Disturbed intracellular folate homeostasis impairs autophagic flux and increases hepatocytic lipid accumulation.

BACKGROUND: Metabolic associated fatty liver disease (MAFLD), a prevalent liver disorder affecting one-third of the global population, encompasses a spectrum ranging from fatty liver to severe hepatic steatosis. Both genetic and lifestyle factors, particularly diet and nutrition, contribute to its etiology. Folate deficiency, a frequently encountered type of malnutrition, has been associated with the pathogenesis of MAFLD and shown to impact lipid deposition. However, the underlying mechanisms of this relationship remain incompletely understood. We investigated the impact of disturbed folate-mediated one-carbon metabolism (OCM) on hepatic lipid metabolism both in vitro using human hepatoma cells and in vivo using transgenic fluorescent zebrafish displaying extent-, stage-, and duration-controllable folate deficiency upon induction. RESULTS: Disturbed folate-mediated one-carbon metabolism, either by inducing folate deficiency or adding anti-folate drug, compromises autophagy and causes lipid accumulation in liver cells. Disturbed folate status down-regulates cathepsin L, a key enzyme involved in autophagy, through inhibiting mTOR signaling. Interfered mitochondrial biology, including mitochondria relocation and increased fusion-fission dynamics, also occurs in folate-deficient hepatocytes. Folate supplementation effectively mitigated the impaired autophagy and lipid accumulation caused by the inhibition of cathepsin L activity, even when the inhibition was not directly related to folate deficiency. CONCLUSIONS: Disruption of folate-mediated OCM diminishes cathepsin L expression and impedes autophagy via mTOR signaling, leading to lipid accumulation within hepatocytes. These findings underscore the crucial role of folate in modulating autophagic processes and regulating lipid metabolism in the liver.

The cooperative interplay among inflammation, necroptosis and YAP pathway contributes to the folate deficiency-induced liver cells enlargement.

Change in cell size may bring in profound impact to cell function and survival, hence the integrity of the organs consisting of those cells. Nevertheless, how cell size is regulated remains incompletely understood. We used the fluorescent zebrafish transgenic line Tg-GGH/LR that displays inducible folate deficiency (FD) and hepatomegaly upon FD induction as in vivo model. We found that FD caused hepatocytes enlargement and increased liver stiffness, which could not be prevented by nucleotides supplementations. Both in vitro and in vivo studies indicated that RIPK3/MLKL-dependent necroptotic pathway and Hippo signaling interactively participated in this FD-induced hepatocytic enlargement in a dual chronological and cooperative manner. FD also induced hepatic inflammation, which convenes a dialog of positive feedback loop between necroptotic and Hippo pathways. The increased MMP13 expression in response to FD elevated TNFα level and further aggravated the hepatocyte enlargement. Meanwhile, F-actin was circumferentially re-allocated at the edge under cell membrane in response to FD. Our results substantiate the interplay among intracellular folate status, pathways regulation, inflammatory responses, actin cytoskeleton and cell volume control, which can be best observed with in vivo platform. Our data also support the use of this Tg-GGH/LR transgenic line for the mechanistical and therapeutic research for the pathologic conditions related to cell size alteration.

Arecoline-induced myofibroblast transdifferentiation from human buccal mucosal fibroblasts is mediated by ZEB1.

Oral submucous fibrosis (OSF) is considered as a pre-cancerous condition of the oral mucosa and is highly associated with habitual areca quid chewing. Arecoline is the major alkaloid in areca quid and is thought to be involved in the pathogenesis of OSF. Our previous studies have demonstrated that arecoline could induce epithelial-mesenchymal transition (EMT)-related factors in primary human buccal mucosal fibroblasts (BMFs). Therefore, we investigated the expression of zinc finger E-box binding homeobox 1 (ZEB1), which is a well-known transcriptional factor in EMT, in OSF tissues and its role in arecoline-induced myofibroblast transdifferentiation from BMFs. The expression of ZEB1, as well as the myofibroblast marker α-smooth muscle actin (α-SMA), was significantly increased in OSF tissues, respectively. With immunofluorescence analysis, arecoline induced the formation of α-SMA-positive stress fibres in BMFs expressing nuclear ZEB1. Arecoline also induced collagen contraction of BMFs in vitro. By chromatin immunoprecipitation, the binding of ZEB1 to the α-SMA promoter in BMFs was increased by arecoline. The promoter activity of α-SMA in BMFs was also induced by arecoline, while knockdown of ZEB1 abolished arecoline-induced α-SMA promoter activity and collagen contraction of BMFs. Long-term exposure of BMFs to arecoline induced the expression of fibrogenic genes and ZEB1. Silencing of ZEB1 in fibrotic BMFs from an OSF patient also suppressed the expression of α-SMA and myofibroblast activity. Inhibition of insulin-like growth factor receptor-1 could suppress arecoline-induced ZEB1 activation in BMFs. Our data suggest that ZEB1 may participate in the pathogenesis of areca quid-associated OSF by activating the α-SMA promoter and inducing myofibroblast transdifferentiation from BMFs.

An association study on the polymorphisms of dopaminergic genes with working memory in a healthy Chinese Han population.

Working memory (WM) is a highly heritable cognitive trait that is involved in many higher-level cognitive functions. In the past few years, much evidence has indicated that the reduction of dopamine activity in human brain can impair the WM system of the neuropsychiatric disorders. In this study, we hypothesized that some genes in the dopamine system were involved in the individual difference of the cognitive ability in healthy population. To confirm this hypothesis, a population-based study was performed to examine the effects of COMT, DAT (1), DRD (1), DRD (2), DRD (3), and DRD (4) on WM spans. Our results indicated there were significant associations of TaqIA and TaqIB in DRD (2) with digital WM span, respectively (χ(2) = 9.460, p = 0.009; χ(2) = 6.845, p = 0.033). On the other hand, we found a significant interaction between Ser9Gly in DRD (3) and TaqIA of DRD (2) on digital WM span (F = 3.207, p = 0.013). COMT, DAT (1) , DRD (1), and DRD (4), however, had no significant effects on digital and spatial WM spans (χ(2)<3.84, p > 0.05). These preliminary results further indicated that certain functional variants in dopamine system, such as TaqIA and TaqIB of DRD (2), were possibly involved in difference of WM in a healthy population.

Association analysis of TPH2, 5-HT2A, and 5-HT6 with executive function in a young Chinese Han population.

The 5-hydroxytryptamine (5-HT) system is widely distributed in the central nervous system. A growing body of evidence has suggested that the neurotransmitter system is implicated in the functions of the prefrontal cortex. So far, several studies have revealed that some functional genetic variants in TPH2, 5-HT2A, and 5-HT6 genes are possibly related to executive function. To investigate the potential influences of TPH2, 5-HT2A, and 5-HT6 on the components of executive function, the authors performed a population-based study with standard cognitive paradigms in a young Chinese Han group. The results indicated that -703 G/T polymorphism of TPH2 was associated with the performance of response inhibition (p = .002) and the T allele carriers (TT and GT) had fewer errors than the noncarriers (GG) did in the response inhibition test. Furthermore, there were no significant associations of the T102C in 5-HT2A and T267C in 5-HT6 with the components of executive function after correcting for multiple tests (p > .05). The present study suggests that TPH2 contributes distinctively to the inhibition domain of executive function, whereas 5-HT2A and 5-HT6 show no striking effects on executive function in the Chinese Han population.

Variants in COMT and DBH influence on response inhibition ability in Chinese Han females.

Catechol-O-methyltransferase (COMT) and dopamine-beta hydroxylase (DBH) are key enzymes to breakdown dopamine. Some previous studies have indicated that val158met in COMT and 19 bp insertion/deletion in 5' flank of DBH are related to the performance of executive function. To further investigate the associations of the two genes with executive function, we performed a population-based study in a Chinese Han population. The results indicated that val158met in COMT and the 19 bp insertion/deletion of DBH were associated with the average reaction time of response inhibition in female group (P = 0.01, P = 0.03), respectively. Furthermore, there was a significant interaction of the two genes on the reaction time (P = 0.006). This present study suggests that not only do COMT and DBH influence independently on response inhibition in females, but also exert a significant interaction on response inhibition.

Validation of Agitated Patient Remote Monitoring Alarm System in the Intensive Care Unit.

The purpose of this research is to innovate and develop a vision-based remote monitoring alarm system for agitated patients to provide intensive care unit (ICU) nurses with action warnings for agitated patients during their busy work. After the system is completed, preliminary laboratory verification is carried out, and the results are 94.87% in sensitivity, 97.44% in specificity, and 96.15% in accuracy, which enhances the confidence of the follow-up system in clinical testing.

Generation of Self-Assembled 3D Network in TPU by Insertion of Al2O3/h-BN Hybrid for Thermal Conductivity Enhancement.

Thermal management has become one of the crucial factors in designing electronic equipment and therefore creating composites with high thermal conductivity is necessary. In this work, a new insight on hybrid filler strategy is proposed to enhance the thermal conductivity in Thermoplastic polyurethanes (TPU). Firstly, spherical aluminium oxide/hexagonal boron nitride (ABN) functional hybrid fillers are synthesized by the spray drying process. Then, ABN/TPU thermally conductive composite material is produced by melt mixing and hot pressing. Then, ABN/TPU thermally conductive composite material is produced by melt mixing and hot pressing. Our results demonstrate that the incorporation of spherical hybrid ABN filler assists in the formation of a three-dimensional continuous heat conduction structure that enhances the thermal conductivity of the neat thermoplastic TPU matrix. Hence, we present a valuable method for preparing the thermal interface materials (TIMs) with high thermal conductivity, and this method can also be applied to large-scale manufacturing.

The Transgenic Zebrafish Display Fluorescence Reflecting the Expressional Dynamics of Dihydrofolate Reductase.

Dihydrofolate reductase (DHFR) reduces folic acid and recycles dihydrofolate generated during dTMP biosynthesis to tetrahydrofolate. DHFR is upregulated in rapidly proliferating cells and hence a favored target of antifolate drug against cancers, autoimmune diseases, and microbial infections. However, increased expression of dhfr contributed to the often emerging drug resistance and impeded the therapeutic efficacy of antifolate drugs. Therefore, comprehensive knowledge on the expressional control of dhfr becomes crucial. We generated two zebrafish transgenic lines, Tg(zdhfr+91:EGFP) and Tg(zdhfr+79:EGFP), which express green fluorescent protein driven by two zebrafish dhfr promoter fragments separately. The fluorescence intensity displayed in these transgenic embryos recapitulated the expressional dynamics of endogenous dhfr and reflected changes in dhfr mRNA and protein levels. The fluorescence intensity of these transgenic embryos was responsive to both genetic and environmental factors potentially modulating dhfr promoter activity. Sequence analyses revealed partial conservation on the landscape of transcription factor arrangement between zebrafish and human dhfr promoters. A noncanonical and inhibitory Sp1 site was identified 170 base-pair upstream to the conserved Sp1 site in close proximity to the translation initiation codon. Our results supported the potential use of these transgenic embryos for studying the expressional dynamics of dhfr and preliminary screening for dhfr promoter modulators.

Ovatodiolide Inhibits Breast Cancer Stem/Progenitor Cells through SMURF2-Mediated Downregulation of Hsp27.

Cancer stem/progenitor cells (CSCs) are a subpopulation of cancer cells involved in tumor initiation, resistance to therapy and metastasis. Targeting CSCs has been considered as the key for successful cancer therapy. Ovatodiolide (Ova) is a macrocyclic diterpenoid compound isolated from Anisomeles indica (L.) Kuntze with anti-cancer activity. Here we used two human breast cancer cell lines (AS-B145 and BT-474) to examine the effect of Ova on breast CSCs. We first discovered that Ova displayed an anti-proliferation activity in these two breast cancer cells. Ova also inhibited the self-renewal capability of breast CSCs (BCSCs) which was determined by mammosphere assay. Ova dose-dependently downregulated the expression of stemness genes, octamer-binding transcription factor 4 (Oct4) and Nanog, as well as heat shock protein 27 (Hsp27), but upregulated SMAD ubiquitin regulatory factor 2 (SMURF2) in mammosphere cells derived from AS-B145 or BT-474. Overexpression of Hsp27 or knockdown of SMURF2 in AS-B145 cells diminished the therapeutic effect of ovatodiolide in the suppression of mammosphere formation. In summary, our data reveal that Ova displays an anti-CSC activity through SMURF2-mediated downregulation of Hsp27. Ova could be further developed as an anti-CSC agent in the treatment of breast cancer.

A family-based association study of dopamine receptor D4 and mental retardation in Qinba region of China.

Dopamine receptor D4 (DRD4) is activated by the neurotransmitter dopamine and links to many neurological and psychiatric conditions because of its close relationship with prefrontal cortex and other important brain regions. To explore the possibility that genetic variants of DRD4 gene predispose to children with mental retardation (MR), five target SNPs of DRD4 were selected and genotyped in the samples of 163 MR pedigrees from the Qinba region of China. Two SNPs (rs752306 and rs3758653) showed weak association with MR (the P values were 0.022 and 0.015 for dominant model, and 0.027 and 0.015 for recessive model, respectively). Although they did not bear the multiple testing corrections, the haplotype which contained rs3758653 exhibited a significant association with MR (global P values were 0.018 for dominant model and 0.028 for recessive model, respectively). The in silico analysis also indicated that rs752306 and rs3758653 would be biologically meaningful SNPs. Therefore, the present study suggested that the genetic variants of DRD4 gene may play an important role in human MR. Further investigations, such as confirmation with other independent samples and functional studies, may elucidate their effect on gene expression and MR susceptibility.

An association study of the genetic polymorphisms in 13 neural plasticity-related genes with semantic and episodic memories.

Semantic and episodic memories were two different attributes of long-term memory. In the past few years, plenty of physiological evidence has indicated that neural plasticity is involved in the formation of long-term memory. In the present study, we hypothesized that some functional variants of neural plasticity-related genes were related to episodic and semantic memories. To confirm this hypothesis, we examined the relationship of 13 plasticity-related genes with episodic and semantic memories. The results indicated that there was a statistically significant difference in semantic memory scores among the three genotype groups of T267C in 5-HT ( 6 ) (χ (2) = 16.638, p = 0.0002). However, the functional variations in BDNF, COMT, DBH, DRD ( 2 ), DRD ( 3 ), DRD ( 4 ), MAOA, TPH ( 2 ), 5-HT ( 2A ), GRM ( 1 ), and GRIN2B had no observable effects on the memories. Our preliminary results confirm the hypothesis that a small number of functional variants of the neural plasticity-related genes, such as T267C in 5-HT ( 6 ), play important roles in human specific memory.

Association analysis between 12 genetic variants of ten genes and personality traits in a young chinese Han population.

Some genes involved in neurotransmission synthesis and transmission have been hypothesized to affect personality traits. To investigate the possible roles of these genes in personality traits of 16 Personality Factor Questionnaire, we performed a population-based study in a young Chinese Han cohort. In the study, we selected some functional variations in ten candidate genes (COMT, DBH, DRD(2), DRD(3), DAT, MAOA, GRM(1), GRIN2B, 5-TH(2A), and 5-TH(6)) encoding components in dopamine, glutamate, and 5-hydroxytryptamine pathways. The results showed the T102C in 5-TH(2A) was associated with X3 (emotional and quiet alertness) and B (reasoning) (F = 4.71 and 6.23; p = 0.009 and 0.002), Val158Met in COMT with E (dominance) (F = 7.01; p = 0.0009), while the variations in DBH, DRD(2), DRD(3), MAOA, GRM(1), GRIN2B, and 5-TH(6) were not associated with any of the personality traits. This finding suggests that T102C in 5-TH(2A) and Val158Met in COMT play roles in some human personality traits.