syndrome (HRS) is the most prevalent form of acute kidney injury in cirrhotic patients. It is characterized by reduced renal blood flow and represents the most severe complication in cirrhotic patients with advanced disease. Previous research has indicated that antioxidants can delay the onset of a hyperdynamic circulatory state in cirrhosis and improve renal function in HRS patients. Regular omega-3 supplementation has significantly reduced the risk of liver disease. This supplementation could represent an additional therapy for individuals with HRS.

AIM

To evaluated the antioxidant effect of omega-3 polyunsaturated fatty acid supplementation on the kidneys of cirrhotic rats.

METHODS

Secondary biliary cirrhosis was induced in rats by biliary duct ligation (BDL) for 28 d. We used 24 male Wistar rats divided into the following groups: I (control); II (treated with omega-3, 1 g/kg of body weight); III (BDL treated with omega-3, 1 g/kg of body weight); and IV (BDL without treatment). The animals were killed by overdose of anesthetic; the kidneys were dissected, removed, frozen in liquid nitrogen, and stored in a freezer at -80℃ for later analysis. We evaluated oxidative stress, nitric oxide (NO) metabolites, DNA damage by the comet assay, cell viability test, and apoptosis in the kidneys. Data were analyzed by one-way analysis of variance, and means were compared using the Tukey test, with P ≤ 0.05.

RESULTS

Omega-3 significantly decreased the production of reactive oxygen species (P < 0.001) and lipoperoxidation in the kidneys of cirrhotic rats treated with omega-3 (P < 0.001). The activity of the antioxidant enzymes superoxide dismutase and catalase increased in the BDL+omega-3 group compared to the BDL group (P < 0.01). NO production, DNA damage, and caspase-9 cleavage decreased significantly in the omega-3-treated BDL group. There was an increase in mitochondrial electrochemical potential (P < 0.001) in BDL treated with omega-3 compared to BDL. No changes in the cell survival index in HRS with omega-3 compared to the control group (P > 0.05) were observed.

CONCLUSION

The study demonstrates that omega-3 can protect cellular integrity and function by increasing antioxidant enzymes, inhibiting the formation of free radicals, and reducing apoptosis.

Insights on E1-like enzyme ATG7: functional regulation and relationships with aging-related diseases

Autophagy is a dynamic self-renovation biological process that maintains cell homeostasis and is responsible for the quality control of proteins, organelles, and energy metabolism. The E1-like ubiquitin-activating enzyme autophagy-related gene 7 (ATG7) is a critical factor that initiates classic autophagy reactions by promoting the formation and extension of autophagosome membranes. Recent studies have identified the key functions of ATG7 in regulating the cell cycle, apoptosis, and metabolism associated with the occurrence and development of multiple diseases. This review summarizes how ATG7 is precisely programmed by genetic, transcriptional, and epigenetic modifications in cells and the relationship between ATG7 and aging-related diseases.