Hypoxia-Induced Myocardial Hypertrophy Companies with Apoptosis Enhancement and p38-MAPK Pathway Activation.

Li, Xiaoxu, Zhijun Pu, Gang Xu, Yidong Yang, Yu Cui, Xiaoying Zhou, Chenyuan Wang, Zhifeng Zhong, Simin Zhou, Jun Yin, Fabo Shan, Chengzhong Yang, Li Jiao, Dewei Chen, and Jian Huang. Hypoxia-induced myocardial hypertrophy companies with apoptosis enhancement and p38-MAPK pathway activation. High Alt Med Biol. 25:186-196, 2024. Background: Right ventricular function and remodeling are closely associated with symptom severity and patient survival in hypoxic pulmonary hypertension. However, the detailed molecular mechanisms underlying hypoxia-induced myocardial hypertrophy remain unclear. Methods: In Sprague-Dawley rats, hemodynamics were assessed under both normoxia and hypobaric hypoxia at intervals of 7 (H7), 14 (H14), and 28 (H28) days. Morphological changes in myocardial tissue were examined using hematoxylin and eosin (HE) staining, while myocardial hypertrophy was evaluated with wheat germ agglutinin (WGA) staining. Apoptosis was determined through TUNEL assays. To further understand the mechanism of myocardial hypertrophy, RNA sequencing was conducted, with findings validated via Western blot analysis. Results: The study demonstrated increased hypoxic pulmonary hypertension and improved right ventricular diastolic and systolic function in the rat models. Significant elevations in pulmonary arterial systolic pressure (PASP), mean pulmonary arterial pressure (mPAP), right ventricular mean pressure (RVMP), and the absolute value of +dp/dtmax were observed in the H14 and H28 groups compared with controls. In addition, right ventricular systolic pressure (RVSP), -dp/dtmax, and the mean dp/dt during isovolumetric relaxation period were notably higher in the H28 group. Heart rate increased in the H14 group, whereas the time constant of right ventricular isovolumic relaxation (tau) was reduced in both H14 and H28 groups. Both the right heart hypertrophy index and the heart weight/body weight ratio (HW/BW) were elevated in the H14 and H28 groups. Myocardial cell cross-sectional area also increased, as shown by HE and WGA staining. Western blot results revealed upregulated HIF-1α levels and enhanced HIF-2α expression in the H7 group. In addition, phosphorylation of p38 and c-fos was augmented in the H28 group. The H28 group showed elevated levels of Cytochrome C (Cyto C), whereas the H14 and H28 groups exhibited increased levels of Cleaved Caspase-3 and the Bax/Bcl-2 ratio. TUNEL analysis revealed a rise in apoptosis with the extension of hypoxia duration in the right ventricle. Conclusions: The study established a link between apoptosis and p38-MAPK pathway activation in hypoxia-induced myocardial hypertrophy, suggesting their significant roles in this pathological process.

Regulation of Microglia-Activation-Mediated Neuroinflammation to Ameliorate Ischemia-Reperfusion Injury via the STAT5-NF-κB Pathway in Ischemic Stroke.

Inflammatory reaction after ischemia-reperfusion contributes significantly to a worsened prognosis, and microglia activation is the main resource of inflammation in the nervous system. Targeting STAT5 has been shown to be a highly effective anti-inflammatory therapy; however, the mechanism by which the STAT5 signaling pathway regulates neuroinflammation following brain injury induced by ischemia-reperfusion remains unclear. Dauricine is an effective agent in anti-inflammation and neuroprotection, but the mechanism by which dauricine acts in ischemia-reperfusion remained unknown. This study is the first to find that the anti-inflammation mechanism of dauricine mainly occurs through the STAT5-NF-κB pathway and that it might act as a STAT5 inhibitor. Dauricine suppresses the inflammation caused by cytokines Eotaxin, KC, TNF-α, IL-1α, IL-1ß, IL-6, IL-12ß, and IL-17α, as well as inhibiting microglia activation. The STAT5b mutant at Tyr-699 reverses the protective effect of dauricine on the oxygen-glucose deprivation-reperfusion injury of neurons and reactivates the P-NF-κB expression in microglia. These results suggest that dauricine might be able to suppress the neuroinflammation and protect the neurons from the injury of post-ischemia-reperfusion injury via mediating the microglia activation through the STAT5-NF-κB pathway. As a potential therapeutic target for neuroinflammation, STAT5 needs to be given further attention regarding its role in ischemic stroke.

Serpine1 Regulates Peripheral Neutrophil Recruitment and Acts as Potential Target in Ischemic Stroke.

Introduction: Peripheral neutrophil infiltration can exacerbate ischemia-reperfusion injury. We focused on the relationship between various peripheral immune cells and cerebral ischemia-reperfusion (I/R) injury. Methods: In this study, we investigated the effects of dauricine on neuronal injury induced by ischemia-reperfusion and peripheral immune cells after ischemic stroke in mouse model, and we explored the undefined mechanisms of regulating peripheral immune cells through RNA sequencing and various biochemical verification in vitro and in vivo. Results: We found that dauricine improved the neurological deficits of I/R injury, reduced the infarct volume, and improved the neurological scores. Furthermore, dauricine reduced the infiltration of neutrophils into the brain after MCAO-R and increased peripheral neutrophils but unchanged the permeability of the endotheliocyte Transwell system in an in vitro blood-brain barrier (BBB) model. RNA sequencing showed that chemotaxis factors, such as CXCL3, CXCL11, CCL20, CCL22, IL12a, IL23a, and serpine1, might play a crucial role. Overexpression of serpine1 reversed LPS-induced migration of neutrophils. Dauricine can directly bind with serpine1 in ligand-receptor docking performed with the Autodock and analyzed with PyMOL. Conclusion: We identified chemotaxis factor serpine1 played a crucial role in peripheral neutrophil infiltration, which may contribute to reduce the neuronal injury induced by ischemia-reperfusion. These findings reveal that serpine1 may act as a potential treatment target in the acute stage of ischemic stroke.

Synthetic VSMCs induce BBB disruption mediated by MYPT1 in ischemic stroke.

Vascular smooth muscle cells (VSMCs) have been widely recognized as key players in regulating blood-brain barrier (BBB) function, and their roles are unclear in ischemic stroke. Myosin phosphatase target subunit 1 (MYPT1) is essential for VSMC contraction and maintaining healthy vasculature. We generated VSMC-specific MYPT1 knockout (MYPT1SMKO) mice and cultured VSMCs infected with Lv-shMYPT1 to explore phenotypic switching of VSMCs and the accompanied impacts on BBB integrity. We found that MYPT1 deficiency induced phenotypic switching of synthetic VSMCs, which aggravated BBB disruption. Proteomic analysis identified evolutionarily conserved signaling intermediates in Toll pathways (ECSIT) as a downstream molecule that promotes activation of synthetic VSMCs and contributed to IL-6 expression. Knocking down ECSIT rescued phenotypic switching of VSMCs and BBB disruption. Additionally, inhibition of IL-6 decreased BBB permeability. These findings reveal that MYPT1 deficiency activated phenotypic switching of synthetic VSMCs and induced BBB disruption through ECSIT-IL-6 signaling after ischemic stroke.

Antioxidative and antiapoptosis: Neuroprotective effects of dauricine in Alzheimer's disease models.

AIMS: Dauricine has been found that has significant neuroprotective effect on Alzheimer's disease (AD), but the mechanism is unclear, so we further investigated the possible mechanism of dauricine on AD. MAIN METHODS: Cell counting kit-8 (CCK8) was applied to measure the cytotoxicity of dauricine on SH-SY5Y cells that overexpress the Swedish mutant form of human ß-amyloid precursor protein (APPsw) and control cells (Neo). We used the Cu2+ to induce oxidative damage on APPsw cells, then tested the effect of dauricine on the damage and relative factors including reactive oxygen species (ROS), mitochondrial membrane potential (MMP) and superoxide dismutase (SOD) activity. The secretion level of amyloid beta 1-42(Aß1-42), protein expression of apoptosis-related factors and the components of nuclear factor erythroid 2-related factor 2 (Nrf2) pathway were determined by western blotting. Aß1-42-transgenic Caenorhabditis elegans GMC101, a model of AD, was applied to evaluate the neuroprotective effect of dauricine through the behavioral experiment and relative anti-oxidative tests. KEY FINDINGS: In vitro, dauricine decreased the secretion level of Aß1-42, significantly reduced the level of Cu2+-induced ROS, and restored MMP and SOD activity in APPsw cells. Meanwhile, dauricine could suppress the activation of caspase-3 and to upregulate the expression of Bcl-2. Dauricine also regulated the proteins levels of Nrf2, and Kelch-like ECH-associated protein 1 (Keap1) that is necessary for the activation of Nrf2 in APPsw cell. As oxidative stress induced by Aß or paraquat (PQ), dauricine showed protective effects in the survival experiment of GMC101 worms. SIGNIFICANCE: Those data revealed that dauricine has the pharmacological activity of anti-oxidative and anti-apoptosis, and shows the potential therapeutic value for AD.

Amyloid-beta Degradation and Neuroprotection of Dauricine Mediated by Unfolded Protein Response in a Caenorhabditis elegans Model of Alzheimer's disease.

Amyloid plaque is a prominent pathologic hallmark in the brains of patients with Alzheimer's disease (AD), and it has been shown to be associated with endoplasmic reticulum (ER) stress response. However the precise regulation mechanism of amyloid-beta (Aß) toxicity remains unclear. Here, we found that dauricine could activate X-box binding protein 1 (XBP-1; active form XBP-1S) and eukaryotic translation initiation factor eIF2α and thus delay the progression of AD in the Aß1-42-transgenic Caenorhabditis elegans CL2120. The ER stress response factor XBP-1 can be activated and shows neuroprotective activity through acceleration of Aß clearance. Our study reveals that dauricine activates the ire-1/xbp-1 and perk/eIF2α pathways of the unfolded protein response, attenuates translation, and enhances ER-associated degradation, which reduces Aß expression and attenuates Aß-associated toxicity. On the contrary, xbp-1 depletion counteracts the effects of dauricine on Aß-associated toxicity. These results underscore the functional relevance of XBP-1 in Aß toxicity and degradation, and highlight the potentially pharmacodynamic value of dauricine in preventing the progression of AD.

Curcumin: a calixarene derivative micelle potentiates anti-breast cancer stem cells effects in xenografted, triple-negative breast cancer mouse models.

Triple-negative breast cancer (TNBC) is a heterogeneous and clinically aggressive disease with no approved targeted therapy. Curcumin has shown therapeutic potential against TNBC, but it shows low bioavailability and low efficacy when administered as a free drug. Here we describe a novel vehicle for in vivo delivery of curcumin based on the phosphorylated calixarene POCA4C6. Curcumin-loaded POCA4C6 micelles (CPM) were prepared using the thin-film method and they showed a unilamellar structure with an average particle size of 3.86 nm. The micelles showed high curcumin encapsulation efficiency and loading was based on liquid chromatography-tandem mass spectrometry. Studies with cell cultures suggest that CPM can sustainably release curcumin in a pH-dependent manner. The micelles efficiently inhibited proliferation, invasion, migration and tumor spheroid formation by BT-549 human breast cancer cells. These effects involved increased apoptosis and reduced levels of nuclear ß-catenin and androgen receptor. After injection into tumor xenografts, CPM persisted in the tumor tissue and efficiently inhibited tumor growth without causing obvious systemic toxicity. CPM also significantly reduced levels of CD44+/CD133+ breast cancer stem cells. Our results highlight the potential of CPM as an effective therapy against TNBC.

Oxoisoaporphine alkaloid derivative 8-1 reduces Aß1-42 secretion and toxicity in human cell and Caenorhabditis elegans models of Alzheimer's disease.

Alzheimer's disease (AD) is a multifactorial neurodegenerative disease and a growing health problem worldwide. Because the drugs currently used to treat AD have certain drawbacks such as single targeting, there is a need to develop novel multi-target compounds, among which oxoisoaporphine alkaloid derivatives are promising candidates. In this study, the possible anti-AD activities of 14 novel oxoisoaporphine alkaloid derivatives that we synthesized were screened and evaluated. We found that, in the 14 novel derivatives, compound 8-1 significantly reduced Aß1-42 secretion in SH-SY5Y cells overexpressing the Swedish mutant form of human ß-amyloid precursor protein (APPsw). Next, we found that compound 8-1 could down-regulate the expression level of ß-amyloid precursor protein (APP) in APPsw cells. Moreover, compound 8-1 significantly delayed paralysis in the Aß1-42-transgenic Caenorhabditis elegans strain GMC101, which could be explained by the fact that compound 8-1 down-regulated acetylcholinesterase activity, protected against H2O2-induced acute oxidative stress and paraquat-induced chronic oxidative stress, and enhanced autophagy activity. Taken together, our data suggest that compound 8-1 could attenuate the onset and development of AD.

Lycopene attenuates Aß1-42 secretion and its toxicity in human cell and Caenorhabditis elegans models of Alzheimer disease.

Growing evidence suggests concentration of lycopene was reduced in plasma of patients with Alzheimer disease (AD). Lycopene, a member of the carotenoid family, has been identified as an antioxidant to attenuate oxidative damage and has neuroprotective role in several AD models. However, whether lycopene is involved in the pathogenesis of AD and molecular underpinnings are elusive. In this study, we found that lycopene can significantly delay paralysis in the Aß1-42-transgenic Caenorhabditis elegans strain GMC101. Lycopene treatment reduced Aß1-42 secretion in SH-SY5Y cells overexpressing the Swedish mutant form of human ß-amyloid precursor protein (APPsw). Next, we found lycopene can down-regulate expression level of ß-amyloid precursor protein(APP) in APPsw cells. Moreover, lycopene treatment can not change endogenous reactive oxygen species level and apoptosis in APPsw cells. However, lycopene treatment protected against H2O2-induced oxidative stress and copper-induced damage in APPsw cells. Collectively, our data support that elevated lycopene contributes to the lower pathogenesis of AD. Our findings suggest that increasing lycopene in neurons may be a novel approach to attenuate onset and development of AD.