ObjectiveThis study employs a special conformational engineering (CE) technology to construct an α-chymotrypsin-like active center, which includes a catalytic triad, an oxyanion hole, and a substrate-binding site, on silver nanoparticles (AgNPs), thereby creating an AgNP-based artificial hydrolase with high catalytic activity. This study provides a new approach for the design of highly efficient artificial enzymes and enzyme-mimicking. MethodsAgNPs were chosen as the scaffold to build the an α-chymotrypsin-like active center. A special CE procedure enables the designed peptide, Triad5, to adopt an α‑helical conformation on AgNPs, with the key catalytic residues located on one side of the α-helix forming a catalytic active center with a catalytic triad, an oxyanion hole, and a substrate-binding site. The CE procedure consists of three steps, including conformation induction via trifluoroethanol (TFE), conformation stabilization on AgNPs via Ag-S bonds, and TFE removal via lyophilization. Circular dichroism (CD) spectra were used to confirm the formation and stabilization of the α-helix conformation. Mutations of the key residues combined with stopped-flow kinetic experiments were used to demonstrate the indispensability of each key residue and the synergistic effects among the catalytic triad, the oxyanion hole, and the substrate-binding site. ResultsCD spectra show that the designed Triad5 alone is in random coil conformation; when conjugated on AgNPs, Triad5 still remains largely unstructured; but after the CE treatment, Triad5 adopts a typical α-helical conformation on AgNPs as designed, thus produces an AgNP-based artificial hydrolase, Silverzyme. Silverzyme exhibits extremely high hydrolytic activity towards p-nitrophenyl acetate (p-NPA), with an extremely high catalytic turnover number per active site of 3.5 s^-1, which is even higher than that of α-chymotrypsin. As a comparison, the AgNP-Triad5 conjugate without CE treatment shows much lower catalytic activity than Silverzyme, highlighting the important role of the right conformation of the active center for the catalytic activity and the power of the CE treatment. When the key residues of the catalytic triad of Silverzyme were mutated to alanine, the overall catalytic efficiency of this mutant dropped by about 2 orders of magnitude, unambiguously demonstrating the key role of the designed catalytic triad. Similarly, when the residues for the oxyanion hole were deleted, the mutant with the intact catalytic triad also showed significantly decreased catalytic activity, highlighting the indispensable role of the oxyanion hole for the catalytic activity. Unexpectedly, when both the catalytic triad and the oxyanion hole were kept intact, a slight change of the binding site also resulted in significantly decreased catalytic activity, indicating that the designed binding site is at the right position to align the substrate in the right orientation in the active center for catalytic hydrolysis. These results confirm the synergy among the catalytic triad, the oxyanion hole, and the substrate-binding site, indicating successful mimicking of the active center of α-chymotrypsin. Moreover, Silverzyme shows better thermal stability than α-chymotrypsin, and can even hydrolyze the tough non-activated ester diethyl phthalate, a priority pollutant by the United States Environmental Protection Agency (USEPA). ConclusionThis study successfully mimicked the complex catalytic active center of α-chymotrypsin using a conformational engineering strategy, and produced a highly active artificial hydrolase with a well-defined structure and catalytic mechanism. The findings highlight the significant potential of conformational engineering.

Objective:To explore the dual mediating effects of health belief and depression among health knowledge, social support, and health behaviors based on the capacity, opportunity, motivation-behavior (COM-B) model, and analyze the influencing factors of health behaviors in patients with ischemic stroke.Methods:This multi-center cluster sampling research recruited ischemic stroke patients ( n=1 696) who were hospitalized in neurology departments of five tertiary hospitals in Henan Province from October 2023 to October 2024. A cross-sectional investigation was conducted using the general information questionnaire, social support rating scale (SSRS), stroke prevention knowledge questionnaire(SPKQ), short form health belief model scale(SF-HBMS), health promoting lifestyle profile-Ⅱ (HPLP-Ⅱ), and patient health questionnaire-9(PHQ-9) to ultimately reveal the pathways and effect sizes among variables. Partial correlation analysis and multiple linear stepwise regression analysis were conducted to examine the relationships among social support, health knowledge, health belief, health behaviors, and depression in stroke patients by SPSS 26.0 software. Structural equation modeling was constructed using AMOS 28.0 software, and the mediating effect was tested using the Bootstrap method. Results:The scores of social support, health knowledge, health belief, and health behaviors among ischemic stroke patients were (37.46±9.94), (26.56±6.84), (75.62±12.62) and (130.79±26.27), respectively. The score of depression was 5.00 (2.00, 8.00). Health behaviors were positively correlated with health knowledge, social support, and health belief( r=0.333, 0.246, 0.267, all P<0.05), while negatively correlated with depression ( r=-0.146, P<0.05). Multiple linear stepwise regression analysis showed that health knowledge, social support, health belief, and depression were all influencing factors of health behaviors in ischemic stroke patients (all P<0.05). Health belief (effect value=0.068, 95% CI=0.048-0.093) and depression (effect value=0.009, 95% CI=0.003-0.018) both played partial mediating roles between health knowledge and health behaviors, accounting for 17.3%(0.077/0.446) of the total effect. Meanwhile, health belief (effect value=0.045, 95% CI=0.029-0.063) and depression (effect value=0.016, 95% CI=0.008-0.027) both played partial mediating roles between social support and health behaviors, accounting for 26.5%(0.061/0.230) of the total effect. Conclusion:Health knowledge and social support can not only directly influence health behaviors but also indirectly affect them through health belief and depression in patients with ischemic stroke.

Iron overload is strongly associated with heart disease. Ferroptosis is a new form of regulated cell death indicated in cardiac ischemia-reperfusion (I/R) injury. However, the specific molecular mechanism of myocardial injury caused by iron overload in the heart is still unclear, and the involvement of ferroptosis in iron overload-induced myocardial injury is not fully understood. In this study, we observed that ferroptosis participated in developing of iron overload and I/R-induced cardiomyopathy. Mechanistically, we discovered that Parkin inhibited iron overload-induced ferroptosis in cardiomyocytes by promoting the ubiquitination of long-chain acyl-CoA synthetase 4 (ACSL4), a crucial protein involved in ferroptosis-related lipid metabolism pathways. Additionally, we identified p53 as a transcription factor that transcriptionally suppressed Parkin expression in iron-overloaded cardiomyocytes, thereby regulating iron overload-induced ferroptosis. In animal studies, cardiac-specific Parkin knockout mice (Myh6-CreER ^T2 /Parkin ^fl/fl ) fed a high-iron diet presented more severe myocardial damage, and the high iron levels exacerbated myocardial I/R injury. However, the ferroptosis inhibitor Fer-1 significantly suppressed iron overload-induced ferroptosis and myocardial I/R injury. Moreover, Parkin effectively protected against impaired mitochondrial function and prevented iron overload-induced mitochondrial lipid peroxidation. These findings unveil a novel regulatory pathway involving p53-Parkin-ACSL4 in heart disease by inhibiting of ferroptosis.

BACKGROUND:Currently,artificial corneas used for full-thickness transplantation lack biological activity and mechanical adaptability.Composite artificial corneas face interface issues between the corneal button and surrounding components.OBJECTIVE:To prepare an integrated artificial cornea with peptide enhancement,matched mechanical strength to natural cornea,and excellent transparency via in situ ultraviolet light curing of decellularized porcine cornea.METHODS:Non-ionic decellularization reagent Triton X-100 combined with ultrasonic freeze-thawing and super nucleases was utilized to prepare decellularized porcine cornea.Hydroxyethyl methacrylate monomer and photoinitiator were introduced into the decellularized porcine cornea simultaneously.Ultraviolet light with a filter was used to cover the peripheral region except for the central area,where polymerization was initiated using 275 nm ultraviolet light.After removal of unreacted monomers and initiators,the central optical zone was obtained.Similarly,the posterior lamellar layer was polymerized to form the hydrophobic barrier zone.Finally,REG active polypeptide was introduced to obtain in situ integrated full-layer artificial cornea.The physical properties,mechanical properties,transparency,degradation properties and in vivo and in vitro biocompatibility of artificial cornea were characterized.RESULTS AND CONCLUSION:(1)An optical region with the co-existence of polymer and collagen fibers was constructed in situ using hydroxyethyl methacrylate in the central region of decellularized porcine cornea.Under scanning electron microscopy,the upper surface of the artificial cornea was rough and irregular,with obvious concave and convex structure,and the lower surface was relatively smooth.The artificial cornea had mechanical properties close to those of natural cornea.The transparency of the optical zone reached 80%of that of the natural cornea.After soaking in PBS aseptic solution containing collagenase,it could preserve the solidified optical region and hydrophobic barrier zone,and maintain the basic structure of cornea.The artificial cornea had good cytocompatibility,could provide a suitable adhesion and growth environment for cells,was conducive to the migration and adhesion of corneal epithelial cells,promoted the growth of vascular endothelial cells and the formation of new blood vessels,and promoted the epithelialization process.The artificial cornea had good biocompatibility and safety after 12 weeks of subcutaneous implantation in SD rats,and could reduce the acute inflammatory reaction at the initial stage of implantation.(2)The results show that the integrated full-layer artificial cornea prepared by the experiment has the potential as a full-layer artificial cornea scaffold.

Objective:To explore the dual mediating effects of health belief and depression among health knowledge, social support, and health behaviors based on the capacity, opportunity, motivation-behavior (COM-B) model, and analyze the influencing factors of health behaviors in patients with ischemic stroke.Methods:This multi-center cluster sampling research recruited ischemic stroke patients ( n=1 696) who were hospitalized in neurology departments of five tertiary hospitals in Henan Province from October 2023 to October 2024. A cross-sectional investigation was conducted using the general information questionnaire, social support rating scale (SSRS), stroke prevention knowledge questionnaire(SPKQ), short form health belief model scale(SF-HBMS), health promoting lifestyle profile-Ⅱ (HPLP-Ⅱ), and patient health questionnaire-9(PHQ-9) to ultimately reveal the pathways and effect sizes among variables. Partial correlation analysis and multiple linear stepwise regression analysis were conducted to examine the relationships among social support, health knowledge, health belief, health behaviors, and depression in stroke patients by SPSS 26.0 software. Structural equation modeling was constructed using AMOS 28.0 software, and the mediating effect was tested using the Bootstrap method. Results:The scores of social support, health knowledge, health belief, and health behaviors among ischemic stroke patients were (37.46±9.94), (26.56±6.84), (75.62±12.62) and (130.79±26.27), respectively. The score of depression was 5.00 (2.00, 8.00). Health behaviors were positively correlated with health knowledge, social support, and health belief( r=0.333, 0.246, 0.267, all P<0.05), while negatively correlated with depression ( r=-0.146, P<0.05). Multiple linear stepwise regression analysis showed that health knowledge, social support, health belief, and depression were all influencing factors of health behaviors in ischemic stroke patients (all P<0.05). Health belief (effect value=0.068, 95% CI=0.048-0.093) and depression (effect value=0.009, 95% CI=0.003-0.018) both played partial mediating roles between health knowledge and health behaviors, accounting for 17.3%(0.077/0.446) of the total effect. Meanwhile, health belief (effect value=0.045, 95% CI=0.029-0.063) and depression (effect value=0.016, 95% CI=0.008-0.027) both played partial mediating roles between social support and health behaviors, accounting for 26.5%(0.061/0.230) of the total effect. Conclusion:Health knowledge and social support can not only directly influence health behaviors but also indirectly affect them through health belief and depression in patients with ischemic stroke.

Maidong products are categorized into "Hang Maidong" and "Chuan Maidong". Since the Ming and Qing Dynasties, "Hang Maidong" has been regarded as having superior quality, but currently, it remains in name only in the market. This article reviewed historical materia medica and local chronicles from the Ming and Qing Dynasties and analyzed the historical evolution of Maidong production areas. The history of Maidong production in Zhejiang can be traced back to the Song Dynasty, and cultivation had already developed by at least the Ming Dynasty. During the Ming and Qing Dynasties, it was consistently used as a tribute. Ming Dynasty chronicles record "Chuan Maidong", which had already been cultivated on a large scale by the Qing Dynasty. "Hang Maidong" and "Chuan Maidong" share the same origin, with the former identifiable by the "gourd waist" shape of its tuberous root. Based on this, it can be inferred that the "Maimendong" herb illustrated in the Origins of Materia Medica(Ben Cao Yuan Shi) and the Maidong stored in the Qing Palace Imperial Pharmacy were both "Hang Maidong". The protection and development of the authentic "Hang Maidong" medicinal herb are urgently needed.
China ; Drugs, Chinese Herbal/history* ; History, 17th Century ; History, Ancient ; Medicine, Chinese Traditional/history* ; History, Medieval ; History, 16th Century ; History, 18th Century ; History, 15th Century ; Plants, Medicinal/chemistry* ; History, 19th Century ; History, 20th Century ; Humans ; Materia Medica/history* ; History, 21st Century

PURPOSE: To investigate the regulatory role of nerve injury-induced protein 1 (NINJ1) in the anti-inflammatory function of human umbilical cord mesenchymal stem cells (hUC-MSCs) co-stimulated by interferon-gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α). METHODS: hUC-MSCs were expanded in vitro using standard protocols, with stem cell characteristics confirmed by flow cytometry and multilineage differentiation assays. The immunomodulatory properties and cellular activity of cytokine-co-pretreated hUC-MSCs were systematically evaluated via quantitative reverse transcription RT-qPCR, lymphocyte proliferation suppression assays, and Cell Counting Kit-8 viability tests. Transcriptome sequencing, Western blotting and small interfering RNA interference were integrated to analyze the regulatory mechanisms of NINJ1 expression. Functional roles of NINJ1 in pretreated hUC-MSCs were elucidated through gene silencing combined with lactate dehydrogenase release assays, Annexin V/Propidium Iodide apoptosis analysis, macrophage co-culture models, and cytokine Enzyme-Linked Immunosorbent Assay. Therapeutic efficacy was validated in a cecal ligation and puncture-induced septic mouse model: 80 mice were randomly allocated into 4 experimental groups (n=20/group): sham group (laparotomy without cecal ligation); phosphate-buffered saline-treated group (cecal ligation and puncture (CLP) + 0.1 mL phosphate-buffered saline); hUC-MSCs (small interfering RNA (siRNA)-interferon-gamma and tumor necrosis factor-alpha co-stimulation (IT))-treated group (CLP + hUC-MSCs transfected with scrambled siRNA); and hUC-MSCs (siNINJ1-IT)-treated group (CLP + hUC-MSCs with NINJ1-targeting siRNA). RESULTS: hUC-MSCs demonstrated compliance with International Society for Cellular Therapy criteria, confirming their stem cell identity. IFN-γ/TNF-α co-pretreatment enhanced the immunosuppressive capacity of hUC-MSCs, accompanied by the reduction of cellular viability, while concurrently upregulating pro-inflammatory cytokines such as interleukin-6 and interleukin-1β. This co-stimulation significantly elevated NINJ1 expression in hUC-MSCs, whereas genetic silencing of NINJ1 effectively suppressed pro-inflammatory cytokine production and attenuated damage-associated molecular patterns release through inhibition of programmed plasma membrane rupture. Furthermore, the NINJ1 interference potentiated the ability of cytokine-pretreated hUC-MSCs to suppress LPS-induced pro-inflammatory responses in RAW264.7 macrophages. In cecal ligation and puncture-induced sepsis model, NINJ1-silenced hUC-MSCs exhibited enhanced therapeutic efficacy, manifested by reduced systemic inflammation and multi-organ damage. CONCLUSION Our findings shed new light on the immunomodulatory functions of cytokine-primed MSCs, offering groundbreaking insights for developing MSC-based therapies against inflammatory diseases via interfering the expression of NINJ1.
Mesenchymal Stem Cells/drug effects* ; Animals ; Interferon-gamma/pharmacology* ; Tumor Necrosis Factor-alpha/pharmacology* ; Humans ; Mice ; Umbilical Cord/cytology* ; Cells, Cultured ; Apoptosis ; Male

BACKGROUND:Currently,artificial corneas used for full-thickness transplantation lack biological activity and mechanical adaptability.Composite artificial corneas face interface issues between the corneal button and surrounding components.OBJECTIVE:To prepare an integrated artificial cornea with peptide enhancement,matched mechanical strength to natural cornea,and excellent transparency via in situ ultraviolet light curing of decellularized porcine cornea.METHODS:Non-ionic decellularization reagent Triton X-100 combined with ultrasonic freeze-thawing and super nucleases was utilized to prepare decellularized porcine cornea.Hydroxyethyl methacrylate monomer and photoinitiator were introduced into the decellularized porcine cornea simultaneously.Ultraviolet light with a filter was used to cover the peripheral region except for the central area,where polymerization was initiated using 275 nm ultraviolet light.After removal of unreacted monomers and initiators,the central optical zone was obtained.Similarly,the posterior lamellar layer was polymerized to form the hydrophobic barrier zone.Finally,REG active polypeptide was introduced to obtain in situ integrated full-layer artificial cornea.The physical properties,mechanical properties,transparency,degradation properties and in vivo and in vitro biocompatibility of artificial cornea were characterized.RESULTS AND CONCLUSION:(1)An optical region with the co-existence of polymer and collagen fibers was constructed in situ using hydroxyethyl methacrylate in the central region of decellularized porcine cornea.Under scanning electron microscopy,the upper surface of the artificial cornea was rough and irregular,with obvious concave and convex structure,and the lower surface was relatively smooth.The artificial cornea had mechanical properties close to those of natural cornea.The transparency of the optical zone reached 80%of that of the natural cornea.After soaking in PBS aseptic solution containing collagenase,it could preserve the solidified optical region and hydrophobic barrier zone,and maintain the basic structure of cornea.The artificial cornea had good cytocompatibility,could provide a suitable adhesion and growth environment for cells,was conducive to the migration and adhesion of corneal epithelial cells,promoted the growth of vascular endothelial cells and the formation of new blood vessels,and promoted the epithelialization process.The artificial cornea had good biocompatibility and safety after 12 weeks of subcutaneous implantation in SD rats,and could reduce the acute inflammatory reaction at the initial stage of implantation.(2)The results show that the integrated full-layer artificial cornea prepared by the experiment has the potential as a full-layer artificial cornea scaffold.

Objective:To study the feasibility of magnetic resonance imaging(MRI)technique with amide proton transfer(APT)in predicting the prognosis of cerebral stroke.Methods:A total of 71 patients with acute cerebral stroke who admitted to the Nanjing First Hospital,Nanjing Medical University from September 2022 to May 2023 were selected.All of them underwent the test of National Institute of Health Stroke Scale(NIHSS),and received the MRI examination with chemical exchange saturation transfer(CEST).According to the modified Rankin scale(mRS)values of 1-month follow-up,they were divided into favorable recovery group(mRS<2,44 cases)and poor group(mRS≥2,27 cases).The asymmetric magnetization transfer ratio(MTRasym)image(APT)was obtained by analyzing data with special software.And then,the difference(△APTw)of APT values between ischemic zone and contralateral normal tissue was further calculated.The △APTw values of two groups were compared and analyzed,and the Pearson correlation analysis was adopted to analyze the correlation among △APTw,NIHSS and mRS.The receiver operating characteristics(ROC)curve was drawn,and the area under curve(AUC)of ROC curve was calculated.Results:There were significant positive correlations among △APTw,NIHSS and mRS scores(R2=0.659,0.522,P<0.001),and the differences of △APTW,NIHSS and mRS scores between the favorable recovery group and poor group were significant(t=5.73,6.36,13.92,P<0.05),respectively.The AUC value was 0.886,and the sensitivity and specificity of prediction were respectively 77.8%and 95.5%.The positive and negative predictive values were respectively 91.3%and 87.5%.Conclusion:APT imaging technique has feasibility in predicting the prognosis of acute cerebral ischemic stroke.

ObjectiveGastric cancer (GC) seriously affects human health and life, and research has shown that it is closely related to the serine/glycine metabolism. The proliferation ability of tumor cells is greatly influenced by the metabolism of serine and glycine. The aim of this study was to investigate the molecular mechanism of serine/glycine metabolism can affect the proliferation of gastric cancer cells. MethodsIn this work, a stable metabolic dynamic model of gastric cancer cells was established via a large-scale metabolic network dynamic modeling method in terms of a potential landscape description of stochastic and non-gradient systems. Based on the regulation of the model, a quantitative analysis was conducted to investigate the dynamic mechanism of serine/glycine metabolism affecting the proliferation of gastric cancer cells. We introduced random noise to the kinetic equations of the general metabolic network, and applied stochastic kinetic decomposition to obtain the Lyapunov function of the metabolic network parameter space. A stable metabolic network was achieved by further reducing the change in the Lyapunov function tied to the stochastic fluctuations. ResultsDespite the unavailability of a large number of dynamic parameters, we were able to successfully construct a dynamic model for the metabolic network in gastric cancer cells. When extracellular serine is available, the model preferentially consumes serine. In addition, when the conversion rate of glycine to serine increases, the model significantly upregulates the steady-state fluxes of S-adenosylmethionine (SAM) and S-adenosyl homocysteine (SAH). ConclusionIn this paper, we provide evidence supporting the preferential uptake of serine by gastric cancer cells and the important role of serine/glycine conversion rate in SAM generation, which may affect the proliferation ability of gastric cancer cells by regulating the cellular methylation process. This provides a new idea and direction for targeted cancer therapy based on serine/glycine metabolism.