Dual roles of photosynthetic hydrogel with sustained oxygen generation in promoting cell survival and eradicating anaerobic infection.

Tissue engineering offers a promising alternative for oral and maxillofacial tissue defect rehabilitation; however, cells within a sizeable engineered tissue construct after transplantation inevitably face prolonged and severe hypoxic conditions, which may compromise the survivability of the transplanted cells and arouse the concern of anaerobic infection. Microalgae, which can convert carbon dioxide and water into oxygen and glucose through photosynthesis, have been studied as a source of oxygen supply for several biomedical applications, but their promise in orofacial tissue regeneration remains unexplored. Here, we demonstrated that through photosynthetic oxygenation, Chlamydomonas reinhardtii (C. reinhardtii) supported dental pulp stem cell (DPSC) energy production and survival under hypoxia. We developed a multifunctional photosynthetic hydrogel by embedding DPSCs and C. reinhardtii encapsulated alginate microspheres (CAMs) within gelatin methacryloyl hydrogel (GelMA) (CAMs@GelMA). This CAMs@GelMA hydrogel can generate a sustainable and sufficient oxygen supply, reverse intracellular hypoxic status, and enhance the metabolic activity and viability of DPSCs. Furthermore, the CAMs@GelMA hydrogel exhibited selective antibacterial activity against oral anaerobes and remarkable antibiofilm effects on multispecies biofilms by disrupting the hypoxic microenvironment and increasing reactive oxygen species generation. Our work presents an innovative photosynthetic strategy for oral tissue engineering and opens new avenues for addressing other hypoxia-related challenges.

Icariin improves oxidative stress injury during ischemic stroke via inhibiting mPTP opening.

BACKGROUND: Ischemic stroke presents a significant threat to human health due to its high disability rate and mortality. Currently, the clinical treatment drug, rt-PA, has a narrow therapeutic window and carries a high risk of bleeding. There is an urgent need to find new effective therapeutic drugs for ischemic stroke. Icariin (ICA), a key ingredient in the traditional Chinese medicine Epimedium, undergoes metabolism in vivo to produce Icaritin (ICT). While ICA has been reported to inhibit neuronal apoptosis after cerebral ischemia-reperfusion (I/R), yet its underlying mechanism remains unclear. METHODS: PC-12 cells were treated with 200 µM H2O2 for 8 h to establish a vitro model of oxidative damage. After administration of ICT, cell viability was detected by Thiazolyl blue tetrazolium Bromide (MTT) assay, reactive oxygen species (ROS) and apoptosis level, mPTP status and mitochondrial membrane potential (MMP) were detected by flow cytometry and immunofluorescence. Apoptosis and mitochondrial permeability transition pore (mPTP) related proteins were assessed by Western blotting. Middle cerebral artery occlusion (MCAO) model was used to establish I/R injury in vivo. After the treatment of ICA, the neurological function was scored by ZeaLonga socres; the infarct volume was observed by 2,3,5-Triphenyltetrazolium chloride (TTC) staining; HE and Nissl staining were used to detect the pathological state of the ischemic cortex; the expression changes of mPTP and apoptosis related proteins were detected by Western blotting. RESULTS: In vitro: ICT effectively improved H2O2-induced oxidative injury through decreasing the ROS level, inhibiting mPTP opening and apoptosis. In addition, the protective effects of ICT were not enhanced when it was co-treated with mPTP inhibitor Cyclosporin A (CsA), but reversed when combined with mPTP activator Lonidamine (LND). In vivo: Rats after MCAO shown cortical infarct volume of 32-40%, severe neurological impairment, while mPTP opening and apoptosis were obviously increased. Those damage caused was improved by the administration of ICA and CsA. CONCLUSIONS: ICA improves cerebral ischemia-reperfusion injury by inhibiting mPTP opening, making it a potential candidate drug for the treatment of ischemic stroke.

Health Effects of Probiotics on Nonalcoholic Fatty Liver in the Life Cycle Based on Data Analysis.

Objective: To observe the effect of intestinal probiotics in the treatment of nonalcoholic fatty liver disease (NAFLD) and the effect on liver function and inflammatory factors. Methods: 34 healthy rats were selected for the study and divided into 10 rats in the control group, 12 rats in the model group, and 12 rats in the treatment group according to the random number table method. The control group was given behavioral and lifestyle interventions, and the treatment group was given Bifidobacterium minus Black enteric capsules 5 g/(kg-d) by strong feeding method on the basis of the control group. The fatty liver index (FLI), liver ultrasound examination results, liver function, and inflammatory factor levels were compared among the three groups. After 8 weeks of treatment, there were statistically significant differences between the FLI values and liver ultrasound results of the three groups, and the serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), triacylglycerol (TG), and total cholesterol (TC) levels of the observation group were lower than those of the control group and the model group. The levels of serum high molecular weight lipocalin (HMW-APN) and interleukin 22 (IL-22) in the observation group were higher than those in the control group, and the levels of tumor necrosis factor-α (TNF-α) were lower than those in the control and model groups, and the differences were statistically significant (P < 0.05). Conclusion: Intestinal probiotics can improve the clinical efficacy of patients with NAFLD, improve liver function, and alleviate the inflammatory response, in order to provide a theoretical basis for the clinical treatment of patients with NAFLD.

Study on Urine Metabolic Profile of Aß25-35-Induced Alzheimer's Disease Using UHPLC-Q-TOF-MS.

Alzheimer's disease (AD) is a progressive neurodegenerative disorder, with no effective method for its treatment so far. The pathogenesis of AD has been reported, but the endogenous metabolic profile and disease-related biomarkers are still not clear. To better understand AD, an AD model induced by injecting ß-amyloid 25-35 (Aß 25-35) solution into bilateral hippocampus was developed on Sprague-Dawley rats. After 8 weeks of modeling, the impairment of spatial learning and memory ability in AD rats were assessed by Morris water maze task. Hematoxylin and eosin staining and immunohistochemistry were used to investigate the pathological changes of hippocampus. The neurotransmitter concentrations in the hippocampus were measured using UHPLC-TQ-MS. Urinary metabolomics based on UHPLC-Q-TOF-MS was established to delineate the alterations of endogenous metabolites in AD rats. The results showed that compared with healthy control rats, AD rats suffered from cognitive dysfunction, hippocampus damage, Aß formation and tau phosphorylation at 8 weeks after surgery, suggesting that the Aß25-35-induced AD model was successfully established. In addition, the levels of γ-aminobutyric acid, acetylcholine, glycine, norepinephrine, serotonin, taurine and dopamine decreased and glutamate and aspartic acid increased in hippocampal tissue of AD rats. 45 altered metabolites mainly involved in 8 metabolic pathways were identified as the endogenous biomarkers of AD. According to the analysis of the biological significance of metabolic profiles, the pathogenesis of AD was mainly due to gut microbiome dysbiosis, inhibition of energy metabolism, oxidative stress injury and loss of neuronal protective substances.

Real-time imaging of apoptosis induction of human breast cancer cells by the traditional Chinese medicinal herb tubeimu.

Traditional Chinese Medicine (TCM) has been used for thousands of years, including treatment for cancer. Use of modern technology and the scientific method to evaluate the efficacy of TCM for cancer should enable its more widespread use. In the present study, the efficacy of the TCM tubeimu, extracted from the tuber of the plant Bolbostemma paniculatum, on the MDA-MB-231 human breast cancer cell line was evaluated. The MDA-MB-231 cell line was engineered to express red fluorescent protein (RFP) in the cytoplasm and green fluorescent protein (GFP) linked to histone H2B in the nucleus, which allows real-time imaging of nuclear-cytoplasmic dynamics. Apoptosis was readily visualized in these cells by nuclear shape changes and fragmentation. The MDA-MB-231 RFP-GFP cells were cultured either in two-dimensions on plastic or in three-dimensions on Gelfoam®. Cells were treated with a dichloromethane extract of fresh tubeimu. Apoptosis was further monitored by DNA fragmentation determined by gel electrophoresis. Tubeimu induced apoptosis of MDA-MB-231 cells, as observed by fluorescence microscopy, as early as 24 hours of treatment in vitro in two-dimensional culture. By 48 hours' treatment, DNA fragmentation could be observed. The frequency of apoptosis increased through at least 72 hours' treatment, with most of the cells being killed. Tubeimu also induced apoptosis of MDA-MB-231 cells in three-dimensional culture on Gelfoam®, but to a lesser extent than in 2D culture. The results of the present study indicate the potential of tubeimu in breast cancer therapy.