This study elucidated the structure-activity relationships (SAR) of three distinct opioid ligand series at the μ-opioid receptor (μ-OR) and investigated the ligand-dependent role of arrestin in downstream signaling. Radioligand binding assays across 13 compounds revealed that high-affinity μ-OR binding is not restricted to a single chemical scaffold. For fentanyl analogs, SAR analysis identified four key structural determinants: the N-phenethyl group (R1) is essential for μ-OR binding, the piperidine 4-position (R2) is sterically constrained and tolerates only small substituents such as carbomethoxy, the acyl side chain (R3) tolerates diverse chemical modifications including alkyl, alkoxy, and heteroaryl groups without substantial loss of affinity, and para-substitution on the phenethyl ring (R4) with electron-withdrawing groups like fluorine is well-tolerated. Analysis of non-fentanyl scaffolds (2-Methyl AP-237, W-15, and brorphine) demonstrated that specific side-chain functionalization, rather than core scaffold architecture, primarily determines binding potency. Comparison of classical opioids further revealed that structural flexibility, exemplified by methadone, can confer superior binding affinity compared to the rigid morphine scaffold. Consistent with this structural diversity, the contribution of arrestins to ERK activation varied substantially across compounds, suggesting that μ-OR-biased signaling is not dictated exclusively by intrinsic receptor properties but emerges from the interplay between receptor conformation and ligandspecific structural features. Collectively, our results provide a molecular framework for understanding opioid pharmacology with important implications for rational drug design aimed at minimizing adverse effects while maintaining analgesic efficacy.

ObjectiveTo investigate whether the effect of Taohong Siwutang on cerebral ischemia-reperfusion （CIRI） injury in rats is related to the regulation of astrocyte polarization and explore the related mechanism. MethodsEighty-four male SD rats were randomly assigned to the following groups： A sham operation group， a model group， Taohong Siwutang treatment groups （low dose， medium dose， and high dose）， ligustrazine phosphate tablet （LPT） group， and AG490 group. All groups， except for the sham operation group， underwent middle cerebral artery occlusion/reperfusion （MCAO/R） modeling and were treated for seven days. The neurological impairment was evaluated using the Longa score. The volume of cerebral infarction was assessed through 2，3，5-triphenyltetrazolium chloride （TTC） staining. Real-time fluorescent quantitative polymerase chain reaction （Real-time PCR） and Western blot analyses were performed to analyze the mRNA and protein expression levels of cortical complement 3 （C3）， S100 calcium-binding protein A10 （S100A10）， Janus kinase 2 （JAK2）， and signal transducer and activator of transcription 3 （STAT3）. Additionally， protein expression levels of vascular endothelial growth factor-A （VEGF-A） were assessed， and the mRNA expression levels of inflammatory factors， including interleukin-6 （IL-6）， interleukin-1β （IL-1β）， and tumor necrosis factor-α （TNF-α）， were evaluated. Glial fibrillary acidic protein （GFAP） and C3， S100A10 and Co-localization was detected via immunofluorescence double staining. Lastly， VEGF expression levels were measured using enzyme-linked immunosorbent assay （ELISA）. ResultsCompared with the sham operation group， the model group showed a significant increase in cerebral infarction volume and neurological impairment （P<0.01）. C3 protein levels were elevated， while S100A10 levels were decreased. Pathway-related markers were significantly upregulated （P<0.05， P<0.01）， and VEGF-A protein levels were significantly reduced （P<0.01）. The mRNA expression of inflammatory factors was significantly upregulated （P<0.01）. Co-localization analysis showed significantly increased GFAP and C3 fluorescence intensity （P<0.01） and greatly decreased GFAP and S100A10 fluorescence intensity （P<0.01）. Additionally， VEGF content was significantly elevated （P<0.01）. Compared with the model group， medium- and high-dose Taohong Siwutang and LPT groups exhibited a significant reduction in cerebral infarction volume and neurological impairment （P<0.01）. Groups treated with low， medium， and high doses of Taohong Siwutang and LPT group exhibited a decrease in C3 protein expression levels and an increase in S100A10 expression levels （P<0.01）. In the high-dose Taohong Siwutang and AG490 groups， both protein and mRNA expression of C3 and pathway-related markers were significantly downregulated （P<0.05， P<0.01）， while S100A10 expression and VEGF-A protein levels were significantly increased （P<0.01）. Additionally， the mRNA expression levels of inflammatory factors were significantly reduced （P<0.01）. The co-localization fluorescence intensity of GFAP and C3 significantly decreased （P<0.01）， while that of GFAP and S100A10 greatly increased （P<0.01）. Furthermore， VEGF content exhibited a marked elevation （P<0.01）. ConclusionTaohong Siwutang exerts a protective effect in rats with cerebral CIRI injury. The underlying mechanism is associated with the downregulation of the JAK2/STAT3 signaling pathway， promotion of A2-type astrocyte polarization， reduction of inflammatory factor release， and enhancement of VEGF production.

ObjectiveTo investigate whether the effect of Taohong Siwutang on cerebral ischemia-reperfusion （CIRI） injury in rats is related to the regulation of astrocyte polarization and explore the related mechanism. MethodsEighty-four male SD rats were randomly assigned to the following groups： A sham operation group， a model group， Taohong Siwutang treatment groups （low dose， medium dose， and high dose）， ligustrazine phosphate tablet （LPT） group， and AG490 group. All groups， except for the sham operation group， underwent middle cerebral artery occlusion/reperfusion （MCAO/R） modeling and were treated for seven days. The neurological impairment was evaluated using the Longa score. The volume of cerebral infarction was assessed through 2，3，5-triphenyltetrazolium chloride （TTC） staining. Real-time fluorescent quantitative polymerase chain reaction （Real-time PCR） and Western blot analyses were performed to analyze the mRNA and protein expression levels of cortical complement 3 （C3）， S100 calcium-binding protein A10 （S100A10）， Janus kinase 2 （JAK2）， and signal transducer and activator of transcription 3 （STAT3）. Additionally， protein expression levels of vascular endothelial growth factor-A （VEGF-A） were assessed， and the mRNA expression levels of inflammatory factors， including interleukin-6 （IL-6）， interleukin-1β （IL-1β）， and tumor necrosis factor-α （TNF-α）， were evaluated. Glial fibrillary acidic protein （GFAP） and C3， S100A10 and Co-localization was detected via immunofluorescence double staining. Lastly， VEGF expression levels were measured using enzyme-linked immunosorbent assay （ELISA）. ResultsCompared with the sham operation group， the model group showed a significant increase in cerebral infarction volume and neurological impairment （P<0.01）. C3 protein levels were elevated， while S100A10 levels were decreased. Pathway-related markers were significantly upregulated （P<0.05， P<0.01）， and VEGF-A protein levels were significantly reduced （P<0.01）. The mRNA expression of inflammatory factors was significantly upregulated （P<0.01）. Co-localization analysis showed significantly increased GFAP and C3 fluorescence intensity （P<0.01） and greatly decreased GFAP and S100A10 fluorescence intensity （P<0.01）. Additionally， VEGF content was significantly elevated （P<0.01）. Compared with the model group， medium- and high-dose Taohong Siwutang and LPT groups exhibited a significant reduction in cerebral infarction volume and neurological impairment （P<0.01）. Groups treated with low， medium， and high doses of Taohong Siwutang and LPT group exhibited a decrease in C3 protein expression levels and an increase in S100A10 expression levels （P<0.01）. In the high-dose Taohong Siwutang and AG490 groups， both protein and mRNA expression of C3 and pathway-related markers were significantly downregulated （P<0.05， P<0.01）， while S100A10 expression and VEGF-A protein levels were significantly increased （P<0.01）. Additionally， the mRNA expression levels of inflammatory factors were significantly reduced （P<0.01）. The co-localization fluorescence intensity of GFAP and C3 significantly decreased （P<0.01）， while that of GFAP and S100A10 greatly increased （P<0.01）. Furthermore， VEGF content exhibited a marked elevation （P<0.01）. ConclusionTaohong Siwutang exerts a protective effect in rats with cerebral CIRI injury. The underlying mechanism is associated with the downregulation of the JAK2/STAT3 signaling pathway， promotion of A2-type astrocyte polarization， reduction of inflammatory factor release， and enhancement of VEGF production.

Objective To investigate the role of Taohong Siwu Decoction(THSWD)in microglia pyroptosis mediated neuronal injury in PC12 under oxygen-glucose deprivation/reperfusion(OGD/R)and related mechanisms.Methods PC12 and BV2 cells were co-cultured using the OGD/R model to simulate ischemia-reperfusion injury of in vitro.The experiment was grouped as follows:control(PC12,PC12+BV2),OGD/R group(PC12,PC12+BV2),and OGD/R+10％THSWD-containing serum group(PC12,PC12+BV2).Oxygen and glucose was restored for 24h after 4-6h of deprivation.The severity of damage to PC12 cells was evaluated by cell counting kit-8(CCK-8)and flow cytometry.BV2 cells were used for the experiments and were divided into control,OGD/R and OGD/R+THSWD-containing serum(5％,10％,15％)groups,which were moulded and administered in the same way,and cell py-roptosis proteins proteinscysteinyl aspartate specific proteinase-1(caspase-1),apoptosis-associated speck-like protein containing a CARD(ASC),gasdermin D(GSDMD),interleukin-1β(IL-1β),interleukin-18(IL-18)and nucleotide-binding oligomeriza-tion domain-like receptor protein 3(NLRP3)inflammasome-associated proteins were detected by Western blot.Results In the pres-ence of BV2 cells,THSWD was able to further restore the morphology,increase cell viability(P＜0.05)and reduce apoptosis of PC12 cells after OGD/R injury(P＜0.05).In addition,THSWD was able to reduce the expression of OGD/R-induced pyroptosis proteins(caspase-1,ASC,GSDMD,IL-1β,IL-18)in BV2 microglia cells(P＜0.05).In contrast,the inhibitory effects of THSWD on BV2 cells pyroptosis proteins and NLRP3 inflammasome were reversed by NLRP3/caspase-1 agonist(P＜0.05).Conclusion THSWD protects PC 12 cells against OGD/R injury via inhibiting microglia pyroptosis mediated by the NLRP3/caspase-1 pathway.

Objective To investigate the role of Taohong Siwu Decoction(THSWD)in microglia pyroptosis mediated neuronal injury in PC12 under oxygen-glucose deprivation/reperfusion(OGD/R)and related mechanisms.Methods PC12 and BV2 cells were co-cultured using the OGD/R model to simulate ischemia-reperfusion injury of in vitro.The experiment was grouped as follows:control(PC12,PC12+BV2),OGD/R group(PC12,PC12+BV2),and OGD/R+10％THSWD-containing serum group(PC12,PC12+BV2).Oxygen and glucose was restored for 24h after 4-6h of deprivation.The severity of damage to PC12 cells was evaluated by cell counting kit-8(CCK-8)and flow cytometry.BV2 cells were used for the experiments and were divided into control,OGD/R and OGD/R+THSWD-containing serum(5％,10％,15％)groups,which were moulded and administered in the same way,and cell py-roptosis proteins proteinscysteinyl aspartate specific proteinase-1(caspase-1),apoptosis-associated speck-like protein containing a CARD(ASC),gasdermin D(GSDMD),interleukin-1β(IL-1β),interleukin-18(IL-18)and nucleotide-binding oligomeriza-tion domain-like receptor protein 3(NLRP3)inflammasome-associated proteins were detected by Western blot.Results In the pres-ence of BV2 cells,THSWD was able to further restore the morphology,increase cell viability(P＜0.05)and reduce apoptosis of PC12 cells after OGD/R injury(P＜0.05).In addition,THSWD was able to reduce the expression of OGD/R-induced pyroptosis proteins(caspase-1,ASC,GSDMD,IL-1β,IL-18)in BV2 microglia cells(P＜0.05).In contrast,the inhibitory effects of THSWD on BV2 cells pyroptosis proteins and NLRP3 inflammasome were reversed by NLRP3/caspase-1 agonist(P＜0.05).Conclusion THSWD protects PC 12 cells against OGD/R injury via inhibiting microglia pyroptosis mediated by the NLRP3/caspase-1 pathway.

Objective To explore the therapeutic mechanism of Liuwei Buqi(LWBQ)Formula for chronic obstructive pulmonary disease(COPD)in rat models.Methods SD rat models of COPD established by cigarette smoking combined with intratracheal lipopolysaccharide(LPS)instillation and hormone injection were treated with LWBQ Formula by gavage with or without intraperitoneal injection of MCC950 for 3 weeks,starting at the 5th week of modeling.After the treatments,the rats were examined for lung pathologies,lung function,total cell count and white blood cell count in bronchoalveolar lavage fluid(BALF),and serum levels of IL-6,TNF-α,IL-18 and NO.The mRNA expressions of NLRP3,ASC,caspase-1,GSDMD-N,IL-1β,and IL-18 in the lung tissue were detected with qRT-PCR.Results Compared with the normal control rats,the COPD rat models had severe lung pathologies and showed significantly decreased lung function,increased total cell and leukocyte subset counts in BALF,and increased serum levels of IL-6,TNF-α,IL-18 and NO and mRNA expressions of pyroptosis-related proteins in the lung tissue.Treatment of the rat models with LWBQ Formula significantly improved lung pathology and lung function,reduced total cell and leukocyte counts in BALF,and decreased serum levels of the inflammatory factors and expressions of pyroptosis-related proteins in the lung tissue.The combined treatment with MCC950 further improved lung pathology and function in spite of a significant difference,but BALF cell counts,serum inflammatory factor levels and pulmonary expressions of pyroptosis-related proteins were all significantly reduced following the treatment.Conclusion LWBQ Formula can delay the progression of COPD in rats possibly by inhibiting lung tissue pyroptosis via regulating the NLRP3/caspase-1/GSDMD pathway to reduce inflammatory response and lung damage.

Objective To explore the therapeutic mechanism of Liuwei Buqi(LWBQ)Formula for chronic obstructive pulmonary disease(COPD)in rat models.Methods SD rat models of COPD established by cigarette smoking combined with intratracheal lipopolysaccharide(LPS)instillation and hormone injection were treated with LWBQ Formula by gavage with or without intraperitoneal injection of MCC950 for 3 weeks,starting at the 5th week of modeling.After the treatments,the rats were examined for lung pathologies,lung function,total cell count and white blood cell count in bronchoalveolar lavage fluid(BALF),and serum levels of IL-6,TNF-α,IL-18 and NO.The mRNA expressions of NLRP3,ASC,caspase-1,GSDMD-N,IL-1β,and IL-18 in the lung tissue were detected with qRT-PCR.Results Compared with the normal control rats,the COPD rat models had severe lung pathologies and showed significantly decreased lung function,increased total cell and leukocyte subset counts in BALF,and increased serum levels of IL-6,TNF-α,IL-18 and NO and mRNA expressions of pyroptosis-related proteins in the lung tissue.Treatment of the rat models with LWBQ Formula significantly improved lung pathology and lung function,reduced total cell and leukocyte counts in BALF,and decreased serum levels of the inflammatory factors and expressions of pyroptosis-related proteins in the lung tissue.The combined treatment with MCC950 further improved lung pathology and function in spite of a significant difference,but BALF cell counts,serum inflammatory factor levels and pulmonary expressions of pyroptosis-related proteins were all significantly reduced following the treatment.Conclusion LWBQ Formula can delay the progression of COPD in rats possibly by inhibiting lung tissue pyroptosis via regulating the NLRP3/caspase-1/GSDMD pathway to reduce inflammatory response and lung damage.

The presence of replication-competent HBV DNA in the liver and/or serum of HBsAg-negative individuals is a sufficient and necessary condition for the diagnosis of occult hepatitis B virus infection (OBI). In recent years, Chinese scholars have proposed what is considered a more "rigorous" definition, i.e., on this basis, HBV window period (WP) infection is excluded, which corresponds to a serum HBV DNA level of below the lower limit of detection or a low positive value (< 200 IU/mL). As the definition of WP for HBV infection remains unclear and its duration is highly variable, "HBV DNA < 200 IU/mL" is not the only criterion in OBI patients. Therefore, it is believed that there is still a lack of sufficient basis and operability for the definition of OBI based on "the exclusion of HBV WP infection" and "HBV DNA < 200 IU/mL" as "rigorous" conditions for the diagnosis of OBI.

Objective:To analyze the status of hepatitis B virus (HBV) infection in pregnant women in Taizhou City in recent years and the effect of immunization management of hepatitis B vaccine project on the status.Methods:The pregnant women hospitalized in Taizhou People′s Hospital, Taizhou Second People′s Hospital, Taizhou Traditional Chinese Medicine Hospital and Taixing People′s Hospital from 2014 to 2017 were enrolled. According to the HBV serological results, the pregnant women were divided into non-immune population, successful immunization population, previous HBV infection population, HBV infection population and atypical manifestation population. The year of immunization management for the implementation of the hepatitis B vaccine plan was 1992. The HBV infection status of the pregnant women was analyzed based on the year of delivery and vaccination status, respectively. Chi-square test and trend chi-square test were used for statistical analysis.Results:A total of 31 449 cases were included in this study, of which 13 203 (41.98%) were non-immunized, 10 123 (32.19%) were successfully immunized, 6 409 (20.38%) were previous HBV infected, 1 566(4.98%) were HBV infected, and 148(0.47%) cases were atypical manifestation. The negative rate of all HBV serological markers of pregnant women born before 1992 and after 1992 (including 1992) were 42.07%(10 794/25 657) and 41.59%(2 409/5 792), respectively, with no statistically significant difference ( χ2=0.44, P=0.51). The hepatitis B surface antibody (anti-HBs) positive rate of pregnant women born before 1992 was 28.95%(7 428/25 657), which was lower than 46.53%(2 695/5 792) of pregnant women born after 1992 (including 1992). The difference was statistically significant ( χ2=668.94, P<0.01), and showed an upward trend year by year ( χ2=602.11, P<0.01). The hepatitis B core antibody (anti-HBc) positive rate of pregnant women born after 1992 (including 1992) was 8.81%(510/5 792), which was lower than 22.99%(5 899/25 657) of pregnant women born before 1992, the difference was statistically significant ( χ2=589.10, P<0.01), and the overall trend was declining year by year ( χ2=478.72, P<0.01). The hepatitis B surface antigen (HBsAg) positive rate of pregnant women born before 1992 was 5.46%(1 402/25 657), which was higher than 2.83%(164/5 792) of pregnant women born after 1992 (including 1992), the difference was statistically significant ( χ2 =69.23, P <0.01), and the overall trend was decreasing ( χ2=49.25, P<0.01). Among pregnant women infected with HBV, the negative rate of hepatitis B e antigen (HBeAg) was 78.16%(1 224/1 566). Conclusions:Pregnant women with HBV infection in Taizhou City are mainly HBeAg negative. Hepatitis B vaccine immunization management significantly reduces the HBsAg positive rate and anti-HBc positive rate of pregnant women, and increases the positive rate of anti-HBs, while the rate of all HBV serum marker negative is not significantly decreased. Horizontal transmission may still be a risk factor for HBV present and previous infections.