Protective Roles of Xijiao Dihuang Tang on Coronary Artery Injury in Kawasaki Disease.

PURPOSE: Xijiao Dihuang Tang (XJDHT) is a classical formula of traditional Chinese medicine constituted of Cornu Bubali, Rehmannia glutinosa (Gaertn.) DC., Paeonia lactiflora Pall., and Paeonia suffruticosa Andrews. It was first mentioned in the medical classic "Beiji Qianjin Yaofang" written by Simiao Sun in Tang Dynasty. It shows very strong antipyretic and anticoagulant effects and has been clinically applied to treat various type of blood loss, purple and black spots, heat stroke, and glossitis. Kawasaki disease (KD) is considered as a kind of acute febrile illness in children with systemic vasculitis as the main lesions. The aim of this research is to clarify whether XJDHT can play a protective role in KD. METHODS: A mouse model of Candida albicans water-soluble fraction (CAWS)-induced coronary arteritis and a KD cell model with tumor necrosis factor (TNF)-α induction were employed to investigate the potential effect and mechanism of XJDHT on coronary artery injury in KD. RESULTS: Data showed that XJDHT remarkably alleviated the coronary artery injury of KD mice, as evidenced by reduced inflammation and downregulated expression of pro-inflammatory cytokines interleukin (IL)-1ß and TNF-α. In vitro investigation showed that XJDHT could promote cell proliferation, inhibit cell apoptosis, and improve mitochondrial functions. Subsequent studies demonstrated that XJDHT rescued endothelial cell injury by PI3K/Akt-NFκB signaling pathway. Component analysis of XJDHT detected thirty-eight chemically active ingredients, including paeoniflorin, albiflorin, and paeoniflorigenone, which in in vitro experiments exhibited significant rescue effects on TNF-α-mediated endothelial cell injury. CONCLUSION: Our findings demonstrated that XJDHT mitigated coronary artery injury of KD through suppressing endothelial cell damage via PI3K/Akt-NFκB signaling.

IL-37b alleviates endothelial cell apoptosis and inflammation in Kawasaki disease through IL-1R8 pathway.

Kawasaki disease (KD) is an acute vasculitis of pediatric populations that may develop coronary artery aneurysms if untreated. It has been regarded as the principal cause of acquired heart disease in children of the developed countries. Interleukin (IL)-37, as one of the IL-1 family members, is a natural suppressor of inflammation that is caused by activation of innate and adaptive immunity. However, detailed roles of IL-37 in KD are largely unclear. Sera from patients with KD displayed that IL-37 level was significantly decreased compared with healthy controls (HCs). QRT-PCR and western blot analyses showed that the expression level of IL-37 variant, IL-37b, was remarkably downregulated in human umbilical vein endothelial cells (HUVECs) exposed to KD sera-treated THP1 cells. Therefore, we researched the role of IL-37b in the context of KD and hypothesized that IL-37b may have a powerful protective effect in KD patients. We first observed and substantiated the protective role of IL-37b in a mouse model of KD induced by Candida albicans cell wall extracts (CAWS). In vitro experiments demonstrated that IL-37b alleviated endothelial cell apoptosis and inflammation via IL-1R8 receptor by inhibiting ERK and NFκB activation, which were also recapitulated in the KD mouse model. Together, our findings suggest that IL-37b play an effective protective role in coronary endothelial damage in KD, providing new evidence that IL-37b is a potential candidate drug to treat KD.

Role of smooth muscle cells in Cardiovascular Disease.

Normally, smooth muscle cells (SMCs) are localized in the tunica media of the vasculature, where they take responsibility for vascular contraction and extracellular matrix (ECM) generation. SMCs also play a significant role in obedience and elastic rebound of the artery in response to the haemodynamic condition. However, under pathological or stressed conditions, phenotype switching from contractile to synthetic state or other cell types will occur in SMCs to positively or negatively contribute to disease progression. Various studies demonstrated that functional changes of SMCs are implicated in several cardiovascular diseases. In this review, we present the function of vascular SMCs (VSMCs) and the involved molecular mechanisms about phenotype switching, and summarize the roles of SMCs in atherosclerosis, hypertension, arterial aneurysms and myocardial infarction, hoping to obtain potential therapeutic targets against cardiovascular disease in the clinical practices.

Carvacrol Induces Candida albicans Apoptosis Associated With Ca2+/Calcineurin Pathway.

As the prevalence of systemic fungal infections caused by Candida albicans gradually increases, it is necessary to explore potential and effective antifungals. Carvacrol is reported to be lethally toxic to C. albicans, involving several potential mechanisms. However, the form and specific mechanism of cell death caused by this compound has not been delineated. In this study, we found that carvacrol could significantly decrease C. albicans survival rates, consistent with previous researches. Further examination proved that carvacrol treatment caused cell membrane permeability and depolarization. To elucidate the association between cell death and apoptosis, DNA fragmentation and metacaspase activation were determined; as expected, these two apoptosis-related markers were clearly observed. Moreover, total and mitochondrial reactive oxygen species (ROS) levels were elevated, and both mitochondrial transmembrane potential and morphology were disrupted. Additionally, cytosolic and mitochondrial calcium levels were also increased by carvacrol. Calcineurin inhibition experiments revealed cyclosporine A (CsA) addition notably rescued cell growth and inhibited metacaspase activation, indicating that carvacrol triggered C. albicans apoptosis through inducing calcineurin activation. Carvacrol was demonstrated to both have low toxicity and be effective in alleviating systemic infections with C. albicans, which might be via its antifungal and immunomodulation activities. This study suggests that carvacrol has excellent potential as a natural protective compound against C. albicans infections.

Synergistic effects of geldanamycin with fluconazole are associated with reactive oxygen species in Candida tropicalis resistant to azoles and amphotericin B.

With a significant increase in the incidence of system invasive fungal infections, the limited antifungal drugs and increased frequency of cross-resistance make it necessary to explore new and effective therapeutic strategies. Combination drug therapy has become one widely used choice to alleviate this problem. Geldanamycin (GdA), as an inhibitor of Hsp90, displayed broad antifungal activity when combined with fluconazole. However, due to its cytotoxicity, the dose and duration of GdA is limited. In this study, we observed the effect of fluconazole plus GdA on Candida tropicalis resistant to azoles and amphotericin B. The results showed that this synergism led to a decrease in growth and survival rate. In addition, fluconazole combined with GdA caused mitochondrial depolarisation, disruption of plasma membrane integrity and multinucleated morphology. However, the supplement of a reactive oxygen species (ROS) scavenger, N-acetylcysteine (NAC), rescued the above phenotypes. This study indicated that the oxidative stress mediated by fluconazole plus GdA played an important role in the antifungal activity, and targeting oxidative stress might extend target choices to treat fungal infections.

Photodynamic Antifungal Activity of Hypocrellin A Against Candida albicans.

Many studies have reported that hypocrellin A (HA) exhibits effective antimicrobial activities with proper irradiation. However, its antifungal activity and the involved mechanism have not been fully defined. In this study, HA-mediated cytotoxicity in Candida albicans cells was evaluated after antimicrobial photodynamic therapy (aPDT). The results showed that 1.0 µg/ml HA significantly decreased the survival rate of C. albicans cells with light illumination. Moreover, the ROS levels were also remarkably elevated by HA. Further study found that HA combined with illumination led to cell membrane potential depolarization and cell membrane integrity damage. To investigate the form of cell death, a series of apoptosis-related parameters, including mitochondrial transmembrane potential, metacaspase activity, DNA fragmentation, nuclear condensation, and cytosolic and mitochondrial calcium, were analyzed. Data showed that all the above mentioned apoptosis hallmarks were affected after treatment with HA, indicating that HA induced C. albicans cell apoptosis. Finally, HA-mediated aPDT was demonstrated to be low-toxic and effective in treating cutaneous C. albicans infections. This study highlights the antifungal effect and mechanism of HA-mediated aPDT against C. albicans and provides a promising photodynamic antifungal candidate for C. albicans skin infections.

Role of pyroptosis in cardiovascular diseases.

Pyroptosis is a form of programmed necrosis, and is morphologically and mechanistically unique form of programmed cell death compared to others, such as apoptosis and autophagic cell death. More specifically, pyroptosis features gasdermin family-mediated membrane pore formation and subsequent cell lysis, as well as release of pro-inflammatory intracellular contents including IL-1ß, IL-18 and HMGB1. Mechanistically, pyroptosis is driven by two main signaling pathways - one mediated by caspase-1 and the other by caspase-4/5/11. Recent studies show that pyroptosis is implicated in several cardiovascular diseases. In this review, we summarize recent scientific discoveries of pyroptosis's involvement in atherosclerosis, myocardial infarction, diabetic cardiomyopathy, reperfusion injury and myocarditis. We also organized new and emerging evidence suggesting that pyroptosis signaling pathways may be potential therapeutic targets in cardiovascular diseases.

Endothelial cell pyroptosis plays an important role in Kawasaki disease via HMGB1/RAGE/cathespin B signaling pathway and NLRP3 inflammasome activation.

Kawasaki disease (KD) is the most common cause of pediatric cardiac disease in developed countries, and can lead to permanent coronary artery damage and long term sequelae such as coronary artery aneurysms. Given the prevalence and severity of KD, further research is warranted on its pathophysiology. It is known that endothelial cell damage and inflammation are two essential processes resulting in the coronary endothelial dysfunction in KD. However, detailed mechanisms are largely unknown. In this study, we investigated the role of pyroptosis in the setting of KD, and hypothesized that pyroptosis may play a central role in its pathophysiology. In vivo experiments of patients with KD demonstrated that serum levels of pyroptosis-related proteins, including ASC, caspase-1, IL-1ß, IL-18, GSDMD and lactic dehydrogenase (LDH), were significantly increased in KD compared with healthy controls (HCs). Moreover, western blot analysis showed that the expression of GSDMD and mature IL-1ß was notably elevated in KD sera. In vitro, exposure of human umbilical vein endothelial cells (HUVECs) to KD sera-treated THP1 cells resulted in the activation of NLRP3 inflammasome and subsequent pyroptosis induction, as evidenced by elevated expression of caspase-1, GSDMD, cleaved p30 form of GSDMD, IL-1ß and IL-18, and increased LDH release and TUNEL and propidium iodide (PI)-positive cells. Furthermore, our results showed that NLRP3-dependent endothelial cell pyroptosis was activated by HMGB1/RAGE/cathepsin B signaling. These findings were also recapitulated in a mouse model of KD induced by Candida albicans cell wall extracts (CAWS). Together, our findings suggest that endothelial cell pyroptosis may play a significant role in coronary endothelial damage in KD, providing novel evidence that further elucidates its pathophysiology.