Jing Ying Lin

Carthamus tinctorius L. prevents LPS-induced TNFα signaling activation and cell apoptosis through JNK1/2–NFκB pathway inhibition in H9c2 cardiomyoblast cells

AIM OF THE STUDY Severe and potentially fatal hypotension and cardiac contractile dysfunction are common symptoms in patients with sepsis. In our previous study, we found that estradiol and estrogen-receptor alpha have cardio-protective effects in myocardial cells exposed to LPS. Estradiol supplementation has been shown to induce breast and cervical cancers. Flos Carthami, the flower of Carthamus tinctorius L. (Compositae) is an important traditional Chinese medicine used for the treatment of heart disease and inflammation, and therefore might be a potential alternative to Estradiol in the prevention of heart damage. This study investigated the effect of Flos Carthami (FC(EtOH)) ethanolic extract on LPS-induced apoptosis in H9c2 cardiomyoblast cells. MATERIALS AND METHODS H9c2 cells induced apoptosis with LPS administration (1 microg/mL). H9c2 cells were divided into five groups: Control, LPS (1 microg/mL), and three FC(EtOH) (31.25, 62.5,and 125 microg/mL). We detected apoptosis using MTT, LDH, TUNEL assay. JC-1 staining and Western blot were used to detect pro-apoptosis proteins, anti-apoptosis proteins, MAPK proteins (JNK, ERK, and P38), and NFkappaB expression. RESULTS FC(EtOH) (62.5 microg/mL) inhibited LPS-induced apoptosis by suppressing JNK1/2 activity, which resulted in the reduction of both IkappaB degradation and NFkappaB activation. In addition, FC(EtOH) led to the activation of anti-apoptotic proteins, Bcl-2 and Bcl-xL, the stabilization of the mitochondria membrane and the down-regulation of extrinsic and intrinsic pro-apoptotic proteins, such as TNFalpha, active caspase-8, t-Bid, Bax, active caspases-9, and -3. CONCLUSIONS Carthamus tinctorius L. possesses the ability to suppress JNK activity and inhibit LPS-induced TNFalpha activation and apoptosis in H9c2 cardiomyoblast cells. Carthamus tinctorius L could potentially serve as a cardio-protective agent against LPS-induced apoptosis.

Mesenchymal stem cell insights: Prospects in cardiovascular therapy

Ischemic heart damage usually triggers cardiomyopathological remodeling and fibrosis, thus promoting the development of heart functional failure. Mesenchymal stem cells (MSCs) are a heterogeneous group of cells in culture, with multipotent and hypoimmunogenic characters to aid tissue repair and avoid immune responses, respectively. Numerous experimental findings have proven the feasibility, safety, and efficiency of MSC therapy for cardiac regeneration. Despite that the exact mechanism remains unclear, the therapeutic ability of MSCs to treat ischemia heart diseases has been tested in phase I/II clinical trials. Based on encouraging preliminary findings, MSCs might become a potentially efficacious tool in the therapeutic options available to treat ischemic and nonischemic cardiovascular disorders. The molecular mechanism behind the efficacy of MSCs on promoting engraftment and accelerating the speed of heart functional recovery is still waiting for clarification. It is hypothesized that cardiomyocyte regeneration, paracrine mechanisms for cardiac repair, optimization of the niche for cell survival, and cardiac remodeling by inflammatory control are involved in the interaction between MSCs and the damaged myocardial environment. This review focuses on recent experimental and clinical findings related to cellular cardiomyoplasticity. We focus on MSCs, highlighting their roles in cardiac tissue repair, transdifferentiation, the MSC niche in myocardial tissues, discuss their therapeutic efficacy that has been tested for cardiac therapy, and the current bottleneck of MSC-based cardiac therapies.

17β-Estradiol and/or Estrogen Receptor β Attenuate the Autophagic and Apoptotic Effects Induced by Prolonged Hypoxia Through HIF-1α-Mediated BNIP3 and IGFBP-3 Signaling Blockage

Background/Aims: The risk of heart disease is higher in males than in females. However, this advantage of females declines with increasing age, presumably a consequence of decreased estrogen secretion and malfunctioning of the estrogen receptor. We previously demonstrated that 17β-estradiol (E2) prevents cardiomyocyte hypertrophy, autophagy and apoptosis via estrogen receptor α (ERα), but the effects of ERβ on myocardial injury remained elusive. The present paper thus, investigated the cardioprotective effects of estrogen (E2) and ERβ against hypoxia-induced cell death. Methods: Transient transfection of Tet-On ERβ gene construct was used to overexpress ERβ in hypoxia-treated H9c2 cardiomyoblast cells. Results: Our data revealed that IGF1R, Akt phosphorylation and Bcl-2 expression are enhanced by ERβ in H9c2 cells. Moreover, ERβ overexpression reduced accumulation of hypoxia-related proteins, autophagy-related proteins and mitochondria-apoptotic proteins and enhanced the protein levels of Bcl-2, pAkt and Bad under hypoxic condition. In neonatal rat ventricular myocytes (NRVMs), we observed that hypoxia induced cell apoptosis as measured by TUNEL staining, and E2 and/or ERβ could totally abolish hypoxia-induced apoptosis. The suppressive effects of E2 and/or ERβ in hypoxia-treated NRVMs were totally reversed by ER antagonist, ICI. Taken together, E2 and/or ERβ exert the protective effect through repressed hypoxia-inducible HIF-1α, BNIP3 and IGFBP-3 levels to restrain the hypoxia-induced autophagy and apoptosis effects in H9c2 cardiomyoblast cells. Conclusion: The results suggest that females probably could tolerate better prolonged hypoxia condition than males, and E2/ERβ treatment could be a potential therapy to prevent hypoxia-induced heart damage.”

17β-Estradiol inhibits prostaglandin E2-induced COX-2 expressions and cell migration by suppressing Akt and ERK1/2 signaling pathways in human LoVo colon cancer cells

Epidemiological studies demonstrate that the incidence and mortality rates of colorectal cancer in women are lower than in men. However, it is unknown if 17β-estradiol treatment is sufficient to inhibit prostaglandin E2 (PGE2)-induced cellular motility in human colon cancer cells. Upregulation of cyclooxygenase-2 (COX-2) is reported to associate with the development of cancer cell mobility, metastasis, and subsequent malignant tumor. After administration of inhibitors including LY294002 (Akt activation inhibitor), U0126 (ERK1/2 inhibitor), SB203580 (p38 MAPK inhibitor), SP600125 (JNK1/2 inhibitor), or QNZ (NFκB inhibitor), we found that PGE2 treatment increases COX-2 via Akt and ERK1/2 pathways, thus promoting cellular motility in human LoVo cancer cells. We further observed that 17β-estradiol treatment inhibits PGE2-induced COX-2 expression and cellular motility via suppressing activation of Akt and ERK1/2 in human LoVo cancer cells. Collectively, these results suggest that 17β-estradiol treatment dramatically inhibits PGE2-induced progression of human LoVo colon cancer cells.

Role of ERK Signaling in the Neuroprotective Efficacy of Magnesium Sulfate Treatment During Focal Cerebral Ischemia in the Gerbil Cortex

Magnesium sulfate (MgSO4) ameliorates focal ischemia-induced neuronal death in the rat and gerbil models. However, the molecular mechanisms for this neuroprotection are not known. Focal cerebral ischemia was produced by unilateral occlusion of the right common carotid artery and the right middle cerebral artery (CCAO + MCAO) for 30 min or 60 min. Treatment with MgSO4 significantly increased the level of mitogen-activated protein kinase/extra-cellular signal-regulated kinase kinase 1/2 (MEK1/2), extra-cellular signal-regulated kinase 1/2 (ERK1/2), cyclic-AMP response element binding protein (CREB) phosphorylation and the anti-apoptotic protein Bcl-2 both in the non-ischemic (contralateral) and ischemic (ipsilateral) cortex. However, these effects were reversed by administration of U0126, a MEK kinase inhibitor. In the ipsilateral cortex, a significant increase in the level of the proapoptotic proteins Bax, Bad, BNIP3 and activated caspase 3 were detected at the end of focal ischemia compared to the non-ischemic cortex. Treatment of MgSO4 prevented these ischemia-induced activations of the death cascade. Collectively, these data indicate that the ERK-CREB-Bcl-2 signaling pathway might be involved in MgSO4-induced neuroprotection following focal ischemia. Moreover, MgSO4 treatment also resulted in a reduction in pro-apoptotic proteins. These results enhance our understanding on the role of MgSO4 in treating cerebral ischemia.

Tetramethylpyrazine Ameliorated Hypoxia- Induced Myocardial Cell Apoptosis via HIF-1α/JNK/p38 and IGFBP3/BNIP3 Inhibition to Upregulate PI3K/Akt Survival Signaling

Background: Hemorrhagic shock (HS) is the major cause of death from trauma. Hemorrhagic shock may lead to cellular hypoxia and organ damage. Our previous findings showed that HS induced a cardiac apoptosis pathway and synergistically caused myocardial cell damage in diabetic rats under trauma-induced HS. Tetramethylpyrazine (TMP) is a major biologically active ingredient purified from the rhizome of Ligusticum wallichii (called Chuang Xiong in Chinese). Chuan Xiong rescued cells from synergistic cardiomyoblast cell injury under high-glucose (HG) conditions plus hypoxia. TMP is one of the most important active ingredients that elevated the survival rate in ischemic brain injury and prevented inducible NO synthase expression to have anti-inflammatory effects against cell damage in different cell types. Method: Here, we further investigate whether TMP can protect against hypoxic (<1% oxygen) conditions in H9c2 cardiomyoblast cells for 24 hrs. Results: Our results showed that hypoxia mediated through HIF-1α/JNK/p38 activation significantly elevated the levels of the hypoxia-related proteins HIF-1α, BNIP3 and IGFBP3, further enhanced the pro-apoptotic protein Bak and upregulated downstream Caspase 9 and 3, resulting in cell death. All of these phenomena were fully recovered under TMP treatment. We observed that TMP exerted this effect by activating the IGF1 receptor survival pathway, dependent primarily on PI3K/Akt. When PI3K (class I) was blocked by specific siRNA, the hypoxia-induced activated caspase 3 and cell apoptosis could not be reversed by TMP treatment. Conclusion: Our results strongly suggest that TMP could be used to restore hypoxia-induced myocardial cell apoptosis and cardiac hypoxic damage.

Hypoxia suppresses myocardial survival pathway through HIF-1α-IGFBP-3-dependent signaling and enhances cardiomyocyte autophagic and apoptotic effects mainly via FoxO3a-induced BNIP3 expression.

Abstract The HIF-1α transcriptional factor and the BH-3 only protein BNIP3 are known to play fundamental roles in response to hypoxia. The objective of this research is to investigate the molecular mechanisms and the correlation of HIF-1α, BNIP3 and IGFBP-3 in hypoxia-induced cardiomyocytes injuries. Heart-derived H9c2 cells and neonatal rat ventricular myocytes (NRVMs) were incubated in normoxic or hypoxic conditions. Hypoxia increased HIF-1α expression and activated the downstream BNIP3 and IGFBP-3 thereby triggered mitochondria-dependent apoptosis. Moreover, IGF1R/PI3K/Akt signaling was attenuated by HIF-1α-dependent IGFBP-3 expression to enhance hypoxia-induced apoptosis. Autophagy suppression with 3-methyladenine or siATG5 or siBeclin-1 significantly decreased myocardial apoptosis under hypoxia. Knockdown of FoxO3a or BNIP3 significantly abrogated hypoxia-induced autophagy and mitochondria-dependent apoptosis. Moreover, prolonged-hypoxia induced HIF-1α stimulated BNIP3 and enhanced IGFBP-3 activation to inhibit IGF1R/PI3K/Akt survival pathway and mediate mitochondria-dependent cardiomyocyte apoptosis. HIF-1α and FoxO3a blockage are sufficient to annul the change of excessive hypoxia of hearts.

Deep sea minerals prolong life span of streptozotocin-induced diabetic rats by compensatory augmentation of the IGF-I-survival signaling and inhibition of apoptosis.

Consumption of deep sea minerals (DSM), such as magnesium, calcium, and potassium, is known to reduce hypercholesterolemia‐induced myocardial hypertrophy and cardiac‐apoptosis and provide protection against cardiovascular diseases. Heart diseases develop as a lethal complication among diabetic patients usually due to hyperglycemia‐induced cardiac‐apoptosis that causes severe cardiac‐damages, heart failure, and reduced life expectancy. In this study, we investigated the potential of DSM and its related cardio‐protection to increase the life expectancy in diabetic rats. In this study, a heart failure rat model was developed by using streptozotocin (65 mg kg−1) IP injection. Different doses of DSM‐1× (37 mg kg−1 day−1), 2× (74 mg kg−1 day−1) and 3× (111 mg kg−1 day−1), were administered to the rats through gavages for 4 weeks. The positive effects of DSM on the survival rate of diabetes rats were determined with respect to the corresponding effects of MgSO4. Further, to understand the mechanism by which DSM enhances the survival of diabetic rats, their potential to regulate cardiac‐apoptosis and control cardiac‐dysfunction were examined. Echocardiogram, tissue staining, TUNEL assay, and Western blotting assay were used to investigate modulations in the myocardial contractile function and related signaling protein expression. The results showed that DSM regulate apoptosis and complement the cardiomyocyte proliferation by enhancing survival mechanisms. Moreover DSM significantly reduced the mortality rate and enhanced the survival rate of diabetic rats. Experimental results show that DSM administration can be an effective strategy to improve the life expectancy of diabetic subjects by improving cardiac‐cell proliferation and by controlling cardiac‐apoptosis and associated cardiac‐dysfunction.

Mesenchymal stem cell insights: Prospects in hematological transplantation

Adult stem cells have been proven to possess tremendous potential in the treatment of hematological disorders, possibly in transplantation. Mesenchymal stem cells (MSCs) are a heterogeneous group of cells in culture, with hypoimmunogenic character to avoid alloreactive T-cell recognition as well as inhibition of T-cell proliferation. Numerous experimental findings have shown that MSCs also possess the ability to promote engraftment of donor cells and to accelerate the speed of hematological recovery. Despite that the exact mechanism remains unclear, the therapeutic ability of MSCs on hematologic transplantation have been tested in preclinical trials. Based on encouraging preliminary findings, MSCs might become a potentially efficacious tool in the therapeutic options available to treat and cure hematological malignancies and nonmalignant disorders. The molecular mechanisms behind the real efficacy of MSCs on promoting engraftment and accelerating hematological recovery are awaiting clarification. It is hypothesized that direct cell-to-cell contact, paracrine factors, extracellular matrix scaffold, BM homing capability, and endogenous metabolites of immunologic and nonimmunologic elements are involved in the interactions between MSCs and HSCs. This review focuses on recent experimental and clinical findings related to MSCs, highlighting their roles in promoting engraftment, hematopoietic recovery, and GvHD/graft rejection prevention after HSCT, discussing the potential clinical applications of MSC-based treatment strategies in the context of hematological transplantation.

Lumbrokinase attenuates side-stream-smoke-induced apoptosis and autophagy in young hamster hippocampus: Correlated with eNOS induction and NFκB/iNOS/COX-2 signaling suppression

Recent studies have found that cigarette smoke is epidemiologically linked to an increased risk for impaired cognitive development in adolescents. This study evaluated the influence of side stream smoke (SSS) exposure on hippocampal apoptosis and of the lumbrokinase (LK) effects on SSS induced apoptosis in young hamster hippocampus. Twenty male hamsters at six weeks of age were randomly divided into control group, SSS group (exposed to tobacco cigarettes smoke at doses of 10 cigarettes for 30 min twice a day for 1 month), and SSS hamsters with LK treatment (1.2 mg/kg, ip) for twice a week for 1 month. TUNEL assay and Western blotting were performed. The TUNEL-positive apoptotic cells, as well as Fas-dependent activity and mitochondria-dependent apoptotic pathways, such as Fas, FADD, activated caspase-8, t-Bid, activated caspase-9, and activated caspase-3, were significantly increased in the SSS-exposed hippocampus compared to the control and highly attenuated in the LK treatment group. Additionally, SSS exposure significantly increased the autophagy marker proteins, Beclin-1, ATG7, and LC3-II levels, in the hippocampus compared to those in the control group and obviously attenuated after LK treatment. LK also reduced hippocampus injury by enhancing eNOS expression and remarkably inhibited the proinflammatory NFκB/iNOS/COX-2 signaling activity. We found that the detrimental effects of SSS on the hippocampus are truly mediated by cell apoptosis and autophagy. However, LK reduced the hippocampus apoptosis and autophagy related injuries induced by SSS in a widespread manner. We suggest that LK presents protective effects on hippocampus apoptosis and has therapeutic potential against abnormal hippocampal function.