Molecular mechanism of the anti-inflammatory and skin protective effects of Syzygium formosum in human skin keratinocytes.

Irradiation injury, especially caused by UVB, of the skin is one of the critical reasons for skin inflammation and damage. The present study aimed to explore the protective effect of Syzygium formosum leafy extract (SFLE) and its mechanism of action against UVB-induced damages of human keratinocytes. In this study, SFLE was prepared from 100 kg dried leaves using industrial-scale processes. We found that SFLE markedly reduced markers of the skin inflammation in UVB-induced pro-inflammatory cytokines. Only 2 µg/mL of SFLE exhibited significantly stronger anti-inflammatory effects than the fivefold concentration of positive control. Intriguingly, an anti-inflammatory enzyme, heme oxygenase-1 expression was significantly induced by SFLE treatment. MMP-3 and -9 were, but not MMP-1, significantly reduced. SFLE inhibited the expression of the MAPK pathway, resulting in a decrease on UVB-induced reactive oxygen species. In conclusion, SFLE can potentially be used to treat skin inflammatory diseases. Supplementary Information: The online version contains supplementary material available at 10.1007/s10068-023-01380-4.

Preventive effects of inotodiol on polyinosinic-polycytidylic acid-induced inflammation in human dermal fibroblasts.

Double-strand RNA(dsRNA), which can induce inflammation, can be generated by necrotic keratinocytes in the skin environment. As an analog of dsRNA, polyinosinic-polycytidylic acid (poly(I:C)) is used to induce inflammation via the Toll-like Receptor 3 (TLR3) signaling pathway. Inotodiol, isolated from Inonotus obliquus, known as Chaga mushroom, is a natural lanostane-type triterpenoid with significant pharmacological activity and notable anti-inflammatory effects. However, the functions of inotodiol on dsRNA-induced inflammation in human dermal fibroblast (HDFs) remains unclear. In this study, we evaluated the anti-inflammatory effects of inotodiol inflammation induced on by poly(I:C) in HDFs. After pre-treatment with inotodiol, poly (I:C) was used to induce inflammation. Subsequently, mRNA expression and protein secretion of inflammatory cytokines, as well as TLR3 signaling protein levels were assessed. Inflammatory cytokines IL-1ß, IL-6, and TNF-α's increased mRNA expression by poly(I:C) in HDFs was significantly suppressed in the inotodiol pre-treatment group in a dose-dependent manner. A similar pattern was evaluated in the protein levels of these three cytokines. The inflammatory signals of TLR3 via p-IKK, p-p38, and NF-κB was reduced by inotodiol pre-treatment. Taken together, inotodiol possesses strong anti-inflammatory activity against poly(I:C)-induced inflammation in HDFs. Therefore, our findings support potential application of inotodiol as an effective anti-inflammatory agent in cosmetics.

Antiaging effect of inotodiol on oxidative stress in human dermal fibroblasts.

Oxidative damage is one of the major causes of human skin aging. Inotodiol is a lanostane triterpenoid that demonstrates antiviral, anticancer, and anti-inflammatory activities. Previous studies have reported that inotodiol also has antiallergic effects. However, whether inotodiol inhibits oxidative stress-induced human skin aging is not known. Stimulation of human dermal fibroblast cells with hydrogen peroxide is related to skin aging. Inotodiol inhibited the expression of mitogen-activated protein kinase (MAPK) and NADPH Oxidase 5 (NOX5). Moreover, inotodiol effectively decreased nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), as well as nitric oxide (NO), reactive oxygen species (ROS), cyclooxygenase-2 (COX-2), and cytokines such as IL-1ß, IL-6, and TNF-α. Based on our results, inotodiol protects human dermal fibroblast by preventing MAPK-NOX5 and NF-κB activation and attenuates the expression of aging genes. Inotodiol may therefore be considered a potential candidate for developing natural antiaging products, because it protects the human skin from oxidative stress-induced skin aging by inhibiting the MAPK-NOX5 and NF-κB signaling pathways.

Polymorphism in the HaeIII single nucleotide polymorphism of the SLC2A1 gene and cardiovascular disease in the early type 2 diabetes mellitus.

INTRODUCTION: SLC2A1 polymorphism may play a role in the smooth muscle cell proliferation and extracellular matrix synthesis in vessels. However, the role of SLC2A1 polymorphism on diabetic cardiovascular disease (CVD) have not yet been identified. In this study, we aimed to investigate the association between SLC2A1 HaeIII polymorphism and CVD in Korean patients with type 2 diabetes mellitus (T2DM) according to disease duration. METHODS: A total of 846 patients with T2DM who visited the Chungbuk National University Hospital were investigated. The HaeIII polymorphism of SLC2A1 gene was determined by real time polymerase chain reaction method. Genotyping results were presented GG, AG, or AA. Subgroup analysis was performed according to duration of T2DM (⩽10, 11-20, >20 years). RESULTS: The AA genotype was significantly associated with higher prevalence of CVD in patients with DM duration less than 10 years (26.3% vs 9.2%, p = 0.014). There was no significant association between SLC2A1 HaeIII polymorphism and other diabetic complications including, retinopathy, nephropathy, neuropathy, cerebrovascular disease, and peripheral artery disease. CONCLUSIONS: The SLC2A1 HaeIII polymorphism was associated with CVD in Korean patients with T2DM with short disease duration.

MST2 silencing induces apoptosis and inhibits tumor growth for estrogen receptor alpha-positive MCF-7 breast cancer.

Mammalian sterile 20-like kinase 1/2 (MST1/2) plays an important role in cell growth and apoptosis and functions as a tumor suppressor. Previously, we showed that MST2 overexpression activates Estrogen receptor alpha (ERα) in human breast cancer MCF-7 cells in the absence of a ligand. Here, we examined the role of MST2 in the growth of ER-positive MCF-7 cells. Cell cycle, apoptosis, and mammosphere formation assay method were implemented to detect the biological effects of MST2 ablation on the growth of MCF-7 cells in vitro. The effect of MST2-siRNA on MCF-7 cells tumor growth in vivo was studied in tumor-bearing mouse model. Kaplan-Meier plotter analysis was used to determine the effect of MST2 on overall survival in breast cancer patients. MST2 overexpression increased cell viability marginally. The ablation of MST2 using siRNA dramatically suppressed the viability of the MCF-7 cells, but not ER-negative MDA-MB-231 breast cancer cells. Furthermore, MST2 knockdown increased caspase-dependent apoptosis and led to decreased mammosphere formation. Treatment of MCF-7 tumor-bearing mice with MST2 siRNA significantly inhibited tumor growth. The tumor weight was reduced further when tamoxifen was added. Patients with ER-positive breast cancer with low MST2 expression had better overall survival than did those with high MST2 expression in Kaplan-Meier survival analyses using public datasets. Our results provide new insight into the role of MST2, a key component of the Hippo signaling pathway, in mediating breast cancer progression.

Genetic variation in TCF7L2 rs7903146 correlating with peripheral arterial disease in long-standing type 2 diabetes.

AIM: The aim of this study was to investigate the association between the transcription factor 7-like 2 gene (TCF7L2) rs7903146 polymorphism and peripheral arterial disease in type 2 diabetes. METHODS: In total, 1818 Korean type 2 diabetes patients were enrolled from January 2013 to December 2017. Subjects were categorized into two groups according to their duration of type 2 diabetes: long (⩾10 years, n = 771) and short (<10 years, n = 1047) durations. A multivariate logistic regression model was used for assuming an additive effect on peripheral arterial disease for the presence of a variant allele in TCF7L2 rs7903146. RESULTS: The frequency of the minor T-allele was 7.6% (n = 139), and this allele was significantly associated with a 2.6-fold higher risk of peripheral arterial disease (odds ratio = 2.595, 95% confidence interval = 1.177-5.722, p = 0.018) in patients exhibiting a long duration of type 2 diabetes (⩾10 years). This result was significant after adjusting for age, sex, body mass index, familial history of diabetes, smoking, duration of diabetes and laboratory measurements, which included glycated haemoglobin, fasting plasma glucose and lipid profiles. In patients with diabetes < 10 years, there was no significant association between TCF7L2 rs7903146 and peripheral arterial disease (odds ratio = 1.233, 95% confidence interval = 0.492-3.093, p = 0.655). CONCLUSION: Our results provide evidence that genetic variation in TCF7L2 rs7903146 could increase risk for peripheral arterial disease in patients exhibiting long-standing type 2 diabetes.

Associations between the HaeIII Single Nucleotide Polymorphism in the SLC2A1 Gene and Diabetic Nephropathy in Korean Patients with Type 2 Diabetes Mellitus.

BACKGROUND: Diabetic nephropathy (DN) is the most serious microvascular complication of diabetes mellitus and is one of the leading causes of end stage renal failure. In previous studies, the contribution of genetic susceptibility to DN showed inconsistent results. In this study, we investigated the association between the solute carrier family 2 facilitated glucose transporter member 1 (SLC2A1) HaeIII polymorphism and DN in Korean patients with type 2 diabetes mellitus (T2DM) according to disease duration. METHODS: A total of 846 patients with T2DM (mean age, 61.3 ± 12.3 years; mean duration of T2DM, 10.3 ± 7.9 years; 55.3% men) who visited the Chungbuk National University Hospital were investigated. The HaeIII polymorphism of the SLC2A1 gene was determined by the real time polymerase chain reaction method. Genotyping results were presented as GG, AG, or AA. A subgroup analysis was performed according to duration of T2DM (≤ 10 years, > 10 years). RESULTS: The AG + AA genotype showed a significantly higher risk of DN compared with the GG genotype in patients with a type 2 DM duration less than 10 years (12.4% vs. 4.2%; P < 0.001). No significant differences were observed in terms of other diabetic complications, including retinopathy, peripheral neuropathy, cardiovascular disease, cerebrovascular disease or peripheral artery disease, according to the genotypes of the SLC2A1 HaeIII polymorphism. CONCLUSION: The SLC2A1 HaeIII polymorphism was associated with DN in Korean patients with T2DM, particularly in the group with a relatively short disease duration.

MST2 kinase regulates osteoblast differentiation by phosphorylating and inhibiting Runx2 in C2C12 cells.

The mammalian Ste20-like kinase (MST) pathway or Hippo pathway plays essential roles in cell proliferation, apoptosis, organ size control, and development. Runx2 is a key transcription factor in osteoblast differentiation. The objective of this study was to investigate whether the MST pathway could modulate Runx2 and osteoblast differentiation. First, we found that Runx2 interacted with MST2 and SAV1 via the WW domain of SAV1 and amino acid 292-445 of Runx2 containing a PY motif. Results of OSE luciferase reporter assay revealed that co-expression of MST2 and SAV1 inhibited the transcriptional activity of Runx2 whereas siRNA-mediated down-regulation of Mst1 and Mst2 increased its activity. MST2 and SAV1 significantly reduced mRNA levels of osteoblast differentiation marker genes such as alkaline phosphatase and osteocalcin in differentiating C2C12 cells. MST2 and SAV1 also hampered osteoblast differentiation of C2C12 cells induced by Runx2 as shown by alkaline phosphatase activity assay and Alizarin Red staining. Mass spectrometric analysis of immunoprecipitated Runx2 protein from HEK293 cells overexpressing MST2 and SAV1 revealed two novel phosphorylation sites at Ser-339 and Ser-370 residues of mouse Runx2 protein. Mutation of both serine residues to alanine interfered with the inhibitory effect of MST2 and SAV1 on the transcriptional activity of Runx2 and osteoblast differentiation induced by Runx2. Our results suggest that the MST kinase pathway can directly regulate osteoblast differentiation by modulating Runx2 activity through phosphorylation.

Mammalian Hippo kinase pathway is downregulated by BCL-2 via protein degradation.

Mammalian ste20-like kinase (MST) signaling pathway plays a significant part in control of cell death and cell cycle. It was originally found as Hippo pathway in Drosophila and composed of MST kinase and Salvador-1 (SAV1), a scaffold protein. In mammalian cells, MST pathway induces cell-cycle exit and apoptosis in response to various signals. BCL-2, an anti-apoptotic protein, inhibits cell death and plays an important part in tumorigenesis. In the present report, we present evidence showing that BCL-2 is a new regulator of MST pathway. First, protein levels of MST2 and SAV1 were reduced significantly by co-expression of BCL-2. Physical interaction of BCL-2 with SAV1 was correlated with proteasomal degradation of SAV1 and MST2 proteins. In SH-SY5Y neuroblastoma cell line expressing a high level of BCL-2 but low levels of MST2 and SAV1, siRNA-induced knockdown of BCL-2 restored the expression of MST2 and SAV1. Inhibition of BCL-2 with BAD or ABT-737, a BCL-2 inhibitor, reversed its effect on MST2 and SAV1 proteins. ABT737 increased HEK293 cell death significantly when both MST2 and SAV1 were co-expressed. These results suggest that cancer cells may avoid cell death through enhanced expression of BCL-2 which down-regulates the pro-apoptotic MST pathway.

Mammalian ste20-like kinase and SAV1 promote 3T3-L1 adipocyte differentiation by activation of PPARγ.

The mammalian ste20 kinase (MST) signaling pathway plays an important role in the regulation of apoptosis and cell cycle control. We sought to understand the role of MST2 kinase and Salvador homolog 1 (SAV1), a scaffolding protein that functions in the MST pathway, in adipocyte differentiation. MST2 and MST1 stimulated the binding of SAV1 to peroxisome proliferator-activated receptor γ (PPARγ), a transcription factor that plays a key role in adipogenesis. The interaction of endogenous SAV1 and PPARγ was detected in differentiating 3T3-L1 adipocytes. This binding required the kinase activity of MST2 and was mediated by the WW domains of SAV1 and the PPYY motif of PPARγ. Overexpression of MST2 and SAV1 increased PPARγ levels by stabilizing the protein, and the knockdown of SAV1 resulted in a decrease of endogenous PPARγ protein in 3T3-L1 adipocytes. During the differentiation of 3T3-L1 cells into adipocytes, MST2 and SAV1 expression began to increase at 2 days when PPARγ expression also begins to increase. MST2 and SAV1 significantly increased PPARγ transactivation, and SAV1 was shown to be required for the activation of PPARγ by rosiglitazone. Finally, differentiation of 3T3-L1 cells was augmented by MST2 and SAV1 expression and inhibited by knockdown of MST1/2 or SAV1. These results suggest that PPARγ activation by the MST signaling pathway may be a novel regulatory mechanism of adipogenesis.