Metabolic diseases characterized by an imbalance in energy homeostasis represent a significant global health challenge. Individuals with metabolic diseases often suffer from complications related to disorders in lipid metabolism, such as obesity and non-alcoholic fatty liver disease (NAFLD). Understanding core genes involved in lipid metabolism can advance strategies for the prevention and treatment of these conditions. Stearoyl-CoA desaturase 1 (SCD1) is a key enzyme in lipid metabolism that converts saturated fatty acids into monounsaturated fatty acids. SCD1 plays a crucial regulatory role in numerous physiological and pathological processes, including energy homeostasis, glycolipid metabolism, autophagy, and inflammation. Abnormal transcription and epigenetic activation of Scd1 contribute to abnormal lipid accumulation by regulating multiple signaling axes, thereby promoting the development of obesity, NAFLD, diabetes, and cancer. This review comprehensively summarizes the key role of SCD1 as a metabolic hub gene in various (patho)physiological contexts. Further it explores potential translational avenues, focusing on the development of novel SCD1 inhibitors across interdisciplinary fields, aiming to provide new insights and approaches for targeting SCD1 in the prevention and treatment of metabolic diseases.
Stearoyl-CoA Desaturase/metabolism* ; Humans ; Metabolic Diseases/physiopathology* ; Lipid Metabolism/physiology* ; Animals ; Obesity/enzymology* ; Non-alcoholic Fatty Liver Disease

Cancer stem cells (CSCs) are widely acknowledged as primary mediators to the initiation and progression of tumors. The association between microbial infection and cancer stemness has garnered considerable scholarly interest in recent years. Porphyromonas gingivalis (P. gingivalis) is increasingly considered to be closely related to the development of oral squamous cell carcinoma (OSCC). Nevertheless, the role of P. gingivalis in the stemness of OSCC cells remains uncertain. Herein, we showed that P. gingivalis was positively correlated with CSC markers expression in human OSCC specimens, promoted the stemness and tumorigenicity of OSCC cells, and enhanced tumor formation in nude mice. Mechanistically, P. gingivalis increased lipid synthesis in OSCC cells by upregulating the expression of stearoyl-CoA desaturase 1 (SCD1) expression, a key enzyme involved in lipid metabolism, which ultimately resulted in enhanced acquisition of stemness. Moreover, SCD1 suppression attenuated P. gingivalis-induced stemness of OSCC cells, including CSCs markers expression, sphere formation ability, chemoresistance, and tumor growth, in OSCC cells both in vitro and in vivo. Additionally, upregulation of SCD1 in P. gingivalis-infected OSCC cells was associated with the expression of KLF5, and that was modulated by P. gingivalis-activated NOD1 signaling. Taken together, these findings highlight the importance of SCD1-dependent lipid synthesis in P. gingivalis-induced stemness acquisition in OSCC cells, suggest that the NOD1/KLF5 axis may play a key role in regulating SCD1 expression and provide a molecular basis for targeting SCD1 as a new option for attenuating OSCC cells stemness.
Porphyromonas gingivalis/pathogenicity* ; Stearoyl-CoA Desaturase/metabolism* ; Humans ; Carcinoma, Squamous Cell/pathology* ; Mouth Neoplasms/metabolism* ; Animals ; Neoplastic Stem Cells/microbiology* ; Mice, Nude ; Mice ; Nod1 Signaling Adaptor Protein/metabolism* ; Kruppel-Like Transcription Factors/metabolism* ; Cell Line, Tumor

Toxoplasmosis is a serious disease caused by Toxoplasma gondii, one of the most widespread parasites in the world. Lipid metabolism is important in the intracellular stage of T. gondii. Stearoyl-CoA desaturase (SCD), a key enzyme for the synthesis of unsaturated fatty acid is predicted to exist in T. gondii. Sterculic acid has been shown to specifically inhibit SCD activity. Here, we examined whether sterculic acid and its methyl ester analogues exhibit anti-T. gondii effects in vitro. T. gondii-infected Vero cells were disintegrated at 36 hr because of the propagation and egress of intracellular tachyzoites. All test compounds inhibited tachyzoite propagation and egress, reducing the number of ruptured Vero cells by the parasites. Sterculic acid and the methyl esters also inhibited replication of intracellular tachyzoites in HFF cells. Among the test compounds, sterculic acid showed the most potent activity against T. gondii, with an EC50 value of 36.2 μM, compared with EC50 values of 248-428 μM for the methyl esters. Our study demonstrated that sterculic acid and its analogues are effective in inhibition of T. gondii growth in vitro, suggesting that these compounds or analogues targeting SCD could be effective agents for the treatment of toxoplasmosis.
Esters ; Lipid Metabolism ; Parasites ; Stearoyl-CoA Desaturase ; Toxoplasma* ; Toxoplasmosis ; Vero Cells

OBJECTIVETo investigate the protective mechanism of stearoyl-CoA desaturase 1 (SCD1) over-expression against the pro-apoptotic affects of palmitic acid on hepatocytes using the rat BRL cell line.

METHODSConcentration effect curves were generated using the trypan blue exclusion test to assess the death rate of BRL cells upon exposure to a dilution series of palmitic acid. The multiplicity of infection (MOI) of a lentiviral expression vector, pGC-FU-GFP, was determined for the BRL cells. Unmanipulated BRL cells were divided into two groups: the non-palmitate groups were composed of ordinary cultured cells (CON) alone, infected with lentivirus empty expression vector (negative control, NC), and infected with lentivirus overexpressing SCD1 (SCD1-LV); the palmitate groups were composed of ordinary cultured cells plus palmitate (CON+) alone, infected with lentivirus empty expression vector plus palmitate (NC+), and infected with lentivirus overexpressing SCD1 plus palmitate (SCD1-LV+). SCD1 mRNA expression was detected by real-time PCR. Propidium iodide (PI) single-staining was used to detect apoptosis and assess the cell cycle. Inter-group differences were analyzed statistically.

RESULTSThe death rate of BRL cells increased significantly after 72 h of exposure to 400 mumol/L palmitate (P less than 0.01). The MOI of pGC-FU-GFP in BRL cells was 20. The expression of SCD1 was significantly higher in the SCD1-LV and SCD1-LV+ groups than in the respective controls (vs. CON: F = 289, P less than 0.01; vs. CON+: F = 1522, P less than 0.01). Palmitate exposure led to decreased expression of SCD1 (CON+ vs. CON, F = 22, P less than 0.05 and NC+ vs. NC: F = 34, P less than 0.05). The ratio of S stage cells was similar in all non-palmitate groups (CON, NC and SCD1-LV, P = 0.137). However, there was a significant apoptotic peak and lower ratio of S stage cells in the control palmitate groups (CON+ and NC+) and the activity of cell proliferation was decreased as well. The ratio of apoptotic cells was decreased significantly in the SCD1-LV+ group compared to the CON+ group (P less than 0.01).

CONCLUSIONThe expression of SCD1 and its desaturation activity increased in BRL cells upon infection with the pGC-FU-SCD1-GFP lentiviral vector, suggesting that SCD1 over-expression can decrease palmitic acid-induced toxicity and apoptosis in hepatocytes.

Animals ; Apoptosis ; Cell Line ; Genetic Vectors ; Hepatocytes ; metabolism ; Lentivirus ; genetics ; Palmitic Acid ; toxicity ; Rats ; Stearoyl-CoA Desaturase ; metabolism

The possibility of heterologous expression of human Stearoyl-CoA Desaturase (scd1) was investigated. The scd1 encoding sequence was inserted into the pNZ8149 to generate the pNZ8149-scd1 expression plasmids. Then we introduced the pNZ8149-scd1 construct into the Lactococcus lactis NZ3900 to investigate its enzyme activity. The results show that heterologous expressed SCD1 enzyme resulted in a 92%-169% increase in the C16:1n-7 and a 53-127% increase in the C18:1n-7 (P<0.05). The SCD1 enzyme was capable of producing n-7 fatty acids in Lactococcus lactis efficiently. It also suggests that the fatty acid desaturases can be heterologous expressed in Lactococcus lactis to produce the helpful fatty acids.
Electroporation ; Humans ; Lactococcus lactis ; genetics ; metabolism ; Mutagenesis, Insertional ; Nisin ; pharmacology ; Recombinant Proteins ; biosynthesis ; genetics ; Stearoyl-CoA Desaturase ; biosynthesis ; genetics

BACKGROUNDLiver fibrosis is the process through which numerous chronic liver diseases develop into liver cirrhosis. Leptin can activate hepatic stellate cells (HSCs) and play an important role in the formation of liver fibrosis. However, the process by which leptin activates HSCs is complicated, and research on this process is limited. The aim of this study was to explore the related changes in gene expression and the control mechanisms involved in leptin activated HSCs to understand the overall mechanism of liver fibrosis development.

METHODSWe cultivate rat HSCs, with and without stimulation by leptin, and extracted mRNA. Differentially expressed genes were detected by microarray analysis.

RESULTSThe differentially expressed genes identified included six upregulated genes and six downregulated genes. The representative upregulated genes included short chain dehydrogenase (CY5/CY3 = 2.265) and pulmonary surfactant protein A1 (CY5/CY3 = 2.036). The significant downregulated gene encoded hepatic stearoyl coenzyme A desaturase 1 (SCD-1) (CY5/CY3 = 0.351).

CONCLUSIONLeptin might mediate the molecular biological mechanisms of liver fibrosis.

Animals ; Cells, Cultured ; Gene Expression Profiling ; Hepatic Stellate Cells ; drug effects ; metabolism ; Leptin ; pharmacology ; Oligonucleotide Array Sequence Analysis ; methods ; Pulmonary Surfactant-Associated Protein A ; genetics ; Rats ; Stearoyl-CoA Desaturase ; genetics

AIMBy genechip cDNA microarray, the genes expressions of Stearoyl-coenzyme A desaturase (Scd-2) and brain fatty acid-binding protein (B-FABP) were studied in the central nervous system (CNS) of the mice to discuss the mechanism of exercise-induced fatigue.

METHODSBuilding the model of fatigued animal and using the genechip cDNA microarray, the genes expressions were analyzed between the control group and fatigue group mice.

RESULTSThe genes expression of Scd-2 and B-FABP were obvious different in the brain of fatigued group mice than of control group.

CONCLUSIONExercise-induced nerve center fatigue is correlated with genes expressions of lipid metabolism.

Animals ; Base Sequence ; Brain ; metabolism ; Fatigue ; genetics ; metabolism ; Fatty Acid-Binding Protein 7 ; Fatty Acid-Binding Proteins ; genetics ; metabolism ; Gene Expression ; Male ; Mice ; Mice, Inbred BALB C ; Molecular Sequence Data ; Nerve Tissue Proteins ; genetics ; metabolism ; Oligonucleotide Array Sequence Analysis ; Stearoyl-CoA Desaturase ; genetics ; metabolism