Carrier Proteins ; Autophagy ; Lipid Metabolism

Lipophagy, the selective engulfment of lipid droplets (LDs) by autophagosomes for lysosomal degradation, is critical to lipid and energy homeostasis. Here we show that the lipid transfer protein ORP8 is located on LDs and mediates the encapsulation of LDs by autophagosomal membranes. This function of ORP8 is independent of its lipid transporter activity and is achieved through direct interaction with phagophore-anchored LC3/GABARAPs. Upon lipophagy induction, ORP8 has increased localization on LDs and is phosphorylated by AMPK, thereby enhancing its affinity for LC3/GABARAPs. Deletion of ORP8 or interruption of ORP8-LC3/GABARAP interaction results in accumulation of LDs and increased intracellular triglyceride. Overexpression of ORP8 alleviates LD and triglyceride deposition in the liver of ob/ob mice, and Osbpl8-/- mice exhibit liver lipid clearance defects. Our results suggest that ORP8 is a lipophagy receptor that plays a key role in cellular lipid metabolism.
Animals ; Mice ; Lipid Droplets ; Autophagy ; Autophagosomes ; Homeostasis ; Triglycerides

In the context of non-alcoholic fatty liver disease (NAFLD), characterized by dysregulated lipid metabolism in hepatocytes, the quest for safe and effective therapeutics targeting lipid metabolism has gained paramount importance. Sanhuang Xiexin Tang (SXT) and Baihu Tang (BHT) have emerged as prominent candidates for treating metabolic disorders. SXT combined with BHT plus Cangzhu (SBC) has been used clinically for Weihuochisheng obese patients. This retrospective analysis focused on assessing the anti-obesity effects of SBC in Weihuochisheng obese patients. We observed significant reductions in body weight and hepatic lipid content among obese patients following SBC treatment. To gain further insights, we investigated the effects and underlying mechanisms of SBC in HFD-fed mice. The results demonstrated that SBC treatment mitigated body weight gain and hepatic lipid accumulation in HFD-fed mice. Pharmacological network analysis suggested that SBC may affect lipid metabolism, mitochondria, inflammation, and apoptosis-a hypothesis supported by the hepatic transcriptomic analysis in HFD-fed mice treated with SBC. Notably, SBC treatment was associated with enhanced hepatic mitochondrial biogenesis and the inhibition of the c-Jun N-terminal kinase (JNK)/nuclear factor-kappa B (NF-κB) and extracellular signal-regulated kinase (ERK)/NF-κB pathways. In conclusion, SBC treatment alleviates NAFLD in both obese patients and mouse models by improving lipid metabolism, potentially through enhancing mitochondrial biogenesis. These effects, in turn, ameliorate inflammation in hepatocytes.
Humans ; Mice ; Animals ; Non-alcoholic Fatty Liver Disease/metabolism* ; NF-kappa B/metabolism* ; Organelle Biogenesis ; Retrospective Studies ; Mice, Inbred C57BL ; Obesity/metabolism* ; Liver ; Inflammation/metabolism* ; Body Weight ; Lipid Metabolism ; Lipids ; Diet, High-Fat/adverse effects*

OBJECTIVES: To observe the effects on the glucose-lipid metabolism and the expression of zinc-α2-glycoprotein (ZAG) and glucose transporter 4 (GLUT4) in the femoral quadriceps and adipose tissue after electroacupuncture (EA) at "Pishu" (BL 20), "Weiwanxiashu" (EX-B 3), "Zusanli" (ST 36) and "Sanyinjiao" (SP 6) in the rats with diabetes mellitus type 2 (T2DM), so as to explore the effect mechanism of EA in treatment of T2DM. METHODS: Twelve ZDF male rats were fed with high-sugar and high-fat fodder, Purina #5008 for 4 weeks to induce T2DM model. After successfully modeled, the rats were randomly divided into a model group and an EA group, with 6 rats in each one. Additionally, 6 ZL male rats of the same months age were collected as the blank group. The rats in the EA group were treated with EA at bilateral "Pishu" (BL 20), "Weiwanxiashu" (EX-B 3), "Zusanli" (ST 36) and "Sanyinjiao" (SP 6), with continuous wave, 15 Hz in frequency, and 2 mA in intensity. The electric stimulation lasted 20 min each time. EA was delivered once daily, 6 times a week for 4 weeks. Separately, the levels of fasting blood glucose (FBG) was measured before modeling, before and after intervention, and the body mass of each rat was weighted before and after intervention. After intervention, the levels of the total cholesterol (TC), triacylglycerol (TG) and free fatty acid (FFA) in serum were detected using enzyme colorimetric method; and the levels of the serum insulin (INS) and ZAG were detected by ELISA. Besides, the insulin sensitivity index (HOMA-ISI) was calculated. With Western blot technique adopted, the protein expressions of ZAG and GLUT4 in the femoral quadriceps and adipose tissue were determined. RESULTS: After intervention, compared with the blank group, the levels of FBG and body mass, and the levels of serum TC, TG, FFA and INS increased (P<0.01), while HOMA-ISI decreased (P<0.01); the level of ZAG in the serum and the protein expressions of ZAG and GLUT4 in the femoral quadriceps and adipose tissue dropped (P<0.01) in the model group. In the EA group, compared with the model group, the levels of FBG and body mass, and the levels of serum TC, TG, FFA and INS were reduced (P<0.01), and HOMA-ISI increased (P<0.01); the level of ZAG in the serum and the protein expressions of ZAG and GLUT4 in the femoral quadriceps and adipose tissue increased (P<0.01, P<0.05). CONCLUSIONS Electroacupuncture can effectively regulate glucose-lipid metabolism, improve insulin resistance and sensitivity in the rats with T2DM, which is associated with the modulation of ZAG and GLUT4 expression in the skeletal muscle and adipose tissue.
Rats ; Male ; Animals ; Glucose/metabolism* ; Electroacupuncture ; Rats, Sprague-Dawley ; Diabetes Mellitus, Type 2/therapy* ; Lipid Metabolism ; Triglycerides ; Adipose Tissue/metabolism* ; Acupuncture Points

Lipids droplets are organelles that store neutral lipids and are closely related to lipid accumulation. Long chain acyl-coenzyme A synthetase 3 (ACSL3) is a lipid droplet-associated protein mainly distributed in the cell membrane, endoplasmic reticulum, and intracellular lipid droplets, and its distribution depends on cell type and fatty acid supply. ACSL3 is a key regulator of fatty acid metabolism that is closely related to intracellular lipid accumulation, and plays an important role in various pathophysiological processes such as lipid droplet synthesis and lipid metabolism, cellular inflammation, and ferroptosis. This paper mainly reviews the role of ACSL3 in lipid synthesis, ferroptosis, and inflammatory response, with focus on the mechanism of its role in lipid accumulation in atherosclerosis, and provides new ideas for exploring potential therapeutic targets in atherosclerotic diseases.
Humans ; Atherosclerosis ; Coenzyme A Ligases/metabolism* ; Endoplasmic Reticulum/metabolism* ; Fatty Acids/metabolism* ; Lipid Metabolism

As a member of the apolipoprotein C (ApoC) family with a relatively high content, ApoC3 plays a major role in the regulation of triglyceride metabolism, and plays an important role in the occurrence and development of cardiovascular diseases, glucose and lipid metabolism disorders. Nonalcoholic fatty liver disease (NAFLD) refers to the accumulation of a large amount of fat in the liver in the absence of a history of chronic alcohol consumption or other damage to the liver. A large number of previous studies have shown that there is a correlation between the gene polymorphism and high expression of ApoC3 and NAFLD. In the context of hypertriglyceridemia (HTG), this article reviews the relationship between ApoC3 and NAFLD, glucose and lipid metabolism, and islet β cell function, showing that ApoC3 can not only inhibit lipoprotein lipase (LPL) and hepatic lipase (HL) activity, delay the decomposition of triglyceride in plasma to maintain the body's energy metabolism during fasting, but also be significantly increased under insulin resistance, prompting the liver to secrete a large amount of very low-density lipoprotein (VLDL) to induce HTG. Therefore, targeting and inhibiting ApoC3 might become a new approach to treat HTG. Increasing evidence suggests that ApoC3 does not appear to be an independent "contributor" to NAFLD. Similarly, our previous studies have shown that ApoC3 is not an independent factor triggering islet β cell dysfunction in ApoC3 transgenic mice, but in a state of excess nutrition, HTG triggered by ApoC3 high expression may exacerbate the effects of hyperglycemia and insulin resistance on islet β cell function, and the underlying mechanism remains to be further discussed.
Apolipoprotein C-III/genetics* ; Non-alcoholic Fatty Liver Disease/pathology* ; Glucose/metabolism* ; Lipid Metabolism ; Humans ; Animals ; Hypertriglyceridemia/metabolism* ; Islets of Langerhans/metabolism*

As specialized intracellular parasite, viruses have no ability to metabolize independently, so they completely depend on the metabolic mechanism of host cells. Viruses use the energy and precursors provided by the metabolic network of the host cells to drive their replication, assembly and release. Namely, viruses hijack the host cells metabolism to achieve their own replication and proliferation. In addition, viruses can also affect host cell metabolism by the expression of auxiliary metabolic genes (AMGs), affecting carbon, nitrogen, phosphorus, and sulfur cycles, and participate in microbial-driven biogeochemical cycling. This review summarizes the effect of viral infection on the host's core metabolic pathway from four aspects: cellular glucose metabolism, glutamine metabolism, fatty acid metabolism, and viral AMGs on host metabolism. It may facilitate in-depth understanding of virus-host interactions, and provide a theoretical basis for the treatment of viral diseases through metabolic intervention.
Humans ; Metabolic Networks and Pathways ; Virus Diseases ; Carbohydrate Metabolism ; Host Microbial Interactions ; Lipid Metabolism

The growth, differentiation and proliferation of adipose cells run through the whole life process. Dysregulation of lipid metabolism in adipose cells affects adipose tissue immunity and systemic energy metabolism. Increasingly available data suggest that lipid metabolism is involved in regulating the occurrence and development of various diseases, such as hyperlipidemia, nonalcoholic fatty liver disease, diabetes and cancer, which pose a major threat to human and animal health. Hypoxia inducible factor (HIF) is a major transcription factor mediating oxygen receptors in tissues and organs. HIF can induce disease by regulating lipid synthesis, fatty acid metabolism and lipid droplet formation. However, due to the difference of hypoxia degree, time and mode of action, there is no conclusive conclusion whether it has harmful or beneficial effects on the development of adipocytes and lipid metabolism. This article summarizes the regulation of hypoxia stress mediated transcription regulators and regulation of adipocyte development and lipid metabolism, aiming to reveal the potential mechanism of hypoxia induced changes in adipocyte metabolism pathways.
Animals ; Humans ; Lipid Metabolism ; Adipocytes/metabolism* ; Adipose Tissue/metabolism* ; Hypoxia/metabolism* ; Transcription Factors/metabolism*

Objective To investigate the role of ATP citrate lyase(ACLY)in the development of hepatocellular carcinoma(HCC)and the impact of this enzyme on the immune microenvironment of HCC.Methods We utilized the University of Alabama at Birmingham Cancer Data Analysis Portal and the Gene Expression Profiling Interactive Analysis to identify the changes in ACLY expression and prognosis across different tumor types from The Cancer Genome Atlas.With HCC as the disease model,we analyzed the ACLY expression in HCC samples from the gene expression database.Furthermore,we collected the clinical specimens from HCC patients to verify the mRNA and protein levels of ACLY.In addition,we conducted transcriptome sequencing after knocking down the expression of ACLY to analyze the differentially expressed genes and investigated the impact of ACLY expression interference on cell proliferation and other functions.Finally,we explored the correlations of ACLY with immune cells and immune infiltration in the tumor microenvironment,new antigens,and immune checkpoint genes.Results ACLY expression was significantly up-regulated in solid tumors including HCC(all P<0.05),and high ACLY expression was associated with overall survival rate in HCC(P=0.005).Furthermore,high ACLY expression affected the presence of immune cells(e.g.,tumor-associated fibroblasts)and the expression of genes involved in lipid metabolism(all P<0.05).Conclusions ACLY is closely related to the occurrence and development of HCC and lipid metabolism abnormalities.Moreover,it has a specific impact on the immune microenvironment of HCC.
Humans ; ATP Citrate (pro-S)-Lyase/metabolism* ; Carcinoma, Hepatocellular ; Clinical Relevance ; Lipid Metabolism ; Liver Neoplasms ; Tumor Microenvironment

Chronic heart failure is the end stage of heart diseases caused by multiple causes. Myocardial cell injury is the key cause of cardiac function deterioration. Ferroptosis, an iron-dependent programmed death mode, is characterized by iron overload and excessive accumulation of lipid peroxides. Studies have demonstrated that inhibiting ferroptosis has a protective effect on myocardial cells. The theory of "harmful hyperactivity and responding inhibition" is an important rule developed by physicians to explain the generation and restriction of the five elements and the pathological imbalance of the human body, and can guide medication. Correlating with the nature, humans need to rely on the law of responding inhibition to maintain the harmony of five Zang-organs and the steady state of Fu-organs. The pathogenesis of ferroptosis in chronic heart failure highly coincides with the process of failing to "inhibition and hyperactivity becoming harmful". The initial factor of ferroptosis is the deficiency of heart Qi, which results in the inability to maintain the balance of cardiomyocyte redox system. The involvement of the five Zang-organs leads to the loss of distribution of body fluid and blood. As a result, the phlegm turbidity, blood stasis, and water retention in the meridians occur, which are manifested as the accumulation of iron and lipid peroxides, which is the aggravating factor of ferroptosis. The two factors interact with each other, leading to the spiral development and thus aggravating heart failure. According to the traditional Chinese medicine(TCM) pathogenesis of ferroptosis, the authors try to treat the chronic heart failure by stages in accordance with the general principle of restraining excess and alleviating hyperactivity. The early-stage treatment should "nourish heart Qi, regulate the five Zang-organs, so as to restrain excess". The middle-stage treatment should "active blood, resolve phlegm, dispel pathogen, and eliminate turbidity", so as to alleviate hyperactivity. The late-stage treatment should "warm Yang, replenish Qi, active blood, and excrete water". Following the characteristics of pathogenesis, the TCM intervention can reduce iron accumulation and promote the clearance of lipid peroxide, thus inhibiting ferroptosis and improving cardiac function.
Humans ; Ferroptosis ; Lipid Peroxides ; Medicine, Chinese Traditional ; Heart Failure/drug therapy* ; Chronic Disease ; Iron ; Water