Neuroprotective effects of mesenchymal stromal cells in mouse models of Alzheimer's Disease: The Mediating role of gut microbes and their metabolites via the Microbiome-Gut-Brain axis.

The intricacy and multifaceted nature of Alzheimer's disease (AD) necessitate therapies that target multiple aspects of the disease. Mesenchymal stromal cells (MSCs) emerge as potential agents to mitigate AD symptoms; however, whether their therapeutic efficacy involves modulation of gut microbiota and the microbiome-gut-brain axis (MGBA) remains unexplored. In this study, we evaluated the effects of three distinct MSCs types-derived from the umbilical cord (UCMSC), dental pulp (SHED), and adipose tissue (ADSC)-in an APP/PS1 mouse model of AD. In comparison to saline control, MSCs administration resulted in a significant reduction of behavioral disturbances, amyloid plaques, and phosphorylated tau in the hippocampus and frontal cortex, accompanied by an increase in neuronal count and Nissl body density across AD-afflicted brain regions. Through 16S rRNA gene sequencing, we identified partial restoration of gut microbial balance in AD mice post-MSCs treatment, evidenced by the elevation of neuroprotective Akkermansia and reduction of the AD-associated Sphingomonas. To examine whether gut microbiota involved in MSCs efficacy in treating AD, SHED with better anti-inflammatory and gut microbiota recovery effects among three MSCs, and another AD model 5 × FAD mice with earlier and more pathological proteins in brain than APP/PS1, were selected for further studies. Antibiotic-mediated gut microbial inactivation attenuated MSCs efficacy in 5 × FAD mice, implicating the involvement of gut microbiota in the therapeutic mechanism. Functional analysis of altered gut microbiota and targeted bile acid metabolism profiling revealed a significant enhancement in bile acid variety following MSCs therapy. A chief bile acid constituent, taurocholic acid (TCA), was orally administered to AD mice and similarly abated AD symptoms. Nonetheless, the disruption of intestinal neuronal integrity with enterotoxin abrogated the ameliorative impact of both MSCs and TCA treatments. Collectively, our findings substantiate that MSCs confer therapeutic benefits in AD within a paradigm that primarily involves regulation of gut microbiota and their metabolites through the MGBA.

Induction of autophagy via the PI3K/Akt/mTOR signaling pathway by Pueraria flavonoids improves non-alcoholic fatty liver disease in obese mice.

Non-alcoholic fatty liver disease (NAFLD) is the most common among lipid metabolism disorders. Autophagy plays an important role in lipid metabolism in NAFLD. Pueraria flavonoids, the main active ingredients of Pueraria lobata, exert antioxidant and anti-inflammatory effects. Herein, we report the potential lipid-lowering and anti-inflammatory effects of Pueraria flavonoids on NAFLD induced by a high-fat diet. In vivo and in vitro experiments showed that Pueraria flavonoids reduced intracellular lipid deposition by inhibiting lipid synthesis and the release of pro-inflammatory cytokines. We analyzed the autophagy flux by mRFP-GFP-LC3 plasmid transfection to assess the role of autophagy in intracellular scavenging. After treating mice fed on high fat and HepG2 cells with Pueraria flavonoids, the number of autophagosomes increased significantly, along with the level of autophagy. The autophagy loss after siRNA transfection aggravated lipid deposition and the release of inflammatory cytokines. Mechanistically, Pueraria flavonoids trigger autophagy through PI3K/Akt/mTOR signaling pathway to reduce lipid deposition and inflammation. In summary, our results showed that Pueraria flavonoids stimulated autophagy by inhibiting the PI3K/Akt/mTOR signaling pathway, thereby reducing intracellular lipid accumulation and inflammation levels and alleviating NAFLD.

Gastrodia remodels intestinal microflora to suppress inflammation in mice with early atherosclerosis.

Atherosclsis is a critical actuator causing cardiac-cerebral vascular disease with a complicated pathogeneon, refered to the disorders of intestinal flora and persistent inflammation. Gastrodin (4-(hydroxymethyl) phenyl-ß-D- Glucopyranoside) is the most abundant glucoside extracted from the Gastrodiaelata, which is a traditional Chinese herbal medicine for cardiac-cerebral vascular disease, yet its mechanisms remain little known. In the present study, the gastrodia extract and gastrodin attenuate the lipid deposition and foam cells on the inner membrane of the inner membrane of the thoracic aorta in the early atherosclerosis mice. Blood lipid detection tips that TC and LDL-C were reduced in peripheral blood after treatment with the gastrodia extract and gastrodin. Furthermore, unordered gut microbes are remodeled in terms of bacterial diversity and abundance at family and genus level. Also, the intestinal mucosa damage and permeability were reversed, accompaniedwith the reducing of inflammatory cytokines. Our findings revealed that the functions of gastrodia extract and gastrodin in cardiac-cerebral vascular disease involved to rescued gut microbes and anti-inflammation may be the mechanismof remission lipid accumulation.

Induction of autophagy via the TLR4/NF-κB signaling pathway by astragaloside â £ contributes to the amelioration of inflammation in RAW264.7 cells.

Cigarette smoking-related lung injury is one of the most common and fatal etiologies of many respiratory diseases, for which no effective interventions are available. Astragaloside Ⅳ (ASⅣ) is an active component extracted from Astragalus membranaceus. It is prescribed as a treatment for upper respiratory tract infections. Here, we report the potential anti-inflammatory effects and mechanisms of ASⅣ on cigarette smoking extract- (CSE)-exposed RAW264.7 cells. Murine macrophages were exposed to CSE, followed by administration of ASⅣ at 25-100 µg/mL for 24 h. ASⅣ significantly rescued CSE-induced cell death by inhibition of release pro-inflammatory cytokines. We measured autophagy as an intracellular scavenger by analyzing autophagic flux using tandem mRFP-GFP-LC3 fluorescence microscopy. Following administration with ASⅣ in CSE-exposed RAW264.7 cells, there was a notable increase in autophagosomes and a range of autophagic vacuoles were generated, as seen with transmission electron microscopy. Loss of autophagy following transfection siRNA aggravated inflammatory injury and release of inflammatory cytokines. Mechanistically, ASⅣ-triggered autophagy is mediated by the TLR4/NF-κB signaling pathway to reduce inflammation. Taken together, our findings suggest that ASⅣ acts stimulates autophagy, and that ASⅣ induces autophagy by inhibiting the TLR4/NF-κB signaling pathway, contributing to alleviation of inflammation.

Antifibrotic action of Yifei Sanjie formula enhanced autophagy via PI3K-AKT-mTOR signaling pathway in mouse model of pulmonary fibrosis.

Pulmonary fibrosis (PF) is a crippling disease characterized by progressive dyspnea and associated with a high mortality rate, but its origin is unknown and there is no effective treatment. Yifei Sanjie formula (YFSJF) is a Chinese medicine that is widely used for treatment of respiratory systems disease. However, the molecular basis for the function of YFSJF has not been determined. Here we investigate the contribution of YFSJF in BLM-induced PF mice. Administration with YFSJF significantly alleviated the degree of BLM-induced collagen I and III deposition and the inflammatory injuring in the lungs and suppressed hydroxyproline release in PF animals. The active components of YFSJF are comprised with flavonoid, amino acids, saponins, oligosaccharide, organic acid, vitamin, esters, purine nucleosides. Additionally, there was a significant increase in autophagosomes, after treatment with YFSJF in PF animals. Interestingly, autophagy dysfunction by the blocker chloroquine (CQ) resulted in collagen deposition and inducing the expression of fibrosis-related genes. In addition, YFSJF-induced autophagy is mediated by the PI3K-AKT-mTOR pathway, and knockdown of PI3K by siRNA up-regulated the expression of autophagy-related genes and down-regulated the expression of collagen in human lung fibroblasts (HLF). Our findings provide a detailed understanding that YFSJF-antifibrotic effects are mainly mediated by triggering autophagy, and suppressing phosphorylation of the PI3K-AKT-mTOR pathway is required for YFSJF-curative effect.