Decoupling the dynamic mechanism revealed by FGFR2 mutation-induced population shift.

The fibroblast growth factor receptor 2 (FGFR2) is a key component in cellular signaling networks, and its dysfunctional activation has been implicated in various diseases including cancer and developmental disorders. Mutations at the activation loop (A-loop) have been suggested to trigger an increased basal kinase activity. However, the molecular mechanism underlying this highly dynamic process has not been fully understood due to the limitation of static structural information. Here, we conducted multiple, large-scale Gaussian accelerated molecular dynamics simulations of five (K659E, K659N, K659M, K659Q, and K659T) FGFR2 mutants at the A-loop, and comprehensively analyzed the dynamic molecular basis of FGFR2 activation. The results quantified the population shift of each system, revealing that all mutants had a higher proportion of active-like states. Using Markov state models, we extracted the representative structure of different conformational states and identified key residues related to the increased kinase activity. Furthermore, community network analysis showed enhanced information connections in the mutants, highlighting the long-range allosteric communication between the A-loop and the hinge region. Our findings may provide insights into the dynamic mechanism for FGFR2 dysfunctional activation and allosteric drug discovery.Communicated by Ramaswamy H. Sarma.

Astrocytic connexin 43 deletion ameliorates SNI-induced neuropathic pain by reducing microglia activation.

Neuropathic pain (NP) is a chronic disease caused by damage to the peripheral or central nervous system. Connexin 43 (Cx43), the primary connexin expressed by astrocytes, has been reported to be significantly increased in NP. However, the roles and mechanisms of Cx43 in the development and maintenance of NP remain largely unknown, while microglia activation has been commonly regarded as a key factor of NP. In the present study, we found that Cx43 deletion significantly ameliorated spared nerve injury (SNI)-induced NP and suppressed SNI induced c-Fos expression in the spinal cord. Notably, Cx43 deletion led to much less SNI-induced microglia activation in the spinal cord. These results suggest that astrocyte Cx43 may play a significant role in regulating microglial activation and NP.

Chinese patent medicines combined with hormone replacement therapy for premature ovarian failure: A Bayesian network meta-analysis.

Objective: The objective of this study was to compare the efficacy differences between Chinese patent medicines combined with hormone replacement therapy (HRT) in the treatment of premature ovarian failure (POF) by the Bayesian network meta-analysis (NMA) method. Methods: Randomized controlled trials (RCTs) reporting Chinese patent medicine combined with HRT for POF included Medline (via PubMed), Embase, Cochrane Library, China National Knowledge Infrastructure Database (CNKI), Wanfang Database (Wanfang), VIP Database (VIP), and China Biology Medicine Database (CBM) from the inception of the databases to July 2022. Two researchers independently screened the articles, extracted data, and evaluated the quality. The literature that met the inclusion criteria was screened out, the quality and risk of bias of the included studies were assessed according to the Cochrane 5.1 manual and RevMan 5.4, and NMA was performed using Stata 15.0 and R software. Results: Sixty-four RCTs involving 5,675 individuals containing 12 oral Chinese patent medicines combined with HRT were enrolled into the current NMA. The results showed that when compared with patients using only HRT, the total clinical response rate is greater in patients using HRT combined with one of these 12 oral Chinese patent medicines. Among them, Zuogui pills + HRT [odds ratio (OR) = 3.92; 95% credible interval (CrI) = 0.86, 23.84; SUCRA = 73.76%] is most likely to be the best intervention, and the suboptimal intervention is Guishen pills + HRT (OR = 3.22, 95% CrI = 1.16, 9.44, SUCRA = 70.60%). Conclusion: Chinese patent medicines combined with HRT were more effective than HRT alone in the treatment of POF. Zuogui pills are good at decreasing follicle-stimulating hormone (FSH) and luteinizing hormone (LH) and more effective in the improvement of total clinical response rate; Xuefu Zhuyu capsule is also good at decreasing FSH. Ziheche capsule is an expert in improving estradiol level; Kuntai capsule shows the lowest incidence of adverse reactions. However, the quality of the literature included in this study is relatively low, so it may affect the results of the study. Therefore, higher quality and multi-center trial would be necessary for supporting these results. Systematic review registration: [www.crd.york.ac.uk/prospero], identifier [CRD42022350587].

Conformational Selection Mechanism Provides Structural Insights into the Optimization of APC-Asef Inhibitors.

Metastasis is the major cause of death in colorectal cancer and it has been proven that inhibiting an interaction between adenomatous polyposis coli (APC) and Rho guanine nucleotide exchange factor 4 (Asef) efficaciously restrain metastasis. However, current inhibitors cannot achieve a satisfying effect in vivo and need to be optimized. In the present study, we applied molecular dynamics (MD) simulations and extensive analyses to apo and holo APC systems in order to reveal the inhibitor mechanism in detail and provide insights into optimization. MD simulations suggested that apo APC takes on a broad array of conformations and inhibitors stabilize conformation selectively. Representative structures in trajectories show specific APC-ligand interactions, explaining the different binding process. The stability and dynamic properties of systems elucidate the inherent factors of the conformation selection mechanism. Binding free energy analysis quantitatively confirms key interface residues and guide optimization. This study elucidates the conformation selection mechanism in APC-Asef inhibition and provides insights into peptide-based drug design.

Tojapride Reverses Esophageal Epithelial Inflammatory Responses on Reflux Esophagitis Model Rats.

OBJECTIVE: To investigate the mechanism of Tojapride, a Chinese herbal formula extract, on strengthening the barrier function of esophageal epithelium in rats with reflux esophagitis (RE). METHODS: Ten out of 85 SD rats were randomly selected as the sham group (n10), and 75 rats were developed a reflux esophagitis model (RE) by the esophageal and duodenal side-to-side anastomosis. Fifty successful modeling rats were divided into different medicated groups through a random number table including the model, low-, medium-, and high-dose of Tojapride as well as omeprazole groups (n10). Three doses of Tojapride [5.73, 11.46, 22.92 g/(kg•d)] and omeprazole [4.17 mg/(kg•d)] were administrated intragastrically twice daily for 3 weeks. And the rats in the sham and model groups were administered 10 mL/kg distilled water. Gastric fluid was collected and the supernatant was kept to measure for volume, pH value and acidity. Esophageal tissues were isolated to monitor the morphological changes through hematoxylin-eosin (HE) staining, and esophageal epithelial ultrastructure was observed by transmission electron microscopy. The expressions of nuclear factor kappa-light-chain-enhancer of activated B cells p65 (NF-KBp65), κB kinase beta (IKKß), occludin, and zonula occludens-1 (ZO-1) in the esophageal tissues were measured by immunohistochemistry and Western blot, respectively. RESULTS: The gastric pH value in the model group was significantly lower than the sham group (P<0.05). Compared with the model group, gastric pH value in the omeprazole and medium-dose of Tojapride groups were significantly higher (P<0.05). A large area of ulceration was found on the esophageal mucosa from the model rats, while varying degrees of congestion and partially visible erosion was observed in the remaining groups. Remarkable increase in cell gap width and decrease in desmosome count was seen in RE rats and the effect was reversed by Tojapride treatment. Compared with the sham group, the IKKß levels were significantly higher in the model group (P<0.05). However, the IKKß levels were down-regulated after treatment by all doses of Tojapride (P<0.01 or P<0.05). The occluding and ZO-1 levels decreased in the model group compared with the sham group (Ps0.01 or Ps0.05), while both indices were significantly up-regulated in the Tojapride-treated groups (P<0.01 or P<0.05). CONCLUSIONS: Tojapride could improve the pathological conditions of esophageal epithelium in RE rats. The underlying mechanisms may involve in down-regulating the IKKß expression and elevating ZO-1 and occludin expression, thereby alleviating the inflammation of the esophagus and strengthening the barrier function of the esophageal epithelium.

Possible mechanisms of lycopene amelioration of learning and memory impairment in rats with vascular dementia.

Oxidative stress is involved in the pathogenesis of vascular dementia. Studies have shown that lycopene can significantly inhibit oxidative stress; therefore, we hypothesized that lycopene can reduce the level of oxidative stress in vascular dementia. A vascular dementia model was established by permanent bilateral ligation of common carotid arteries. The dosage groups were treated with lycopene (50, 100 and 200 mg/kg) every other day for 2 months. Rats without bilateral carotid artery ligation were prepared as a sham group. To test the ability of learning and memory, the Morris water maze was used to detect the average escape latency and the change of search strategy. Hematoxylin-eosin staining was used to observe changes of hippocampal neurons. The levels of oxidative stress factors, superoxide dismutase and malondialdehyde, were measured in the hippocampus by biochemical detection. The levels of reactive oxygen species in the hippocampus were observed by dihydroethidium staining. The distribution and expression of oxidative stress related protein, neuron-restrictive silencer factor, in hippocampal neurons were detected by immunofluorescence histochemistry and western blot assays. After 2 months of drug administration, (1) in the model group, the average escape latency was longer than that of the sham group, and the proportion of straight and tend tactics was lower than that of the sham group, and the hippocampal neurons were irregularly arranged and the cytoplasm was hyperchromatic. (2) The levels of reactive oxygen species and malondialdehyde in the hippocampus of the model group rats were increased, and the activity of superoxide dismutase was decreased. (3) Lycopene (50, 100 and 200 mg/kg) intervention improved the above changes, and the lycopene 100 mg/kg group showed the most significant improvement effect. (4) Neuron-restrictive silencer factor expression in the hippocampus was lower in the sham group and the lycopene 100 mg/kg group than in the model group. (5) The above data indicate that lycopene 100 mg/kg could protect against the learning-memory ability impairment of vascular dementia rats. The protective mechanism was achieved by inhibiting oxidative stress in the hippocampus. The experiment was approved by the Animal Ethics Committee of Fujian Medical University, China (approval No. 2014-025) in June 2014.

Tojapride prevents CaSR-mediated NLRP3 inflammasome activation in oesophageal epithelium irritated by acidic bile salts.

Impairment of the oesophageal epithelium in patients with reflux oesophagitis (RE) is a cytokine-mediated injury rather than a chemical burn. The present study was conducted to explore CaSR/NLRP3 inflammasome pathway activation and cytokines IL-1ß and IL-18 release in oesophageal epithelia injured by refluxates and the effects of Tojapride on that signal regulation. Using a modified RE rat model with Tojapride administration and Tojapride-pretreated SV40-immortalized human oesophageal epithelial cells (HET-1A) exposed to acidic bile salts pretreated with Tojapride, we evaluated the therapeutic effects of Tojapride on oesophageal epithelial barrier function, the expression of CaSR/NLRP3 inflammasome pathway-related proteins and the release of downstream cytokines in response to acidic bile salt irritation. In vivo, Tojapride treatment ameliorated the general condition and pathological lesions of the oesophageal epithelium in modified RE rats. In addition, Tojapride effectively blocked the CaSR-mediated NLRP3 inflammasome activation in modified RE rats. In vitro, Tojapride treatment can reverse the harmful effect of acidic bile salts, which reduced transepithelial electrical resistance (TEER), up-regulated the CaSR-mediated NLRP3 inflammasome pathway and increased caspase-1 activity, LDH release and cytokines secretion. Taken together, these data show that Tojapride can prevent CaSR-mediated NLRP3 inflammasome activation and alleviate oesophageal epithelial injury induced by acidic bile salt exposure.

Chang'an II Decoction ( II )-Containing Serum Ameliorates Tumor Necrosis Factor-α-Induced Intestinal Epithelial Barrier Dysfunction via MLCK-MLC Signaling Pathway in Rats.

OBJECTIVE: To investigate the effect of Chang'an II Decoction ( II ))-containing serum on intestinal epithelial barrier dysfunction in rats. METHODS: Tumor necrosis factor (TNF)-α-induced injury of Caco-2 monolayers were established as an inflammatory model of human intestinal epithelium. Caco-2 monolayers were treated with blank serum and Chang'an II Decoction-containing serum that obtained from the rats which were treated with distilled water and Chang'an II Decoction intragastrically at doses of 0.49, 0.98, 1.96 g/(kg·d) for 1 week, respectively. After preparation of containing serum, cells were divided into the normal group, the model group, the Chang'an II-H, M, and L groups (treated with 30 ng/mL TNF-α and medium plus 10% high, middle-, and low-doses Chang'an II serum, respectively). Epithelial barrier function was assessed by transepithelial electrical resistance (TER) and permeability of fluorescein isothiocyanate (FITC)-labeled dextran. Transmission electron microscopy was used to observe the ultrastructure of tight junctions (TJs). Immunofluorescence of zonula occludens-1 (ZO-1), claudin-1 and nuclear transcription factor-kappa p65 (NF-κ Bp65) were measured to determine the protein distribution. The mRNA expression of myosin light chain kinase (MLCK) was measured by real-time polymerase chain reaction. The expression levels of MLCK, myosin light chain (MLC) and p-MLC were determined by Western blot. RESULTS: Chang'an II Decoction-containing serum significantly attenuated the TER and paracellular permeability induced by TNF-α. It alleviated TNF-α-induced morphological alterations in TJ proteins. The increases in MLCK mRNA and MLCK, MLC and p-MLC protein expressions induced by TNF-α were significantly inhibited in the Chang'an II-H group. Additionally, Chang'an II Decoction significantly attenuated translocation of NF-κ Bp65 into the nucleus. CONCLUSION: High-dose Chang'an II-containing serum attenuates TNF-α-induced intestinal barrier dysfunction. The underlying mechanism may be involved in inhibiting the MLCK-MLC phosphorylation signaling pathway mediated by NF-κ Bp65.

Berberine hydrochloride counteracts enhanced IL-8 expression induced by SN 38 in AGS cells.

IL-8 over-expression could enhance cancer metastasis. In present study, berberine hydrochloride (BER) triggered proliferative inhibition and G2/M arrest in AGS cells, down-regulated protein expression of cyclin B1, Bcl-2, up-regulated expression of p21, p53 and cleaved caspase 3, but showed no effect on protein expression of CHOP, Bip, and caspase 4. BER could down-regulate the enhanced IL-8 expression through down-regulating ERK1/2 and p38 MAPK over-activation induced by SN 38. The increased IL-8 mediated adhesive ability of AGS cells to HUVECs induced by SN 38, could be reduced by BER. Thus, BER could reduce the side-effect of SN 38 in clinic.

Efficacy and safety of Xiangsha Liujunzi granules for functional dyspepsia: A multi-center randomized double-blind placebo-controlled clinical study.

AIM: To assess the efficacy and safety of a Chinese herbal medicine (CHM), Xiangsha Liujunzi granules, in the treatment of patients with functional dyspepsia (FD). METHODS: We performed a randomized, double-blind, placebo-controlled trial with patients from three centers. Two hundred and sixteen subjects diagnosed with FD according to ROME III criteria and confirmed by upper gastrointestinal endoscopy and spleen-deficiency and Qi-stagnation syndrome were selected to receive Xiangsha Liujunzi granules or placebo for 4 wk in a 2:1 ratio by blocked randomization. The subjects also received follow-up after the 4-wk intervention. Herbal or placebo granules were dissolved in 300 mL of water. Participants in both groups were administered 130 mL (45 °C) three times a day. Participants were evaluated prior to and following 4 wk of the intervention in terms of changes in the postprandial discomfort severity scale (PDSS) score, clinical global impression (CGI) scale score, hospital anxiety and depression scale (HADS) score, traditional Chinese medicine symptoms score (SS), scores of various domains of the 36-item short form health survey (SF-36), gastric emptying (GE) and any observed adverse effects. RESULTS: Compared with the placebo group, patients in the CHM group showed significant improvements in the scores of PDSS, HADS, SS, SF-36 and CGI scale (P < 0.05 or P < 0.01). They also showed the amelioration in the GE rates of the proximal stomach and distal stomach (P < 0.05 or P < 0.01). CONCLUSION: Xiangsha Liujunzi granules offered significant symptomatic improvement in patients with FD.

[Advances in polymer-drug conjugated micelles in the delivery of anticancer drugs].

Polymer-drug conjugated micelles have many advantages as delivery vehicles of anticancer drugs. They can increase the solubility of hydrophobic drugs, extend the circulation time in vivo, improve the stability of anticancer drugs, reduce systemic toxicity and enhance the therapeutic effect of anticancer drugs, etc. moreover, a variety of polymers containing functional groups can also be used to prepare multi-functional polymer-drug conjugated micelles. In this article,polymer-drug conjugated micelles are reviewed and various multi-functional modification of polymer-drug conjugated micelles are introduced, and the recent progress of polymer-drug conjugated micelles in the delivery of anticancer drugs is summarized.