Biology subjects

Tong, H.

Publications and source records attributed to Tong, H..

3 recordsLinked to original sources

bioRxiv2020

Thiamine pyrophosphokinase deficiency induces Alzheimer's pathology

BackgroundThiamine diphosphate (TDP) reduction plays an important role in cerebral glucose hypometabolism, the neurodegenerative indicator, in Alzheimers disease (AD). The mechanism underlying TDP reduction remains elusive. Thus, it is critical to define the mechanism and its effect on neurodegeneration, the pathological basis of the disease occurrence and progression. MethodsThe mRNA levels of all known genes associated with thiamine metabolism, including thiamine pyrophosphokinase (TPK), Solute Carrier Family 19 Member 2 (SLC19A2), SLC19A3, and SLC25A19, in brain samples of patients with AD and other neurodegenerative disorders in multiple independent datasets were analyzed. TPK protein levels were further examined in the brain tissues of AD patients and control subjects. A mouse model with conditional knockout (cKO) of TPK gene in the excitatory neurons of adult brain was established. ResultsThe brain TPK mRNA level was markedly lower in AD patients, but not in other neurodegenerative disorders. The brain TPK protein level was also significantly decreased in AD patients. TPK gene knockout in the mice caused cerebral glucose hypometabolism, {beta}-amyloid deposition, Tau hyperphosphorylation, neuroinflammation, and neuronal loss and brain atrophy. Cross-species correlation analysis revealed the similar changes of gene profiling between the cKO mice and AD patients. ConclusionsThe deficiency of brain TPK, a key enzyme for TDP synthesis, is specific to AD. The cKO mice show AD-associated phenotypes and could serve as a new mouse model for AD studies. Our study provides a novel insight into the critical role of TPK in AD pathogenesis and its potential for the disease treatment.

neuroscience↗

bioRxiv2020

Metformin alleviates insulin resistance in obese-induced mice via remodeling gut microbiota and intestinal metabolites

Metformin is widely used to surmount insulin resistance (IR) and type 2 diabetes. Evidence indicates that metformin improves insulin resistance associated with gut microbiota, but the underlying mechanism remains unclear. In the present study, metformin effectively improved insulin sensitivity and alleviated liver inflammation and oxidative stress in high-fat diet (HFD)-fed mice. Metabolomics analysis showed that metformin increased tauroursodeoxycholic acid (TUDCA) levels both in intestinal content and liver by reducing the production and activity of bile salt hydrolase (BSH). We further found that TUDCA was able to antagonize with KEAP1 to prevent its binding to Nrf2 and activate Nrf2/ARE pathway, thereby reducing intracellular ROS and improving insulin signaling. Moreover, metformin increased the proportion of Akkermanisia muciniphlia in the HFD-fed mice, while in vitro growth curve test confirmed that its TUDCA, not metformin, promoted the proliferation of A. muciniphlia. Subsequently, TUDCA administration could effectively ameliorate insulin resistance, activate hepatic Nrf2/ARE pathways, and increase the abundance of intestinal A. muciniphlia in ob/ob mice. These findings reveal that metformin remodels the gut microbiota, reduces oxidative stress and enhances insulin sensitivity partly due to increasing the production of TUDCA. This provides a novel mechanism by which metformin alleviates diet-induced insulin resistance and improves metabolism.

biochemistry↗

bioRxiv2020

Studies on trans-sutural distraction osteogenesis-related genes based on transcriptome sequencing

Trans-sutural distraction osteogenesis (TSDO) is an important approach to improve mid-face hypoplasia. In recent years, many studies have been carried out on physical mechanisms of TSDO; however, its specific cytological and molecular mechanisms are still unclear. In this study, we performed transcriptome sequencing analysis in Sprague Dawley rats at 1 and 2 weeks after suture osteogenesis and compared RNA expression levels between experimental and control groups. At one week, enrichment pathways were mainly up-regulated in muscle- and bone-related pathways. By contrast, pathways of the immune system showed a state of inhibition and down-regulation, especially for B cells; the main immune pathways showed significant down-regulation. However, two weeks later, the experimental group showed positive up-regulation of the pathways related to DNA synthesis and replication, cell cycle, and chromosome replication. At the same time, the immune pathways that were down-regulated in the first week were up-regulated in the second week. In other words, the up-regulated muscle- and bone-related pathways show opposite trends. The expression of bone- and myogenesis-related transcriptome was up-regulated and the immune-related pathways were down-regulated in the experimental group at 1 week. At 2 weeks, the pathways related to bone- and muscle were down-regulated, while those related to cell cycle regulation and DNA replication were up-regulated. These results suggest that musculoskeletal-related molecules may play an important role during suture osteogenesis at 1 week, and immune regulation may be involved in this process; however, at 2 weeks, molecules related to cell proliferation and replication may be a major role.

bioinformatics↗