1.Antibody levels of diphtheria and tetanus in healthy population in Pudong New Area, Shanghai, 2018-2024
Yu BAI ; Dandan YANG ; Wanran CHENG ; Rui ZHANG ; Pengfei DENG ; Caoyi XUE ; Laibao YANG ; Yi FEI
Journal of Public Health and Preventive Medicine 2026;37(3):52-55
Objective To understand the antibody levels of diphtheria and tetanus among healthy population in Shanghai Pudong New Area, and to provide a scientific basis for improving the vaccine immunization strategy. Methods Random sampling was used to select healthy people of all ages in 16 communities in Shanghai Pudong New Area from 2018 to 2024, and serum samples were collected and tested for serum anti-diphtheria and tetanus toxin IgG antibodies by enzyme-linked immunosorbent assay (ELISA) method to analyze the antibody positivity rate (≥0.1 IU/ml) and the geometric mean concentration (GMC) of antibodies. Results A total of 3 312 serum samples were included, with a male-to-female ratio of 0.76:1, and 53.77% were local residents. The seropositivity rates and geometric mean concentrations (GMC) of both diphtheria and tetanus antibodies generally declined with increasing age, but exhibited a transient rebound in the 7y-. A total of 1 175 individuals (35.48%) were seropositive for diphtheria, with a GMC of 0.054 IU/mL. For tetanus, 988 individuals (29.83%) were seropositive, with a GMC of 0.033 IU/mL. Significant differences in seropositivity rates (χ2diphtheria=950.005,χ2tetanus=1 324.393) and GMC (Hdiphtheria=1027.160,Htetanus=1 142.007) were observed among different age groups (P<0.001). Significant differences in seropositivity rates (χ2diphtheria=950.005,χ2tetanus=1324.393) and GMC (Hdiphtheria=1027.160,Htetanus=1142.007) were also found across different years (P<0.001). Conclusion The prevalence of diphtheria and tetanus antibodies in the healthy population of Pudong New Area is relatively low, particularly among adults over 20 years of age with inadequate immunization. This underscores the need to reinforce the National Immunization Program (NIP) vaccine specifications for children under 6 years of age and implement an immunization strategy for adolescents or adults against diphtheria and tetanus.
2.The Diversity of Filamentous Morphologies and Magnetic Sensitivity Modulated by Diverse MagR Expression in Bacteria
Ya-Fei CHANG ; Jing ZHANG ; Peng ZHANG ; Xiu-Juan ZHOU ; Meng-Ke WEI ; Tian-Tian CAI ; Pei-Qi HE ; Jun-Feng WANG ; Can XIE
Progress in Biochemistry and Biophysics 2026;53(5):1439-1456
Objective Magnetoreception, the remarkable ability of diverse animals to sense and utilize the geomagnetic field for orientation and navigation, remains a molecularly unresolved mystery in sensory biology. The putative magnetoreceptor (MagR, previously known as IscA1) is a highly conserved iron-sulfur protein implicated in both magnetoreception and iron metabolism; however, the functional diversity among its cross-species homologs remains poorly understood. Cellular morphology is a key genetically determined trait that can be altered through genetic or environmental modifications—a process known as cell morphology engineering. Constructing engineered cells with specific morphological features and magnetic sensitivity to achieve remote, non-invasive magnetic modulation represents a crucial goal in this field with significant application potential. Therefore, this study aims to systematically investigate the effects of MagR heterologous expression on bacterial morphology and magnetic sensing capabilities, screen for MagR-based magnetically sensitive morphology engineering pathways, and reveal the underlying molecular mechanisms. Methods We systematically screened 28 MagR homologous genes from diverse prokaryotic and animal taxa to evaluate their expression and corresponding phenotypic effects in Escherichia coli (E. coli). To compare the differential magnetic responses among bacteria expressing various recombinant MagR proteins, we utilized high-throughput automated bright-field microscopic imaging and scanning electron microscopy (SEM). Furthermore, comprehensive biochemical and biophysical characterizations of iron and iron-sulfur cluster binding were performed using Ferrozine colorimetric assays, electron paramagnetic resonance (EPR) spectroscopy, ultraviolet-visible (UV-Vis) absorption, and circular dichroism (CD) spectroscopy. Additionally, 100 mT static magnetic field (SMF) exposure experiments were conducted to assess magnetically tunable phenotypes, while the intrinsic magnetic properties of purified MagR proteins were directly measured using a superconducting quantum interference device (SQUID) magnetometer. Results Our results demonstrated that the heterologous expression of MagR homologs induced varying degrees of bacterial filamentation. From this comprehensive screen, two distinct morphological patterns were identified: hydra (Hydra vulgaris) MagR (hyMagR) promoted uniform cell elongation and filamentation, exhibiting robust magnetic sensitivity manifested as significantly enhanced filamentation under the 100 mT SMF. In contrast, pigeon (Columba livia) MagR (clMagR) induced only low-frequency, extreme filamentation (sporadically exceeding 80 μm) with a relatively weaker magnetic morphological response. Mechanistically, our data unambiguously proved that these phenotypic differences are primarily driven by distinct iron redox preferences rather than total cellular iron accumulation. Specifically, hyMagR preferentially binds ferrous iron (Fe2+), whereas clMagR favors ferric iron (Fe3+) and forms more stable iron-sulfur clusters. Intriguingly, although SQUID magnetometry showed that purified clMagR exhibited approximately five-fold higher mass magnetic susceptibility than hyMagR, its cellular magnetic response was weaker. We hypothesize that the Fe2+-preferred intracellular environment associated with hyMagR overexpression primes the cell for enhanced generation of reactive oxygen species (ROS) via the Fenton reaction. Exposure to an SMF synergizes with this primed redox state, triggering the bacterial SOS response and upregulating cell division inhibitors to efficiently induce uniform filamentation. Conclusion Our findings identify the Fe2+/Fe3+ redox state as a critical determinant of MagR-mediated morphological remodeling and magnetic responsiveness. This discovery suggests a potential strategy for engineering magnetically responsive cellular systems for synthetic biology applications, and provides a plausible framework, which potentially combines intrinsic protein magnetism with redox-state modulation, for further investigating the evolutionary mechanisms of MagR-mediated magnetoreception.
3.Molecular characterization analyses of a human metapneumovirus outbreak in Gongshu District of Hangzhou City
Jianyi LIU ; Chenye ZHANG ; Lei ZHAO ; Huiqun SHUAI ; Huanhuan YU ; Qingyu SUN ; Fei LU ; Shengjun XI
Shanghai Journal of Preventive Medicine 2026;38(3):216-220
ObjectiveTo analyze the epidemiological and etiological characteristics of a cluster of human metapneumovirus (HMPV) infection in a kindergarten in Gongshu District of Hangzhou City in May 2024, and to provide reference for the prevention and control of similar outbreaks. MethodsAn on-site investigation was conducted using an epidemiological case investigation form. Throat swab specimens collected from cases were screened for 13 respiratory pathogens using real-time fluorescent polymerase chain reaction (PCR). For HMPV nucleic acid positive specimens, the F gene of HMPV was used as the target gene for amplification and sequencing. The sequencing results were then compared with sequences in GenBank database to determine the virus subtypes and perform phylogenetic analyses. ResultsThe outbreak occurred in a kindergarter junior class with a total of 28 preschoolers and 3 teachers and childcare workers. A total of 11 cases (10 preschoolers and 1 teacher) were identified, including 8 male cases and 3 female cases. Clinical manifestations included fever in all 11 cases (100.00%), cough in 8 cases (72.72%), catarrhal symptoms in 4 cases (36.36%), and headache in 3 cases (27.27%). All symptoms were mild, and no severe cases were observed. A total of 11 throat swab samples were collected. Real-time fluorescent PCR test results showed that 3 samples were positive for HMPV nucleic acid, 2 samples were positive for both HMPV and Streptococcus pneumoniae, and 1 sample was positive for both HMPV and rhinovirus. The sequences of the 6 HMPV nucleic acid positive specimens were amplified and analyzed using specific primers, and all were determined to be HMPV subtype A2b. The F gene fragment sequence showed the highest similarity to PV081665.1/Brazil/2024 (99.65%), and also exhibited high similarity to PP683455.1/Indonesia/2021 (99.48%), PV016275.1/Beijing/2024 (99.31%), and PV052230.1/USA/2024 (99.13%). ConclusionThis cluster of acute respiratory tract infection was caused by HMPV subtype A2b, with co-infection of rhinovirus and Streptococcus pneumoniae. The F gene fragment sequences of the HMPV in this outbreak were highly homologous to those of the A2b strains isolated from Brazil, Beijing, Indonesia, and the the United States.
4.The Diversity of Filamentous Morphologies and Magnetic Sensitivity Modulated by Diverse MagR Expression in Bacteria
Ya-Fei CHANG ; Jing ZHANG ; Peng ZHANG ; Xiu-Juan ZHOU ; Meng-Ke WEI ; Tian-Tian CAI ; Pei-Qi HE ; Jun-Feng WANG ; Can XIE
Progress in Biochemistry and Biophysics 2026;53(5):1439-1456
Objective Magnetoreception, the remarkable ability of diverse animals to sense and utilize the geomagnetic field for orientation and navigation, remains a molecularly unresolved mystery in sensory biology. The putative magnetoreceptor (MagR, previously known as IscA1) is a highly conserved iron-sulfur protein implicated in both magnetoreception and iron metabolism; however, the functional diversity among its cross-species homologs remains poorly understood. Cellular morphology is a key genetically determined trait that can be altered through genetic or environmental modifications—a process known as cell morphology engineering. Constructing engineered cells with specific morphological features and magnetic sensitivity to achieve remote, non-invasive magnetic modulation represents a crucial goal in this field with significant application potential. Therefore, this study aims to systematically investigate the effects of MagR heterologous expression on bacterial morphology and magnetic sensing capabilities, screen for MagR-based magnetically sensitive morphology engineering pathways, and reveal the underlying molecular mechanisms. Methods We systematically screened 28 MagR homologous genes from diverse prokaryotic and animal taxa to evaluate their expression and corresponding phenotypic effects in Escherichia coli (E. coli). To compare the differential magnetic responses among bacteria expressing various recombinant MagR proteins, we utilized high-throughput automated bright-field microscopic imaging and scanning electron microscopy (SEM). Furthermore, comprehensive biochemical and biophysical characterizations of iron and iron-sulfur cluster binding were performed using Ferrozine colorimetric assays, electron paramagnetic resonance (EPR) spectroscopy, ultraviolet-visible (UV-Vis) absorption, and circular dichroism (CD) spectroscopy. Additionally, 100 mT static magnetic field (SMF) exposure experiments were conducted to assess magnetically tunable phenotypes, while the intrinsic magnetic properties of purified MagR proteins were directly measured using a superconducting quantum interference device (SQUID) magnetometer. Results Our results demonstrated that the heterologous expression of MagR homologs induced varying degrees of bacterial filamentation. From this comprehensive screen, two distinct morphological patterns were identified: hydra (Hydra vulgaris) MagR (hyMagR) promoted uniform cell elongation and filamentation, exhibiting robust magnetic sensitivity manifested as significantly enhanced filamentation under the 100 mT SMF. In contrast, pigeon (Columba livia) MagR (clMagR) induced only low-frequency, extreme filamentation (sporadically exceeding 80 μm) with a relatively weaker magnetic morphological response. Mechanistically, our data unambiguously proved that these phenotypic differences are primarily driven by distinct iron redox preferences rather than total cellular iron accumulation. Specifically, hyMagR preferentially binds ferrous iron (Fe2+), whereas clMagR favors ferric iron (Fe3+) and forms more stable iron-sulfur clusters. Intriguingly, although SQUID magnetometry showed that purified clMagR exhibited approximately five-fold higher mass magnetic susceptibility than hyMagR, its cellular magnetic response was weaker. We hypothesize that the Fe2+-preferred intracellular environment associated with hyMagR overexpression primes the cell for enhanced generation of reactive oxygen species (ROS) via the Fenton reaction. Exposure to an SMF synergizes with this primed redox state, triggering the bacterial SOS response and upregulating cell division inhibitors to efficiently induce uniform filamentation. Conclusion Our findings identify the Fe2+/Fe3+ redox state as a critical determinant of MagR-mediated morphological remodeling and magnetic responsiveness. This discovery suggests a potential strategy for engineering magnetically responsive cellular systems for synthetic biology applications, and provides a plausible framework, which potentially combines intrinsic protein magnetism with redox-state modulation, for further investigating the evolutionary mechanisms of MagR-mediated magnetoreception.
5.Evaluation of CARIFS Score and Negative Antigen Conversion Rate of Qingxuan Daozhi Formula in Treatment of Influenza in Children (Heat Accumulation in Lung and Stomach Syndrome):A Multi-center Randomized Controlled Clinical Study
Jing WANG ; Liqun WU ; Tiegang LIU ; Yongning CAO ; Jing QIU ; Jing LI ; Huaqing TAN ; Ying ZHANG ; Xulei GOU ; Jia WANG ; Jing LI ; Haipeng CHEN ; Xueying QIN ; Yuanshuo TIAN ; Yang WANG ; Chen BAI ; Zhendong WANG ; Qianqian LI ; He YU ; Xueyan MA ; Fei DONG ; Lin JIANG ; Yingqi XU ; Jianping LIU ; Xiaohong GU
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(13):188-196
ObjectiveThis paper aims to observe the syndrome improvement and negative antigen conversion rate of Qingxuan Daozhi formula in the treatment of influenza in children (heat accumulation in the lung and stomach syndrome). MethodsThrough a multi-center randomized controlled methodology design,confirmed influenza cases were collected from October 2022 to April 2023 in the pediatrics department of eight hospitals,such as Dongfang Hospital of Beijing University of Chinese Medicine. A total of 180 children with influenza and heat accumulation in the lung and stomach syndrome conforming to the standard were recruited through the clinic. The sick children meeting the inclusion criteria were randomly divided into groups by a block-randomized method. The children in the experimental group were treated with Qingxuan Daozhi formula for five days,and those in the control group were treated with Oseltamivir Phosphate Granules for five days. The primary efficacy indicator was the negative conversion rate of influenza antigen detection. Secondary efficacy indicators were the Canadian acute respiratory illness and flu scale (CARIFS) and the incidence of complications,severe cases, and critical cases. Follow-up observation was conducted on the day of enrollment,48 hours after medication,72 hours after medication, and (6+1) d after medication. ResultsOne hundred and eighty participants were randomly assigned to the experimental group (90 cases) or the control group (90 cases). All participants were followed up during the study. Comparison of influenza antigen detection results in the primary efficacy indicators showed that the average time of negative influenza antigen conversion in the experimental group was (5.29±1.25) d,and that in the control group was (5.40±1.68) d,without a statistically significant difference. After five days of intervention,52 cases in the experimental group and 51 cases in the control group converted to negative,without a statistically significant difference. CARIFS score results in the secondary efficacy indicators showed that during 72 hours after intervention,there were statistically significant differences between the experimental group and the control group in three dimensions, including headache,muscle soreness, and the need for extra care (P<0.05). On the (6+1) days after the intervention,the differences in both the experimental group and the control group were statistically significant in 10 dimensions, including sore throat,bad sleep,uncomfortable feeling,poor spirit and fatigue,crying more than usual,the need for extra care,symptom,function,influence on parents,and total score (P<0.05). The comparison results within the group in the dimensional scores of symptom, function, and influence on parents,as well as the CARIFS total score showed that with the delay of follow-up time,scores of both groups decreased significantly,with a statistically significant difference (P<0.01). Inter-group comparison results showed that the mean score of the experimental group was higher than that of the control group at the time of enrollment. With the progress of intervention,the score of the experimental group was significantly decreased compared with that of the control group. At the end of follow-up,the mean score of the experimental group was lower than that of the control group,with no statistically significant difference. In terms of the incidence of complications,severe cases, and critical cases, there were no complications,severe cases, and critical cases in the two groups,without a statistically significant difference. ConclusionThe symptom improvement effect and negative antigen conversion rate of Qingxuan Daozhi formula in the treatment of influenza in children (heat accumulation in the lung and stomach syndrome) are not inferior to Oseltamivir Phosphate granules, and children's acceptance is better. It can be more widely used in clinical treatment of influenza in children (heat accumulation in the lung and stomach syndrome).
6.CLDN18.2 in Gastric Cancer: Current Therapeutic Landscape and Future Perspectives
Fei ZHANG ; Ukyo OKAZAKI ; Izuma NAKAYAMA ; Kohei SHITARA
Journal of Gastric Cancer 2026;26(1):127-145
Claudin 18.2 (CLDN18.2), a tight junction protein selectively expressed in normal gastric epithelium and widely retained during carcinogenesis, has emerged as a promising therapeutic target for advanced gastric cancer (AGC). SPOTLIGHT and GLOW trials evaluated the anti-CLDN18.2 monoclonal antibody (mAb) zolbetuximab in combination with first-line chemotherapy, and established CLDN18.2 as a therapeutic target, initiating a paradigm shift toward a biomarker-driven treatment approach in AGC. In addition, from zolbetuximab to a diverse pipeline of promising high-affinity mAbs, bispecific antibodies, antibody-drug conjugates and chimeric antigen receptor T cells, this target has established a new and highly effective therapeutic avenue for CLDN18.2-expressing AGC. Therefore, as research progresses, CLDN18.2-targeted therapy is poised to become a cornerstone of treatment across multiple disease stages and cancer types. This review describes the biological role of CLDN18.2 in normal gastric epithelium and gastric carcinogenesis and summarizes the current therapeutic landscape and future perspectives targeting CLDN18.2 in AGC.
7.Benefits and risks of participating in video games among children and adolescents
ZHANG Chuanmin, GAO Fei, WEI Huqiang
Chinese Journal of School Health 2026;47(2):300-304
Abstract
To explore the benefits and risks of active video games (AVGs) for health promotion among children and adolescents, the study reviews relevant domestic and international literature and details the benefits of AVGs, including increased physical activity and energy expenditure, improved physical fitness, better mental health, enhanced social interaction, improved cognitive function and attention, and heightened body awareness. At the same time, it also addresses potential risks, such as gaming addiction and excessive use, sports related injuries and other risks, thereby providing a theoretical reference for children and adolescents to engage in AVGs in a healthy manner.
8.Genetic analysis and reproductive intervention for 46 Chinese pedigrees affected with Hereditary multiple exostoses.
Lilan SU ; Xiao HU ; Jing DAI ; Zhengxing WAN ; Duo YI ; Shuangfei LI ; Liang HU ; Yueqiu TAN ; Fei GONG ; Ge LIN ; Guangxiu LU ; Qianjun ZHANG ; Juan DU ; Wenbin HE
Chinese Journal of Medical Genetics 2026;43(4):253-258
OBJECTIVE:
To explore the genetic etiology of 46 Chinese pedigrees affected with Hereditary multiple exostoses (HME) and provide genetic counseling and reproductive intervention.
METHODS:
Whole-exome sequencing and Sanger sequencing were carried out on 87 patients from the 46 pedigrees to analyze the variants of EXT1 and EXT2 genes. Pathogenicity of the variants was assessed based on the guidelines from the American College of Medical Genetics and Genomics and Association for Molecular Pathology (ACMG/AMP). Prenatal diagnosis and preimplantation genetic testing (PGT) were provided for couples with identified pathogenic mutations. This study was approved by the Medical Ethics Committee of the hospital (Ethics No.: LL-SC-SG-2014-010).
RESULTS:
In total 17 and 22 pathogenic variants were respectively identified in the EXT1 and EXT2 genes, among which 5 EXT1 and 12 EXT2 variants were unreported previously. Three patients with no family history were found to harbor de novo variants of the EXT1 gene. Twenty nine couples had opted for PGT or underwent prenatal diagnosis following natural conception, and 17 healthy babies were born.
CONCLUSION
This study has clarified the genetic etiology of 45 HME pedigrees and identified 17 novel variants, which has enriched the mutational spectrum of the EXT1 and EXT2 genes. Reproductive intervention through PGT and prenatal diagnosis have prevented the recurrence of HME in these families.
Humans
;
Female
;
Male
;
Pedigree
;
Exostoses, Multiple Hereditary/diagnosis*
;
N-Acetylglucosaminyltransferases/genetics*
;
Adult
;
Exostosin 1
;
Asian People/genetics*
;
Genetic Testing
;
Exostosin 2
;
Mutation
;
China
;
Prenatal Diagnosis
;
Pregnancy
;
Genetic Counseling
;
Preimplantation Diagnosis
;
Exome Sequencing
;
East Asian People
9.The Regulatory Effects and Mechanisms of Piezo1 Channel on Chondrocytes and Bone Metabolic Dysregulation in Osteoarthritis
Yan LI ; Tao LIU ; Yu-Biao GU ; Hui-Qing TIAN ; Lei ZHANG ; Bi-Hui BAI ; Zhi-Jun HE ; Wen CHEN ; Jin-Peng LI ; Fei LI
Progress in Biochemistry and Biophysics 2026;53(3):564-576
Osteoarthritis (OA), a highly prevalent degenerative joint disease worldwide, is defined by articular cartilage degradation, abnormal bone remodeling, and persistent chronic inflammation. It severely compromises patients’ quality of life, and currently, there is no radical cure. Abnormal mechanical stress is widely regarded as a core driver of OA pathogenesis, and the exploration of mechanical signal perception and transduction mechanisms has become crucial for deciphering OA’s pathophysiological processes. Piezo1, a key mechanosensitive cation channel belonging to the Piezo protein family, has recently gained significant attention due to its pivotal role in mediating cellular responses to mechanical stimuli in joint tissues. This review systematically examines Piezo1’s expression patterns, regulatory mechanisms, and pathological functions in OA, with a particular focus on its dual roles in modulating chondrocyte homeostasis and bone metabolism disorders, while also delving into the underlying molecular signaling pathways and potential therapeutic implications. Piezo1, consisting of approximately 2 500 amino acids and forming a unique trimeric propeller-like structure, is widely expressed in chondrocytes, osteocytes, mesenchymal stem cells, and synovial cells. It exhibits permeability to cations such as Ca2+, K+, and Na+, and directly responds to membrane tension changes induced by mechanical stimuli like fluid shear stress and mechanical overload. In OA patients and animal models, Piezo1 expression is significantly upregulated, especially in cartilage regions subjected to abnormal mechanical stress (e.g., human temporomandibular joint cartilage). This overexpression is closely associated with aggravated cartilage degeneration, increased chondrocyte apoptosis, accelerated cellular senescence, and intensified inflammatory responses. Mechanical overload and pro-inflammatory cytokines (e.g., IL-1β) are key inducers of Piezo1 upregulation: IL-1β activates the PI3K/AKT/mTOR signaling pathway to enhance Piezo1 expression, forming a pathogenic positive feedback loop that inhibits chondrocyte autophagy, promotes apoptosis, and further accelerates joint degeneration. Mechanistically, Piezo1 mediates OA progression through multiple interconnected pathways. When activated by mechanical stress, Piezo1 triggers excessive Ca2+ influx, leading to endoplasmic reticulum stress (ERS) and mitochondrial dysfunction, which directly induce chondrocyte apoptosis. This process involves the activation of downstream signaling cascades such as cGAS-STING and YAP-MMP13/ADAMTS5. YAP, a transcriptional regulator, upregulates the expression of matrix metalloproteinase 13 (MMP13) and aggrecanase (ADAMTS5), thereby accelerating cartilage matrix degradation. Additionally, Piezo1-driven Ca2+ overload promotes the accumulation of reactive oxygen species (ROS) and upregulates senescence markers (p16 and p21), accelerating chondrocyte senescence via the p38MAPK and NF-κB pathways. Senescent chondrocytes secrete senescence-associated secretory phenotype (SASP) factors (e.g., IL-6, IL-1β), further amplifying joint inflammation. In terms of bone metabolism, Piezo1 maintains joint homeostasis by promoting the differentiation of fibrocartilage stem cells into chondrocytes and balancing bone formation and resorption through regulating the FoxC1/YAP axis and RANKL/OPG ratio. Therapeutically, targeting Piezo1 shows promising potential. Preclinical studies have demonstrated that Piezo1 inhibitors (e.g., GsMTx4) can reduce joint damage and alleviate pain in OA mice. Simultaneously, siRNA-mediated co-silencing of Piezo1 and TRPV4 (another mechanosensitive channel) decreases intracellular Ca2+ concentration, inhibits chondrocyte apoptosis, and promotes cartilage repair. Conditional knockout of Piezo1 using Gdf5-Cre transgenic mice alleviates cartilage degeneration in post-traumatic OA models by downregulating MMP13 and ADAMTS5 expression. Despite existing challenges, such as off-target effects of inhibitors, inefficient local drug delivery, and interindividual genetic variability, strategies like developing selective Piezo1 antagonists, optimizing targeted nanocarriers, and combining Piezo1-targeted therapy with physical therapy provide viable avenues for clinical translation. The authors propose that Piezo1 serves as a critical therapeutic target for OA, and future research should focus on deciphering its context-dependent regulatory networks, developing tissue-specific intervention strategies, and validating their efficacy and safety in clinical trials to address the unmet medical needs of OA patients.
10.Study on the role and mechanism of SPP1+ macrophages in the formation of chronic renal allograft fibrosis
Zexin YANG ; Zeping GUI ; Junqi ZHANG ; Gang ZHANG ; Hao CHEN ; Li SUN ; Shuang FEI ; Min GU ; Zijie WANG
Organ Transplantation 2026;17(3):413-421
Objective To investigate the role and potential mechanism of secreted phosphoprotein 1 (SPP1)+ macrophages in the formation of chronic renal allograft fibrosis. Methods The expression features of SPP1+ macrophages in renal allografts of chronic allograft dysfunction (CAD) patients were analyzed based on single-cell transcriptome data of renal tissues from patients with CAD. Transcription factor VIPER analysis and DoRothEA transcription factor activity analysis were performed on the single-cell transcriptome data. Renal tissue samples were collected from kidney transplant recipients, including the CAD group (n=5) and the non-renal allograft fibrosis group (CTL group, n=5). A mouse model of chronic allograft rejection was established and divided into the allogeneic kidney transplantation group (CAD group, n=3) and the syngeneic kidney transplantation group (SYN group, n=3). Hematoxylin-eosin staining was used to detect renal tissue injury in mice, and Masson staining was used to detect renal tissue fibrosis. Immunofluorescence staining was performed to detect SPP1 expression in renal tissues of transplant recipients and mouse renal allografts. Bone marrow-derived macrophages (BMDMs) were extracted from mice and subjected to hypoxia stimulation. The expression of hypoxia-inducible factor (HIF)-1α and SPP1 was detected by Western blot, and SPP1 expression was detected by flow cytometry. BMDMs were transfected with HIF-1α overexpression plasmid and HIF-1α small interfering RNA (siRNA) followed by hypoxia intervention, and the expression of HIF-1α and SPP1 was detected by Western blot. Mouse aortic endothelial cells (MAECs) were co-cultured with the supernatant of BMDMs, and the expression of endothelial-mesenchymal transition (EndMT)-related markers was detected by Western blot and immunofluorescence. Results Single-cell transcriptome analysis showed that the proportion of SPP1+ macrophages in renal allograft tissues was significantly higher in the CAD group than in the CTL group (P<0.05). The renal injury score and the percentage of interstitial fibrotic area in the CAD group were significantly higher than those in the SYN group (both P<0.05). Immunofluorescence staining showed that the proportion of SPP1+ macrophages was increased in the CAD group compared with the CTL group, and also increased in the CAD group compared with the SYN group (both P<0.05). VIPER analysis and DoRothEA transcription factor activity analysis revealed activation of the hypoxia pathway and upregulated expression of transcription factors such as HIF-1α in SPP1+ macrophages. SPP1 expression was elevated in BMDMs under hypoxic conditions. Knockdown of HIF-1α inhibited hypoxia-induced SPP1 protein expression, whereas overexpression of HIF-1α upregulated SPP1 protein levels. After co-culture of hypoxia-induced BMDMs with MAECs, the expression levels of EndMT-related markers were increased. Conclusions SPP1+ macrophages differentiated under hypoxia are significantly infiltrated in the formation of chronic renal allograft fibrosis, and may promote renal allograft fibrosis by inducing EndMT in renal vascular endothelial cells.


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