Transcriptomic screening of novel targets of sericin in human hepatocellular carcinoma cells

Sericin, a natural protein derived from Bombyx mori, is known to ameliorate liver tissue damage; however, its molecular mechanism remains unclear. Herein, we aimed to identify the possible novel targets of sericin in hepatocytes and related cellular pathways. RNA sequencing analysis indicated that a low dose of sericin resulted in 18 differentially expressed genes (DEGs) being upregulated and 68 DEGs being downregulated, while 61 DEGs were upregulated and 265 DEGs were downregulated in response to a high dose of sericin (FDR ≤ 0.05, fold change > 1.50). Functional analysis revealed that a low dose of sericin regulated pathways associated with the complement and coagulation cascade, metallothionine, and histone demethylate (HDMs), whereas a high dose of sericin was associated with pathways involved in lipid metabolism, mitogen-activated protein kinase (MAPK) signaling and autophagy. The gene network analysis highlighted twelve genes, A2M, SERPINA5, MT2A, MT1G, MT1E, ARID5B, POU2F1, APOB, TRAF6, HSPA8, FGFR1, and OGT, as novel targets of sericin. Network analysis of transcription factor activity revealed that sericin affects NFE2L2, TFAP2C, STAT1, GATA3, CREB1 and CEBPA. Additionally, the protective effects of sericin depended on the counterregulation of APOB, POU2F1, OGT, TRAF6, and HSPA5. These findings suggest that sericin exerts hepatoprotective effects through diverse pathways at different doses, providing novel potential targets for the treatment of liver diseases.

Regulatory effect of Phikud Navakot extract on HMG-CoA reductase and LDL-R: potential and alternate agents for lowering blood cholesterol

Background

For decades, various cardiovascular symptoms have been relieved by the use of Ya-Hom Navakot, which is a formulation comprising 54 herbal medicines. The Thailand Ministry of Public Health listed Ya-Hom Navakot’s nine active principle and nomenclative herbal ingredients and termed them ‘Phikud Navakot’ (PN). Several reports have confirmed that PN has cardiovascular benefits similar to Ya-Hom Navakot. However, whether PN facilitates lipid-lowering activity remains unclear.

Methods

The present study investigated an in vitro model for examining the gene expression levels of 3-hydroxyl-3-methylglutaryl-CoA reductase (HMGCR) and low-density lipoprotein receptor (LDL-R) in HepG2 cells using qRT-PCR. The ethanol and water extractions of Ya-Hom Navakot, PN and Ya-Hom Navakot without PN were compared.

Results

One mg/ml of both NYEF and NYWF were found to significantly lower cholesterol by either the up-regulation of LDL-R or down-regulation of HMGCR compared with negative controls and 1 mg/ml simvastatin (p < 0.05). PNEF also up-regulated LDL-R gene expression, even more than NYEF (p < 0.05). In addition, the ethanol and water extracts of PN significantly down-regulated HMGCR gene expression compared with those of Ya-Hom Navakot without PN (p < 0.05).

Conclusion

The use of Ya-Hom Navakot or PN may provide an alternative treatment to lower cholesterol through HMGCR gene inhibition and LDL-R gene enhancement.

Determination of the Apo E genotype using LightCycler Apo E mutation detection kit

Apolipoprotein E (Apo E) is found to be genetically polymorphic. There are 3 common alleles designated as E2, E3 and E4. Polymorphism of the Apo E DNA is associated with the risk increase of many diseases such as dyslipidemia, cardiovascular diseases, Alzheimer's diseases, etc. Hence, the interest in genotyping of the Apo E is now rising for the purpose of pre-diagnosis. The aim of this study was to characterize the Apo E DNA polymorphism using LightCycleríApo E mutation detection kit (Roche) in the Thai normal healthy subjects. The genomic DNA was extracted from the blood of 133 normal healthy subjects using DNA extraction kit (Roche). Exon 4 of the Apo E gene was amplified by the extracted genomic DNA using the real-time PCR. The simultaneous analysis of the two polymorphic codons (Codons 112 and 158) in a single reaction was conducted by using the two reporter dyes with the different excitation and emission spectrum LightCycler-Red 640 (LC-Red 640) and LC-Red 705 followed by the color compensation software to correct the temperature-dependent crossover among the emission spectra of the dyes. The different genotypes were then determined by performing the melting curve analysis in the two different channels. The results showed that the allele frequencies of the Apo E2, E3 and E4 were 0.26, 0.63 and 0.11 respectively and the genotype frequencies of the E2/3, E2/4, E3/3, E3/4 and E4/4 were 47.37, 5.26, 32.33, 14.28 and 0.75% respectively. This study found that E2/3 was the most common genotype of the Apo E. In conclusion, the LightCycler (LC) allelic discrimination method to genotype the Apo E is rapid, simple, reliable and strongly recommended for being successful diagnostic tests in the future.

Analysis of polymorphisms in the 5'-flanking region of the apolipoprotein(a) [Apo(a)] gene in Thai subjects with coronary artery diseases

Lipoprotein(a) [Lp(a)] is a complex lipoprotein particle in human plasma. It is composed of apolipoprotein B (Apo B)-100 and apolipoprotein(a) which are linked by a disulfide bond. Plasma levels of the Lp(a) vary greatly (over 1,000 folds) among individuals. Elevated plasma levels of the Lp(a) have been shown to be an independent risk factor for coronary artery diseases (CAD). The level of Lp(a) is controlled by a single gene, the Apo(a) gene, with multiple alleles; each encodes different concentrations of the Lp(a). Previous studies revealed the presence of polymorphisms in the 5'-flanking region (FL) of the Apo(a) gene at 3 positions: G or A (-914), C or T(-49), and G or A (-21), which can be detected by cleavage of PCR-amplified DNA products with TaqI, MaeII and HhaI, respectively. The 5'-FL genotypes of the Apo(a) gene can be classified by the combination of the presence (+) or absence (-) of these restriction sites into 5 types; type A, +++, type B, -++, type C, -+-, type D, --+ and type E, +-+. In the present study, the authors analyzed the 5' FL types of the Apo(a) gene by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) in 100 healthy control subjects, 26 CAD patients with [Lp(a)] < or = 30 mg/dL, and 94 CAD patients with [Lp(a)] > 30 mg/dL. The authors found that the genotype frequencies of the Apo(a) gene were 53, 16, 27 and 4%, for types A, B, C and D respectively in normal healthy controls. In CAD patients with [Lp(a)] < or = 30 mg/dL, the distribution of the genotype frequencies were 53.8, 11.5, 30.8 and 3.9% for types A, B, C and D, respectively. Additionally in CAD patients with [Lp(a)] > 30 mg/dL, the genotype frequencies were 60.6, 11.7, 21.3 and 6.4% for types A, B, C and D, respectively. The present study might shed some light to understand CAD at the molecular level.

Antioxidant status and lipid peroxidation end products in patients of type 1 diabetes mellitus

BACKGROUND AND OBJECTIVE

In Type 1 diabetes mellitus (DM), hyperglycemia is considered a primary cause of diabetic vascular complications and is associated with oxidative stress. The role of antioxidants, particularly alpha tocopherol, in Type 1 DM and its contribution in the development of vascular complications is not clear. Therefore, the present study aims to investigate the relationship between antioxidant status (alpha tocopherol) and lipid peroxidation end products (malondialdehyde; MDA) in the plasma of 20 Type 1 DM and 20 nondiabetic healthy control subjects.

MATERIAL AND METHOD

Lipid levels in all subjects were analyzed spectrophotometrically by enzymatic reagent kits. Plasma MDA was assessed by spectrofluorometry, whereas plasma alpha tocopherol was estimated by high performance liquid chromatography in Type 1 DM as well as in the control subjects of matched sex and ages. The results of Type 1 DM were compared with a control group using unpaired Student's t-test. The correlations between fasting plasma glucose and other laboratory parameters were assessed by Pearson rank correlation coefficient.

RESULTS

The plasma MDA concentration was significantly higher in Type 1 diabetic patients as compared to controls, (p < 0.01). A significantly reduced plasma antioxidant status of Type 1 DM patients was found only in alpha tocopherol / total lipid as compared to controls (p < 0.05). However, no significant difference was observed in plasma a tocopherol and a tocopherol / total cholesterol (p > 0.05) as compared to the control subjects. The positive correlation between MDA and FPG was demonstrated in Type 1 diabetic compared with normal subjects.

CONCLUSION

We conclude that antioxidant supplementation may be necessary for treatment to reduce oxidative stress for diabetic complication protection in Type 1 DM.