AIM: To study a novel gene that probably related with liver regeneration, which was found by representational difference analysis(RDA). METHODS: cDNA sequence, tissue distribution and functions of the novel gene were studied by slot blot, Northern blot, RT-PCR, cDNA library screening and sequence analyzing. RESULTS: Two full-length clones were isolated from cDNA library of rat fetal livers and the sequence analysis identified that the positive cDNA encoded 76 amino acids only; Using the cDNA as a probe, the novel gene showed a specific liver distribution, a moment increasing expression in one hour after partial hepatectomy (PH) and high expression in fetal liver or liver tumor by Northern blot; EGF quickly induced its high expression in primary culture rat hepatocytes(FCS free).CONCLUSION: These results show that the novel gene is an early phase response gene that is closely related to a liver regeneration adjustment. It may encode peptide or has longer sequence at N tip.

OBJECTIVETo construct a lentiviral vector for RNA interference (RNAi) of human glycerol kinase (GK) gene to stably down-regulate GK expression in human hepatocytes.

METHODSThe sequence of siRNA for GK interference were cloned into the pSicoR vector. Following packaging in 293T cells, the lentivirus was titrated using fluorescence activated cell sorting. Human hepatocyte L02 cells was infected with the lentivirus and the expression of GK was analyzed using Western blotting.

RESULTSThe lentiviral particle pSicoR-GK was successfully packaged with a virus titer reaching 3×10(7) pfu/ml. The expression level of GK protein was down-regulated to 20% of the control level in L02 cells infected with the lentivirus.

CONCLUSIONThe lentiviral vector for RNAi of human GK gene has been successfully constructed, which can significantly down-regulate GK expression in human hepatocytes.

Cell Line ; Gene Expression Regulation ; Genetic Vectors ; Glycerol Kinase ; genetics ; Hepatocytes ; enzymology ; Humans ; Lentivirus ; genetics ; Plasmids ; RNA Interference ; RNA, Small Interfering ; genetics ; Transfection

BACKGROUND:It has also been confirmed that ferroptosis is closely related to a variety of musculoskeletal diseases,such as rheumatoid arthritis,osteosarcoma,and osteoporosis.The pathophysiological mechanisms of ferroptosis and osteoporosis need to be further studied and elucidated to broaden our understanding of iron metabolism and osteoporosis.It will provide research ideas for the future elucidation of new mechanisms of osteoporosis and the development of new technologies and drugs for the treatment of osteoporosis. OBJECTIVE:To provide an overview of the current status of research on ferroptosis in osteoporosis,to provide a new direction for future research on the specific molecular mechanisms of osteoporosis,and to provide more effective and better options for osteoporosis treatment strategies. METHODS:The first author used the computer to search the literature published from 2000 to 2024 in CNKI,WanFang,VIP,and PubMed databases with search terms"ferroptosis,iron metabolism,osteoporosis,osteoblast,osteoclast,bone metabolism,signal pathway,musculoskeletal,review"in Chinese and English.A total of 68 articles were finally included according to the selection criteria. RESULTS AND CONCLUSION:(1)Ferroptosis is a new type of cell death discovered in recent years,which is usually accompanied by a large amount of iron accumulation and lipid peroxidation during cell death,and its occurrence is iron-dependent.This is distinctly different from several types of cell death that are currently being hotly studied(e.g.,cellular pyroptosis,necrotic apoptosis,cuproptosis,and autophagy).(2)Intracellular iron homeostasis is manifested as a balance between iron uptake,export,utilization,and storage.The body's iron regulatory system includes systemic and intracellular regulation.The main factor of systemic regulation is hepcidin produced by hepatic secretion,and cellular regulation depends on the iron regulatory protein/iron response element system.Of course,intracellular iron homeostasis can be controlled by other factors,such as hypoxia,cytokines,and hormones.(3)Lipid peroxidation causes oxidative damage to biological membranes(plasma membrane and internal organelle membranes),lipoproteins,and other lipid-containing molecules.Polyunsaturated fatty acid-containing phospholipids are important targets of lipid peroxidation.Free polyunsaturated fatty acid is an important substrate for lipid oxidation and can bind to the phospholipid bilayer,leading to over-oxidation and thus triggering lipid apoptosis.(4)Several studies have shown that osteoblasts are overloaded with iron in different ways,resulting in the accumulation of unstable ferrous iron and the generation of reactive oxygen species and lipid peroxides,causing ferroptosis of osteoblasts and ultimately a decrease in bone formation,affecting bone homeostasis and the development of osteoporosis.(5)Osteoclasts are large multinucleated cells formed by the fusion of mononuclear macrophage cell lines or bone marrow mesenchymal stem cells induced by nuclear factor-κB ligand receptor activator,and they have the function of bone resorption.Iron ions can promote osteoclast differentiation and bone resorption through the production of intracellular lipid reactive oxygen species,while iron chelators can inhibit osteoclast formation in vitro and thus affect the occurrence and development of osteoporosis.