Mechanism of action of sterol regulatory element-binding proteins in nonalcoholic fatty liver disease and related therapeutic targets / 临床肝胆病杂志

Nonalcoholic fatty liver disease （NAFLD） has become the most common liver disease in the world and is an important risk factor for the progression to hepatocellular carcinoma. However， the pathogenesis of NAFLD remains unclear， and there is still a lack of specific treatment measures. Sterol regulatory element-binding proteins （SREBP） are an important nuclear transcription factor， which mainly maintains the balance of lipid metabolism inside the body by activating the genes associated with the synthesis and uptake of cholesterol， fatty acids， and triglycerides， and therefore， SREBP are a target for the treatment of metabolic diseases. This article reviews the latest advances in SREBP in the pathogenesis of NAFLD and the latest evidence of SREBP-targeted therapy for NAFLD. It is worth noting that recent studies have shown that SREBP inhibition can cause liver injury together with autophagy damage. Therefore， excessive inhibition of lipogenesis may exert a counterproductive effect on the treatment of NAFLD. In conclusion， SREBP is a promising therapeutic target for NAFLD； the molecular mechanism of SREBP in lipid metabolism is regulated by many factors， and these factors are being deeply explored and analyzed， which has an important clinical significance for the treatment of NAFLD.

Bioinformatics analysis of sterol O⁃acyltransferase 1 gene related to hepatocellular carcinoma / 中国生物制品学杂志

@#Abstract：Objective To predict the structure and function of sterol O⁃acyltransferase 1（SOAT1）related to hepatocellular carcinoma（HCC）by using bioinformatics tools，in order to understand its mechanism as the marker and therapeutic target of S⁃Ⅲ subtype. Methods The structure，function and protein interaction of SOAT1 were predicted and analyzed by using databases or softwares such as NCBI，STRING，Protscale，SignalP，TMHMM，PSORT，SOPMA，SWISS ⁃ MODEL， NetNGlyc，NetOGlyc，Netphos and ProtParam. Results The protein encoded by SOAT1 was a hydrophobic protein with good stability，which was a nonclassical pathway protein with 8 transmembrane regions，mainly distributed among the cell membrane. SOAT1 was expressed in many tissues，while most of them in the adrenal gland，which showed multiple phosphorylation sites and was mainly involved in the synthesis and catabolism of cholesterol. Conclusion Bioinformatics analysis of structure and function of SOAT1 showed that SOAT1 lipid synthesis and catabolism pathways played an important role，and lipid expression was closely related to the development of cancer，indicating that the treatment of HCC may be achieved by regulating the expression of SOAT1 gene.

Gene clone and functional identification of sterol glycosyltransferases from Paris polyphylla var. yunnanensis / 中国中药杂志

In this study, the authors cloned a glycosyltransferase gene PpUGT2 from Paris polyphylla var. yunnanensis with the ORF length of 1 773 bp and encoding 590 amino acids. The phylogenetic tree revealed that PpUGT2 belonged to the UGT80A subfamily and was named as UGT80A49 by the UDP-glycosyltransferase(UGT) Nomenclature Committee. The expression vector pET28a-PpUGT2 was constructed, and enzyme catalytic reaction in vitro was conducted via inducing protein expression and extraction. With UDP-glucose as sugar donor and diosgenin and pennogenin as substrates, the protein was found with the ability to catalyze the C-3 hydroxyl β-glycosylation of diosgenin and pennogenin. To further explore its catalytic characteristic, 15 substrates including steroids and triterpenes were selected and PpUGT2 showed its activity towards the C-17 position of sterol testosterone with UDP-glucose as sugar donor. Homology modelling and molecule docking of PpUGT2 with substrates predicted the key residues interacting with ligands. The re-levant residues of PpUGT2-ligand binding model were scanned to calculate the corresponding mutants, and the optimized mutants were obtained according to the changes in binding affinity of the ligand with protein and the surrounding residues within 5.0 Å of ligands, which had reference value for design of the mutants. This study laid a foundation for further exploring the biosynthetic pathway of polyphyllin as well as the structure of sterol glycosyltransferases.

Research progress in the correlation between SREBP/PCSK9 pathway and lipid metabolism disorders induced by antipsychotics / 中南大学学报(医学版)

Antipsychotic medications are commonly used to treat schizophrenia,but they can have negative effects on lipid metabolism,leading to an increased risk of cardiovascular diseases,reduced life expectancy,and difficulties with treatment adherence.The specific mechanisms by which antipsychotics disrupt lipid metabolism are not well understood.Sterol regulatory element-binding proteins(SREBPs)are important transcriptional factors that regulate lipid metabolism.Proprotein convertase subtilisin/kexin type 9(PCSK9),a gene regulated by SREBPs,plays a critical role in controlling levels of low-density lipoprotein cholesterol(LDL-C)and has become a focus of research on lipid-lowering drugs.Recent studies have shown that antipsychotic drugs can affect lipid metabolism through the SREBP/PCSK9 pathway.A deep understanding of the mechanism for this pathway in antipsychotic drug-related metabolic abnormalities will promote the prevention of lipid metabolism disorders in patients with schizophrenia and the development and application of new drugs.

Correlation of serum and follicular fluid SREBP1c and LRG1 levels with insulin resistance in PCOS patients / 中华内分泌代谢杂志

Objective:To investigate the serum and follicular fluid levels of sterol regulatory element-binding protein 1c(SREBP-1c), leucine-rich α-2-glycoprotein 1(LRG1) and the correlation with insulin resistance(IR) in non-ovarian etiology infertility patients and polycystic ovary syndrome(PCOS) patients with or without IR.Methods:Forty-nine PCOS patients and 66 infertility patients with non-ovarian etiology were collected in this retrospective study, homeostasis model assessment for insulin resistance(HOMA-IR) was used to evaluate IR, and were divided into control group( n=36), IR group( n=30), PCOS alone group( n=28) and PCOS-IR group(PCOS with IR group, n=21). The concentrations of serum, follicular fluid LRG1 and SREBP1c levels in each group were compared, and their correlation with relevant hormones and glycolipid metabolism were analyzed. Results:The levels of serum, follicular fluid LRG1 and SREBP1c in IR group, PCOS alone group and PCOS-IR group were significantly higher than those in control group; The PCOS-IR group showed a more significant increase in the levels of serum, follicular fluid LRG1 and SREBP1c( P<0.05). Correlation analysis showed that serum, follicular fluid LRG1 was positively correlated with body mass index, fasting plasma glucose(FPG), fasting insulin(FINS), triglycerides(TG), and HOMA-IR( P<0.05). Serum, follicular fluid SREBP1c was positively correlated with body mass index, FPG, FINS, TG, total cholesterol, LDL-C, LH, total teststerone, DHEAS, FAI, and HOMA-IR( P<0.05). Binary logistic regression analysis showed that serum SREBP1c was a risk factor for PCOS( P<0.05). Conclusion:The serum and follicular fluid levels of LRG1 and SREBP-1c were elevated in PCOS patients, especially in those with IR. The elevated levels of serum and follicular fluid LRG1 and SREBP-1c may be associated with IR and glucose-lipid metabolism abnormalities in PCOS patients. Serum LRG1 and SREBP-1c levels may serve as new indicators for predicting IR, early diagnosis, and intervention in PCOS patients.

Study on the mechanism of Yishen tongluo formula improving abnormal lipid metabolism based on SREBPs pathway / 中国药房

OBJECTIVE To explore the mechanism of Yishen tongluo formula （YSTLF） in improving abnormal lipid metabolism based on the sterol regulatory element binding proteins （SREBPs） pathway. METHODS Using C57BLKS/J （db/db） mice as model and C57BLKS/J （db/m） mice as normal control， the mechanism of 1， 2.5 and 5 g/kg YSTLF improving abnormal lipid metabolism of db/db mice was investigated by determining the liver coefficient， the contents of serum total cholesterol （TC）， triglyceride （TG）， low-density lipoprotein （LDL） and high-density lipoprotein （HDL）， observing steatosis and lipid accumulation in liver tissue of mice， detecting the protein expressions of SREBP-1 and SREBP-2 as well as mRNA transcription levels of Srebp- 1c， Srebp-2 and their downstream lipid metabolism-related target genes （Fasn， Acc1， Scd5， Fads1， Hmgcr， Dhcr24， Insig-1， Fdps） in liver tissue of mice. Using low-fat cultured human liver cancer cell HepG2 as an in vitro cell model for abnormal lipid metabolism， and 25-HC （SREBPs inhibitor， 10 μmol/L） as the control， the effects of 125， 250 and 500 μg/mL YSTLF on protein expressions of SREBP-1 and SREBP-2 as well as mRNA transcription of SREBP-1c， SREBP-2 and their downstream lipid metabolism-related target genes were investigated to verify the mechanism in vitro. RESULTS 1， 2.5， 5 g/kg YSTLF significantly reduced the levels of TC， TG and LDL， the percentage of lipid droplet-positive region in liver tissue and liver coefficient， significantly down-regulated protein expressions of Pre-SREBP-1， n-SREBP-1， Pre-SREBP-2 and n-SREBP-2， and mRNA transcription of Srebp-1c， Srebp-2 and their downstream target genes in liver tissue， while significantly increased HDL level， with statistical significance （P＜0.05 or P＜0.01）. In the cell experiment in vitro， the expressions of the above-mentioned proteins and genes in the cells treated with YSTLF at 125， 250 and 500 μg/mL for 24 hours were consistent with those in the animal experiment； there was no significant difference in the expressions of the above-mentioned proteins and genes between inhibitor control group and 250， 500 μg/mL YSTLF groups （P＞0.05）. CONCLUSIONS YSTLF can regulate the expression of transcription factor SREBPs， so as to inhibit the high expression of fatty acid and cholesterol synthesis-related genes， promote the degradation of TC and TG， improve the abnormality of lipid metabolism and inhibit lipid accumulation， thus playing the role of lipid-lowering.

Sterol transport proteins in yeast: a review / 生物工程学报

Sterols are a class of cyclopentano-perhydrophenanthrene derivatives widely present in living organisms. Sterols are important components of cell membranes. In addition, they also have important physiological and pharmacological activities. With the development of synthetic biology and metabolic engineering technology, yeast cells are increasingly used for the heterologous synthesis of sterols in recent years. Nevertheless, since sterols are hydrophobic macromolecules, they tend to accumulate in the membrane fraction of yeast cells and consequently trigger cytotoxicity, which hampers the further improvement of sterols yield. Therefore, revealing the mechanism of sterol transport in yeast, especially understanding the working principle of sterol transporters, is vital for designing strategies to relieve the toxicity of sterol accumulation and increasing sterol yield in yeast cell factories. In yeast, sterols are mainly transported through protein-mediated non-vesicular transport mechanisms. This review summarizes five types of sterol transport-related proteins that have been reported in yeast, namely OSBP/ORPs family proteins, LAM family proteins, ABC transport family proteins, CAP superfamily proteins, and NPC-like sterol transport proteins. These transporters play important roles in intracellular sterol gradient distribution and homeostasis maintenance. In addition, we also review the current status of practical applications of sterol transport proteins in yeast cell factories.

A STUDY TO EVALUATE THE IMPORTANCE OF FASTING LIPID PROFILE ESTIMATION AS THE PART OF INITIAL EVALUATION OF HIV POSITIVE PATIENTS BEFORE STARTING HAART

BACKGROUND:-There is evidence that ART is associated with lipodystrophy syndrome, a disturbance of lipid metabolism characterised by insulin resistance, dyslipidaemia, and fat maldistribution, metabolic bone disease (osteopenia and/or osteoporosis), and lactic acidosis. ART- associated dyslipidaemia is characterized by elevated serum concentrations of total cholesterol, triglycerides, low density lipoprotein 2(LDL-c), very low-density lipoprotein (VLDL), and Apo lipoprotein B (apoB) and low levels of high density lipoprotein (HDL-c) constituting an atherogenic lipid 1pro?le . In this study 143 young patients who were attending the Antiretroviral Therapy Plus MATERIAL AND METHODS:- Centre & Medicine Wards, ACSR GMC NELLORE were included randomly. 5ml Sample preparation and Biochemical assay :- of venous blood sample was collected by venipuncture from 12 hours overnight fast and centrifuged at 3000 cycles per minute and serum was separated for lipid pro?le measurement within one hour of blood collection. The serum levels of TC, HDL-C, LDL-C, VLDL and TG were measured using AU480 BECKMANS random access fully automated auto analyzer at Biochemistry laboratory, ACSR GMC, NELLORE. TC, LDL and TC/HDL lipid pro?les are signi?cant. F-Signi?cant values are RESULTS;- <0.05, reject null hypothesis. It means that the difference among the lipid pro?les of TC, LDL and TC/HDL in the study group is statistically signi?cant with respect to regimen groups. HDL, TG and VLDL lipid pro?les are not signi?cant. F-Signi?cant values are >0.05, no evidence to reject null hypothesis. It means that the no signi?cant difference among the lipid pro?les of HDL, TG, and VLDL in the study group is not statistically signi?cant with respect to regimen groups. Signi?cant CONCLUSIONS:- metabolic and morphological alterations occur in HIV infected patients especially in patients on HAART. The patients on HAART had an elevated Castelli Index I, indicating an increased risk for atherosclerotic cardiovascular disease in this population. There is need to assess lipid pro?les at baseline before initiation of HAART treatment and lipid pro?le monitoring during therapy to monitor any rising trends. New medications with more lipid friendly pro?les within existing drugs such as darunavir (PI), etravirine (NNRTI), new classes of drugs such as integrase inhibitors (raltegravir) and CCR5 inhibitors (maraviroc) can be used to avoid dyslipidaemia

Effect of milk on sebaceous gland spots and the IGF-1/SREBP-1/ACC-1 signaling pathway in golden hamsters / 中华皮肤科杂志

Objective:To investigate the effect of milk on sebum secretion in golden hamsters, and to explore its possible mechanism of action.Methods:Eighteen golden hamsters were randomly and equally divided into 3 groups: blank control group receiving no intervention, whole-milk group gavaged with whole milk, and skimmed-milk group gavaged with skimmed milk. The gavage feeding was performed at a dose of 2.5 ml twice a day for 4 consecutive weeks. The maximum transverse diameter and maximum longitudinal diameter of bilateral sebaceous gland spots were measured on days 0, 7, 14, 21 and 28 after the start of intervention, and the area of sebaceous gland spots was calculated; at 24 hours after the last gavage, bilateral sebaceous gland spot tissues were resected, and subjected to immunohistochemical study to determine the expression of insulin-like growth factor-1 (IGF-1) /sterol regulatory element-binding protein-1 (SREBP-1) /acetyl-coenzyme A carboxylase (ACC-1) signaling pathway in sebaceous gland spots. Statistical analysis was carried out by using repeated measures analysis of variance, one-way analysis of variance for independent groups, Kruskal-Wallis H test, and least significant difference- t test for multiple comparisons. Results:Repeated measures analysis of variance showed that there was no significant difference in the area of sebaceous gland spots of golden hamsters among the 3 groups ( F= 0.96, P= 0.417) . The IGF-1 expression was significantly higher in the skimmed-milk group (0.39 ± 0.03) than in the blank control group (0.35 ± 0.03, t= 2.62, P= 0.021) and whole-milk group (0.33 ± 0.02, t= 3.82, P= 0.002) ; compared with the blank control group (0.36 ± 0.02) , the skimmed-milk group showed significantly increased SREBP-1 expression (0.42 ± 0.04, t= 2.64, P= 0.021) ; the ACC-1 expression was significantly higher in the skimmed-milk group (0.40 ± 0.03) and whole-milk group (0.40 ± 0.05) than in the blank control group (0.34 ± 0.03; t= 2.39, 2.47, P= 0.031, 0.026, respectively) . Conclusion:Milk may promote sebum secretion in golden hamsters through the IGF-1/SREBP-1/ACC-1 signaling pathway.

Research on the mechanism of hypoxia promoting the migration of lung adenocarcinoma A549 cells / 中国应用生理学杂志

Objective: To investigate the mechanism that hypoxia promotes the migration of lung adenocarcinoma A549 cells. Methods: A549 cells were cultured and cells that knockdown of acetyl-CoA carboxylase 1 (ACC1) were obtained by transfection with lentivirus, and cells that knockdown of sterol regulatory element-binding proteins-1 (SREBP-1) were obtained by treated with si-RNA. A549 cells were treated with hypoxia combined with hypoxia inducible factor-1α (HIF-1α) inhibitor PX-478 (25 μmol); Hypoxia combined with linoleic acid (LA) (20 μmol) treated A549 cells with ACC1 knockdown, and A549 cells with SREBP-1 knockdown were treated by hypoxia. Transwell migration assay was used to detect cell migration. Western blot was conducted to detect HIF-1α, ACC1 and epithelial mesenchymal transition (EMT) related proteins, Vimentin, E-Cadherin and SREBP-1; Real-time fluorescent quantitative polymerase chain reaction (RT-qPCR) was performed to detect the changes of ACC1 and SREBP-1 mRNA in A549 cells after hypoxia and HIF-1α inhibitor PX-478 (25 μmol) treatment. Each experiment was repeated three times. Results: Compared with the normoxic control group, hypoxia promoted the migration of A549 cells (P＜0.01), and up-regulated the expressions of ACC1, HIF-1α (all P＜0.01) and SREBP-1 (P＜0.05). PX-478 (25 μmol) inhibited the migration of A549 cells induced by hypoxia and down-regulated the expression of SREBP-1 (all P＜0.05). ACC1 mRNA and SREBP-1 mRNA levels were increased after hypoxia treatment of A549 cells (all P＜0.05). The levels of ACC1 mRNA and SREBP-1 mRNA were decreased after A549 cells treated with hypoxia combined with PX-478 (25 μmol) for 24 h (P＜0.05, P＜0.01). Knockdown of SREBP-1 in A549 cells was obtained by transfection with si-RNA. Transwell migration assay showed the number of cell migration in si-SREBP-1 group was less than that in normoxia control group (P＜0.01). The si-SREBP-1 group and the si-NC group were treated with hypoxia. Compared with the control group, the number of cell migration in the si-SREBP-1 group was decreased (P＜0.01), however, the difference was not statistically significant compared with the normoxia si-SREBP-1 group (P＞0.05). Western blot showed that the expression of ACC1 in the si-SREBP-1 group was lower than that in the control group (P＜0.01). Compared with the control group, the expression of ACC1 was decreased after si-SREBP-1 group treated with hypoxia (P＜0.01). Knockdown of ACC1 inhibited the migration of A549 cells (P＜0.05). After knockdown of ACC1, the migration number of A549 cells under normoxia and 5% O2 conditions had no significant difference (P＞0.05). Application of LA under hypoxia condition rescued ACC1-knockdown induced inhibitory effect on hypoxia-promoted A549 cell migration (P＜0.05). Conclusion: Hypoxia promotes migration of lung adenocarcinoma A549 cells by regulating fatty acid metabolism through HIF-1α/SREBP-1/ACC1 pathway.

Metformin regulates AMPK/SREBP-1 pathway and its clinical application / 中国临床药理学与治疗学

Metformin is one of the commonly used hypoglycemic drugs in clinical practice. In addition to hypoglycemia, there are a variety of medical biological values that have been constantly discovered and attracted much attention. In recent years, studies have shown that metformin through activation of AMPK inhibition of sterols regulating element binding protein 1 (SREBP-1) reduce lipid synthesis, in the treatment of liver steatosis, improve insulin sensitivity, prevention Metformin is one of the commonly used hypoglycemic drugs in clinical practice. In addition to hypoglycemia, there are a variety of medical biological values that have been constantly discovered and attracted much attention. In recent years, studies have shown that metformin through activation of AMPK inhibition of sterols regulating element binding protein 1 (SREBP-1) reduce lipid synthesis, in the treatment of liver steatosis, improve insulin sensitivity, prevention of atherosclerosis and cardiovascular dysfunction, tumor, polycystic ovary syndrome and adjuvant therapy of COVID-19 aspects play a role. Therefore, this article reviews the possible mechanism and clinical application of metformin in regulating glucose and lipid metabolism by inhibiting SREBP-1 through activating AMPK.

Mitochondrial dysfunction on Leishmania (Leishmania) amazonensis induced by ketoconazole: insights into drug mode of action

BACKGROUND Leishmania parasites cause leishmaniasis that range from self-limiting cutaneous lesions to more serious forms of the disease. The search for potential drug targets focusing on biochemical and metabolic pathways revealed the sterol biosynthesis inhibitors (SBIs) as a promising approach. In this class of inhibitors is found ketoconazole, a classical inhibitor of 14α-methysterol 14-demethylase. OBJECTIVE The present study aimed to better understand the biological response of Leishmania (Leishmania) amazonensis promastigotes at the cellular level after ketoconazole treatment. METHODS Herein, techniques, such as fluorimetry, flow cytometry, fluorescence microscopy, electron and scanning microscopy were used to investigate the cellular structures and to identify organelles affected by ketoconazole treatment. FINDINGS The study demonstrated, for the first time, the effect of ketoconazole on mitochondrion functioning and its probable relationship to cell cycle and death on L. (L.) amazonensis promastigotes (IFLA/BR/67/PH8 strain). MAIN CONCLUSIONS Ketoconazole-induced mitochondrial damages led to hyperpolarisation of this single organelle and autophagic vacuoles formation, as a parasite survival strategy. These damages did not reflect directly on the parasite cell cycle, but drove the parasites to death, making them susceptible to ketoconazole treatment in in vitro models.

Relationship between serum SREBP-1, SAP and endocrine metabolism in patients with polycystic ovary syndrome / 中华内分泌外科杂志

Objective:To investigate the relationship between serum sterol regulatory element binding protein-1 (SREBP-1) , serum amyloid P (SAP) and endocrine metabolism in patients with polycystic ovary syndrome.Methods:75 patients with polycystic ovary syndrome (study group) and 70 healthy women (control group) admitted to the First People’s Hospital of Yuhang District from Mar. 2018 to Feb. 2020 were enrolled. Various indexes were detected in both groups, including body mass index (BMI) , SREBP-1, SAP, triglyceride (TG) , total cholesterol (TC) , high-density lipoprotein (HDL-C) , and low-density lipoprotein (LDL-C) , fasting blood glucose (FBG) , fasting insulin (FINS) , and insulin resistance index (HOMA-IR) . The study group was further divided into two subgroups according to BMI, overweight group and normal group. SREBP-1 and SAP were compared between the two groups. Pearson correlation analysis was used to analyze the correlation between SREBP-1, SAP, blood lipid index, blood glucose index and BMI in patients with polycystic ovary syndrome.Results:The body weight and BMI index of study group were higher than those of control group [ (72.23±4.84) kg vs (58.23±3.25) kg, (25.02±2.75) kg/m 2 vs (22.11±1.34) kg/m 2, P<0.05]. The levels of serum SREBP-1 and SAP in the study group were significantly higher than those in the control group [ (334.78±32.06) pg/ml vs (206.34±25.71) pg/ml, (206.34±25.71) mg/U vs (39.16 ±0.58) mg/U, P<0.05]. The expression levels of TG, TC, LDL-C, FBG, FINS, and HOMA-IR in the study group were higher than those in the control group [ (2.32±0.71) vs (1.53±0.52) , (4.85±0.54) vs (3.41±0.66) , (3.06±0.75) vs (2.11±0.89) , (6.45±0.62) vs (5.59±0.76) , (16.14±1.03) vs (13.02±1.34) , (1.67±0.38) vs (1.18± 0.26) , P<0.05]; HDL-C expression level in the study group was lower than that in the control group [ (1.43±0.56) vs (1.71±0.42) , P<0.05]. The levels of SREBP-1 and SAP in overweight group were higher than those in normal group [ (339.19±27.63) pg/ml vs (281.67±20.18) pg/ml, (53.26±0.59) mg/U vs (42.48±0.67) mg/U, P<0.05]. Serum SREBP-1 and SAP in the study group were positively correlated with TG, TC, LDL-C, HOMA-IR, and BMI, and were negatively correlated with HDL-C ( P<0.05) . Conclusion:SREBP-1 and SAP levels are elevated in patients with polycystic ovary syndrome, which are significantly correlated with TG, TC, LDL-C, HOMA-IR, BMI, and HDL-C, and can cause endocrine disorder by affecting glucose and lipid metabolism.

Reinforcement of sterols production through directed storage and transportation in yeast: a review / 生物工程学报

Sterols, a class of cyclopentane poly-hydrophenanthrene derivatives, are the predominant membrane constituent of eukaryotes. These substances have a variety of biological activities and have been widely used in food and pharmaceutical industries. The presence of endogenous ergosterol biosynthetic pathway in Saccharomyces cerevisiae cells make it an ideal chassis for the de novo synthesis of sterol and its derivatives. Most recently, the rational modification of organelles provides a novel strategy for the directed transportation and storage of target products and the ultimate enhanced product synthesis. This review summarizes the phenotypic responses of S. cerevisiae cells upon different physiological stimulations and the underlying molecular mechanisms. Reinforcement of sterol production through directed storage, transportation, and excretion of sterols offers a novel strategy for breaking the limitation of de novo biosynthesis of sterols in yeast.

Influence of Schisandrae Fructus and compatible with Glycyrrhiza on level of serum lipids and synthesis pathway of triglyceride / 中国药理学通报

Aim To investigate the influence of Schisandrae Fructus ( Wuweizi in Chinese) and com¬patible with Glycyrrhiza ( Gancao in Chinese ) on the levels of serum lipids and their influence on liver syn¬thesis pathway of triglyceride ( TG ). Methods ICR mice were divided, according to weight randomized block method, into four groups; normal control group ( Control, C ), Schisandrae Fructus ethanolic extract group (SF) , Schisandrae Fructus compatible with Gly¬cyrrhiza ethanolic extract (SG) 1 : 1 and 1 : 1.5. The control group was intragastrically given normal saline (10 mL • kg-1), SF group, SG 1 : 1 and 1 : 1. 5 group were given the extract 3. 9 g • kg"1 in crude of Schisandrae Fructus for 10 days. The levels of TG, to¬tal cholesterol (TC) , low-density lipoprotein-cholester¬ol ( LDL-C ) and high-density lipoprotein-cholesterol ( HDL-C ) were detected by biochemical method, as well as alanine aminotransferase (ALT) activity. The activities of liver fatty acid synthase (FAS) and acctyl-COA carboxylase ( ACC ), and levels of GPAT, acy- CoA oxidase ( ACO ) were detected by enzyme immu¬noassay ( ELISA ). The protein expressions of sterol regulatory element-binding protein-lc (SREBP-lc) and peroxisome proliferator-activiated receptor-a ( PPARa ) were detected by immunohistochemistry technique. Results Compared with C group, the lev¬els of TG and TC increased significantly, the level of serum LDL-C decreased significantly, the activities of liver ACC and GPAT level increased markedly, the protein expression of SREBP-1 c was markedly up-regu¬lated, and the protein expression of PPARa was evi¬dently down-regulated in SF group. When compared with SF group, the levels of serum TG and ACO, the activities of serum ALT and GPAT apparently de¬creased in SG 1 : 1 group. The protein expression of SREBP-1 c in SG 1 : 1 and 1 : 1.5 group was signifi¬cantly down-regulated, and the protein expression of PPARa was markedly up-regulated. Conclusions High dose of SF can increase the serum TG and TC levels , and the mechanisms may be related to that SF can promote the expression of liver SREBP-lc, in¬crease the activities and levels of FAS, ACC and GPAT in TG synthesis pathway, and down-regulate protein expression of PPARct and ACO for promoting liver TG synthesis. Compatible with Glycyrrhiza can significantly improve the elevated blood lipids and the proteins in the TG synthesis pathway.

Effects of different transdermal penetration enhancers applied to herbal cake-partitioned moxibustion on liver lipids, HSL and HMG-CoA reductase in hyperlipidemia rabbits / 针灸推拿医学（英文版）

Objective: To observe the effects of laurocapram and borneol as transdermal penetration enhancers applied to herbal cake-partitioned moxibustion on liver lipids, hormone-sensitive lipase (HSL) and hydroxymethylglutaryl CoA (HMG-CoA) reductase in hyperlipidemia rabbits.Methods: Forty New-Zealand rabbits were randomly divided into 5 groups using the random number table method, with 8 rats in each group. Rabbits in the blank group were fed routinely with a normal diet; rabbits in the other groups were fed with high-fat diet for 12 weeks to establish the hyperlipidemia model. Rabbits in the blank and the model groups were not given any intervention. After the model was prepared successfully, rabbits in the non-transdermal penetration enhancer group received herbal cake-partitioned moxibustion without transdermal penetration enhancers; rabbits in the laurocapram group and the borneol group received herbal cake-partitioned moxibustion with laurocapram or borneol respectively. After 4 weeks of treatment, the serum was isolated and enzyme-linked immunosorbent assay (ELISA) was applied for the detection of HSL and HMG-CoA reductase. The liver tissues were isolated, and total cholesterol (TC) and triglycerides (TG) were measured by enzymatic methods. One-step method was applied for high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) detection, and transmission turbidimetry was for apolipoprotein A1 (Apo-A1) and apolipoprotein B (Apo-B) detection. Results: The serum concentrations of the drugs in the laurocapram and the borneol groups were significantly higher than those in the non-transdermal penetration enhancer group (both P<0.05); all drug penetrations in the borneol group were significantly higher than those in the laurocapram group (both P<0.05), except for tanshinone ⅡA. Compared with the non-transdermal penetration enhancer group, the HSL was significantly increased while the HMG-CoA reductase was significantly decreased in the laurocapram and the borneol groups (both P<0.05); between groups, the HSL in the borneol group was significantly higher than that in the laurocapram group (P<0.05). Compared with the blank group, the levels of LDL-C, TG, TC and Apo-B in rabbit liver were significantly increased in the model group (P<0.05); compared with the model group, the levels of LDL-C, TG, TC and Apo-B in the non-transdermal penetration enhancer, the laurocapram, and the borneol groups were significantly decreased (all P<0.05); between groups, the TG and TC in the laurocapram group and the LDL-C, TG, TC and Apo-B in the borneol group were significantly lower than those in the non-transdermal penetration enhancer group (all P<0.05), and the TG, LDL-C and Apo-B in the borneol group were significantly lower than those in the laurocapram group (all P<0.05). Compared with the blank group, the HDL-C and Apo-A1 were significantly decreased in the model group (both P<0.05), while compared with the model group, the HDL-C and Apo-A1 were significantly increased in the non-transdermal penetration enhancer, the laurocapram, and the borneol groups (all P<0.05). Between groups, the Apo-A1 in the laurocapram group, the HDL-C and Apo-A1 in the borneol group were significantly higher than those in the non-transdermal penetration enhancer group (all P<0.05).Conclusion: The application of laurocapram and borneol, as transdermal penetration enhancers, in herbal cake-partitioned moxibustion can promote the penetration of the drugs in the herbal cake, increase the levels of HDL-C and Apo-A1, improve the metabolism of HSL and HMG-CoA reductase, and also simultaneously reduce the levels of TC, TG, LDL-C and Apo-B in the liver. The transdermal penetration enhancement effect of borneol is slightly better than or equivalent to that of laurocapram.

Promoter methylation of SREBP-2 in circulating leukocytes correlates with relevant risk factors in patients with coronary artery disease / 中华检验医学杂志

Objective@#To examine the correlation between the promoter methylation of Sterol regulatory-element binding protein-2 (SREBP-2) and miR-33a expression as well as serum markers in patients with coronary artery disease (CAD).@*Methods@#The case-control study. 100 participants who underwent coronary angiography from August 2017 to April 2018 in TaiheHospital, Hubei University of Medicine, were recruited in this study.The methylation level of two fragments, including 12 CpG sites in the promoter region of SREBP-2, have been detected by pyrosequencing in 50 patients with coronary artery disease (CAD) and 50 non-CAD controls. Serum miR-33a level and a panel of 15 CAD related biomarkers were examined by qPCR and routine biochemistry methods.@*Results@#Methylation level of one CpG site (F1-4 loci) in SREBP-2 promoter region were significant higher in CAD patients than in controls(4.56%±0.70% vs 3.54%±0.72%, t=-3.864, P<0.001); methylation level of F1-4 site was negatively correlates with the serum miR-33a levels and high-density lipoprotein cholesterol (HDL-C) levels(r=-0.318, P=0.001; r=-0.225, P=0.024, respectively). Furthermore, F1-4 hypermethylation was an independent risk factor of CAD, independent of age, gender, histories of hypertension, hyperlipidemia, and diabetes(OR=2.452, 95%CI=1.398-4.299, P=0.002).@*Conclusion@#These results suggest that DNA methylation and miRNA might cooperate to regulate the lipid metabolism in CAD.

Research progress on role of cholesterol in liposomes and replacement with sterols and saponins / 中草药

With the development of process study of liposomes, the design of multifunctional liposomes has been a research hotspot. Cholesterol is one of the main components in liposome preparations, and plays an important role in the liposome's structure and stability. Sterols, saponins with the similar structure and certain pharmacological activities can be used to replace cholesterol in liposomes, which can also form good liposomes. Also, the pharmacological activities of sterols and saponins endow the liposomes with better application value. With the relevant literatures at home and abroad in recent years, this paper reviews the research progress of the role of cholesterol and the replacement design of cholesterol in liposomes with sterols and saponins.

Cloning and expression analysis of PlERG24 gene in ergosterol biosynthesis of Phellinus linteus / 中草药

Objective: To clone the gene full length of ergosterol C14 reductase (ERG24) in Phellinus linteus and analyze its bioinformatics and expression pattern. Methods: The primers of PlERG24 were designed according to the transcription sequence of P. linteus, the cDNA full-length sequence of PlERG24 was obtained by PCR, its bioinformatics was analyzed by Ex PASy and other online analysis software, and its expression pattern in mycelia of P. linteus was analyzed by real-time fluorescence quantitative PCR. Results: The full-length cDNA of PlERG24 gene was 1 412 bp, which encoding a protein of 441 amino acids with a predicted molecular weight of 49 358.61 and isoelectric point of 5.28; ERG24 protein was a hydrophobic protein without signal peptide, which was presumably located in the plasma membrane with six phosphorylation sites. Phylogenetic tree analysis indicated that amino acid sequences of ERG24 in P. linteus were genetically closely related to ERG24 in Sanghuangporus baumii. The qRT-PCR results showed that gene expression of PlERG24 reached the highest level of 6.36 at 25d during the growth cycle of mycelia in P. linteus. Conclusion The full length of PlERG24 gene was obtained, which lays a foundation for further studies on gene function and genetic regulatory mechanism of ergosterol biosynthesis.

Protective effect of Xiaochaihu Decoction on non-alcoholic steatohepatitis model mice / 中草药

Objective: The protective effect of Xiaochaihu Decoction on non-alcoholic steatohepatitis (NASH) model mice was studied by constructing a methionine-choline deficiency (MCD) diet-induced NASH model in mice. Methods: C57BL/6 mice, as the research objects, were randomly divided into normal control group, model group, Xiaochaihu Decoction (high, medium and low doses) group, Yishanfu group and Qianggan Capsule group. The NASH model was established by feeding MCD feeds, and model intervention was carried out at the same time by giving different drugs in groups; Changes in body weight, daily food intake, and daily water volume of the mice were recorded during the experiment. HE staining of liver tissue was performed at the end of the experiment to observe pathological changes. and the levels of biochemical indicator of alanine aminotransferase (ALT), Aspartate aminotransferase (AST), total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), interleukin 6 (IL-6), and tumor necrosis factor-α (TNF-α) in serum, and the changes of TC and TG levels in liver tissue were detected, RT-PCR was used to detect the expression levels of fatty acid synthase (FAS) and sterol regulatory element binding protein 1c (SREBP-1c) in liver tissues. Results: Data such as mouse weight, daily food intake, daily water intake, and organ coefficients indicated that MCD diet-induced model mice showed weight loss, decreased intake, and decreased liver wet weight. The weight, intake and liver coefficient of mice in Xiaochaihu Decoction group were significantly higher than those in the model group; The results of HE staining showed that Xiaochaihu Decoction could significantly reduce the degree of steatosis and inflammation of liver tissue, and improve the morphology and structure of liver cells; The results of serum biochemical indicators showed that Xiaochaihu Decoction significantly reduced the levels of TG, TC, AST, ALT, IL-6, TNF-α and increased the level of HDL-C in NASH model mice; RT-PCR results showed that the gene expression levels of FAS and SREBP-1c in the liver tissue of the model group mice were significantly increased, and the administration of Xiaochaihu Decoction could significantly reduce the gene expression levels of FAS and SREBP-1c. Conclusion: Xiaochaihu Decoction has obvious protective effect on NASH mouse model induced by MCD diet. It may play a lipid-lowering role by regulating the expression of inhibitors of fatty acid synthetase genes (FAS, SREBP-1c), reducing fat accumulation, and inhibiting the expression of inflammatory factors to improve liver tissue damage.