The mechanism of bile acid metabolism regulating lipid metabolism and inflammatory response in T2DM through the gut-liver axis.

Aims: The main objective of this study was to analyze the changes of intestinal microflora and how bile acid metabolic pathways affect lipid metabolism in T2DM through the gut-liver axis. Methods: Firstly, 16S rRNA sequencing, metabolomics and transcriptomic sequencing were performed on plasma and feces of clinical subjects to determine the changes of intestinal flora and its metabolites. Finally, T2DM mice model was verified in vivo. Results: T2DM patients have significant intestinal flora metabolism disorders. The differential fecal metabolites were mainly enriched in primary bile acid biosynthesis and cholesterol metabolism pathways in T2DM patients. After verification, the changes in gut microbiota and metabolites in T2DM patients (including up-regulated bacteria associated with BA metabolism, such as lactobacillus and bifidobacterial, and down-regulated bacteria capable of producing SCFAs such as Faecalibacterium, Bacteroides, Romboutsia and Roseburia); and the changes in the flora and metabolites that result in impairment of intestinal barrier function and changes of protein expression in the blood, intestine and liver of T2DM patients (including FGFR4↑, TRPM5↑ and CYP27A1↓, which are related to BA and lipid metabolism homeostasis, and TLR6↑, MYD88↑ and NF-κB↑, which are related to inflammatory response). These aspects together contribute to the development of further disorders of glucolipid metabolism and systemic inflammation in T2DM patients. Conclusions: Changes in intestinal flora and its metabolites may affect lipid metabolism and systemic inflammatory response in T2DM patients through the gut-liver axis mediated by bile acids.

Lysophosphatidylcholine trigger myocardial injury in diabetic cardiomyopathy via the TLR4/ZNF480/AP-1/NF-kB pathway.

Background: Diabetic cardiomyopathy (DC), a frequent complication of type 2 diabetes mellitus (T2DM), is mainly associated with severe adverse outcomes. Previous research has highlighted the role of Lysophosphatidylcholine (LPC) in inducing myocardial injury; however, the specific mechanisms through which LPC mediate such injury in DC remain elusive. The existing knowledge gap underscores the need for additional clarification. Consequently, this study aimed to explore the impact and underlying mechanisms of LPC on myocardial injury in DC. Methods: A total of 55 patients diagnosed with T2DM and 62 healthy controls were involved. A combination of 16s rRNA sequencing, metabolomic analysis, transcriptomic RNA-sequencing (RNA-seq), and whole exome sequencing (WES) was performed on fecal and peripheral blood samples collected from the participants. Following this, correlation analysis was carried out, and the results were further validated through the mouse model of T2DM. Results: Four LPC variants distinguishing T2DM patients from healthy controls were identified, all of which were upregulated in T2DM patients. Specifically, Lysopc (16:0, 2 N isoform) and LPC (16:0) exhibited a positive correlation with nuclear factor kappa B subunit 2 (NFKB2) and a negative correlation with Zinc finger protein 480 (ZNF480) Furthermore, the expression levels of Toll-like receptor 4 (TLR4), c-Jun, c-Fos, and NFKB2 were upregulated in the peripheral blood of T2DM patients and in the myocardial tissue of T2DM mice, whereas ZNF480 expression level was downregulated. Lastly, myocardial injury was identified in T2DM mice. Conclusions: The results indicated that LPC could induce myocardial injury in DC through the TLR4/ZNF480/AP-1/NF-kB pathway, providing a precise target for the clinical diagnosis and treatment of DC.

QKL injection ameliorates Alzheimer's disease-like pathology by regulating expression of RAGE.

The onset of Alzheimer's disease is related to neuron damage caused by massive deposition of Aß in the brain. Recent studies suggest that excessive Aß in the brain mainly comes from peripheral blood, and BBB is the key to regulate Aß in and out of the brain. In this study, we explored the pathogenesis of AD from the perspective of Aß transport through the BBB and the effect of QKL injection in AD mice. The results showed that QKL could improve the cognitive dysfunction of AD mice, decrease the level of Aß and Aß transporter-RAGE, which was supported by the results of network pharmacology, molecular docking and molecular dynamics simulation. In conclusion, RAGE is a potential target for QKL's therapeutic effect on AD.

Perivascular fat tissue and vascular aging: A sword and a shield.

The understanding of the function of perivascular adipose tissue (PVAT) in vascular aging has significantly changed due to the increasing amount of information regarding its biology. Adipose tissue surrounding blood vessels is increasingly recognized as a key regulator of vascular disorders. It has significant endocrine and paracrine effects on the vasculature and is mediated by the production of a variety of bioactive chemicals. It also participates in a number of pathological regulatory processes, including oxidative stress, immunological inflammation, lipid metabolism, vasoconstriction, and dilation. Mechanisms of homeostasis and interactions between cells at the local level tightly regulate the function and secretory repertoire of PVAT, which can become dysregulated during vascular aging. The PVAT secretion group changes from being reducing inflammation and lowering cholesterol to increasing inflammation and increasing cholesterol in response to systemic or local inflammation and insulin resistance. In addition, the interaction between the PVAT and the vasculature is reciprocal, and the biological processes of PVAT are directly influenced by the pertinent indicators of vascular aging. The architectural and biological traits of PVAT, the molecular mechanism of crosstalk between PVAT and vascular aging, and the clinical correlation of vascular age-related disorders are all summarized in this review. In addition, this paper aims to elucidate and evaluate the potential benefits of therapeutically targeting PVAT in the context of mitigating vascular aging. Furthermore, it will discuss the latest advancements in technology used for targeting PVAT.

A study on the association between gut microbiota, inflammation, and type 2 diabetes.

Type 2 diabetes mellitus (T2DM) was reported to be associated with impaired immune response and alterations in microbial composition and function. However, the underlying mechanism remains elusive. To investigate the association among retinoic acid-inducible gene-I-like receptors (RLRs) signaling pathway, intestinal bacterial microbiome, microbial tryptophan metabolites, inflammation, and a longer course of T2DM, 14 patients with T2DM and 7 healthy controls were enrolled. 16S rRNA amplicon sequencing and untargeted metabolomics were utilized to analyze the stool samples. RNA sequencing (RNA-seq) was carried out on the peripheral blood samples. Additionally, C57BL/6J specific pathogen-free (SPF) mice were used. It was found that the longer course of T2DM could lead to a decrease in the abundance of probiotics in the intestinal microbiome. In addition, the production of microbial tryptophan derivative skatole declined as a consequence of the reduced abundance of related intestinal microbes. Furthermore, low abundances of probiotics, such as Bacteroides and Faecalibacterium, could trigger the inflammatory response by activating the RLRs signaling pathway. The increased level of the member of TNF receptor-associated factors (TRAF) family, nuclear factor kappa-B (NF-κB) activator (TANK), in the animal colon activated nuclear factor kappa B subunit 2 (NFκB2), resulting in inflammatory damage. In summary, it was revealed that the low abundances of probiotics could activate the RLR signaling pathway, which could in turn activate its downstream signaling pathway, NF-κB, highlighting a relationship among gut microbes, inflammation, and a longer course of T2DM. KEY POINTS: Hyperglycemia may suppress tryptophanase activity. The low abundance of Bacteroides combined with the decrease of Dopa decarboxylase (DDC) activity may lead to the decrease of the production of tryptophan microbial derivative skatole, and the low abundance of Bacteroides or reduced skatole may further lead to the increase of blood glucose by downregulating the expression of glucagon-like peptide-1 (GLP1). A low abundance of anti-inflammatory bacteria may induce an inflammatory response by triggering the RLR signaling pathway and then activating its downstream NF-κB signaling pathway in prolonged T2DM.

Quinoa alleviates osteoporosis in ovariectomized rats by regulating gut microbiota imbalance.

BACKGROUND: Postmenopausal osteoporosis (PMO) is associated with dysregulation of bone metabolism and gut microbiota. Quinoa is a grain with high nutritional value, and its effects and potential mechanisms on PMO have not been reported yet. Therefore, the purpose of this study is to investigate the bone protective effect of quinoa on ovariectomy (OVX) rats by regulating bone metabolism and gut microbiota. RESULTS: Quinoa significantly improved osteoporosis-related biochemical parameters of OVX rats and ameliorated ovariectomy-induced bone density reduction and trabecular structure damage. Quinoa intervention may repair the intestinal barrier by upregulating the expression of tight junction proteins in the duodenum. In addition, quinoa increased the levels of Firmicutes, and decreased the levels of Bacteroidetes and Prevotella, reversing the dysregulation of the gut microbiota. This may be related to estrogen signaling pathway, secondary and primary bile acid biosynthesis, benzoate degradation, synthesis and degradation of ketone bodies, NOD-like receptor signaling pathway and biosynthesis of tropane, piperidine and pyridine alkaloids. Correlation analysis showed that there is a strong correlation between gut microbiota with significant changes in abundance and parameters related to osteoporosis. CONCLUSION: Quinoa could significantly reverse the high intestinal permeability and change the composition of gut microbiota in OVX rats, thereby improving bone microstructure deterioration and bone metabolism disorder, and ultimately protecting the bone loss of OVX rats. © 2024 Society of Chemical Industry.

Trajectory variations of optical Bloch oscillations for Airy beams in transversely and longitudinally modulated photonic lattices.

We consider four types of modulated photonic lattices and numerically study the optical Bloch oscillations of Airy beams in these periodic structures. Our results demonstrate that in transversely modulated photonic lattices, the oscillation period increases and the amplitude reduces as the separation variation index increases. However, the increasing of the width variation index could lead to a consistent reduction of oscillation period and amplitude. On the other hand, in three kinds of longitudinally bent photonic lattices, the optical Bloch oscillation trajectories of Airy beams follow the waveguide shape perfectly within the whole propagation length. For another three kinds of refractive index longitudinally varied lattices, the optical Bloch oscillation period and amplitude are limited with the increasing of refractive index, contributing to the presentation of dramatically different Airy propagation trajectories. Our study proposes a new view to manipulate the Airy trajectory in periodic structures.