1.The Structure and Function of The YopJ Family Effectors in The Bacterial Type III Secretion System
Ao-Ning LI ; Wen-Bo LI ; Yu-Ying LU ; Min-Hui ZHU ; Yu-Long QIN ; Yong ZHAO ; Zhao-Huan ZHANG
Progress in Biochemistry and Biophysics 2026;53(3):516-533
The Type III Secretion System (T3SS) serves as a pivotal virulence apparatus for numerous Gram-negative bacterial pathogens, enabling them to infect both animal and plant hosts. Functioning as a molecular syringe, the T3SS directly translocates bacterial effector proteins from the bacterial cytoplasm into the interior of eukaryotic host cells. These effectors are central weapons that precisely manipulate a wide spectrum of host cellular physiological processes, ranging from cytoskeletal dynamics to immune signaling, to establish a favorable niche for bacterial survival and proliferation. Among the diverse arsenal of T3SS effectors, the YopJ family constitutes a critical group of virulence factors. Members of this family are characterized by a conserved catalytic triad structure—a hallmark of the CE clan of cysteine proteases that has been evolutionarily repurposed to confer acetyltransferase activity. A defining and intriguing feature of these enzymes is their stringent dependence on a host-derived eukaryotic cofactor, inositol hexakisphosphate (IP6), for allosteric activation. This requirement acts as a sophisticated molecular safeguard, ensuring enzymatic activity only within the appropriate host environment, thereby preventing detrimental effects on the bacterium itself. While seminal studies on individual members such as Yersinia’s YopJ and Salmonella’s AvrA have provided deep mechanistic insights, a systematic and integrative understanding of the structure-function relationships across the entire family remains fragmented. Key questions persist regarding how a conserved catalytic core has diverged to recognize distinct host substrates in different kingdoms of life. To address this gap, this article provides a systematic review of the YopJ family, focusing on three interconnected aspects: their structural features, their catalytic mechanism, and their divergent immunosuppressive strategies in animal versus plant hosts. By conducting a comparative analysis of the sequences and resolved three-dimensional structures of three representative members (e.g., HopZ1a, PopP2, AvrA), we elucidate regions of significant variation embedded within the conserved core catalytic architecture. These variable regions, often involving surface loops and substrate-binding interfaces, are crucial determinants of target specificity and functional specialization. The functional divergence of this effector family is most apparent when comparing their modes of action in different hosts. In animal hosts, YopJ-family effectors primarily sabotage innate immune signaling pathways. They achieve this by acetylating key serine and threonine residues within the activation loops of critical kinases in the MAPK and NF‑κB pathways. This post-translational modification blocks the phosphorylation and subsequent activation of these kinases, leading to potent suppression of inflammatory cytokine production. Conversely, in plant hosts, the strategy broadens to dismantle the two-tiered plant immune system. YopJ homologs target a more diverse set of substrates, including immune-associated receptor-like cytoplasmic kinases (RLCKs), microtubule networks via tubulin acetylation (which disrupts cellular trafficking and signaling), and transcription factors central to defense gene regulation. This multi-target approach effectively suppresses both Pattern-Triggered Immunity (PTI) and Effector-Triggered Immunity (ETI). In conclusion, this synthesis aims to deepen the mechanistic understanding of YopJ family-mediated pathogenesis by integrating structural biology with cellular function across host kingdoms. Elucidating the precise molecular basis for substrate selection—how conserved platforms achieve target diversity—is a major frontier. Furthermore, this knowledge provides a vital theoretical foundation for developing novel anti-virulence strategies. Targeting the conserved IP6-binding pocket or the catalytic acetyltransferase activity itself represents a promising avenue for designing broad-spectrum inhibitors that could disarm this critical family of bacterial effectors, potentially offering new therapeutic approaches against a range of pathogenic bacteria.
2.Targeted Regulation of Oocyte Quality by Traditional Chinese Medicine Compound Formula: A Review
Zhicheng JIA ; Yong LIU ; Guotao HU ; Ruoxi ZHAO ; Weisen FAN ; Ying GUO ; Ruihua ZHAO
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(10):328-336
The oocyte, as the origin of life, provides half the chromosomes to the embryo and supplies the proteins, substrates, energy, and other support necessary for embryonic development. It is the decisive factor determining the embryo's developmental potential. Infertility caused by reproductive endocrine diseases targets the oocyte as the final target cell. Improving oocyte quality represents a key and difficult point in the field of modern reproductive medicine. The decline of oocyte quality is related to meiosis abnormalities, DNA damage, mitochondrial dysfunction, oxidative stress, and other mechanisms. For oocyte quality problems, there is no unified international guideline to recommend drugs. Because the drug intervention research on oocytes involves strict clinical ethical restrictions, the current relevant research only stays in the animal and in vitro experimental stage and has not yet been applied to the clinic. Traditional Chinese medicine compound formula has a multi-target and multi-pathway regulation mechanism and is widely used in clinics. More and more research began to pay attention to the potential mechanism of traditional Chinese medicine compound formulas in improving oocyte quality. Traditional Chinese medicine compound formula has the advantages of multi-target and multi-channel synergy as well as better safety, individualization, and conformity to clinical ethics in improving oocyte quality. This article systematically reviewed the research progress on traditional Chinese medicine compound formula interventions for oocyte quality, aiming to summarize existing findings and provide recommendations to improve oocyte quality and optimize the clinical diagnosis and treatment of female infertility within traditional Chinese medicine.
3.Targeted Regulation of Oocyte Quality by Traditional Chinese Medicine Compound Formula: A Review
Zhicheng JIA ; Yong LIU ; Guotao HU ; Ruoxi ZHAO ; Weisen FAN ; Ying GUO ; Ruihua ZHAO
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(10):328-336
The oocyte, as the origin of life, provides half the chromosomes to the embryo and supplies the proteins, substrates, energy, and other support necessary for embryonic development. It is the decisive factor determining the embryo's developmental potential. Infertility caused by reproductive endocrine diseases targets the oocyte as the final target cell. Improving oocyte quality represents a key and difficult point in the field of modern reproductive medicine. The decline of oocyte quality is related to meiosis abnormalities, DNA damage, mitochondrial dysfunction, oxidative stress, and other mechanisms. For oocyte quality problems, there is no unified international guideline to recommend drugs. Because the drug intervention research on oocytes involves strict clinical ethical restrictions, the current relevant research only stays in the animal and in vitro experimental stage and has not yet been applied to the clinic. Traditional Chinese medicine compound formula has a multi-target and multi-pathway regulation mechanism and is widely used in clinics. More and more research began to pay attention to the potential mechanism of traditional Chinese medicine compound formulas in improving oocyte quality. Traditional Chinese medicine compound formula has the advantages of multi-target and multi-channel synergy as well as better safety, individualization, and conformity to clinical ethics in improving oocyte quality. This article systematically reviewed the research progress on traditional Chinese medicine compound formula interventions for oocyte quality, aiming to summarize existing findings and provide recommendations to improve oocyte quality and optimize the clinical diagnosis and treatment of female infertility within traditional Chinese medicine.
4.Association between rotational vertebral artery occlusion syndrome and posterior circulation ischemic events
Qianfan FENG ; Ying WEI ; Yong ZHANG
Journal of Apoplexy and Nervous Diseases 2025;42(3):239-243
Objective To investigate the incidence rate and location of rotational vertebral artery occlusion syndrome and its association with the symptoms of posterior circulation ischemia, the lesions of posterior circulation infarction, and newly-onset posterior circulation stroke. Methods A total of 283 patients who met the criteria were included, and the patients with positive results of neck rotation test and those with negative results were compared in terms of symptoms, imaging findings, and newly-onset posterior circulation stroke during follow-up. The chi-square test or the Fisher’s exact test was used for comparison of categorical data between two groups, with P<0.05 indicating statistical significance. Results Among the 283 patients enrolled, 23 (8.13%) met the diagnostic criteria for rotational vertebral artery occlusion syndrome. There was no significant difference in posterior circulation ischemic symptoms between the positive group and the negative group (P=0.089), and compared with the negative group, the positive group had significantly higher numbers of posterior circulation infarcts at baseline and newly-onset cases of posterior circulation stroke during follow-up (P=0.010 and 0.009). Conclusion Rotational vertebral artery occlusion syndrome significantly increases the risk of posterior circulation infarction.
Stroke
5.Study on Kinetic and Static Tasks With Different Resistance Coefficients in Post-stroke Rehabilitation Training Based on Functional Near-infrared Spectroscopy
Ling-Di FU ; Jia-Xuan DOU ; Ting-Ting YING ; Li-Yong YIN ; Min TANG ; Zhen-Hu LIANG
Progress in Biochemistry and Biophysics 2025;52(7):1890-1903
ObjectiveFunctional near-infrared spectroscopy (fNIRS), a novel non-invasive technique for monitoring cerebral activity, can be integrated with upper limb rehabilitation robots to facilitate the real-time assessment of neurological rehabilitation outcomes. The rehabilitation robot is designed with 3 training modes: passive, active, and resistance. Among these, the resistance mode has been demonstrated to yield superior rehabilitative outcomes for patients with a certain level of muscle strength. The control modes in the resistance mode can be categorized into dynamic and static control. However, the effects of different control modes in the resistance mode on the motor function of patients with upper limb hemiplegia in stroke remain unclear. Furthermore, the effects of force, an important parameter of different control modes, on the activation of brain regions have rarely been reported. This study investigates the effects of dynamic and static resistance modes under varying resistance levels on cerebral functional alterations during motor rehabilitation in post-stroke patients. MethodsA cohort of 20 stroke patients with upper limb dysfunction was enrolled in the study, completing preparatory adaptive training followed by 3 intensity-level tasks across 2 motor paradigms. The bilateral prefrontal cortices (PFC), bilateral primary motor cortices (M1), bilateral primary somatosensory cortices (S1), and bilateral premotor and supplementary motor cortices (PM) were examined in both the resting and motor training states. The lateralization index (LI), phase locking value (PLV), network metrics were employed to examine cortical activation patterns and topological properties of brain connectivity. ResultsThe data indicated that both dynamic and static modes resulted in significantly greater activation of the contralateral M1 area and the ipsilateral PM area when compared to the resting state. The static patterns demonstrated a more pronounced activation in the contralateral M1 in comparison to the dynamic patterns. The results of brain network analysis revealed significant differences between the dynamic and resting states in the contralateral PFC area and contralateral M1 area (F=4.709, P=0.038), as well as in the contralateral PM area and ipsilateral M1 area (F=4.218, P=0.049). Moreover, the findings indicated a positive correlation between the activation of the M1 region and the increase in force in the dynamic mode, which was reversed in the static mode. ConclusionBoth dynamic and static resistance training modes have been demonstrated to activate the corresponding brain functional regions. Dynamic resistance modes elicit greater oxygen changes and connectivity to the region of interest (ROI) than static resistance modes. Furthermore, the effects of increasing force differ between the two modes. In patients who have suffered a stroke, dynamic modes may have a more pronounced effect on the activation of exercise-related functional brain regions.
6.Application and clinical efficacy of red blood cell therapeutic apheresis in erythropoietic protoporphyria and hereditary hemochromatosis
Haoqiang LIU ; Caihan ZHAO ; Qing YUAN ; Lixia XIE ; Yong ZOU ; Ying LU
Chinese Journal of Blood Transfusion 2025;38(7):915-921
Objective: To explore the application and clinical efficacy of red blood cell therapeutic apheresis in erythropoietic protoporphyria (EPP) and hereditary hemochromatosis (HH). Methods: 1) The EPP patient was hospitalized twice for "abdominal pain, nausea, vomiting, and brown urine". One and two sessions of red blood cell exchange/therapeutic plasma exchange (RCE/TPE) were respectively performed during the two hospitalizations. During each session, one RCE with 6-8 units of leukoreduced RBCs and 3-4 TPE procedures with 1 800-2 000 mL of frozen plasma was conducted. Biochemical parameters were monitored before and after treatment. 2) The HH patient was hospitalized for “repeatedly elevated aminotransferases”. Erythrocytapheresis was performed once, removing 550 mL of red blood cells, and venous phlebotomy was conducted once every 2 months subsequently. Blood routine and ferritin levels were assessed before and after treatment. Results: 1) During the first hospitalization, the EPP patient was relieved of the abdominal pain and brown urine after therapeutic apheresis. The total bilirubin level decreased from 141.8 μmol/L on admission to 68.6 μmol/L at discharge, with a symptom remission duration of 10 months. During the second hospitalization, the EPP patient still had recurrent abdominal pain after therapeutic apheresis. He developed psychiatric symptoms and gastrointestinal bleeding subsequently, accompanied by elevated bilirubin levels. Liver function deteriorated and the patient went into the state of the end-stage liver disease (ESLD). 2) For the HH patient, the hemoglobin level prior to erythrocytapheresis and vein phlebotomy was 150-160 g/L, with the lowest value occurring two days after erythrocytapheresis, decreasing to 107 g/L. The ferritin level before erythrocytapheresis was 2 428.08 ng/mL and it declined gradually after theraphy, with the lowest value occurring two months after erythrocytapheresis, decreasing to 1 094 ng/mL. The ferritin level was 1 114 ng/mL two months following the first vein phlebotomy, however it increased to 1 472 ng/mL two months after the second vein phlebotomy. Conclusion: RCE/TPE may alleviate protoporphyrin liver disease and help patients with bridging liver transplantation before EPP developments to ESLD. For HH patients with significantly elevated ferritin levels, erythrocytapheresis reduces serum ferritin more quickly and maintains its level longer relative to phlebotomy.
7.Application and clinical efficacy of red blood cell therapeutic apheresis in erythropoietic protoporphyria and hereditary hemochromatosis
Haoqiang LIU ; Caihan ZHAO ; Qing YUAN ; Lixia XIE ; Yong ZOU ; Ying LU
Chinese Journal of Blood Transfusion 2025;38(7):915-921
Objective: To explore the application and clinical efficacy of red blood cell therapeutic apheresis in erythropoietic protoporphyria (EPP) and hereditary hemochromatosis (HH). Methods: 1) The EPP patient was hospitalized twice for "abdominal pain, nausea, vomiting, and brown urine". One and two sessions of red blood cell exchange/therapeutic plasma exchange (RCE/TPE) were respectively performed during the two hospitalizations. During each session, one RCE with 6-8 units of leukoreduced RBCs and 3-4 TPE procedures with 1 800-2 000 mL of frozen plasma was conducted. Biochemical parameters were monitored before and after treatment. 2) The HH patient was hospitalized for “repeatedly elevated aminotransferases”. Erythrocytapheresis was performed once, removing 550 mL of red blood cells, and venous phlebotomy was conducted once every 2 months subsequently. Blood routine and ferritin levels were assessed before and after treatment. Results: 1) During the first hospitalization, the EPP patient was relieved of the abdominal pain and brown urine after therapeutic apheresis. The total bilirubin level decreased from 141.8 μmol/L on admission to 68.6 μmol/L at discharge, with a symptom remission duration of 10 months. During the second hospitalization, the EPP patient still had recurrent abdominal pain after therapeutic apheresis. He developed psychiatric symptoms and gastrointestinal bleeding subsequently, accompanied by elevated bilirubin levels. Liver function deteriorated and the patient went into the state of the end-stage liver disease (ESLD). 2) For the HH patient, the hemoglobin level prior to erythrocytapheresis and vein phlebotomy was 150-160 g/L, with the lowest value occurring two days after erythrocytapheresis, decreasing to 107 g/L. The ferritin level before erythrocytapheresis was 2 428.08 ng/mL and it declined gradually after theraphy, with the lowest value occurring two months after erythrocytapheresis, decreasing to 1 094 ng/mL. The ferritin level was 1 114 ng/mL two months following the first vein phlebotomy, however it increased to 1 472 ng/mL two months after the second vein phlebotomy. Conclusion: RCE/TPE may alleviate protoporphyrin liver disease and help patients with bridging liver transplantation before EPP developments to ESLD. For HH patients with significantly elevated ferritin levels, erythrocytapheresis reduces serum ferritin more quickly and maintains its level longer relative to phlebotomy.
8.Recommendations for enhanced primary series (third dose) COVID-19 vaccination for people with rheumatic diseases: chapter of Rheumatologists, College of Physicians, Singapore.
Chuanhui XU ; Manjari LAHIRI ; Amelia SANTOSA ; Li-Ching CHEW ; Stanley ANGKODJOJO ; Melonie SRIRANGANATHAN ; Warren FONG ; Thaschawee ARKACHAISRI ; Ernest SURESH ; Kok Ooi KONG ; Aisha LATEEF ; Tau Hong LEE ; Keng Hong LEONG ; Andrea LOW ; Teck Choon TAN ; Ying-Ying LEUNG
Singapore medical journal 2025;66(10):532-539
INTRODUCTION:
This review aims to provide evidence-based recommendations for an enhanced primary series (third dose) coronavirus disease 2019 (COVID-19) vaccination in people with rheumatic diseases (PRDs) in the local and regional context.
METHODS:
Literature reviews were performed regarding the necessity, efficacy, safety and strategies for enhanced primary series COVID-19 vaccination in PRDs. Recommendations were developed based on evidence according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology. Evidence was synthesised by eight working group members, and the consensus was achieved by a Delphi method with nine members of an expert task force panel.
RESULTS:
Two graded recommendations and one ungraded position statement were developed. PRDs have impaired immunogenicity from the COVID-19 vaccine and are at an increased risk of postvaccine breakthrough severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and poor clinical outcomes, compared to the general population. We strongly recommend that PRDs on immunomodulatory drugs be offered a third dose of the messenger RNA (mRNA) vaccine as part of an enhanced primary series, after the standard two-dose regimen. We conditionally recommend that the third dose of mRNA vaccine against SARS-CoV-2 be given at least 4 weeks after the second dose or as soon as possible thereafter. There is insufficient data to inform whether the third mRNA vaccine should be homologous or heterologous in PRDs.
CONCLUSION
These recommendations that were developed through evidence synthesis and formal consensus process provide guidance for an enhanced primary series COVID-19 vaccination in PRDs.
Humans
;
COVID-19/prevention & control*
;
COVID-19 Vaccines/administration & dosage*
;
Rheumatic Diseases/immunology*
;
Singapore
;
SARS-CoV-2
;
Vaccination/methods*
;
Delphi Technique
;
Immunization, Secondary
9.Burnout among COVID-19 hospital-based contact tracers in Singapore: results of a mixed-method, cross-sectional multicentre study.
Ian Matthias NG ; Tzu-Jung WONG ; Yong YANG ; Indumathi VENKATACHALAM ; Jean Xiang Ying SIM ; Liang En WEE ; Tau Ming LIEW ; Evelyn BOON ; Tong Yong NG ; Hwi Kwang HAN ; Diana Yuen Lan TAN
Singapore medical journal 2025;66(12):651-658
INTRODUCTION:
During the coronavirus disease 2019 (COVID-19) pandemic, contact tracers were under immense pressure to deliver effective and timely contact tracing, raising concerns of higher susceptibility to burnout. Our study aimed to determine burnout prevalence among hospital-based contact tracers and associated risk factors, so that interventions to reduce burnout risk could be formulated.
METHODS:
One hundred and ninety-six active contact tracers across three hospitals within a healthcare cluster were invited to complete an anonymous online survey. To identify burntout, data such as demographics, work-related variables and contact tracing-related variables were collected using the Copenhagen Burnout Inventory. Associated factors were identified using multivariate statistics. Open-ended questions were included to understand the challenges and potential improvements through qualitative analysis.
RESULTS:
A total of 126 participants completed the survey, giving a completion rate of 64%, and almost half of these participants (42.9%) reported burnout. Protective factors included being on work-from-home arrangements (adjusted odds ratio [OR] 0.22, 95% confidence interval [CI] 0.08-0.56), perception of being well supported by their institution (adjusted OR 0.25, 95% CI 0.08-0.80) and being married (adjusted OR 0.28, 95% CI 0.12-0.64). Risk factors included having an administrative role pre-COVID-19 (adjusted OR 3.62, 95% CI 1.33-9.83). Work-related burnout was related to being activated for more than 1 day in the preceding week (unadjusted OR 3.25, 95% CI 1.33-7.94) and multiple activations in a day (unadjusted OR 3.54, 95% CI 1.44-4.41). Biggest challenges identified by participants were language barrier (62.7%), followed by workflow-related issues (42.1%).
CONCLUSION
Our study demonstrated burnout and other challenges faced by a team of mostly hospital-based administrative staff redeployed on a part-time basis to ensure timely contact tracing. To mitigate burnout, we recommend choosing staff on work-from-home arrangements and ensuring adequate manpower and rostering arrangements.
Humans
;
COVID-19/epidemiology*
;
Burnout, Professional/epidemiology*
;
Singapore/epidemiology*
;
Female
;
Male
;
Cross-Sectional Studies
;
Adult
;
Middle Aged
;
Risk Factors
;
Surveys and Questionnaires
;
Contact Tracing/methods*
;
SARS-CoV-2
;
Prevalence
;
Pandemics
10.Premature ovarian insufficiency: When ovaries retire early.
Stella Rizalina Sasha SUGIANTO ; Lisa WEBBER ; Farah SAFDAR HUSAIN ; Veronique VIARDOT-FOUCAULT ; Sadhana NADARAJAH ; Jiin Ying LIM ; Ee Shien TAN ; Tze Tein YONG ; Rukshini PUVANENDRAN
Annals of the Academy of Medicine, Singapore 2025;54(3):178-191
INTRODUCTION:
Premature ovarian insufficiency (POI) refers to loss of ovarian activity before the age 40 years. POI has significant detrimental effects on health (infertility, cardiovascular diseases, type 2 diabetes, reduced bone density, dementia), well-being and longevity. This summary is a practical toolkit for health-care professionals (HCPs) looking after women with POI.
METHOD:
A workgroup comprising specialists in gynaecology, reproductive medicine, endocrinology, genetics and family medicine reviewed relevant guidelines and literature on POI to establish recom-mendations for the diagnosis and management of POI in Singapore.
RESULTS:
A summary to assist HCPs manage POI was produced, outlining: (1) the aetiology and conse-quences of POI; (2) making the diagnosis; (3) hormone therapy (HT) prescribing options including for those with additional medical conditions; (4) counselling women with POI about HT; and (5) long-term management of POI.
CONCLUSION
Timely diagnosis and management of POI is vital to prevent long-term adverse consequences, except infertility. HT is the mainstay of treatment and there are no alternatives as effective. Contraindications are very few; estrogen-sensitive cancer is the main contraindication, and caution in prescribing may be needed with established coexisting cardiovascular disease. Estrogen dosage is higher than when treating normal menopause, and as a result, the patient might require more progestogen for endometrial protection. Minimising cardiovascular risk factors by following a healthy lifestyle is important. POI is a significant public health issue and it is imperative that women have affordable access to appropriate HT. Large-scale research on POI in Asian women is needed.
Humans
;
Primary Ovarian Insufficiency/drug therapy*
;
Female
;
Estrogen Replacement Therapy
;
Singapore
;
Adult

Result Analysis
Print
Save
E-mail