Sirtuin-6 knockout causes exacerbated stalled healing of diabetic ulcers in mice.

BACKGROUND: Diabetic ulcers (DUs) are characterized by chronic inflammation and delayed re-epithelialization, with a high incidence and weighty economic burden. The primary therapeutic strategies for refractory wounds include surgery, non-invasive wound therapy, and drugs, while the optimum regimen remains controversial. Sirtuin-6 (SIRT6) is a histone deacetylase and a key epigenetic factor that exerts anti-inflammatory and pro-proliferatory effects in wound healing. However, the exact function of SIRT6 in DUs remains unclear. METHODS: We generated tamoxifen-inducible SIRT6 knockout mice by crossing SIRT6flox/flox homozygous mice with UBC-creERT2+ transgenic mice. Systemic SIRT6 null mice, under either normal or diabetic conditions, were utilized to assess the effects of SIRT6 in DUs treatment. Gene and protein expressions of SIRT6 and inflammatory cytokines were measured by Western blotting and RT-qPCR. Histopathological examination confirmed the altered re-epithelialization (PCNA), inflammation (NF-κB p50 and F4/80), and angiogenesis (CD31) markers during DUs restoration. RESULTS: Knockout of SIRT6 inhibited the healing ability of DUs, presenting attenuated re-epithelialization (PCNA), exacerbated inflammation responses (NF-κB p50, F4/80, Il-1ß, Tnf-α, Il-6, Il-10, and Il-4), and hyperplasia vascular (CD31) compared with control mice. CONCLUSIONS: SIRT6 could boost impaired wound healing through improving epidermal proliferation, inflammation, and angiogenesis. Our study highlighted the therapeutic potential of the SIRT6 agonist for DUs treatment.

Identification of Angiogenesis-Related Genes and Molecular Subtypes for Psoriasis Based on Random Forest Algorithm.

Psoriasis is a chronic immune-mediated recurrent skin disease causing systemic damage. Increased angiogenesis has been reported to participate in the progression of psoriasis. However, angiogenesis-related genes (ARGs) in psoriasis have not been systematically elucidated. Therefore, we aim to identify potential biomarkers and subtypes using two algorithms. Transcriptome sequencing data of patients with psoriasis were obtained, in which differentially expressed genes were assessed by principal component analysis (PCA). A diagnostic model was developed using random forest algorithm (ntree=400) and validated by ROC curves. Subsequently, we performed consensus clustering to calculate angiogenesis-associated molecular subtypes of psoriasis. Additionally, a correlation analysis was conducted between ARGs and immune cell infiltration. Finally, validation of potential ARG genes was performed by qRT-PCR. We identified 29 differentially expressed ARGs, including 13 increased and 16 decreased. Ten ARGs, CXCL8, ANG, EGF, HTATIP2, ANGPTL4, TNFSF12, RHOB, PML, FOXO4, and EMCN were subsequently sifted by the diagnostic model based on a random forest algorithm. Analysis of the ROC curve (area under the curve [AUC] = 1.0) indicated high diagnostic performance in internal validation. The correlation analysis suggested that CXCL8 has a high positive correlation with neutrophil (R =0.8, P<0.0001) and interleukins pathway (R=0.79, P<0.0001). Furtherer, two ARG-mediated subtypes were obtained, indicating potential heterogeneity. Finally, the qRT-PCR demonstrated that the mRNA expression levels of CXCL8 and ANGPTL4 were elevated in psoriasis patients, with a reduced expression of EMCN observed. The current paper indicated potential ARG-related biomarkers of psoriasis, including CXCL8, ANGPTL4, and EMCN, with two molecular subtypes.

Porphyromonas gingivalis promotes the progression of oral squamous cell carcinoma by stimulating the release of neutrophil extracellular traps in the tumor immune microenvironment.

BACKGROUND: The aim of this study was to investigate the impact of Porphyromonas gingivalis (P. gingivalis) on the progression of oral squamous cell carcinoma (OSCC) through neutrophil extracellular traps (NETs) in the tumor immune microenvironment. METHODS: The expression of NETs-related markers was identified through immunohistochemistry, immunofluorescence, and Western blotting in different clinical stages of OSCC samples. The relationship between NETs-related markers and clinicopathological characteristics in 180 samples was analyzed using immunohistochemistry data. Furthermore, the ability to predict the prognosis of OSCC patients was determined by ROC curve analysis and survival analysis. The effect of P. gingivalis on the release of NETs was identified through immunofluorescence and immunohistochemistry, both in vitro and in vivo. CAL27 and SCC25 cell lines were subjected to NETs stimulation to elucidate the influence of NETs on various cellular processes, including cell proliferation, migration, invasion, and metastasis in vitro. Furthermore, the impact of NETs on the growth and metastatic potential of OSCC was assessed using in vivo models involving tumor-bearing mice and tumor metastasis mouse models. RESULTS: Immunochemistry analysis revealed a significant correlation between the NETs-related markers and clinical stage, living status as well as TN stage. P. gingivalis has demonstrated its ability to effectively induce the release of NETs both in vivo and in vitro. NETs have the potential to facilitate cell migration, invasion, and colony formation. Moreover, in vivo experiments have demonstrated that NETs play a pivotal role in promoting tumor metastasis. CONCLUSION: High expression of NETs-related markers demonstrates a strong correlation with the progression of OSCC. Inhibition of the NETs release process stimulated by P. gingivalis and targeted NETs could potentially open up a novel avenue in the field of immunotherapy for patients afflicted with OSCC.

Association of phthalate exposure with all-cause mortality across renal function status: The U.S. National Health and Nutrition Examination Survey, 2005-2018.

BACKGROUND: Wide phthalate exposure has been associated with both declines in renal function and an elevated risk of mortality. Whether phthalate-associated risk of premature mortality differs by renal function status remains unclear. METHODS: This study included 9605 adults from the U.S. National Health and Nutrition Examination Survey. Urinary concentrations of 11 phthalate metabolites were assessed using high-performance liquid chromatography-electrospray ionization tandem mass spectrometry. According to estimated glomerular filtration rate (eGFR), participants were grouped as having normal or modestly declined renal functions, or chronic kidney disease (CKD). Multivariable Cox regression models estimated all-cause mortality associated with phthalate exposure, overall and by renal function status. RESULTS: Overall, Mono-n-butyl phthalate (MnBP), Mono-benzyl phthalate (MBzP), Mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) and Mono-(2-ethyl-5-carbox-ypentyl) phthalate (MECPP) were associated with an elevated risk of mortality (P-trend across tertile <0.05). Moreover, significant interactions were observed between eGFR and MEHHP, MEOHP, MECPP, DEHP in the whole population (P for interactions <0.05). After stratification by renal function, total Di (2-ethylhexyl) phthalate (DEHP) was additionally found to be associated with mortality risk in the CKD group (HR = 1.12; 95% CI: 1.01, 1.25). Co-exposure to the 11 phthalate metabolites was associated with a higher risk of all-cause mortality in the CKD (HR = 1.47; 95% CI: 1.18, 1.84) and modestly declined renal function group (HR = 1.25; 95% CI: 1.09, 1.44). CONCLUSIONS: The associations between phthalate exposure and risk of all-cause mortality were primarily observed in CKD patients, reinforcing the need for monitoring phthalate exposure in this patient population.

A randomized controlled clinical trial of concentrated growth factor combined with sodium hyaluronate in the treatment of temporomandibular joint osteoarthritis.

OBJECTIVE: To investigate the effect of concentrated growth factor (CGF) combined with sodium hyaluronate (SH) on temporomandibular joint osteoarthritis (TMJOA). METHODS: Sixty patients with TMJOA who were diagnosed by cone-beam computed tomography (CBCT) between March 2020 and March 2023 at the Stomatological Hospital of Xi'an Jiaotong University were randomly divided into a control group (n = 30) and an experimental group (n = 30). The patients in the experimental group were treated with CGF + SH, and those in the control group were treated with SH only. The visual analogue scale (VAS) score indicating pain in the temporomandibular joint (TMJ) area; the Helkimo Clinical Dysfunction Index (Di); and changes in condylar CBCT at the first visit and 2 weeks, 3 months and 6 months after treatment were recorded. The CBCT data of the patients in the experimental and control groups were collected, and the three-dimensional CBCT image sequences were imported into Mimics Medical 19.0 software in DICOM format for condylar reconstruction. RESULTS: The VAS scores at 2 weeks, 3 months and 6 months after treatment were significantly lower in the experimental group than in the control group (P < 0.05), and the pain in the experimental group was significantly relieved. The Di was significantly lower in the experimental group than in the control group (P < 0.05), and the clinical function of the TMJ improved. After treatment, the CBCT score was significantly lower in the experimental group than in the control group (P < 0.05), and the condylar bone cortex was obviously repaired. Observation of the condylar bone cortex by three-dimensional reconstruction showed the same results as those obtained by CBCT. CONCLUSION: CGF combined with SH is effective in the treatment of TMJOA and can improve muscle pain, TMJ pain, Impaired TMJ function, Impaired range of movement, Pain on movement of the mandible and promote bone repair. THE REGISTRATION NUMBER (TRN): ChiCTR2400082712. THE DATE OF REGISTRATION: April 5, 2024.

Porphyromonas gingivalis promotes the progression of oral squamous cell carcinoma by activating the neutrophil chemotaxis in the tumour microenvironment.

BACKGROUND: We aimed to determine the significance of Porphyromonas gingivalis (P. gingivalis) in promoting tumour progression in the tumour microenvironment (TME) of oral squamous cell carcinoma (OSCC). METHODS: The Gene Expression Omnibus (GEO) was used to screen out the differentially expressed genes from the two datasets of GEO138206 and GSE87539. Immunohistochemistry and immunofluorescence analysis of samples, cell biological behaviour experiments, and tumour-bearing animal experiments were used to verify the results in vivo and in vitro. The mechanism was revealed at the molecular level, and rescue experiments were carried out by using inhibitors and lentiviruses. RESULTS: CXCL2 was selected by bioinformatics analysis and was found to be related to a poor prognosis in OSCC patients. Samples with P. gingivalis infection in the TME of OSCC had the strongest cell invasion and proliferation and the largest tumour volume in tumour-bearing animal experiments and exhibited JAK1/STAT3 signalling pathway activation and epithelial-mesenchymal transition (EMT). The expression of P. gingivalis, CXCL2 and TANs were independent risk factors for poor prognosis in OSCC patients. A CXCL2/CXCR2 signalling axis inhibitor significantly decreased the invasion and proliferation ability of cells and the tumour volume in mice. When lentivirus was used to block the CXCL2/CXCR2 signalling axis, the activity of the JAK1/STAT3 signalling pathway was decreased, and the phenotype of EMT was reversed. CONCLUSION: Porphyromonas gingivalis promotes OSCC progression by recruiting TANs via activation of the CXCL2/CXCR2 axis in the TME of OSCC.

Phosphorylation of Neurofilament Light Chain in the VLO Is Correlated with Morphine-Induced Behavioral Sensitization in Rats.

Neurofilament light chain (NF-L) plays critical roles in synapses that are relevant to neuropsychiatric diseases. Despite postmortem evidence that NF-L is decreased in opiate abusers, its role and underlying mechanisms remain largely unknown. We found that the microinjection of the histone deacetylase (HDAC) inhibitor Trichostatin A (TSA) into the ventrolateral orbital cortex (VLO) attenuated chronic morphine-induced behavioral sensitization. The microinjection of TSA blocked the chronic morphine-induced decrease of NF-L. However, our chromatin immunoprecipitation (ChIP)-qPCR results indicated that this effect was not due to the acetylation of histone H3-Lysine 9 and 14 binding to the NF-L promotor. In line with the behavioral phenotype, the microinjection of TSA also blocked the chronic morphine-induced increase of p-ERK/p-CREB/p-NF-L. Finally, we compared chronic and acute morphine-induced behavioral sensitization. We found that although both chronic and acute morphine-induced behavioral sensitization were accompanied by an increase of p-CREB/p-NF-L, TSA exhibited opposing effects on behavioral phenotype and molecular changes at different addiction contexts. Thus, our findings revealed a novel role of NF-L in morphine-induced behavioral sensitization, and therefore provided some correlational evidence of the involvement of NF-L in opiate addiction.

Metabolism-related biomarkers, molecular classification, and immune infiltration in diabetic ulcers with validation.

Diabetes mellitus (DM) can lead to diabetic ulcers (DUs), which are the most severe complications. Due to the need for more accurate patient classifications and diagnostic models, treatment and management strategies for DU patients still need improvement. The difficulty of diabetic wound healing is caused closely related to biological metabolism and immune chemotaxis reaction dysfunction. Therefore, the purpose of our study is to identify metabolic biomarkers in patients with DU and construct a molecular subtype-specific prognostic model that is highly accurate and robust. RNA-sequencing data for DU samples were obtained from the Gene Expression Omnibus (GEO) database. DU patients and normal individuals were compared regarding the expression of metabolism-related genes (MRGs). Then, a novel diagnostic model based on MRGs was constructed with the random forest algorithm, and classification performance was evaluated utilizing receiver operating characteristic (ROC) analysis. The biological functions of MRGs-based subtypes were investigated using consensus clustering analysis. A principal component analysis (PCA) was conducted to determine whether MRGs could distinguish between subtypes. We also examined the correlation between MRGs and immune infiltration. Lastly, qRT-PCR was utilized to validate the expression of the hub MRGs with clinical validations and animal experimentations. Firstly, 8 metabolism-related hub genes were obtained by random forest algorithm, which could distinguish the DUs from normal samples validated by the ROC curves. Secondly, DU samples could be consensus clustered into three molecular classifications by MRGs, verified by PCA analysis. Thirdly, associations between MRGs and immune infiltration were confirmed, with LYN and Type 1 helper cell significantly positively correlated; RHOH and TGF-ß family remarkably negatively correlated. Finally, clinical validations and animal experiments of DU skin tissue samples showed that the expressions of metabolic hub genes in the DU groups were considerably upregulated, including GLDC, GALNT6, RHOH, XDH, MMP12, KLK6, LYN, and CFB. The current study proposed an auxiliary MRGs-based DUs model while proposing MRGs-based molecular clustering and confirmed the association with immune infiltration, facilitating the diagnosis and management of DU patients and designing individualized treatment plans.

The Transcription Factor MYB59 Regulates K+/NO3 - Translocation in the Arabidopsis Response to Low K+ Stress.

Potassium and nitrogen are essential nutrients for plant growth and development. Plants can sense potassium nitrate (K+/NO3 -) levels in soils, and accordingly they adjust root-to-shoot K+/NO3 - transport to balance the distribution of these ions between roots and shoots. In this study, we show that the transcription factorMYB59 maintains this balance by regulating the transcription of the Arabidopsis (Arabidopsis thaliana) Nitrate Transporter1.5 (NRT1.5)/ Nitrate Transporter/Peptide Transporter Family7.3 (NPF7.3) in response to low K+ (LK) stress. The myb59 mutant showed a yellow-shoot sensitive phenotype when grown on LK medium. Both the transcript and protein levels of NPF7.3 were remarkably reduced in the myb59 mutant. LK stress repressed transcript levels of both MYB59 and NPF7.3 The npf7.3 and myb59 mutants, as well as the npf7.3 myb59 double mutant, showed similar LK-sensitive phenotypes. Ion content analyses indicated that root-to-shoot K+/NO3 - transport was significantly reduced in these mutants under LK conditions. Moreover, chromatin immunoprecipitation and electrophoresis mobility shift assay assays confirmed that MYB59 bound directly to the NPF7.3 promoter. Expression of NPF7.3 in root vasculature driven by the PHOSPHATE 1 promoter rescued the sensitive phenotype of both npf7.3 and myb59 mutants. Together, these data demonstrate that MYB59 responds to LK stress and directs root-to-shoot K+/NO3 - transport by regulating the expression of NPF7.3 in Arabidopsis roots.

Efficacy and safety profile of antioxidants in the treatment of atopic dermatitis: A systematic review and meta-analysis of randomized controlled trials.

The use of antioxidants in atopic dermatitis (AD) is controversial. We conducted a systematic review and meta-analysis to evaluate the efficacy and safety of antioxidants therapy in AD. Randomized clinical trials were identified from Medline, Embase, and Cochrane library. Changes from baseline in severity and itch score were extracted from individual studies and pooled using random-effects. Eighteen trials including 763 AD patients were eligible. Overall, antioxidants were associated with statistically significant reductions in diseases severity (p < 0.0001), but not with itch score (p = 0.59). No serious adverse events were recorded. Subgroup analyses revealed that antioxidants were associated with a significant reduction in severity score regardless of disease severity at baseline and treatment duration (p < 0.05). However, antioxidants had additional benefit only in children (p = 0.02) but not in adults (p = 0.30). Oral supplementation with vitamin D, combined vitamins D and E, combined vitamins A, D and E and topical vitamin B12 was associated with significantly lower severity score (p < 0.05). There was significant heterogeneity between studies (I2  = 50%; p = 0.003). The effect estimates did not change statistically after excluding sources of study heterogeneity. This meta-analysis suggests that antioxidants may be a safe and effective treatment for AD patients, especially when supplemented with oral vitamin D and topical vitamin B12 , as well as in pediatric patients.

Long non-coding RNAs in diabetic wound healing: Current research and clinical relevance.

Diabetic wounds are a protracted complication of diabetes mainly characterised by chronic inflammation, obstruction of epithelialization, damaged blood vessels and collagen production (maturation), as well as neuropathy. As a non-coding RNA (ncRNA) that lack coding potential, long non-coding RNAs (lncRNAs) have recently been reported to play a salient role in diabetic wound healing. Here, this review summarises the roles of lncRNAs in the pathology and treatments of diabetic wounds, providing references for its potential clinical diagnostic criteria or therapeutic targets in the future.

Characteristics of amino acid metabolism in preterm infants in Guangxi, China. / å¹¿è¥¿åœ°åŒºæ—©äº§å„¿æ°¨åŸºé ¸ä»£è°¢ç‰¹ç‚¹ç ”ç©¶.

OBJECTIVES: To study the characteristics of amino acid metabolism in preterm infants in Guangxi, China. METHODS: A retrospective analysis was performed on the medical data of 30 757 neonates who underwent the screening for inherited metabolic diseases and had negative results in Guangxi Neonatal Disease Screening Center from 2018 to 2020. Among these neonates, there were 28 611 normal full-term infants (control group) and 2 146 preterm infants (preterm birth group). According to gestational age, the preterm infants were further divided into four groups: very preterm (n=209), moderately preterm (n=307), and late preterm group (n=1 630). According to birth weight, they were divided into three groups: very low birth weight group (n=161), low birth weight group (n=1 085), and normal birth weight group (n=900). According to blood collection time, they were divided into three groups: 3-7 days group (n=1 664), 8-14 days group (n=314) and 15-28 days group (n=168). Tandem mass spectrometry was performed to measure the levels of 11 amino acids in dried blood spots, which were then compared between groups. RESULTS: After adjustment for confounding factors, there were significant differences in the levels of 11 amino acids among different gestational age groups (P<0.05), and significant differences were observed in the levels of the 11 amino acids between the control group and the various preterm groups (except for citrulline and methionine in the late preterm group). There were significant differences in the levels of 11 amino acids among different birth weight groups (P<0.05). Except for ornithine, there were significant differences in the levels of other amino acids among the different blood collection time groups (P<0.05). CONCLUSIONS: Gestational age, birth weight and blood collection time all affect amino acid metabolism in preterm infants in Guangxi, China. This provides a basis for the laboratory to establish the reference standard and clinical interpretation of blood amino acid levels in preterm infants, and to improve the nutritional metabolism of preterm infants.

Vitamin A deficiency exacerbates extrinsic atopic dermatitis development by potentiating type 2 helper T cell-type inflammation and mast cell activation.

BACKGROUND: Vitamin A deficiency (VAD) has been hypothesized to play a role in the pathophysiology of atopic dermatitis (AD). OBJECTIVE: We sought to verify whether VAD can exacerbate AD development, and explore the possible pathophysiologic mechanism. METHODS: We detected serum vitamin A (VA) concentration in different phenotypes of AD infants (intrinsic AD, iAD and extrinsic AD, eAD), and established ovalbumin (OVA) percutaneous sensitized AD model and passive cutaneous anaphylaxis (PCA) model on VAD and vitamin A supplementation (VAS) model in wild-type mice (C57BL/6) and established AD model on both normal VA (VAN) and VAD feeding mast cell deficiency mice (ckitw-sh/w-sh ). RESULTS: The average serum VA concentration of eAD was significantly lower than that of iAD, as well as healthy controls. In OVA-induced C57BL/6 mouse AD model, compared with VAN group, VAD mice manifested significantly more mast cells accumulation in the skin lesions, more severe Th2-mediated inflammation, including higher serum IgG1 and IgE levels, more IL-4, IL-13 mRNA expression in OVA-sensitized skin, and lower Th1 immune response, including lower serum IgG2a and IFN-γ mRNA expression in the skin. But there was no significant difference in the expression of IL-17 mRNA between OVA-treated skin of VAN and VAD mice. However, in OVA-induced ckitw-sh/w-sh mouse AD model, we did not find any significant differences in the above measurements between VAD and VAN group. In PCA model, VAD mice showed remarkable more blue dye leakage than that in VAN mice. Compared with VAD group, the above-mentioned inflammatory measurements in VAS group and VAN group were similar in OVA-induced AD model mice. CONCLUSIONS AND CLINICAL RELEVANCE: VAD can exacerbate extrinsic AD by augmenting Th2-mediated inflammation and mast cell activation. Therapeutic VAS can rescue VAD-aggravated eAD. It may provide a new strategy for future prevention or treatment of atopic dermatitis.

Cardiac-specific methylation patterns of circulating DNA for identification of cardiomyocyte death.

BACKGROUND: Correct detection of human cardiomyocyte death is essential for definitive diagnosis and appropriate management of cardiovascular diseases. Although current strategies have proven utility in clinical cardiology, they have some limitations. Our aim was to develop a new approach to monitor myocardial death using methylation patterns of circulating cell-free DNA (cf-DNA). METHODS: We first examined the methylation status of FAM101A in heart tissue and blood of individual donors using quantitative methylation-sensitive PCR (qMS-PCR). The concentrations and kinetics of cardiac cf-DNA in plasma from five congenital heart disease (CHD) children before and after they underwent cardiac surgery at serial time points were then investigated. RESULTS: We identified demethylated FAM101A specifically present in heart tissue. Importantly, our time course experiments demonstrated that the plasma cardiac cf-DNA level increased quickly during the early post-cardiac surgery phase, peaking at 4-6 h, decreased progressively (24 h) and returned to baseline (72 h). Moreover, cardiac cf-DNA concentrations pre- and post-operation were closely correlated with plasma troponin levels. CONCLUSIONS: We proposed a novel strategy for the correct detection of cardiomyocyte death, based on analysis of plasma cf-DNA carrying the cardiac-specific methylation signature. Our pilot study may lead to new tests for human cardiac pathologies.

A case of abdominal bleeding after mitral valvuloplasty assisted by da Vinci robotic surgery.

A 66-year-old female patient was admitted with abdominal bleeding as an unexpected complication of robotic surgery. Assessments included the patient's medical history, physical examination, laboratory data, and abdominal ultrasound scan results. In our case, laparotomy revealed an injury to the diaphragm and liver of the patient caused by the previous robotic surgery. In conclusion, although abdominal bleeding is a rare condition, it should be taken into consideration as a complication of robotic cardiac surgery.

The Redox Coupling Effect in a Photocatalytic RuII -PdII Cage with TTF Guest as Electron Relay Mediator for Visible-Light Hydrogen-Evolving Promotion.

A nanocage coupling effect from a redox RuII -PdII metal-organic cage (MOC-16) is demonstrated for efficient photochemical H2 production by virtue of redox-guest modulation of the photo-induced electron transfer (PET) process. Through coupling with photoredox cycle of MOC-16, tetrathiafulvalene (TTF) guests act as electron relay mediator to improve the overall electron transfer efficiency in the host-guest system in a long-time scale, leading to significant promotion of visible-light driven H2 evolution. By contrast, the presence of larger TTF-derivatives in bulk solution without host-guest interactions results in interference with PET process of MOC-16, leading to inefficient H2 evolution. Such interaction provides an example to understand the interplay between the redox-active nanocage and guest for optimization of redox events and photocatalytic activities in a confined chemical nanoenvironment.

Cysteine-Aminoethylation-Assisted Chemical Ubiquitination of Recombinant Histones.

Histone ubiquitination affects the structure and function of nucleosomes through tightly regulated dynamic reversible processes. The efficient preparation of ubiquitinated histones and their analogs is important for biochemical and biophysical studies on histone ubiquitination. Here, we report the CAACU (cysteine-aminoethylation assisted chemical ubiquitination) strategy for the efficient synthesis of ubiquitinated histone analogs. The key step in the CAACU strategy is the installation of an N-alkylated 2-bromoethylamine derivative into a recombinant histone through cysteine aminoethylation, followed by native chemical ligation assisted by Seitz's auxiliary to produce mono- and diubiquitin (Ub) and small ubiquitin-like modifier (SUMO) modified histone analogs. This approach enables the rapid production of modified histones from recombinant proteins at about 1.5-6 mg/L expression. The thioether-containing isopeptide bonds in the products are chemically stable and bear only one atomic substitution in the structure, compared to their native counterparts. The ubiquitinated histone analogs prepared by CAACU can be readily reconstituted into nucleosomes and selectively recognized by relevant interacting proteins. The thioether-containing isopeptide bonds can also be recognized and hydrolyzed by deubiquitinases (DUBs). Cryo-electron microscopy (cryo-EM) of the nucleosome containing H2BKC34Ub indicated that the obtained CAACU histones were of good quality for structural studies. Collectively, this work exemplifies the utility of the CAACU strategy for the simple and efficient production of homogeneous ubiquitinated and SUMOylated histones for biochemical and biophysical studies.

Age estimation using pulp/enamel volume ratio of impacted mandibular third molars measured on CBCT images in a northern Chinese population.

The present study aims to evaluate the relation between chronological age and the ratio of pulp volume (PV) to enamel volume (EV) of impacted mandibular third molars (IMTMs) by using cone-beam computed tomography (CBCT) images and an improved 3D image segmentation technique. A sample of CBCT images of IMTM was collected from 414 northern Chinese subjects (214 male and 200 female clinical patients) ranging in age from 20 to 65 years. The GrowCut effect image segmentation (GCEIS) module algorithm was used to calculate the PV and EV from CBCT images. The total sample was divided into a training group and validation group in a ratio of 7 to 3. The PV/EV ratio (PEr) in the training sample was used to develop a mathematical formula for age estimation as follows: age = - 5.817-21.726 × Ln PEr (p < 0.0001) (Ln, natural logarithm). The mean absolute error (MAE) and root mean square error (RMSE) were used to determine the precision and accuracy of the mathematical formula in the validation group and all samples. The MAEs in the male, female, and pooled gender samples were 9.223, 7.722, and 8.41, respectively, and the RMSEs in the male, female, and pooled gender samples were 10.76, 9.58, and 9.986, respectively. The precise and accurate results indicate that the PEr of IMTM in CBCT images is a potential index for dental age estimation and is possible to be used in forensic medicine.

NADPH ameliorates MPTP-induced dopaminergic neurodegeneration through inhibiting p38MAPK activation.

Parkinson's disease (PD) is the second most common neurodegenerative disorder characterized by the selective loss of dopaminergic neurons in substantia nigra pars compacta (SNpc). Although the pathogenic mechanism underlying PD remains largely unknown, decreased nigral glutathione (GSH) in postmortem brains of PD patients supports the presence of oxidative stress in PD. We found that Nicotinamide adenine dinucleotide phosphate (NADPH), which is important for maintaining the level of GSH, protected dopaminergic (DA) neurons from neurotoxicity of MPTP/MPP+. In the present study, NADPH prevented DA neurons from MPTP toxicity with increased GSH and decreased reactive oxygen species (ROS) levels in the ventral midbrain of mice, and improved motor activity. Our present results demonstrated that NADPH inhibited the phosphorylation of p38MAPK, decreased the level of TP53 protein, and inhibited TP53 nuclear translocation in DA neurons of SNpc and in MES23.5 cells. Furthermore, NADPH decreased the protein level of TP53 target gene, Bax, cleavage of PARP, and nuclei condensation. Taken together, NADPH abrogated MPTP-induced p38MAPK phosphorylation, TP53 nuclear translocation, and Bax induction, and finally, MPTP/MPP+-induced apoptosis of DA neurons. This study suggests that NADPH may be a novel therapeutic candidate for PD.