Targeted Macromolecules Delivery by Large Lipidic Nanovesicles Electrofusion with Mammalian Cells

Lipidic nanovesicles (so called liposomes) were one the earliest forms of nanovectors. One of their limits was our lack of knowledge on the delivery pathway of their content to the target cell cytoplasm. The present communication describes an efficient way to enhance the delivery. Pulsed electric fields (PEF) are known since the early 80’s to mediate a fusogenic state of plasma membranes when applied to a cell suspension or a tissue. Polykaryons are detected when PEF are applied on cells in contact during or after the pulses. Heterofusion can be obtained when a cell mixture is pulsed. When lipidic nanovesicles, either small unilamellar vesicles (SUVs) or large unilamellar vesicles (LUVs), are electrostatically brought in contact with electropermeabilized cells by a salt bridge, their content is delivered into the cytoplasm in electropermeabilized cells. The PEF parameters are selected to affect specifically the cells leaving the vesicles unaffected. It is the electropermeabilized state of the cell membrane that is the trigger of the merging between the plasma membrane and the lipid bilayer. The present investigation shows that the transfer of macromolecules can be obtained;i.e. 20 kD dextrans can be easily transferred while a direct transfer does not take place under the same electrical parameters. Cell viability was not affected by the treatment. As delivery is present only on electropermeabilized cells, a targeting of the effect is obtained in the volume where the PEF parameters are over the critical value for electropermeabilization. A homogeneous cytoplasm labeling is observed under digitised videomicroscopy. The process is a content and “membrane” mixing, following neither a kiss and run or an endocytotic pathway.

Ferroptosis and endoplasmic reticulum stress in ischemic stroke

Ferroptosis is a form of non-apoptotic programmed cell death,and its mechanisms mainly involve the accumulation of lipid peroxides,imbalance in the amino acid antioxidant system,and disordered iron metabolism.The primary organelle responsible for coordinating external challenges and internal cell demands is the endoplasmic reticulum,and the progression of inflammatory diseases can trigger endoplasmic reticulum stress.Evidence has suggested that ferroptosis may share pathways or interact with endoplasmic reticulum stress in many diseases and plays a role in cell survival.Ferroptosis and endoplasmic reticulum stress may occur after ischemic stroke.However,there are few reports on the interactions of ferroptosis and endoplasmic reticulum stress with ischemic stroke.This review summarized the recent research on the relationships between ferroptosis and endoplasmic reticulum stress and ischemic stroke,aiming to provide a reference for developing treatments for ischemic stroke.

Astrocytic endothelin-1 overexpression impairs learning and memory ability in ischemic stroke via altered hippocampal neurogenesis and lipid metabolism

Vascular etiology is the second most prevalent cause of cognitive impairment globally.Endothelin-1,which is produced and secreted by endothelial cells and astrocytes,is implicated in the pathogenesis of stroke.However,the way in which changes in astrocytic endothelin-1 lead to poststroke cognitive deficits following transient middle cerebral artery occlusion is not well understood.Here,using mice in which astrocytic endothelin-1 was overexpressed,we found that the selective overexpression of endothelin-1 by astrocytic cells led to ischemic stroke-related dementia(1 hour of ischemia;7 days,28 days,or 3 months of reperfusion).We also revealed that astrocytic endothelin-1 overexpression contributed to the role of neural stem cell proliferation but impaired neurogenesis in the dentate gyrus of the hippocampus after middle cerebral artery occlusion.Comprehensive proteome profiles and western blot analysis confirmed that levels of glial fibrillary acidic protein and peroxiredoxin 6,which were differentially expressed in the brain,were significantly increased in mice with astrocytic endothelin-1 overexpression in comparison with wild-type mice 28 days after ischemic stroke.Moreover,the levels of the enriched differentially expressed proteins were closely related to lipid metabolism,as indicated by Kyoto Encyclopedia of Genes and Genomes pathway analysis.Liquid chromatography-mass spectrometry nontargeted metabolite profiling of brain tissues showed that astrocytic endothelin-1 overexpression altered lipid metabolism products such as glycerol phosphatidylcholine,sphingomyelin,and phosphatidic acid.Overall,this study demonstrates that astrocytic endothelin-1 overexpression can impair hippocampal neurogenesis and that it is correlated with lipid metabolism in poststroke cognitive dysfunction.

Ferroptosis mechanism and Alzheimer's disease

Regulated cell death is a genetically determined form of programmed cell death that commonly occurs during the development of living organisms.This process plays a crucial role in modulating homeostasis and is evolutionarily conserved across a diverse range of living organisms.Ferroptosis is a classic regulatory mode of cell death.Extensive studies of regulatory cell death in Alzheimer’s disease have yielded increasing evidence that fe rroptosis is closely related to the occurrence,development,and prognosis of Alzheimer’s disease.This review summarizes the molecular mechanisms of ferroptosis and recent research advances in the role of ferro ptosis in Alzheimer’s disease.Our findings are expected to serve as a theoretical and experimental foundation for clinical research and targeted therapy for Alzheimer’s disease.

Impact of apolipoprotein E isoforms on sporadic Alzheimer's disease:beyond the role of amyloid beta

The impact of apolipoprotein E(ApoE)isoforms on sporadic Alzheimer's disease has long been studied;however,the influences of apolipoprotein E gene(APOE)on healthy and pathological human brains are not fully understood.ApoE exists as three common isoforms(ApoE2,ApoE3,and ApoE4),which differ in two amino acid residues.Traditionally,ApoE binds cholesterol and phospholipids and ApoE isoforms display diffe rent affinities for their receptors,lipids transport and distribution in the brain and periphery.The role of ApoE in the human depends on ApoE isoforms,brain regions,aging,and neural injury.APOE E4 is the strongest genetic risk factor for sporadic Alzheimer's disease,considering its role in influencing amyloid-beta metabolism.The exact mechanisms by which APOE gene variants may increase or decrease Alzheimer's disease risk are not fully understood,but APOE was also known to affect directly and indirectly tau-mediated neurodegeneration,lipids metabolism,neurovascular unit,and microglial function.Consistent with the biological function of ApoE,ApoE4 isoform significantly alte red signaling pathways associated with cholesterol homeostasis,transport,and myelination.Also,the rare protective APOE variants confirm that ApoE plays an important role in Alzheimer's disease pathogenesis.The objectives of the present mini-review were to describe classical and new roles of various ApoE isoforms in Alzheimer's disease pathophysiology beyond the deposition of amyloid-beta and to establish a functional link between APOE,brain function,and memory,from a molecular to a clinical level.APOE genotype also exerted a heterogeneous effect on clinical Alzheimer's disease phenotype and its outcomes.Not only in learning and memory but also in neuro psychiatric symptoms that occur in a premorbid condition.Cla rifying the relationships between Alzheimer's disease-related pathology with neuropsychiatric symptoms,particularly suicidal ideation in Alzheimer's disease patients,may be useful for elucidating also the underlying pathophysiological process and its prognosis.Also,the effects of anti-amyloid-beta drugs,recently approved for the treatment of Alzheimer's disease,could be influenced by the APOE genotype.

Isoform-and cell-state-specific APOE homeostasis and function

Apolipoprotein E is the major lipid transporter in the brain and an important player in neuron-astrocyte metabolic coupling.It ensures the survival of neurons under stressful conditions and hyperactivity by nourishing and detoxifying them.Apolipoprotein E polymorphism,combined with environmental stresses and/or age-related alterations,influences the risk of developing late-onset Alzheimer’s disease.In this review,we discuss our current knowledge of how apolipoprotein E homeostasis,i.e.its synthesis,secretion,degradation,and lipidation,is affected in Alzheimer’s disease.

Current perspectives on mesenchymal stem cells as a potential therapeutic strategy for non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease(NAFLD)has emerged as a significant health challenge,characterized by its widespread prevalence,intricate natural progression and multifaceted pathogenesis.Although NAFLD initially presents as benign fat accumulation,it may progress to steatosis,non-alcoholic steatohepatitis,cirrhosis,and hepatocellular carcinoma.Mesenchymal stem cells(MSCs)are recognized for their intrinsic self-renewal,superior biocompatibility,and minimal immunogenicity,positioning them as a therapeutic innovation for liver diseases.Therefore,this review aims to elucidate the potential roles of MSCs in alleviating the progression of NAFLD by alteration of underlying molecular pathways,including glycolipid metabolism,inflammation,oxidative stress,endoplasmic reticulum stress,and fibrosis.The insights are expected to provide further understanding of the potential of MSCs in NAFLD therapeutics,and support the development of MSC-based therapy in the treatment of NAFLD.

Bromocriptine protects perilesional spinal cord neurons from lipotoxicity after spinal cord injury

Recent studies have revealed that lipid droplets accumulate in neurons after brain injury and evoke lipotoxicity,damaging the neurons.However,how lipids are metabolized by spinal cord neurons after spinal cord injury remains unclear.Herein,we investigated lipid metabolism by spinal cord neurons after spinal cord injury and identified lipid-lowering compounds to treat spinal cord injury.We found that lipid droplets accumulated in perilesional spinal cord neurons after spinal cord injury in mice.Lipid droplet accumulation could be induced by myelin debris in HT22 cells.Myelin debris degradation by phospholipase led to massive free fatty acid production,which increased lipid droplet synthesis,β-oxidation,and oxidative phosphorylation.Excessive oxidative phosphorylation increased reactive oxygen species generation,which led to increased lipid peroxidation and HT22 cell apoptosis.Bromocriptine was identified as a lipid-lowering compound that inhibited phosphorylation of cytosolic phospholipase A2 by reducing the phosphorylation of extracellular signal-regulated kinases 1/2 in the mitogen-activated protein kinase pathway,thereby inhibiting myelin debris degradation by cytosolic phospholipase A2 and alleviating lipid droplet accumulation in myelin debris-treated HT22 cells.Motor function,lipid droplet accumulation in spinal cord neurons and neuronal survival were all improved in bromocriptine-treated mice after spinal cord injury.The results suggest that bromocriptine can protect neurons from lipotoxic damage after spinal cord injury via the extracellular signal-regulated kinases 1/2-cytosolic phospholipase A2 pathway.

Lipid metabolism analysis in esophageal cancer and associated drug discovery

Esophageal cancer is an upper gastrointestinal malignancy with a bleak prognosis.It is still being explored in depth due to its complex molecular mechanisms of occurrence and development.Lipids play a crucial role in cells by participating in energy supply,biofilm formation,and signal transduction processes,and lipid metabolic reprogramming also constitutes a significant characteristic of malignant tumors.More and more studies have found esophageal cancer has obvious lipid metabolism abnormalities throughout its beginning,progress,and treatment resistance.The inhibition of tumor growth and the enhancement of antitumor therapy efficacy can be achieved through the regulation of lipid metabolism.Therefore,we reviewed and analyzed the research results and latest findings for lipid metabolism and associated analysis techniques in esophageal cancer,and comprehensively proved the value of lipid metabolic reprogramming in the evolution and treatment resistance of esophageal cancer,as well as its significance in exploring potential therapeutic targets and biomarkers.

Research progress of ferroptosis regulating lipid peroxidation and metabolism in occurrence and development of primary liver cancer

As a highly aggressive tumor,the pathophysiological mechanism of primary liver cancer has attracted much attention.In recent years,factors such as ferroptosis regulation,lipid peroxidation and metabolic abnormalities have emerged in the study of liver cancer,providing a new perspective for understanding the development of liver cancer.Ferroptosis regulation,lipid peroxidation and metabolic abnormalities play important roles in the occurrence and development of liver cancer.The regulation of ferroptosis is involved in apoptosis and necrosis,affecting cell survival and death.Lipid peroxidation promotes oxidative damage and promotes the invasion of liver cancer cells.Metabolic abnormalities,especially the disorders of glucose and lipid metabolism,directly affect the proliferation and growth of liver cancer cells.Studies of ferroptosis regulation and lipid peroxidation may help to discover new therapeutic targets and improve therapeutic outcomes.The understanding of metabolic abnormalities can provide new ideas for the prevention of liver cancer,and reduce the risk of disease by adjusting the metabolic process.This review focuses on the key roles of ferroptosis regulation,lipid peroxidation and metabolic abnormalities in this process.

Dietary sodium acetate and sodium butyrate improve high-carbohydrate diet utilization by regulating gut microbiota, liver lipid metabolism, oxidative stress, and inflammation in largemouth bass(Micropterus salmoides)

Background Adequate level of carbohydrates in aquafeeds help to conserve protein and reduce cost. However, studies have indicated that high-carbohydrate(HC) diet disrupt the homeostasis of the gut–liver axis in largemouth bass, resulting in decreased intestinal acetate and butyrate level.Method Herein, we had concepted a set of feeding experiment to assess the effects of dietary sodium acetate(SA) and sodium butyrate(SB) on liver health and the intestinal microbiota in largemouth bass fed an HC diet. The experimental design comprised 5 isonitrogenous and isolipidic diets, including LC(9% starch), HC(18% starch), HCSA(18% starch;2 g/kg SA), HCSB(18% starch;2 g/kg SB), and HCSASB(18% starch;1 g/kg SA + 1 g/kg SB). Juvenile largemouth bass with an initial body weight of 7.00 ± 0.20 g were fed on these diets for 56 d.Results We found that dietary SA and SB reduced hepatic triglyceride accumulation by activating autophagy(ATG101, LC3B and TFEB), promoting lipolysis(CPT1α, HSL and AMPKα), and inhibiting adipogenesis(FAS, ACCA, SCD1 and PPARγ). In addition, SA and SB decreased oxidative stress in the liver(CAT, GPX1α and SOD1) by activating the Keap1-Nrf2 pathway. Meanwhile, SA and SB alleviated HC-induced inflammation by downregulating the expression of pro-inflammatory factors(IL-1β, COX2 and Hepcidin1) through the NF-κB pathway. Importantly, SA and SB increased the abundance of bacteria that produced acetic acid and butyrate(Clostridium_sensu_stricto_1). Combined with the KEGG analysis, the results showed that SA and SB enriched carbohydrate metabolism and amino acid metabolism pathways, thereby improving the utilization of carbohydrates. Pearson correlation analysis indicated that growth performance was closely related to hepatic lipid deposition, autophagy, antioxidant capacity, inflammation, and intestinal microbial composition.Conclusions In conclusion, dietary SA and SB can reduce hepatic lipid deposition;and alleviate oxidative stress and inflammation in largemouth bass fed on HC diet. These beneficial effects may be due to the altered composition of the gut microbiota caused by SA and SB. The improvement effects of SB were stronger than those associated with SA.

Apatinib and gamabufotalin co-loaded lipid/Prussian blue nanoparticles for synergistic therapy to gastric cancer with metastasis

Due to the non-targeted release and low solubility of anti-gastric cancer agent,apatinib(Apa),a first-line drug with long-term usage in a high dosage often induces multi-drug resistance and causes serious side effects.In order to avoid these drawbacks,lipid-film-coated Prussian blue nanoparticles(PB NPs)with hyaluronan(HA)modification was used for Apa loading to improve its solubility and targeting ability.Furthermore,anti-tumor compound of gamabufotalin(CS-6)was selected as a partner of Apawith reducing dosage for combinational gastric therapy.Thus,HA-Apa-Lip@PB-CS-6 NPs were constructed to synchronously transport the two drugs into tumor tissue.In vitro assay indicated that HA-Apa-Lip@PB-CS-6 NPs can synergistically inhibit proliferation and invasion/metastasis of BGC-823 cells via downregulating vascular endothelial growth factor receptor(VEGFR)and matrix metalloproteinase-9(MMP-9).In vivo assay demonstrated strongest anti-tumor growth and liver metastasis of HA-Apa-Lip@PB-CS-6 NPs administration in BGC-823 cells-bearing mice compared with other groups due to the excellent penetration in tumor tissues and outstanding synergistic effects.In summary,we have successfully developed a new nanocomplexes for synchronous Apa/CS-6 delivery and synergistic gastric cancer(GC)therapy.

Lipid metabolism-related long noncoding RNA RP11-817I4.1 promotes fatty acid synthesis and tumor progression in hepatocellular carcinoma

BACKGROUND Hepatocellular carcinoma(HCC)is one of the most common types of tumors.The influence of lipid metabolism disruption on the development of HCC has been demonstrated in published studies.AIM To establish an HCC prognostic model for lipid metabolism-related long non-coding RNAs(LMR-lncRNAs)and conduct in-depth research on the specific role of novel LMR-lncRNAs in HCC.METHODS Correlation and differential expression analyses of The Cancer Genome Atlas data were used to identify differentially expressed LMR-lncRNAs.Quantitative real-time polymerase chain reaction analysis was used to evaluate the expression of LMR-lncRNAs.Nile red staining was employed to observe intracellular lipid levels.The interaction between RP11-817I4.1,miR-3120-3p,and ATP citrate lyase(ACLY)was validated through the performance of dual-luciferase reporter gene and RIP assays.RESULTS Three LMR-lncRNAs(negative regulator of antiviral response,RNA transmembrane and coiled-coil domain family 1 antisense RNA 1,and RP11-817I4.1)were identified as predictive markers for HCC patients and were utilized in the construction of risk models.Additionally,proliferation,migration,and invasion were reduced by RP11-817I4.1 knockdown.An increase in lipid levels in HCC cells was significantly induced by RP11-817I4.1 through the miR-3120-3p/ACLY axis.CONCLUSION LMR-lncRNAs have the capacity to predict the clinical characteristics and prognoses of HCC patients,and the discovery of a novel LMR-lncRNAs,RP11-817I4.1,revealed its role in promoting lipid accumulation,thereby accelerating the onset and progression of HCC.

RARRES2 regulates lipid metabolic reprogramming to mediate the development of brain metastasis in triple negative breast cancer

Background Triple negative breast cancer(TNBC),the most aggressive subtype of breast cancer,is characterized by a high incidence of brain metastasis(BrM)and a poor prognosis.As the most lethal form of breast cancer,BrM remains a major clinical challenge due to its rising incidence and lack of effective treatment strategies.Recent evidence suggested a potential role of lipid metabolic reprogramming in breast cancer brain metastasis(BCBrM),but the underlying mechanisms are far from being fully elucidated.Methods Through analysis of BCBrM transcriptome data from mice and patients,and immunohistochemical validation on patient tissues,we identified and verified the specific down-regulation of retinoic acid receptor responder 2(RARRES2),a multifunctional adipokine and chemokine,in BrM of TNBC.We investigated the effect of aberrant RARRES2 expression of BrM in both in vitro and in vivo studies.Key signaling pathway components were evaluated using multi-omics approaches.Lipidomics were performed to elucidate the regulation of lipid metabolic reprogramming of RARRES2.Results We found that downregulation of RARRES2 is specifically associated with BCBrM,and that RARRES2 deficiency promoted BCBrM through lipid metabolic reprogramming.Mechanistically,reduced expression of RARRES2 in brain metastatic potential TNBC cells resulted in increased levels of glycerophospholipid and decreased levels of triacylglycerols by regulating phosphatase and tensin homologue(PTEN)-mammalian target of rapamycin(mTOR)-sterol regulatory element-binding protein 1(SREBP1)signaling pathway to facilitate the survival of breast cancer cells in the unique brain microenvironment.Conclusions Our work uncovers an essential role of RARRES2 in linking lipid metabolic reprogramming and the development of BrM.RARRES2-dependent metabolic functions may serve as potential biomarkers or therapeutic targets for BCBrM.

Metformin alleviates spinal cord injury by inhibiting nerve cell ferroptosis through upregulation of heme oxygenase-1 expression

Previous studies have reported upregulation of heme oxygenase-1 in different central nervous system injury models.Heme oxygenase-1 plays a critical anti-inflammatory role and is essential for regulating cellular redox homeostasis.Metformin is a classic drug used to treat type 2 diabetes that can inhibit ferroptosis.Previous studies have shown that,when used to treat cardiovascular and digestive system diseases,metformin can also upregulate heme oxygenase-1 expression.Therefore,we hypothesized that heme oxygenase-1 plays a significant role in mediating the beneficial effects of metformin on neuronal ferroptosis after spinal cord injury.To test this,we first performed a bioinformatics analysis based on the GEO database and found that heme oxygenase-1 was upregulated in the lesion of rats with spinal cord injury.Next,we confirmed this finding in a rat model of T9 spinal cord compression injury that exhibited spinal cord nerve cell ferroptosis.Continuous intraperitoneal injection of metformin for 14 days was found to both upregulate heme oxygenase-1 expression and reduce neuronal ferroptosis in rats with spinal cord injury.Subsequently,we used a lentivirus vector to knock down heme oxygenase-1 expression in the spinal cord,and found that this significantly reduced the effect of metformin on ferroptosis after spinal cord injury.Taken together,these findings suggest that metformin inhibits neuronal ferroptosis after spinal cord injury,and that this effect is partially dependent on upregulation of heme oxygenase-1.

Global research trends and prospects of cellular metabolism in colorectal cancer

BACKGROUND An increasing number of studies have focused on the role of cellular metabolism in the development of colorectal cancer(CRC).However,no work is currently available to synthesize the field through bibliometrics.AIM To analyze the development in the field of“glucose metabolism”(GM),“amino acid metabolism”(AM),“lipid metabolism”(LM),and“nucleotide metabolism”(NM)in CRC by visualization.METHODS Articles within the abovementioned areas of GM,AM,LM and NM in CRC,which were published from January 1,1991,to December 31,2022,are retrieved from the Web of Science Core Collection and analyzed by CiteSpace 6.2.R4 and VOSviewer 1.6.19.RESULTS The field of LM in CRC presented the largest number of annual publications and the fastest increase in the last decade compared with the other three fields.Meanwhile,China and the United States were two of the most prominent contri-butors in these four areas.In addition,Gang Wang,Wei Jia,Maria Notar-nicola,and Cornelia Ulrich ranked first in publication numbers,while Jing-Yuan Fang,Senji Hirasawa,Wei Jia,and Charles Fuchs were the most cited authors on average in these four fields,respectively.“Gut microbiota”and“epithelial-mesenchymal transition”emerged as the newest burst words in GM,“gut microbiota”was the latest outburst word in AM,“metastasis”,“tumor microenvironment”,“fatty acid metabolism”,and“metabolic reprogramming”were the up-to-date outbreaking words in LM,while“epithelial-mesenchymal transition”and“apoptosis”were the most recently occurring words in NM.CONCLUSION Research in“cellular metabolism in CRC”is all the rage at the moment,and researchers are particularly interested in exploring the mechanism to explain the metabolic alterations in CRC.Targeting metabolic vulnerability appears to be a promising direction in CRC therapy.

Uridine diphosphate glucuronosyltransferase 1A1 prevents the progression of liver injury

BACKGROUND Uridine diphosphate glucuronosyltransferase 1A1(UGT1A1)plays a crucial role in metabolizing and detoxifying endogenous and exogenous substances.However,its contribution to the progression of liver damage remains unclear.AIM To determine the role and mechanism of UGT1A1 in liver damage progression.METHODS We investigated the relationship between UGT1A1 expression and liver injury through clinical research.Additionally,the impact and mechanism of UGT1A1 on the progression of liver injury was analyzed through a mouse model study.RESULTS Patients with UGT1A1 gene mutations showed varying degrees of liver damage,while patients with acute-onchronic liver failure(ACLF)exhibited relatively reduced levels of UGT1A1 protein in the liver as compared to patients with chronic hepatitis.This suggests that low UGT1A1 levels may be associated with the progression of liver damage.In mouse models of liver injury induced by carbon tetrachloride(CCl_(4))and concanavalin A(ConA),the hepatic levels of UGT1A1 protein were found to be increased.In mice with lipopolysaccharide or liver steatosis-mediated liver-injury progression,the hepatic protein levels of UGT1A1 were decreased,which is consistent with the observations in patients with ACLF.UGT1A1 knockout exacerbated CCl_(4)-and ConA-induced liver injury,hepatocyte apoptosis and necroptosis in mice,intensified hepatocyte endoplasmic reticulum(ER)stress and oxidative stress,and disrupted lipid metabolism.CONCLUSION UGT1A1 is upregulated as a compensatory response during liver injury,and interference with this upregulation process may worsen liver injury.UGT1A1 reduces ER stress,oxidative stress,and lipid metabolism disorder,thereby mitigating hepatocyte apoptosis and necroptosis.

Lipid droplets in the nervous system:involvement in cell metabolic homeostasis

Lipid droplets serve as primary storage organelles for neutral lipids in neurons,glial cells,and other cells in the nervous system.Lipid droplet formation begins with the synthesis of neutral lipids in the endoplasmic reticulum.Previously,lipid droplets were recognized for their role in maintaining lipid metabolism and energy homeostasis;however,recent research has shown that lipid droplets are highly adaptive organelles with diverse functions in the nervous system.In addition to their role in regulating cell metabolism,lipid droplets play a protective role in various cellular stress responses.Furthermore,lipid droplets exhibit specific functions in neurons and glial cells.Dysregulation of lipid droplet formation leads to cellular dysfunction,metabolic abnormalities,and nervous system diseases.This review aims to provide an overview of the role of lipid droplets in the nervous system,covering topics such as biogenesis,cellular specificity,and functions.Additionally,it will explore the association between lipid droplets and neurodegenerative disorders.Understanding the involvement of lipid droplets in cell metabolic homeostasis related to the nervous system is crucial to determine the underlying causes and in exploring potential therapeutic approaches for these diseases.

Neuropeptide ACP is required for fat body lipid metabolism homeostasis in locusts

Fat body metabolism plays crucial roles in each aspect of insect life traits.Although neuropeptides have been documented to be one of the major neuroendocrinal regulators involved in fat body metabolism,the detailed regulatory mechanism is poorly explored.Here,we conducted comparative metabolome and transcriptome analyses of fat body between wide type(WT)and adipokinetic hormone/corazonin-related peptide(ACP)loss of function mutants of the migratory locust,Locusta migratoria.We found that knockout of ACP resulted in significantly reduced fat body triacylglycerol content but enhanced abundance of phospholipids,particularly phosphatidylcholine and phos-phatidylethanolamine.Additionally,the expression levels of genes involved in triacylglyc-erol and phospholipid synthesis and degradation were significantly altered in the fat body of ACP mutants.Moreover,female ACP mutants displayed much higher fecundity com-pared to WT females.These findings highlight the important role of neuropeptide ACP in fat body lipid metabolism homeostasis in locusts.

Supplementation of alanine improves biomass accumulation and lipid production of Chlorella pyrenoidosa by increasing the respiratory and metabolic processes

The function of exogenous alanine(Ala)in regulating biomass accumulation,lipid production,photosynthesis,and respiration in Chlorella pyrenoidosa was studied.Result shows that the supplementation of Ala increased C.pyrenoidosa biomass and lipid production in an 8-d batch culture.The concentration of 10 mmol/L of Ala was optimum and increased the microalgal cell biomass and lipid content by 39.3%and 21.4%,respectively,compared with that in the control(0-mmol/L Ala).Ala supplementation reduced photosynthetic activity while boosting respiratory activity and pyruvate levels,indicating that C.pyrenoidosa used exogenous Ala for biomass accumulation through the respiratory metabolic process.The accelerated respiratory metabolism due to Ala supplementation elevated the substrate pool and improved the lipogenic gene expression,promoting lipid production at last.This study provided a novel method for increasing biomass accumulation and lipid production and elucidated the role of Ala in regulating lipid production.