Counteracting TGM2 by a Fibroin peptide ameliorated Adriamycin-induced nephropathy via regulation of lipid metabolism through PANX1-PPAR α/PANK1 pathway.

Peptide drug discovery for the treatment of chronic kidney disease (CKD) has attracted much attention in recent years due to the urge to find novel drugs and mechanisms to delay the progression of the disease. In this study, we identified a novel short peptide (named YR-7, primary sequence 'YEVEDYR') from the natural Fibroin protein, and demonstrated that it significantly alleviated pathological renal changes in ADR-induced nephropathy. PANX1 was identified as the most notably upregulated component by RNA-sequencing. Further analysis showed that YR-7 alleviated the accumulation of lipid droplets via regulation of the lipid metabolism-related proteins PPAR α and PANK1. Using chemical proteomics, fluorescence polarization, microscale thermophoresis, surface plasmon resonance, and molecular docking, YR-7 was proven to directly bind to ß-barrel domains of TGM2 protein to inhibit lipid accumulation. TGM2 knockdown in vivo increased the protein levels of PPAR α and PANK1 while decreased the levels of fibrotic-related proteins to alleviate nephropathy. In vitro, overexpression TGM2 reversed the protective effects of YR-7. Co-immunoprecipitation indicated that TGM2 interacted with PANX1 to promote lipid deposition, and pharmacological inhibition or knockdown of PANX1 decreased the levels of PPAR α and PANK1 induced by ADR. Taken together, our findings revealed that TGM2-PANX1 interaction in promoting lipid deposition may be a new signaling in promoting ADR-induced nephropathy. And a novel natural peptide could ameliorate renal fibrosis through TGM2-PANX1-PPAR α/PANK1 pathway, which highlight the potential of it in the treatment of CKD.

Developing a universal and reliable temporomandibular joint reference system for quantifying morphological and positional changes.

OBJECTIVES: This study aimed to provide a universal and reliable reference system quantifying temporomandibular joint (TMJ) morphological and positional changes. METHODS: Large field-of-view (FOV) cone-beam computed tomography (CBCT) images (20 TMJs) from 10 preorthognathic surgery patients and limited FOV CBCT images (40 TMJs) from 20 splint therapy-treated patients with temporomandibular disorders were collected. TMJ-specific reference system including a TMJ horizontal reference plane (TMJHP) and a local coordinate system (TMJCS) was constructed with landmarks on cranial base. Its application for TMJ measurements and its spatial relationship to common Frankfort horizontal plane (FHP) and maxillofacial coordinate system (MFCS) were evaluated. RESULTS: Five relevant landmarks were selected to optimally construct TMJ-specific reference system. General parallelism between TMJHP and FHP was demonstrated by minimal angular and constant distance deviation (1.714 ±â€…0.811º; 2.925 ±â€…0.817 mm). Additionally, tiny axial orientational deviations (0.181 ±â€…6.805º) suggested TMJCS rivaled MFCS. Moreover, small deviations in orientations and distances (1.232 ±â€…0.609º; 0.310 ±â€…0.202 mm) indicated considerable reliability for TMJCS construction, with intraclass correlation coefficients (ICCs) ranging from 0.999 to 1.000. Lastly, slight discrepancies in translations and rotations revealed high reliability for condylar positional and morphological measurements (ICC, 0.918-0.999). LIMITATIONS: TMJ-specific reference system was merely tested in two representative FOVs. CONCLUSIONS: This study provides a universal and reliable reference system for TMJ assessment that is applicable to both limited and large FOV CBCT. It would improve comparability among diverse studies and enable comprehensive evaluations of TMJ positional and morphological changes during TMJ-related treatment follow-up such as splint therapy and disease progression.

The Lnc-HOTAIR/miR122/PPARγ signaling mediated the occurrence and continuous development of alcohol-induced Osteonecrosis of the femoral head.

This study aimed to explore the mechanism of alcohol-induced Osteonecrosis of the femoral head (ONFH) through in vivo and in vitro experiments. In vitro, the Oil Red O staining showed that ethanol promoted extracellular adipogenesis in a dose-dependent manner. ALP staining and alizarin red staining showed that ethanol inhibited the formation of extracellular mineralization in a dose-dependent manner. The Oil Red O staining showed that miR122 mimics and Lnc-HOTAIR SiRNA rescued extracellular adipogenesis induced by ethanol in BMSCs. Besides, we found that the high expression of PPARγ in BMSCs recruited histone deacetylase 3 (HDAC3) and histone methyltransferase (SUV39H1), which reduced the histone acetylation level and increased the histone methylation level in the miR122 promoter region, respectively. In vivo, the levels of H3K9ac, H3K14ac, and H3K27ac of miR122 promoter region in the ethanol group were significantly decreased compared to the control group, respectively. The levels of H3K9me2 and H3K9me3 of miR122 promoter region in the ethanol group were significantly increased compared to the control group. Lnc-HOTAIR/miR-122/PPARγ signaling mediated the alcohol-induced ONFH in the rat model. Furthermore, the persistent decrease of miR122 expression mediated the continuous progress of alcohol-induced ONFH after stopping alcohol consumption.

Prevalence of Oral Exostoses in Northern China During the Past Six Millennia-From a Sex and Age Perspective.

This study is intended to investigate oral exostoses of 5 sample populations, spanning over 6000 years, from the same region of Northern China, to determine the significance of sex and age on the development of oral exostoses during each time period. The samples analyzed were 306 dry jaws from human skeletons, which were excavated from 4 archeological sites: Banpo (6700-5600 y BP), Shaolingyuan (3000 y BP), Shanren (2200 y BP), and Chang'an (1000-1300 y BP), as well as the modern Xi'an district. The sex and the age of the samples at death were estimated. The degree of buccal exostosis (BE), torus mandibularis (TM), and torus palatinus (TP) and the TP shape were recorded. The results showed BEs in the Banpo and Chang'an regions, TMs in the Banpo region were more often diagnosed in males than in females. Conversely, females in Shaolingyuan showed a higher prevalence and severity of TM than that in males. The occurrence of BEs in the Shanren and Xi'an regions, TMs in the Banpo, Chang'an, and Xi'an regions, as well as TPs in the Banpo region significantly increased with age at death. In conclusion, sex differences and increasing trends with age in relation to oral exostoses were found in samples from Northern China during the past six millennia.

Activating AhR alleviates cognitive deficits of Alzheimer's disease model mice by upregulating endogenous Aß catabolic enzyme Neprilysin.

Rationale: Neprilysin (NEP) is a major endogenous catabolic enzyme of amyloid ß (Aß). Previous studies have suggested that increasing NEP expression in animal models of Alzheimer's disease had an ameliorative effect. However, the underlying signaling pathway that regulates NEP expression remains unclear. The aryl hydrocarbon receptor (AhR) is a ligand-activated cytoplasmic receptor and transcription factor. Recent studies have shown that AhR plays essential roles in the central nervous system (CNS), but its physiological and pathological roles in regulating NEP are not entirely known. Methods: Western blotting, immunofluorescence, quantitative RT-PCR and enzyme activity assay were used to verify the effects of AhR agonists on NEP in a cell model (N2a) and a mouse model (APP/PS1). Luciferase reporter assay and chromatin immunoprecipitation (ChIP) assay were conducted to investigate the roles of AhR in regulating NEP transcription. Object recognition test and the Morris water maze task were performed to assess the cognitive capacity of the mice. Results: Activating AhR by the endogenous ligand L-Kynurenine (L-KN) or FICZ, or by the exogenous ligand diosmin or indole-3-carbinol (I3C) significantly increases NEP expression and enzyme activity in N2a cells and APP/PS1 mice. We also found that AhR is a direct transcription factor of NEP. Diosmin treatment effectively ameliorated the cognitive disorder and memory deficit of APP/PS1 transgenic mice. By knocking down AhR or using a small molecular inhibitor targeting AhR or NEP, we found that diosmin enhanced Aß degradation through activated AhR and increased NEP expression. Conclusions: These results indicate a novel pathway for regulating NEP expression in neurons and that AhR may be a potential therapeutic target for the treatment of Alzheimer's disease.

A M35 family metalloprotease is required for fungal virulence against insects by inactivating host prophenoloxidases and beyond.

A diverse family of metalloproteases (MPs) is distributed in eukaryotes. However, the functions of MPs are still understudied. We report that seven MPs belonging to the M35 family are encoded in the genome of the insect pathogenic fungus Metarhizium robertsii. By gene deletions and insect bioassays, we found that one of the M35-family MPs, i.e. MrM35-4, is required for fungal virulence against insect hosts. MrM35-4 is a secretable enzyme and shows a proteolytic activity implicated in facilitating fungal penetration of insect cuticles. After gene rescue and overexpression, insect bioassays indicated that MrM35-4 contributes to inhibiting insect cuticular and hemocyte melanization activities. Enzymatic cleavage assays revealed that the recombinant prophenoloxidases PPO1 and PPO2 of Drosophila melanogaster could be clipped by MrM35-4 in a manner differing from a serine protease that can activate PPO activities. In addition, it was found that MrM35-4 is involved in suppressing antifungal gene expression in insects. Consistent with the evident apoptogenic effect of MrM35-4 on host cells, we found that the PPO mutant flies differentially succumbed to the infections of the wild-type and mutant strains of M. robertsii. Thus, MrM35-4 plays a multifaceted role beyond targeting PPOs during fungus-insect interactions, which represents a previously unsuspected strategy employed by Metarhizium to outmaneuver insect immune defenses.

The role of Rho-GEF Trio in regulating tooth root development through the p38 MAPK pathway.

Trio, the Rho guanine nucleotide exchange factor (Rho-GEF), plays diverse roles in cell migration, cell axon guidance and cytoskeleton reorganization. Conserved during evolution, Trio encodes two guanine nucleotide exchange factor domains (GEFs) and activates small GTPases. The Rho-family small GTPases RhoA and Rac1, which are target molecules of Trio, have been described to engage in craniofacial development and tooth formation. However, the exact role of Trio in tooth development remains elusive. In this study, we generated Wnt1-cre;Triofl/fl mice to address the potential function of Trio in tooth development. Wnt1-cre;Triofl/fl mice showed short root deformity as well as decreased expression of odontogenic makers such as RUNX2, OSX, OCN, and OPN. In vitro, Trio was silenced in human stem cells of dental papilla (SCAPs). Compared with the control group, the proliferation and migration ability in the experimental group was disrupted. After knocking down Trio in SCAPs, the cells showed phenotypes of poor odontogenic differentiation and weak mineralized nodules. To study the underlying mechanism, we investigated the p38 MAPK pathway and found that loss of Trio blocked the cascade transduction of p38 MAPK signaling. In conclusion, we identified Trio as a novel coordinator in regulating root development and clarified its relevant molecular events.

Pax2 is essential for proliferation and osteogenic differentiation of mouse mesenchymal stem cells via Runx2.

Mesenchymal stem cells (MSCs) have been widely studied in the field of regenerative medicine with the potential to solve osteoporosis. Paired box 2 (Pax2), as a transcription factor, is the master regulator of embryogenesis and oncogenesis. However, the function of Pax2 in osteogenesis is unknown. Here, we reported for the first time that the expression of Pax2 gradually increased during osteogenic differentiation of mouse MSCs, and osteoprogenitor cells. However, detected in osteoblastic cells of mouse tibia, the expression of Pax2 in the embryonic stage was higher than that in adulthood. In C3H/10/T1/2 cells and compact bone-derived mouse MSCs (mMSCs), Pax2 knock-down inhibited the proliferation of these cells, down-regulated the expression of osteogenic marker genes, as well as repressed the ALP activity and mineralization. In addition, Pax2 enhanced the transcriptional activity of Runx2, and activated the MAPK pathway genes (ERK, JNK and p38). Furthermore, knock-down of Pax2 repressed the mMSCs-mediated bone regeneration in an ectopic bone formation model. In conclusion, Pax2 promotes osteogenesis of mouse MSCs, suggesting that Pax2 has a role in the pathophysiology of bone related diseases, and has potential application in bone tissue regeneration.

Functional expression of recombinant human trefoil factor 1 by Escherichia coli and Brevibacillus choshinensis.

BACKGROUND: Trefoil factor 1 (TFF1) mediates mucosal repair and belongs to a highly conserved trefoil factor family proteins which are secreted by epithelial cells in the stomach or colon mucous membrane. TFF1 forms a homodimer via a disulphide linkage that affects wound healing activity. Previous recombinant expressions of TFF1 were too low yield for industrial application. This study aims to improve the expression level of bioactive recombinant TFF1 (rTFF1) and facilitate application potency. METHODS: The rTFF1 gene rtff1 was synthesized, expressed by Escherichia coli and secreted by Brevibacillus choshinensis. The rTFF1s were purified. The polymeric patterns and wound healing capacities of purified rTFF1s were checked. RESULTS: In Escherichia coli, 21.08 mg/L rTFF1 was stably expressed as monomer, dimer and oligomer in soluble fraction. In Brevebacillus choshinensis, the rTFF1 was secreted extracellularly at high level (35.73 mg/L) and formed monomer, dimer and oligomer forms. Both proteins from different sources were purified by Ni-NTA chromatography and exhibited the wound healing activities. The rTFF1 produced by B. choshinensis had better wound healing capability than the rTFF1 produced by E. coli. After pH 2.4 buffer treatments, the purified rTFF1 formed more oligomeric forms as well as better wound healing capability. Glycosylation assay and LC-MS/MS spectrometry experiments showed that the rTFF1 produced by B. choshinensis was unexpectedly glycosylated at N-terminal Ser residue. The glycosylation may contribute to the better wound healing capacity. CONCLUSIONS: This study provides a potent tool of rTFF1 production to be applied in gastric damage protection and wound healing. The protein sources from B. choshinensis were more efficient than rTFF1 produced by E. coli.