Single-cell transcriptome profiling reveals cell type-specific variation and development in HLA expression of human skin.

Skin, the largest organ of body, is a highly immunogenic tissue with a diverse collection of immune cells. Highly polymorphic human leukocyte antigen (HLA) molecules have a central role in coordinating immune responses as recognition molecules. Nevertheless, HLA gene expression patterns among diverse cell types within a specific organ, like the skin, have yet to be thoroughly investigated, with stromal cells attracting much less attention than immune cells. To illustrate HLA expression profiles across different cell types in the skin, we performed single-cell RNA sequencing (scRNA-seq) analyses on skin datasets, covering adult and fetal skin, and hair follicles as the skin appendages. We revealed the variation in HLA expression between different skin populations by examining normal adult skin datasets. Moreover, we evaluated the potential immunogenicity of multiple skin populations based on the expression of classical HLA class I genes, which were well represented in all cell types. Furthermore, we generated scRNA-seq data of developing skin from fetuses of 15 post conception weeks (PCW), 17 PCW, and 22 PCW, delineating the dynamic expression of HLA genes with cell type-dependent variation among various cell types during development. Notably, the pseudotime trajectory analysis unraveled the significant variance in HLA genes during the evolution of vascular endothelial cells. Moreover, we uncovered the immune-privileged properties of hair follicles at single-cell resolution. Our study presents a comprehensive single-cell transcriptomic landscape of HLA genes in the skin, which provides new insights into variation in HLA molecules and offers a clue for allogeneic skin transplantation.

[Therapeutic effect and mechanism of non-polysaccharide fraction of Bletillae Rhizoma in treatment of gastric ulcer based on network pharmacology and animal experiment].

The present study aimed to explore the therapeutic effect and mechanism of non-polysaccharide fraction of Bletillae Rhizoma in the treatment of gastric ulcer by network pharmacology and animal experiments. UPLC-Q-TOF-MS/MS was employed to chara-cterize the chemical components of non-polysaccharide fraction of Bletillae Rhizoma, and the common targets of Bletillae Rhizoma and gastric ulcer were screened out by network pharmacology. The "drug-component-target-disease" network was constructed. Protein-protein interaction(PPI) network was established by STRING. Gene Ontology(GO) and Kyoto Encyclopedia of Genes and Genomes(KEGG) enrichment analyses were performed based on Matescape database to predict the therapeutic effect and mechanism of Bletillae Rhizoma. Finally, the gastric ulcer model was induced in mice by alcohol to verify the therapeutic effect and mechanism of non-polysaccharide fraction of Bletillae Rhizoma on gastric ulcer. Forty-seven chemical components were identified from non-polysaccharide fraction of Bletillae Rhizoma, among which gymnoside Ⅰ, gymnoside Ⅱ, militarine, bletilloside A, and shancigusin I might be the main active components of non-polysaccharide fraction of Bletillae Rhizoma against gastric ulcer. PPI network analysis revealed core targets such as albumin(ALB), serine/threonine kinase 1(AKT1), tumor necrosis factor(TNF), and epidermal growth factor receptor(EGFR). The KEGG enrichment analysis showed that non-polysaccharide fraction of Bletillae Rhizoma mainly exerted the therapeutic effect by regulating the phosphatidylinositol 3-kinase(PI3K)/protein kinase B(AKT) signaling pathway, mitogen-activated protein kinase(MAPK) signaling pathway, and Ras signaling pathway. The results of animal experiments showed that non-polysaccharide fraction of Bletillae Rhizoma could significantly improve alcohol-induced ulceration in mice to increase ulcer inhibition rate, decrease the levels of TNF-α, interleukin(IL)-1ß, IL-6, vasoactive intestinal peptide(VIP), and thromboxane B2(TXB2), elevated the le-vels of IL-10, prostaglandin E2(PGE2), epidermal growth factor(EGF), and vascular endothelial growth factor(VEGF), down-re-gulate the protein levels of PI3K and AKT, and up-regulate the protein levels of p-PI3K and p-AKT. This study indicates that Bletillae Rhizoma may play a role in the treatment of gastric ulcer through multiple components, targets, and pathways and verifies partial prediction results of network pharmacology. The findings of this study provide a scientific and experimental basis for clinical application.

Lactobacillus reuteri for chronic periodontitis: focus on underlying mechanisms and future perspectives.

Chronic periodontitis is a common oral disorder caused by pathogenic bacteria. Despite the wide use of antibiotics as the conventional adjunctive treatment, the challenges of increased antibiotic resistance and limited therapeutic effect receive considerable attention and the developments of alternative treatments gain increasing consideration. Growing evidence showed that Lactobacillus reuteri (LR) may represent a promising alternative adjunct for chronic periodontitis. It can attenuate inflammation and reduce tissue disruption. LR-assisted treatment has been shown to be effective and relatively safe in multiple clinical trials, and accumulating evidence suggests its significant biological roles. In the current review, we focus on capturing the underlying mechanisms of LR involved in chronic periodontitis, thereby representing a scientific foundation for LR-assisted therapy. Furthermore, we point out the challenges and future directions for further clinical trials to improve the clinical applicability for LR.

Effects and safety of Ginkgo biloba on blood metabolism in type 2 diabetes mellitus: a systematic review and meta-analysis.

Background: There has existed controversy regarding the use of Ginkgo biloba (GKB) for blood metabolism among type 2 diabetes mellitus(T2DM) patients, and we tried to analyze the effects and safety of GKB on T2DM patients. Methods: We conducted a literature search between January 2003 and December 2022 of seven online databases (PubMed, Scopus, Embase, Google Scholar, Web of Sciences, Cochrane Library, and China National Knowledge Infrastructure). A systematic literature review and meta-analysis were performed to compare the effects and safety of GKB among T2DM patients. Four groups of parameters were extracted and analyzed: hemorheology parameters, lipid profile, glycemic control markers, and adverse events. Results: In the end, 13 eligible articles with 11 indicators among 1573 patients were included. In the hemorheology parameters section, GKB showed significantly lower plasma viscosity (PV) (SMD=-0.91, 95%CI [-1.45, -0.36], P<0.01) and hematocrit (Hct) (SMD=-0.60, 95%CI [-0.97, -0.24], P<0.01) than the control group. GKB shoed higher velocity of the dorsalis pedis artery (VDPA) (SMD=0.51, 95%CI [0.26, 0.76], P<0.01) and ankle brachial index (ABI) (SMD=0.71, 95%CI [0.32, 1.10], P<0.01) than the control. In both the lipid profile and glycemic control markers sections, we did not find any difference between GKB and control groups, including total cholesterol (TC), triglyceride (TG), low-density lipoprotein (LDL), high-density lipoprotein (HDL), hemoglobin A1c (HbA1c), and fasting serum glucose (FSG). In addition, we saw no difference in adverse events (AE). The sensitivity analysis and funnel plot showed that the results in this research were robust and had no publication bias. Conclusion: In conclusion, GKB might safely reduce the risk of peripheral arterial or even systemic cardiovascular disease. However, GKB did not directly improve lipid and blood glucose levels in T2DM patients. Systematic review registration: https://inplasy.com/, identifier INPLASY202350096.

Total Triterpenes of Wolfiporia cocos (Schwein.) Ryvarden & Gilb Exerts Antidepressant-Like Effects in a Chronic Unpredictable Mild Stress Rat Model and Regulates the Levels of Neurotransmitters, HPA Axis and NLRP3 Pathway.

Purpose: Wolfiporia cocos is frequently used in traditional Chinese medicine to treat depression. However, antidepressant-like effects of the main active ingredients of Wolfiporia cocos, total triterpenes of Wolfiporia cocos (TTWC), are not well studied. This study aimed to investigate those effects and explore their specific mechanisms of action in depth. Methods: Chemical components of TTWC were analyzed using LC-MS. Depression-like behavior in rats were induced by chronic unpredictable mild stress (CUMS). The suppressive effects of TTWC (60, 120, 240 mg/kg) against CUMS-induced depression-like behavior were evaluated using the forced swimming test (FST), open field test (OFT) and sucrose preference test (SPT). Levels of 5-hydroxytryptamine (5-HT), glutamate (GLU), corticotropin-releasing hormone (CRH), interleukin-1 beta (IL-1beta), interleukin-18 (IL-18), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-alpha) in different groups were determined by ELISA. Western blotting (WB) was used to detect the expression of NLRP3, ASC, pro-caspase-1, caspase-1, pro-IL-1beta, IL-1beta, pro-IL-18, and IL-18 in the prefrontal cortex. Additionally, the mRNA levels of NLRP3, ASC, caspase-1, IL-1beta and IL-18 were detected by RT-PCR. Results: A total of 69 lanostane-type triterpene acids of TTWC were identified. The results showed that TTWC exhibited an antidepressant-like effect in CUMS rats, reversed the decreased sugar preference in the SPT, reduction of immobility time in the FST, reduced the rest time, increased the total moving distance in the OFT. TTWC increased 5-HT levels and decreased GLU levels in the hippocampus. Moreover, TTWC decreased CRH levels in serum, indicating the regulation of over-activation of the hypothalamic-pituitary-adrenal (HPA) axis. In addition, reduced serum levels of IL-1beta, IL-18, IL-6, and TNF-alpha. The WB results implied that TTWC inhibited the expression of NLRP3, ASC, caspase-1, IL-1beta, and IL-18 in the prefrontal cortex and enhanced the expression of pro-caspase-1, pro-IL-1beta, and pro-IL-18. Although most of the results were not significant, PCR results showed that TTWC inhibited the expression of NLRP3, ASC, caspase-1, IL-1beta, and IL-18 in the prefrontal cortex. Conclusion: TTWC treatment exerted an antidepressant-like effect and regulates neurotransmitters, HPA axis and NLRP3 signaling pathway. These results indicated the potential of TTWC in preventing the development of depression.

Tandem Oxidative Ring-Opening/Cyclization Reaction in Seconds in Open Atmosphere for the Synthesis of 1-Tetralones in Water-Acetonitrile.

A mild and practical tandem oxidative ring-opening/cyclization reaction mediated by Ce4+ for the synthesis of 1-tetralones is presented. This rapid transformation was completed within 30 s and conducted in an open reactor at 0 °C in a water-acetonitrile mixture. Various cyclobutanol derivatives are transformed into desired products in good to high yields, and this reaction can be easily scaled up to the gram scale.

Caspase­9 was involved in cell apoptosis in human dental pulp stem cells from deciduous teeth.

As one type of adult stem cells (ASCs), human dental pulp stem cells (HDPSCs) have several properties, including high proliferation rate, self­renewal capability, and multi­lineage differentiation. However, the apoptotic mechanism underlying the development of dental pulp cells remains unclear. In the present study, a significant increase of apoptosis was observed in HDPSCs from the deciduous teeth compared with that from adult permanent teeth. In addition, the occurrence of cytochrome c expression and mitochondrial­mediated apoptosis pathway activity in HDPSCs were confirmed by quantitative polymerase chain reaction, and western blotting. Although caspase­8 and caspase­9 showed higher expression in deciduous teeth than in adult permanent teeth, only the knockdown of caspase­9 via RNA interference in HDPSC cells exhibited a significant reduction in apoptosis, and caspase­3 expression and activity. All these results revealed that caspase­9 and activated caspase­3 predominantly regulates cell apoptosis in HDPSCs from deciduous teeth.

Metal-Free, Initiator-Free Graphene Oxide-Catalyzed Trifluoromethylation of Arenes.

The direct C-H trifluoromethylation of arenes catalyzed by graphene oxide (GO) under safe conditions is described. This strategy is metal-free, initiator-free, safe, and scalable. It employs a readily available CF3 source and the reaction can be easily controlled to obtain a mono-trifluorinated product. This method opens a new avenue for GO-catalyzed chemistry.

Dihydroorotate dehydrogenase depletion hampers mitochondrial function and osteogenic differentiation in osteoblasts.

Mutation of the dihydroorotate dehydrogenase (DHODH) gene is responsible for Miller syndrome, which is characterized by craniofacial malformations with limb abnormalities. We previously demonstrated that DHODH was involved in forming a mitochondrial supercomplex and that mutated DHODH led to protein instability, loss of enzyme activity, and increased levels of reactive oxygen species in HeLa cells. To explore the etiology of Miller syndrome in more detail, we investigated the effects of DHODH inhibition in the cells involved in skeletal structure. Dihydroorotate dehydrogenase in MC3T3-E1 cells derived from mouse calvaria osteoblast precursor cells was knocked down by specific small interfering RNAs (siRNAs), and cell proliferation, ATP production, and expression of bone-related genes were investigated in these cells. After depletion of DHODH using specific siRNAs, inhibition of cell proliferation and cell cycle arrest occurred in MC3T3-E1 cells. In addition, ATP production was reduced in whole cells, especially in mitochondria. Furthermore, the levels of runt-related transcription factor 2 (Runx2) and osteocalcin (Ocn) mRNAs were lower in DHODH siRNA-treated cells compared with controls. These data suggest that depletion of DHODH affects the differentiation and maturation of osteoblasts. This study shows that mitochondrial dysfunction by DHODH depletion in osteoblasts can be directly linked to the abnormal bone formation in Miller syndrome.

Dihydro-orotate dehydrogenase is physically associated with the respiratory complex and its loss leads to mitochondrial dysfunction.

Some mutations of the DHODH (dihydro-orotate dehydrogenase) gene lead to postaxial acrofacial dysostosis or Miller syndrome. Only DHODH is localized at mitochondria among enzymes of the de novo pyrimidine biosynthesis pathway. Since the pyrimidine biosynthesis pathway is coupled to the mitochondrial RC (respiratory chain) via DHODH, impairment of DHODH should affect the RC function. To investigate this, we used siRNA (small interfering RNA)-mediated knockdown and observed that DHODH knockdown induced cell growth retardation because of G2/M cell-cycle arrest, whereas pyrimidine deficiency usually causes G1/S arrest. Inconsistent with this, the cell retardation was not rescued by exogenous uridine, which should bypass the DHODH reaction for pyrimidine synthesis. DHODH depletion partially inhibited the RC complex III, decreased the mitochondrial membrane potential, and increased the generation of ROS (reactive oxygen species). We observed that DHODH physically interacts with respiratory complexes II and III by IP (immunoprecipitation) and BN (blue native)/SDS/PAGE analysis. Considering that pyrimidine deficiency alone does not induce craniofacial dysmorphism, the DHODH mutations may contribute to the Miller syndrome in part through somehow altered mitochondrial function.

Protein instability and functional defects caused by mutations of dihydro-orotate dehydrogenase in Miller syndrome patients.

Miller syndrome is a recessive inherited disorder characterized by postaxial acrofacial dysostosis. It is caused by dysfunction of the DHODH (dihydroorotate dehydrogenase) gene, which encodes a key enzyme in the pyrimidine de novo biosynthesis pathway and is localized at mitochondria intermembrane space. We investigated the consequence of three missense mutations, G202A, R346W and R135C of DHODH, which were previously identified in patients with Miller syndrome. First, we established HeLa cell lines stably expressing DHODH with Miller syndrome-causative mutations: G202A, R346W and R135C. These three mutant proteins retained the proper mitochondrial localization based on immunohistochemistry and mitochondrial subfractionation studies. The G202A, R346W DHODH proteins showed reduced protein stability. On the other hand, the third one R135C, in which the mutation lies at the ubiquinone-binding site, was stable but possessed no enzymatic activity. In conclusion, the G202A and R346W mutation causes deficient protein stability, and the R135C mutation does not affect stability but impairs the substrate-induced enzymatic activity, suggesting that impairment of DHODH activity is linked to the Miller syndrome phenotype.