Young osteocyte-derived extracellular vesicles facilitate osteogenesis by transferring tropomyosin-1.

BACKGROUND: Bone marrow mesenchymal stem cells (BMSCs) can undergo inadequate osteogenesis or excessive adipogenesis as they age due to changes in the bone microenvironment, ultimately resulting in decreased bone density and elevated risk of fractures in senile osteoporosis. This study aims to investigate the effects of osteocyte senescence on the bone microenvironment and its influence on BMSCs during aging. RESULTS: Primary osteocytes were isolated from 2-month-old and 16-month-old mice to obtain young osteocyte-derived extracellular vesicles (YO-EVs) and senescent osteocyte-derived EVs (SO-EVs), respectively. YO-EVs were found to significantly increase alkaline phosphatase activity, mineralization deposition, and the expression of osteogenesis-related genes in BMSCs, while SO-EVs promoted BMSC adipogenesis. Neither YO-EVs nor SO-EVs exerted an effect on the osteoclastogenesis of primary macrophages/monocytes. Our constructed transgenic mice, designed to trace osteocyte-derived EV distribution, revealed abundant osteocyte-derived EVs embedded in the bone matrix. Moreover, mature osteoclasts were found to release osteocyte-derived EVs from bone slices, playing a pivotal role in regulating the functions of the surrounding culture medium. Following intravenous injection into young and elderly mouse models, YO-EVs demonstrated a significant enhancement of bone mass and biomechanical strength compared to SO-EVs. Immunostaining of bone sections revealed that YO-EV treatment augmented the number of osteoblasts on the bone surface, while SO-EV treatment promoted adipocyte formation in the bone marrow. Proteomics analysis of YO-EVs and SO-EVs showed that tropomyosin-1 (TPM1) was enriched in YO-EVs, which increased the matrix stiffness of BMSCs, consequently promoting osteogenesis. Specifically, the siRNA-mediated depletion of Tpm1 eliminated pro-osteogenic activity of YO-EVs both in vitro and in vivo. CONCLUSIONS: Our findings suggested that YO-EVs played a crucial role in maintaining the balance between bone resorption and formation, and their pro-osteogenic activity declining with aging. Therefore, YO-EVs and the delivered TPM1 hold potential as therapeutic targets for senile osteoporosis.

A non-linear relationship between blood pressure and mild cognitive impairment in elderly individuals: A cohort study based on the Chinese longitudinal healthy longevity survey (CLHLS).

BACKGROUND: Hypertension is an established risk factor for mild cognitive impairment (MCI) in elderly individuals. Nevertheless, the impact of different levels of blood pressure on the progression of MCI remains uncertain. This study aims to investigate the non-linear relationship between blood pressure and MCI in the elderly and detect the critical blood pressure threshold, thus, improving blood pressure management for individuals at high risk of MCI. METHODS: Data was obtained from the Chinese Longitudinal Healthy Longevity Survey (CLHLS) cohort. We chose normal cognitive elderly individuals who entered the cohort in 2014 for a 5-year follow-up to observe the progression of MCI. Subsequently, we utilized the Cox regression model to identify risk factors for MCI and conducted a Cox-based restricted cubic spline regression (RCS) model to examine the non-linear relationship between systolic blood pressure (SBP) and diastolic blood pressure (DBP) with MCI, determining the critical blood pressure threshold for MCI progression. RESULTS: In the elderly population, female (HR = 1.489, 95% CI: 1.017-2.180), lacking of exercise in the past (HR = 1.714, 95% CI: 1.108-2.653), preferring animal fats (HR = 2.340, 95% CI: 1.348-4.061), increased age (HR = 1.061, 95% CI: 1.038-1.084), increased SBP (HR = 1.036, 95% CI: 1.024-1.048), and increased DBP (HR = 1.056, 95% CI: 1.031-1.081) were associated with MCI progression. After adjusting factors such as gender, exercise, preferred types of fats, and age, both SBP (P non-linear < 0.001) and DBP (P non-linear < 0.001) in elderly individuals exhibited a non-linear association with MCI. The risk of MCI rose when SBP exceeded 135 mmHg and DBP was in the range of 80-88 mmHg. However, when DBP exceeded 88 mmHg, there was a declining trend in MCI progression, although the HR remained above 1. The identified critical blood pressure management threshold for MCI was 135/80 mmHg. CONCLUSION: In this study, we discovered that risk factors affecting the progression of MCI in elderly individuals comprise gender (female), preferring to use animal fat, lack of exercise in the past, increased age, increased SBP, and increased DBP. Additionally, a non-linear relationship between blood pressure levels and MCI progression was confirmed, with the critical blood pressure management threshold for MCI onset falling within the prehypertensive range.

First-round accreditation and pass rates on licensing examination at different medical schools in China: Closing the performance gap.

BACKGROUND: Although the accreditation approach is widely used to ensure the quality of medical education in many countries, there is scant empirical evidence on whether and how it improves actual medical school performance. We focused on conditions in China, which introduced an accreditation system during the 2010s. Specifically, we examined the relationship between first-round accreditation and actual performance based on the results of medical licensing examinations. Referring to organisation theory, we hypothesised that the impacts of accreditation would depend on existing performance gaps. METHOD: In 2022, we analysed panel data from 105 Chinese medical schools during accreditation (2012 to 2021) and pass rates on medical licensing examinations (2011 to 2019), as matched into 834 school-year records in a window of years before and after accreditation. We employed fixed-effects regression models with a comparison group to exclude factors that may have confounded the impacts of accreditation time. We also demonstrated the heterogeneous effects of accreditation by tier and performance gap of medical schools. RESULTS: The conservative estimates showed a substantial cumulative improvement (over 15 percentage points) in pass rates during the years before accreditation, with no clear trend indicating performance drops in the years after accreditation. Lower-tiered medical schools gained greater benefits from accreditation. Medical schools with a larger prior performance gap achieved a greater percentage point increase in pass rates with the passage of time in pre-accreditation years. CONCLUSIONS: This is the first empirical study to investigate whether accreditation has bridged performance gaps among medical schools. The results support the value of accreditation in China, a country that recently established the system, and might work as a substitute for missing information on early accreditation history in countries with long-established accreditation systems. We encourage more studies in countries that have recently introduced accreditation systems.

Enabling Stable and Low-Strain Lithium Plating/Stripping with 2D Layered Transition Metal Carbides by Forming Li-Zipped MXenes and a Li Halide-Rich Solid Electrolyte Interphase.

Two-dimensional (2D) layered materials demonstrate prominent advantage in regulating lithium plating/stripping behavior by confining lithium diffusion/plating within interlayer gaps. However, achieving effective interlayer confined lithium diffusion/plating without compromising the stability of bulk-structural and the solid electrolyte interphase (SEI) remains a considerable challenge. This paper presents an electrochemical scissor and lithium zipper-driven protocol for realizing interlayer confined lithium plating with pretty-low strain and volume change. In this protocol, lithium serves as a "zipper" to reunite the adjacent MXene back to MAX-like phase to markedly enhance the structural stability, and a lithium halide-rich SEI is formed by electrochemically removing the terminals of halogenated MXenes to maintain the stability and rapid lithium ions diffusion of SEI. When the Ti3 C2 I2 serves as the host for lithium plating, the average coulomb efficiency exceeds 97.0 % after 320 lithium plating/stripping cycles in conventional ester electrolyte. Furthermore, a full cell comprising of LiNi0.8 Mn0.1 Co0.1 O2 and Ti3 C2 I2 @Li exhibits a capacity retention rate of 73.4 % after 200 cycles even under high cathode mass-loading (20 mg cm-2 ) and a low negative/positive capacity ratio of 1.4. Our findings advance the understanding of interlayer confined lithium plating in 2D layered materials and provide a new direction in regulating lithium and other metal plating/stripping behaviors.

[Clinical characteristics and prognosis of children with perianal fistulizing Crohn's disease]. / å„¿ç«¥è‚›å‘¨ç˜˜ç®¡åž‹å ‹ç½—æ©ç— çš„ä¸´åºŠç‰¹å¾åŠé¢„åŽ.

OBJECTIVES: To investigate the clinical characteristics, treatment, and prognosis of children with perianal fistulizing Crohn's disease (pfCD). METHODS: A retrospective analysis was conducted on the children, aged 6-17 years, who were diagnosed with Crohn's disease (CD) from April 2015 to April 2023. According to the presence or absence of perianal fistulizing lesions, they were divided into two groups: pfCD (n=60) and non-pfCD (n=82). The two groups were compared in terms of clinical characteristics, treatment, and prognosis. RESULTS: The incidence of pfCD was 42.3% (60/142). The proportion of males in the pfCD group was higher than that in the non-pfCD group. Compared with the non-pfCD group, the pfCD group had a significantly higher proportion of children with involvement of the colon and small intestine or those with upper gastrointestinal lesions (P<0.05). Compared with the non-pfCD group, the pfCD group had a significantly higher rate of use of infliximab during both induction and maintenance treatment (P<0.05). In the pfCD group, the children with complex anal fistula accounted for 62% (37/60), among whom the children receiving non-cutting suspended line drainage accounted for 62% (23/37), which was significantly higher than the proportion among the children with simple anal fistula patients (4%, 1/23) (P<0.05). There were no significant differences between the two groups in mucosal healing rate and clinical remission rate at week 54 of treatment (P>0.05). The pfCD group achieved a fistula healing rate of 57% (34/60) at week 54, and the children with simple anal fistula had a significantly higher rate than those with complex anal fistula (P<0.05). CONCLUSIONS: There is a high incidence rate of pfCD in children with CD, and among the children with pfCD, there is a high proportion of children with the use of biological agents. There is a high proportion of children receiving non-cutting suspended line drainage among the children with complex anal fistula. The occurrence of pfCD should be closely monitored during the follow-up in children with CD.

Human embryonic stem cell-derived organoid retinoblastoma reveals a cancerous origin.

Retinoblastoma (Rb) is the most prevalent intraocular malignancy in children, with a worldwide survival rate <30%. We have developed a cancerous model of Rb in retinal organoids derived from genetically engineered human embryonic stem cells (hESCs) with a biallelic mutagenesis of the RB1 gene. These organoid Rbs exhibit properties highly consistent with Rb tumorigenesis, transcriptome, and genome-wide methylation. Single-cell sequencing analysis suggests that Rb originated from ARR3-positive maturing cone precursors during development, which was further validated by immunostaining. Notably, we found that the PI3K-Akt pathway was aberrantly deregulated and its activator spleen tyrosine kinase (SYK) was significantly up-regulated. In addition, SYK inhibitors led to remarkable cell apoptosis in cancerous organoids. In conclusion, we have established an organoid Rb model derived from genetically engineered hESCs in a dish that has enabled us to trace the cell of origin and to test novel candidate therapeutic agents for human Rb, shedding light on the development and therapeutics of other malignancies.

[Rapid detection technology of chemical component content in Lycii Fructus based on hyperspectral technology].

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Inhibition of TRIM32 by ibr-7 treatment sensitizes pancreatic cancer cells to gemcitabine via mTOR/p70S6K pathway.

Pancreatic cancer is one of the most notorious diseases for being asymptomatic at early stage and high mortality rate thereafter. However, either chemotherapy or targeted therapy has rarely achieved success in recent clinical trials for pancreatic cancer. Novel therapeutic regimens or agents are urgently in need. Ibr-7 is a novel derivative of ibrutinib, displaying superior antitumour activity in pancreatic cancer cells than ibrutinib. In vitro studies showed that ibr-7 greatly inhibited the proliferation of BxPC-3, SW1990, CFPAC-1 and AsPC-1 cells via the induction of mitochondrial-mediated apoptosis and substantial suppression of mTOR/p70S6K pathway. Moreover, ibr-7 was able to sensitize pancreatic cancer cells to gemcitabine through the efficient repression of TRIM32, which was positively correlated with the proliferation and invasiveness of pancreatic cancer cells. Additionally, knockdown of TRIM32 diminished mTOR/p70S6K activity in pancreatic cancer cells, indicating a positive feedback loop between TRIM32 and mTOR/p70S6K pathway. To conclude, this work preliminarily explored the role of TRIM32 in the malignant properties of pancreatic cancer cells and evaluated the possibility of targeting TRIM32 to enhance effectiveness of gemcitabine, thereby providing a novel therapeutic target for pancreatic cancer.

Metformin Relieves Bortezomib-Induced Neuropathic Pain by Regulating AMPKa2-Mediated Autophagy in the Spinal Dorsal Horn.

Chemotherapy-induced neuropathic pain is a major clinical problem with limited treatment options. Here, we show that metformin relieves bortezomib (BTZ)-evoked induction and maintenance of neuropathic pain by preventing the reduction in the expression of Beclin-1, an autophagy marker, in the spinal dorsal horn. Application of rapamycin or 3-methyladenine, autophagy inducer and inhibitor, respectively, affected the mechanical allodynia differently. Co-application of 3-methyladenine and metformin partially inhibited the effect of metformin in recovering Beclin-1 expression and in reducing the pain behavior in rats subjected to BTZ treatment. BTZ treatment also reduced the expression of AMPKa2 in the dorsal horn, which was recovered by metformin treatment. Overexpression of AMPKa2 attenuated the BTZ-evoked reduction in Beclin-1 expression and mechanical allodynia, whereas intrathecal injection of AMPKa2 siRNA decreased the Beclin-1 expression and induced mechanical allodynia in naive rats. Moreover, BTZ treatment increased the GATA3 expression in the dorsal horn, and GATA3 siRNA attenuated the AMPKa2 downregulation and mechanical allodynia induced by BTZ. Chromatin immunoprecipitation further showed that BTZ induced an increased recruitment of GATA3 to multiple sites in the AMPKa2 promoter region. Furthermore, decreased acetylation and increased methylation of histone H3 in the AMPKa2 promoter in the spinal dorsal horn was detected after BTZ treatment. Our findings suggest that metformin may regulate AMPKa2-mediated autophagy in the dorsal horn and alleviate the behavioral hypersensitivity induced by BTZ.

Medical students' rural practice intention: Academic performance matters.

INTRODUCTION: Many countries are driving forward policies and practices to train medical students for later rural practice. Previous research has investigated individual (e.g., rural upbringing) and structural factors (e.g., curricular exposure) associated with rural practice intention. However, the relationship between academic performance in medical school and rural practice intention has been neglected, although optimisation theory suggests there may be a relationship. To address this gap, our aim was to identify the relationship between academic performance and rural practice intention. METHODS: Data were collected via a cross-sectional (self-report) survey in 2021. Participants were students from 60 of the 96 rural order directed (RODs) medical programmes across China. We asked students their rural practice intention. We conducted univariate analyses to test for associations between rural practice intention and independent variables, including socio-demographics, ROD location, grade year and academic performance measures. We used multilevel logistic regression models to test whether students' academic performance in medical school could be used to predict rural practice intention, holding the other factors constant. RESULTS: There were 13 123 respondents, representing roughly 77.6% of the student population from the 60 schools. There was a statistically significant relationship between student (self)-reported academic performance in medical school and rural practice intention. Higher performers had a lower likelihood (ORs: 0.65-0.78) of rural practice intention. This held across all performance measures (GPA rank, academic awards and student leadership) and for the sub-group with rural upbringing (ORs: 0.68-0.78). DISCUSSION: This is the first study to identify a relationship between medical school performance and rural practice intention. The findings suggest that students maximise their utility when choosing career options, with higher performers having lower rural practice intention. These data provide insight into the complexity of medical career decision making and can be used by medical school and workforce planners to inform rural training, recruitment and retention strategies.

[Effectiveness of induction therapy with exclusive enteral nutrition in pediatric Crohn's disease]. / å ¨è‚ å† è¥å »å¯¹å„¿ç«¥å ‹ç½—æ©ç— è¯±å¯¼ç¼“è§£ç–—æ•ˆç ”ç©¶.

OBJECTIVES: To evaluate the effectiveness of induction therapy with exclusive enteral nutrition (EEN) in pediatric Crohn's disease (CD). METHODS: A retrospective analysis was performed on the medical data of 62 children with CD who received EEN in Children's Hospital, Zhejiang University School of Medicine, from March 2013 to August 2021. The medical data included general information and height, weight, Pediatric Crohn's Disease Activity Index (PCDAI), Crohn's Disease Endoscopic Index of Severity, C-reactive protein, erythrocyte sedimentation rate, and serum albumin level before treatment and after 8 weeks of treatment. The changes in the above indicators were compared before and after treatment. RESULTS: Among the 62 children with CD, there were 39 boys (63%) and 23 girls (37%), with a mean age of (11.9±3.0) years at diagnosis. Among the 55 children who completed EEN treatment for at least 8 weeks, 48 (87%) achieved clinical remission at week 8. PCDAI at week 8 was significantly lower than that before treatment (P<0.001). Except for 17 children with involvement of the small intestine alone and 3 children with involvement of the colon who did not receive colonoscopy reexamination, the remaining 35 children with involvement of the colon received colonoscopy reexamination after the 8-week EEN treatment. Of the 35 children, 29 (83%) achieved mucosal healing. As for the 48 children who achieved clinical remission at week 8, there were significant improvements in height-for-age Z-score and body mass index-for-age Z-score at week 8 (P<0.01). As for the 7 children who did not achieve clinical remission at week 8, there were no significant changes in height-for-age Z-score and body mass index-for-age Z-score at week 8 (P>0.05). CONCLUSIONS: The 8-week EEN treatment has a good effect on clinical remission and mucosal healing in children with CD. For the children with CD achieving clinical remission, EEN can improve their height and body mass index.

Harmine targets inhibitor of DNA binding-2 and activator protein-1 to promote preosteoclast PDGF-BB production.

Osteoporosis is one of the most common metabolic bone diseases affecting millions of people. We previously found that harmine prevents bone loss in ovariectomized mice via increasing preosteoclast platelet-derived growth factor-BB (PDGF-BB) production and type H vessel formation. However, the molecular mechanisms by which harmine promotes preosteoclast PDGF-BB generation are still unclear. In this study, we revealed that inhibitor of DNA binding-2 (Id2) and activator protein-1 (AP-1) were important factors implicated in harmine-enhanced preosteoclast PDGF-BB production. Exposure of RANKL-induced Primary bone marrow macrophages (BMMs), isolated from tibiae and femora of mice, to harmine increased the protein levels of Id2 and AP-1. Knockdown of Id2 by Id2-siRNA reduced the number of preosteoclasts as well as secretion of PDGF-BB in RANKL-stimulated BMMs administrated with harmine. Inhibition of c-Fos or c-Jun (components of AP-1) both reversed the stimulatory effect of harmine on preosteoclast PDGF-BB production. Dual-luciferase reporter assay analyses determined that PDGF-BB was the direct target of AP-1 which was up-regulated by harmine treatment. In conclusion, our data demonstrated a novel mechanism involving in the production of PDGF-BB increased by harmine, which may provide potential therapeutic targets for bone loss diseases.

LncRNA CHRF promotes TGF-ß1 induced EMT in alveolar epithelial cells by inhibiting miR-146a up-regulating L1CAM expression.

PURPOSE: Idiopathic pulmonary fibrosis (IPF) is a type of progressive lung fibrosis disease. The survival time of diagnosed IPF patients is often only 2 years. Currently much evidence showed that the epithelial-mesenchymal transition (EMT) process is the main cause of the occurrence and development of IPF. LncRNA cardiac hypertrophy related factor (CHRF) was reported to be related with IPF development. Here we explored the functions and regulatory mechanisms of CHRF on EMT in IPF. MATERIALS AND METHODS: A549 cells were treated with transforming growth factor-ß1 (TGF-ß1) for 48 h to construct IPF cell model. CHRF and miR-146a expression were quantified using qPCR. The expression of L1 cell adhesion molecule (L1CAM) and EMT related indicators (E-cadherin, Vimentin, Slug and N-cadherin) were detected by qPCR and western blot. Dual luciferase reporter experiment was conducted to prove the molecular interaction of miR-146a and L1CAM, as well as CHRF and miR-146a. RESULTS: CHRF and L1CAM expression were significantly upregulated and promoted the EMT process in A549 after treatment of TGF-ß1. MiR-146a was obviously down-regulated, and knockdown of CHRF inhibited the EMT process by up-regulating miR-146a, in A549 after treatment of TGF-ß1. Meanwhile, overexpression of miR-146a inhibited EMT process via targeting L1CAM. In addition, L1CAM overexpression eliminated the inhibitory effect of sh-CHRF on the EMT process. CONCLUSIONS: These results provided evidence that CHRF promoted EMT process in A549 after treatment of TGF-ß1, which proposed a new insight for depth understanding the pathological mechanisms of IPF.

Deletion of TLR4 attenuates lipopolysaccharide-induced acute liver injury by inhibiting inflammation and apoptosis.

Septic acute liver injury is one of the leading causes of fatalities in patients with sepsis. Toll-like receptor 4 (TLR4) plays a vital role in response to lipopolysaccharide (LPS) challenge, but the mechanisms underlying TLR4 function in septic injury remains unclear. In this study, we investigated the role of TLR4 in LPS-induced acute liver injury (ALI) in mice with a focus on inflammation and apoptosis. Wild-type (WT) and TLR4-knockout (TLR4-/-) mice were challenged with LPS (4 mg/kg) for 6 h. TLR4 signaling cascade markers (TLR4, MyD88, and NF-κB), inflammatory markers (TNFα, IL-1ß, and IL-6), and apoptotic markers (Bax, Bcl-2, and caspase 3) were evaluated. We showed that LPS challenge markedly increased the levels of serum alanine aminotransferase (ALT)/aspartate aminotransferase (AST) and other liver pathological changes in WT mice. In addition, LPS challenge elevated the levels of liver carbonyl proteins and serum inflammatory cytokines, upregulated the expression of TLR4, MyD88, and phosphorylated NF-κB in liver tissues. Moreover, LPS challenge significantly increased hepatocyte apoptosis, caspase 3 activity, and Bax level while suppressing Bcl-2 expression in liver tissues. These pathological changes were greatly attenuated in TLR4-/- mice. Similar pathological responses were provoked in primary hepatic Kupffer cells isolated from WT and TLR4-/- mice following LPS (1 µg/mL, 6 h) challenge. In summary, these results demonstrate that silencing of TLR4 attenuates LPS-induced liver injury through inhibition of inflammation and apoptosis via TLR4/MyD88/NF-κB signaling pathway. TLR4 deletion confers hepatoprotection against ALI induced by LPS, possibly by repressing macrophage inflammation and apoptosis.

How to conduct cost and value analyses in health professions education: AMEE Guide No. 139.

Growing demand for accountability, transparency, and efficiency in health professions education is expected to drive increased demand for, and use of, cost and value analyses. In this AMEE Guide, we introduce key concepts, methods, and literature that will enable novices in economics to conduct simple cost and value analyses, hold informed discussions with economic specialists, and undertake further learning on more advanced economic topics. The practical structure for conducting analyses provided in this guide will enable researchers to produce robust results that are meaningful and useful for improving educational practice. Key steps include defining the economic research question, identifying an appropriate economic study design, carefully identifying cost ingredients, quantifying, and pricing the ingredients consumed, and conducting sensitivity analyses to explore uncertainties in the results.

A novel derivative of valepotriate inhibits the PI3K/AKT pathway and causes Noxa-dependent apoptosis in human pancreatic cancer cells.

Natural compound valepotriate exhibits inhibitory activity against a number of cancers, but the effect of valepotriate against pancreatic cancer is unclear, and the structure-activity relationship of valepotriate has not been characterized. In this study, we performed a structure-based similarity search and found 16 hit compounds. Among the 16 hits, (1S,6S,7R)-6-(acetyloxy)-1-[(3-methylbutanoyl)oxy]-4a,5,6,7a-tetrahydro-1H-spiro[cyclopenta[c]pyran-7,2'-oxiran]-4-ylmethyl 3-methylbutanoate (denoted as Amcp) exhibited superior anticancer activity against human pancreatic cancer BxPC-3 and SW1990 cells. The anti-proliferation activity of Amcp was validated in human pancreatic cancer BxPC-3 and SW1990 cells in vitro. Amcp more effectively induced apoptosis in BxPC-3 and SW1990 cells than gemcitabine. At a concentration of 15 µM, Amcp significantly suppressed the PI3K/AKT pathway and disrupted the mitochondrial membrane equilibrium through modulation of Noxa and Mcl-1 balance in both cell lines. Meanwhile, knockdown of Noxa substantially attenuated Amcp-induced reduction of cell viability and anti-apoptotic protein Mcl-1 level in BxPC-3 cells. In addition, Amcp showed synergistic anticancer effects when combined with gemcitabine in BxPC-3 cells. To conclude, this work not only suggests that Amcp possesses a dual-inhibitory activity towards PI3K/AKT pathway and Mcl-1, but also enlightens further development of bioactive valepotriate derivatives.

TNF-α/STAT3 pathway epigenetically upregulates Nav1.6 expression in DRG and contributes to neuropathic pain induced by L5-VRT.

BACKGROUND: Studies showed that upregulation of Nav1.6 increased the neuronal excitability and participated in neuropathic pain in the dorsal root ganglion (DRG). However, the molecular mechanisms underlying Nav1.6 upregulation were not reported yet. METHODS: The paw withdrawal threshold was measured in the rodents following lumbar 5 ventral root transection (L5-VRT). Then qPCR, western blotting, immunoprecipitation, immunohistochemistry, and chromatin immunoprecipitation assays were performed to explore the molecular mechanisms in vivo and in vitro. RESULTS: We found that the levels of Nav1.6 and phosphorylated STAT3 were significantly increased in DRG neurons following L5-VRT, and TNF-α incubation also upregulated the Nav1.6 expression in cultured DRG neurons. Furthermore, immunoprecipitation and chromatin immunoprecipitation assays demonstrated that L5-VRT increased the binding of STAT3 to the Scn8a (encoding Nav1.6) promoter and the interaction between STAT3 and p300, which contributed to the enhanced transcription of Scn8a by increasing histone H4 acetylation in Scn8a promoter in DRG. Importantly, intraperitoneal injection of the TNF-α inhibitor thalidomide reduced the phosphorylation of STAT3 and decreased the recruitment of STAT3 and histone H4 hyperacetylation in the Scn8a promoter, thus subsequently attenuating Nav1.6 upregulation in DRG neurons and mechanical allodynia induced by L5-VRT. CONCLUSION: These results suggested a new mechanism for Nav1.6 upregulation involving TNF-α/STAT3 pathway activation and subsequent STAT3-mediated histone H4 hyperacetylation in the Scn8a promoter region in DRG, which contributed to L5-VRT-induced neuropathic pain.

Identification of new NIK inhibitors by discriminatory analysis-based molecular docking and biological evaluation.

NF-κB inducing kinase (NIK) is a key regulator in the noncanonical nuclear factor κB cells (NF-κB) signaling pathway. Dysregulation of NIK is often related with autoimmune disorders and malignancies. However, the number of reported NIK inhibitors is scarce. Discriminatory analysis-based molecular docking was used to examine the accuracy of the binding conformation and to estimate the binding affinity, leading to the identification of several new NIK inhibitors with moderate IC50 (ranging from 48.9 to 103.4 µM). Among them, compound 5, the most potent one (IC50 48.9 ± 6.9 µM), also showed moderate antiproliferation activity against cancer SW1990 cells, with an IC50 value of 20.1 ± 6.0 µM. Further dynamic simulations were performed to provide more in-depth details on the binding conformation of compound 5 and the NIK protein, providing some structural clues for further optimization of compound 5 as a novel NIK inhibitor.

[Inflammatory bowel disease with growth hormone deficiency in adolescents: an analysis of 4 cases and literature review].

Inflammatory bowel disease (IBD) is a chronic recurrent non-specific inflammatory disease in the intestinal tract. About 10%-56% of children with Crohn's disease and about 10% of children with ulcerative colitis have growth retardation. This study reports four adolescents with IBD and growth hormone deficiency who were diagnosed with Crohn's disease. There were three boys and one girl, with an age of 11.0-13.9 years and a disease duration of 11-85 months at diagnosis. The four patients had the involvement of the small intestine only, the colon only, both the small intestine and the upper gastrointestinal tract, and both the small intestine and the colon respectively. The pediatric Crohn's disease activity index ranged from 27.5 to 45 points. All four patients had a height-for-age Z-score (HAZ) of <-2, and the growth hormone provocative test suggested growth hormone deficiency. Of all four patients, two received recombinant human growth hormone combined with infliximab, one received infliximab only, and one received recombinant human growth hormone combined with mercaptopurine. All four patients had an improvement in HAZ after treatment.

Members of the GH3 Family of Proteins Conjugate 2,4-D and Dicamba with Aspartate and Glutamate.

Auxin homeostasis is a highly regulated process that must be maintained to allow auxin to exert critical growth and developmental controls. Auxin conjugase and hydrolase family proteins play important roles in auxin homeostasis through means of storage, activation, inactivation, response inhibition and degradation of auxins in plants. We systematically evaluated 60 GRETCHEN HAGEN3 (GH3) proteins from diverse plant species for amino acid conjugation activity with the known substrates jasmonic acid (JA), IAA and 4-hydroxybenzoate (4-HBA). While our results largely confirm that Group II conjugases prefer IAA, we observed no clear substrate preference among Group III proteins, and only three of 11 Group I proteins showed the expected preference for JA, indicating that sequence similarity does not always predict substrate specificity. Such a sequence-substrate relationship held true when sequence similarity at the acyl acid-binding site was used for grouping. Several GH3 proteins could catalyze formation of the potentially degradation-destined aspartate (Asp) and glutamate (Glu) conjugates of IAA and the synthetic auxins 2,4-D and dicamba. We found that 2,4-D-Asp/Glu conjugates, but not dicamba and IAA conjugates, were hydrolyzed in Arabidopsis and soybean by AtILL5- and AtIAR3-like amidohydrolases, releasing free 2,4-D in plant cells when conjugates were exogenously applied to seedlings. Dicamba-Asp or dicamba-Glu conjugates were not hydrolyzed in vivo in infiltrated plants nor in vitro with recombinant amidohydrolases. These findings could open the door for exploration of a dicamba herbicide tolerance strategy through conjugation.