Lung Fa Pan

NFIL3 Suppresses Hypoxia-induced Apoptotic Cell Death by Targeting the Insulin-like Growth Factor 2 Receptor

The insulin‐like growth factor‐II/mannose 6‐phosphate receptor (IGF2R) over‐expression correlates with heart disease progression. The IGF2R is not only an IGF2 clearance receptor, but it also triggers signal transduction, resulting in cardiac hypertrophy, apoptosis and fibrosis. The present study investigated the nuclear factor IL‐3 (NFIL3), a transcription factor of the basic leucine zipper superfamily, and its potential pro‐survival effects in cardiomyocytes. NFIL3 might play a key role in heart development and act as a survival factor in the heart, but the regulatory mechanisms are still unclear. IGF2 and IGF2R protein expression were highly increased in rat hearts subjected to hemorrhagic shock. IGF2R protein expression was also up‐regulated in H9c2 cells exposed to hypoxia. Over‐expression of NFIL3 in H9c2 cardiomyoblast cells inhibited the induction of hypoxia‐induced apoptosis and down‐regulated IGF2R expression levels. Gel shift assay, double‐stranded DNA pull‐down assay and chromatin immune‐precipitation analyses indicated that NFIL3 binds directly to the IGF2R promoter region. Using a luciferase assay, we further observed NFIL3 repress IGF2R gene promoter activity. Our results demonstrate that NFIL3 is an important negative transcription factor, which through binding to the promoter of IGF2R, suppresses the apoptosis induced by IGF2R signaling in H9c2 cardiomyoblast cells under hypoxic conditions. J. Cell. Biochem. 116: 1113–1120, 2015.

Silymarin Accelerates Liver Regeneration after Partial Hepatectomy

Partial hepatectomy (PHx) is a liver regeneration physiological response induced to maintain homeostasis. Liver regeneration evolved presumably to protect wild animals from catastrophic liver loss caused by toxins or tissue injury. Silymarin (Sm) ability to stimulate liver regeneration has been an object of curiosity for many years. Silymarin has been investigated for use as an antioxidant and anticarcinogen. However, its use as a supportive treatment for liver damage is elusive. In this study, we fed silymarin (Sm, 25 mg/kg) to male Sprague-Dawley rats for 7 weeks. Surgical 2/3 PHx was then conducted on the rats at 6 hrs, 24 hrs, and 72 hrs. Western blot and RT-PCR were conducted to detect the cell cycle activities and silymarin effects on hepatic regeneration. The results showed that silymarin enhanced liver regeneration by accelerating the cell cycle in PHx liver. Silymarin led to increased G1 phase (cyclin D1/pRb), S phase (cyclin E/E2F), G2 phase (cyclin B), and M phase (cyclin A) protein and mRNA at 6 hrs, 24 hrs, and 72 hrs PHx. HGF, TGFα, and TGFβ1 growth factor expressions were also enhanced. We suggest that silymarin plays a crucial role in accelerated liver regeneration after PHx.

Citrus medica var. sarcodactylis (Foshou) activates fibroblast growth factor-2 signaling to induce migration of RSC96 Schwann cells.

Factors that enhance the intrinsic growth potential of neurons play a major role in the regeneration and repair of adult neurons following an injury. Fibroblast growth factor (FGF-2) is one of the key players in the origin and growth of neuronal and glial cells through autocrine and paracrine signaling. Water extract of Citrus medica var. sarcodactylis (fingered citron, foshou), which is been used effectively as a Chinese herbal medicine, was found to activate the FGF-2 promoter in transgenic luciferase expression models. Foshou treatment on Schwann cells (RSC96) transfected with luciferase reporter plasmid under a FGF-2 promoter was found to induce the FGF-2 promoter and showed enhanced luciferase expression. The FGF-2 expression was accompanied with an increase in the expression of proteins involved in cell migration and cell proliferation in a dose dependent manner. Therefore, foshou potentially enhances nerve regeneration by inducing the Schwann cell proliferation and migration.

CREB negatively regulates IGF2R gene expression and downstream pathways to inhibit hypoxia-induced H9c2 cardiomyoblast cell death

During hypoxia, gene expression is altered by various transcription factors. Insulin-like growth factor-II (IGF2) is known to be induced by hypoxia, which binds to IGF2 receptor IGF2R that acts like a G protein-coupled receptor, might cause pathological hypertrophy or activation of the mitochondria-mediated apoptosis pathway. Cyclic adenosine monophosphate (cAMP) responsive element-binding protein (CREB) is central to second messenger-regulated transcription and plays a critical role in the cardiomyocyte survival pathway. In this study, we found that IGF2R level was enhanced in H9c2 cardiomyoblasts exposed to hypoxia in a time-dependent manner but was down-regulated by CREB expression. The over-expression of CREB in H9c2 cardiomyoblasts suppressed the induction of hypoxia-induced IGF2R expression levels and reduced cell apoptosis. Gel shift assay results further indicated that CREB binds to the promoter sequence of IGF2R. With a luciferase assay method, we further observed that CREB represses IGF2R promoter activity. These results suggest that CREB plays an important role in the inhibition of IGF2R expression by binding to the IGF2R promoter and further suppresses H9c2 cardiomyoblast cell apoptosis induced by IGF2R signaling under hypoxic conditions.

Green tea epigallocatechin gallate enhances cardiac function restoration through survival signaling expression in diabetes mellitus rats with autologous adipose tissue-derived stem cells

The present study tests a hypothesis that cardioprotective effects mediated by autologous adipose-derived stem cells (ADSC) in rats afflicted with insulin-dependent diabetes mellitus (IDDM) may be synergistically enhanced by oral treatment with green tea epigallocatechin gallate (EGCG). Wistar rats were divided into sham, DM, DM+ADSC (autologous transplanted 1 × 106 cells per rat), and DM+ADSC+E (E, green tea oral administration EGCG). Heart tissues were isolated from all rats, and investigations were performed after 2-mo treatment. In the sham, DM, and DM+ADSC groups, we found that DM induced cardiac dysfunction (sham and DM) and autologous ADSC transplantation could partially recover cardiac functions (DM and DM+ADSC) in DM rats. Compared with DM+ADSC, significant improvement in cardiac functions can be observed in DM+ADSC+E in echocardiographic data, histological observations, and even cellular protein expression. Oral green tea EGCG administration and autologous ADSC transplantation show synergistically beneficial effects on diabetic cardiac myopathy in DM rats.NEW & NOTEWORTHY Cardiomyopathy can be induced in rats with diabetes mellitus (DM). Heart function can be restored in DM rats with adipose-derived stem cell treatment. Oral epigallocatechin gallate (EGCG) administration synergistically enhances cardiac function in DM rats with stem cell treatment. The EGCG and stem cell treatment cross-effect occurs via survival protein expression.

Potential phytoestrogen alternatives exert cardio-protective mechanisms via estrogen receptors

The 17 beta-estradiol (E2) is a sex hormone that is most abundant and most active estrogen in premenopausal women. The importance of E2 in providing cardioprotection and reducing the occurrence of heart disease in women of reproductive age has been well recognized. There are three subtype of estrogen receptors (ERs), including ERα, ERβ and GPR30 have been identified and accumulating evidence reveal their roles on E2-mediated genomic and nongenomic pathway in cardiomyocytes against various cardiac insults. In this review, we focus on the estrogen and ERs mediated signaling pathways in cardiomyocytes that determines cardio-protection against various stresses and further discuss the clinical implication of ERs and phytoestrogens. Further we provide some insights on phytoeostrogens which may play as alternatives in estrogen replacement therapies.

Suppression of isoproterenol-induced apoptosis in H9c2 cardiomyoblast cells by daidzein through activation of Akt.

Increased serum norepinephrine level is one of pathological processes relating to heart disease (HD). Estrogens are considered as potential therapeutics for the treatment of HD; however, estrogen supplementation shows some side-effects, such as increasing the risk of developing breast, endometrial and ovarian cancers. This study investigated the cardio-protective effects of daidzein (Dai), a selective estrogen receptor modulator (SERM) from soy bean extract, in H9c2 cardiomyoblast cells treated with isoproterenol (ISO), a norepinephrine analog. In this in vitro model, H9c2 cells treated with Dai at different concentrations showed no statistical difference in cell viability. TdT-mediated digoxigenin-dUTP nick-end labeling (TUNEL) data and western blotting results indicated that Dai treated-H9c2 cells recovered from the damage induced by ISO. The recovery effects of Dai on ISO-induced damage were blocked by inhibition of Akt activation through adding Akt inhibitor. On the other hand, the fold changes of phosphorylated Akt (p-Akt)/Akt normalized with the control for con, 0.25, 0.5, 1, 3 and 24 h of treatment were 1, 2, 5, 13, 11 and 10, respectively. In conclusion, Dai ameliorates apoptosis of cardiomyoblasts induced by ISO through Akt signaling pathway.

Hepatoprotective Effects of Traditional Chinese Medicine on Liver Fibrosis from Ethanol Administration following Partial Hepatectomy

The aim of this study was to establish the effective hepatoprotective properties of traditional Chinese medicines (TCMs) in fibrotic rat liver regeneration after partial hepatectomy (PHx). Fibrosis was induced in rats by ethanol (EtOH, 5 ml/kg) administration for 6, 24, 72, and 168 h. The rats were then fed four TCMs (1 g/kg/day, Codonopsis pilosula (CP), Salvia miltorrhiza Bunge (SMB), Bupleurum kasi (BK), and Elephantopus scaber L (ESL)) to Spraque-Dawley rats for 6, 24, 72 and 168 h, respectively. Surgical 70% cirrhotic fibrosis PHx was then conducted at 6, 24, 72, and 168 h. The effects on liver regeneration were examined to estimate and measure hepatocyte growth factor (HGF), focal adhesion kinase (FAK), Cyclin D1, Cyclin E, and retinoblastoma protein (pRb) protein expression using Western blotting analysis. Cyclin D1, matrix metalloproteinase (MMP)-2, MMP-9, tissue inhibitors of metalloproteinase (TIMP)-1, TIMP-2 and TIMP-3 mRNA by Reverse transcription polymerase chain reaction (RT-PCR) were analyzed in cirrhotic fibrosis rats. Transforming growth factor-β1 (TGF-β1), Cyclin D1, Cyclin E, pRb and E2F mRNA expression levels were determined in fibrotic rats following PHx using RT-PCR. We found elevated glutamyl oxaloacetic transaminase (GOT), glutamyl pyrubic transaminase (GPT), alkaline phosphatase (ALP), gammaglutamyl transpeptidase (γ-GT), glutathione (GSH), nonprotein sulfhydryl (NPSH) and total bilirubin in serum after 6 h EtOH administration. These levels were progressively decreased over 168 h. Total protein and albumin were reduced in serum after 6 h administration and then progressively increased. In contrast, tissues disorder histology and morphology were determined in liver sections. After rats were fed TCMs we found that SMB extraction not only induced HGF, FAK, Cyclin D1, and pRb protein expression and Cyclin D1 mRNA increases, but also reduced MMP-2 and MMP-9 after 24 and 72 h post injury. In the cell cycle S phase the Cyclin E protein expression was increased by ESL. CP induced TIMP-1, TIMP-2 and TIMP-3 mRNA increases in fibrotic rats. We detected liver regeneration in fibrotic rats. We also found that the liver regeneration index increased from 6 to 168 h post PHx. After 168 h fibrotic liver regeneration rats exhibited reduced TGF-β1 mRNA expression and enhanced Cyclin D1, Cyclin E, pRb and E2F mRNA expression. TCMs play a crucial role in the early mediating process in fibrotic rat liver regeneration after PHx.

Stem cells rescue cardiomyopathy induced by P. gingivalis-LPS via miR-181b

Systemic inflammation induced by bacterial infection is one of several causative agents for cardiovascular disorders in patients with periodontal disease. Experimental results indicate that miRNAs play important roles in systemic inflammation induced by endotoxins. Further evidence states that stem cell based therapy shows potential in the treatment of inflammatory responses induced by sepsis. This study investigates if stem cells show protective effects on cardiomyocyte damage induced by porphyromonas gingivalis‐LPS (Pg‐LPS) through regulating miRNAs. H9c2 cardiomyoblasts and neonatal rat cardiomyocytes (NRCMs) were damaged using Pg‐LPS in this study. Pg‐LPS damaged H9c2 or NRCMs were then rescued using adipose‐derived stem cells (ADSC). The experimental results reveal that Pg‐LPS treatment is capable of inducing TLR4/NFκB axis activation, cell death signaling and IGF1R/PI3 K/Akt axis suppression. miR181b was downregulated in Pg‐LPS damaged H9c2/NRCMs. All markers were improved in H9c2/NRCMs cocultured with ADSC. miR181b mimic and inhibitor confirmed that miR181b plays a central role in regulating the cardio protective effect on Pg‐LPS damaged H9c2/NRCMs cocultured with ADSC. miR181b acts as potential therapeutic marker in cardiomyopathy induced by Pg‐LPS. Transplantation of adipose‐derived stem cells show potential in the treatment of cardiomyopathy induced by porphyromonas gingivalis endotoxin via regulation of miR181b.

Adipose-derived stem cells decrease cardiomyocyte damage induced by porphyromonas gingivalis endotoxin through suppressing hypertrophy, apoptosis, fibrosis, and MAPK markers

Heart failure is one of the complications related to periodontal disease. In addition to drugs or herbal medicines, stem cell therapy shows potential in the treatment of cardiomyopathy. This study investigates if stem cells exhibit beneficial effects on cardiomyocyte damage induced by porphyromonas gingivalis endotoxin (Pg‐LPS). From the experimental results we find that Pg‐LPS reduce cardiomyocyte viability via the activation of apoptosis, hypertrophy, fibrosis and MAPK signaling. Pg‐LPS damaged cardiomyocytes co‐cultured with adipose‐derived stem cells (ADSC) increases cardiomyocyte viability through suppressing the pathological markers described above. Further evidence implies that survival marker, IGF1, secreted from ADSC, may play an important role in the Pg‐LPS induced protective effect on cardiomyocyte damage.