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.Four Weeks of HIIT Modulates Lactate-mediated Synaptic Plasticity to Improve Depressive-like Behavior in CUMS Rats
Yu-Mei HAN ; Zi-Wei ZHANG ; Jia-Ren LIANG ; Chun-Hui BAO ; Jun-Sheng TIAN ; Shi ZHOU ; Huan XIANG ; Yong-Hong YANG
Progress in Biochemistry and Biophysics 2025;52(6):1499-1510
ObjectiveThis study aimed to investigate the effects of 4-week high-intensity interval training (HIIT) on synaptic plasticity in the prefrontal cortex (PFC) of rats exposed to chronic unpredictable mild stress (CUMS), and to explore its potential mechanisms. MethodsA total of 48 male Sprague-Dawley rats were randomly divided into 4 groups: control (C), model (M), control plus HIIT (HC), and model plus HIIT (HM). Rats in groups M and HM underwent 8 weeks of CUMS to establish depression-like behaviors, while groups HC and HM received HIIT intervention beginning from the 5th week for 4 consecutive weeks. The HIIT protocol consisted of repeated intervals of 3 min at high speed (85%-90% maximal training speed, Smax) alternated with one minute at low speed (50%-55% Smax), with 3 to 5 sets per session, conducted 5 d per week. Behavioral assessments and tail-vein blood lactate levels were measured at the end of the 4th and 8th weeks. After the intervention, rat PFC tissues were collected for Golgi staining to analyze synaptic morphology. Enzyme-linked immunosorbent assays (ELISA) were employed to detect brain-derived neurotrophic factor (BDNF), monocarboxylate transporter 1 (MCT1), lactate, and glutamate levels in the PFC, as well as serotonin (5-HT) levels in serum. Additionally, Western blot analysis was conducted to quantify the expression of synaptic plasticity-related proteins, including c-Fos, activity-regulated cytoskeleton-associated protein (Arc), and N-methyl-D-aspartate receptor 1 (NMDAR1). ResultsCompared to the control group (C), the CUMS-exposed rats (group M) exhibited significant reductions in sucrose preference rates, number of grid crossings, frequency of upright postures, and entries into and duration spent in open arms of the elevated plus maze, indicating marked depressive-like behaviors. Additionally, the group M showed significantly reduced dendritic spine density in the PFC, along with elevated levels of c-Fos, Arc, NMDAR1 protein expression, and increased concentrations of lactate and glutamate. Conversely, BDNF and MCT1 contents in the PFC and 5-HT levels in serum were significantly decreased. Following HIIT intervention, rats in the group HM displayed considerable improvement in behavioral indicators compared with the group M, accompanied by significant elevations in PFC MCT1 and lactate concentrations. Furthermore, HIIT notably normalized the expression levels of c-Fos, Arc, NMDAR1, as well as glutamate and BDNF contents in the PFC. Synaptic spine density also exhibited significant recovery. ConclusionFour weeks of HIIT intervention may alleviate depressive-like behaviors in CUMS rats by increasing lactate levels and reducing glutamate concentration in the PFC, thereby downregulating the overexpression of NMDAR, attenuating excitotoxicity, and enhancing synaptic plasticity.
3.The Role of Golgi Apparatus Homeostasis in Regulating Cell Death and Major Diseases
Xin-Yue CHENG ; Feng-Hua YAO ; Hui ZHANG ; Yong-Ming YAO
Progress in Biochemistry and Biophysics 2025;52(8):2051-2067
The Golgi apparatus (GA) is a key membranous organelle in eukaryotic cells, acting as a central component of the endomembrane system. It plays an irreplaceable role in the processing, sorting, trafficking, and modification of proteins and lipids. Under normal conditions, the GA cooperates with other organelles, including the endoplasmic reticulum (ER), lysosomes, mitochondria, and others, to achieve the precise processing and targeted transport of nearly one-third of intracellular proteins, thereby ensuring normal cellular physiological functions and adaptability to environmental changes. This function relies on Golgi protein quality control (PQC) mechanisms, which recognize and handle misfolded or aberrantly modified proteins by retrograde transport to the ER, proteasomal degradation, or lysosomal clearance, thus preventing the accumulation of toxic proteins. In addition, Golgi-specific autophagy (Golgiphagy), as a selective autophagy mechanism, is also crucial for removing damaged or excess Golgi components and maintaining its structural and functional homeostasis. Under pathological conditions such as oxidative stress and infection, the Golgi apparatus suffers damage and stress, and its homeostatic regulatory network may be disrupted, leading to the accumulation of misfolded proteins, membrane disorganization, and trafficking dysfunction. When the capacity and function of the Golgi fail to meet cellular demands, cells activate a series of adaptive signaling pathways to alleviate Golgi stress and enhance Golgi function. This process reflects the dynamic regulation of Golgi capacity to meet physiological needs. To date, 7 signaling pathways related to the Golgi stress response have been identified in mammalian cells. Although these pathways have different mechanisms, they all help restore Golgi homeostasis and function and are vital for maintaining overall cellular homeostasis. It is noteworthy that the regulation of Golgi homeostasis is closely related to multiple programmed cell death pathways, including apoptosis, ferroptosis, and pyroptosis. Once Golgi function is disrupted, these signaling pathways may induce cell death, ultimately participating in the occurrence and progression of diseases. Studies have shown that Golgi homeostatic imbalance plays an important pathological role in various major diseases. For example, in Alzheimer’s disease (AD) and Parkinson’s disease (PD), Golgi fragmentation and dysfunction aggravate the abnormal processing of amyloid β-protein (Aβ) and Tau protein, promoting neuronal loss and advancing neurodegenerative processes. In cancer, Golgi homeostatic imbalance is closely associated with increased genomic instability, enhanced tumor cell proliferation, migration, invasion, and increased resistance to cell death, which are important factors in tumor initiation and progression. In infectious diseases, pathogens such as viruses and bacteria hijack the Golgi trafficking system to promote their replication while inducing host defensive cell death responses. This process is also a key mechanism in host-pathogen interactions. This review focuses on the role of the Golgi apparatus in cell death and major diseases, systematically summarizing the Golgi stress response, regulatory mechanisms, and the role of Golgi-specific autophagy in maintaining homeostasis. It emphasizes the signaling regulatory role of the Golgi apparatus in apoptosis, ferroptosis, and pyroptosis. By integrating the latest research progress, it further clarifies the pathological significance of Golgi homeostatic disruption in neurodegenerative diseases, cancer, and infectious diseases, and reveals its potential mechanisms in cellular signal regulation.
4.Comparison of long-term prognosis in elderly stageⅠnon-small cell lung cancer patients undergoing lobectomy or segmentectomy: A propensity score matching study
Hui CUI ; Yong SHI ; Yongkang YU ; Xiang HU
Chinese Journal of Clinical Thoracic and Cardiovascular Surgery 2025;32(06):805-813
Objective To compare the long-term prognosis of elderly patients with stageⅠnon-small cell lung cancer (NSCLC) after lobectomy or segmentectomy. Methods Data of elderly patients with stageⅠNSCLC between 2010 and 2020 were collected from the SEER database. According to the resection method, patients were divided into a lobectomy group and a segmentectomy group. The overall survival (OS) and lung cancer-specific survival (LCSS) of the two groups were compared by propensity score matching (lobectomy : segmentectomy=2 : 1). Results A total of 9990 patients were included, including 5840 (58.46%) females and 4150 (41.54%) males, with an average age of (70.48±6.47) years. Among them, 9029 patients were in the lobectomy group and 961 patients were in the segmentectomy group. After propensity score matching, a total of 2883 patients were matched, including 1 922 patients in the lobectomy group and 961 patients in the segmentectomy group. There was no statistical difference in baseline data between the two groups (P>0.05). The 10-year OS rate and LCSS rate of the lobectomy group were higher than those of the segmentectomy group (OS: 51.15% vs. 38.35%, P<0.01; LCSS: 79.68% vs. 71.52%, P<0.01). Subgroup analysis showed that the survival advantage of lobectomy was found in patients aged 60-<70 years and ≥80 years; for patients 70-<80 years, there was no statistical difference in OS or LCSS between the two surgical methods (P>0.05). In addition, for patients with tumor diameter ≤2 cm (stages ⅠA1-ⅠA2), lymph node dissection number≥10, and receiving adjuvant radiotherapy/chemotherapy, segmentectomy could also achieve a similar prognosis as lobectomy. Conclusion Overall, for elderly patients with stage ⅠNSCLC, lobectomy can achieve better OS and LCSS. However, individual differences, tumor characteristics, and perioperative treatment plans should be considered comprehensively to determine the surgical method for elderly patients with stageⅠNSCLC.
5.The Invariant Neural Representation of Neurons in Pigeon’s Ventrolateral Mesopallium to Stereoscopic Shadow Shapes
Xiao-Ke NIU ; Meng-Bo ZHANG ; Yan-Yan PENG ; Yong-Hao HAN ; Qing-Yu WANG ; Yi-Xin DENG ; Zhi-Hui LI
Progress in Biochemistry and Biophysics 2025;52(10):2614-2626
ObjectiveIn nature, objects cast shadows due to illumination, forming the basis for stereoscopic perception. Birds need to adapt to changes in lighting (meaning they can recognize stereoscopic shapes even when shadows look different) to accurately perceive different three-dimensional forms. However, how neurons in the key visual brain area in birds handle these lighting changes remains largely unreported. In this study, pigeons (Columba livia) were used as subjects to investigate how neurons in pigeon’s ventrolateral mesopallium (MVL) represent stereoscopic shapes consistently, regardless of changes in lighting. MethodsVisual cognitive training combined with neuronal recording was employed. Pigeons were first trained to discriminate different stereoscopic shapes (concave/convex). We then tested whether and how light luminance angle and surface appearance of the stereoscopic shapes affect their recognition accuracy, and further verify whether the results rely on specify luminance color. Simultaneously, neuronal firing activity of neurons was recorded with multiple electrode array implanted from the MVL during the presentation of difference shapes. The response was finally analyzed how selectively they responded to different stereoscopic shapes and whether their selectivity was affected by the changes of luminance condition (like lighting angle) or surface look. Support vector machine (SVM) models were trained on neuronal population responses recorded under one condition (light luminance angle of 45°) and used to decode responses under other conditions (light luminance angle of 135°, 225°, 315°) to verify the invariance of responses to different luminance conditions. ResultsBehavioral results from 6 pigeons consistently showed that the pigeons could reliably identify the core 3D shape (over 80% accuracy), and this ability wasn’t affected by changes in light angle or surface appearance. Statistical analysis of 88 recorded neurons from 6 pigeons revealed that 83% (73/88) showed strong selectivity for specific 3D shapes (selectivity index>0.3), and responses to convex shapes were consistently stronger than to concave shapes. These shape-selective responses remained stable across changes in light angle and surface appearance. Neural patterns were consistent under both blue and orange lighting. The decoding accuracy achieves above 70%, suggesting stable responses under different conditions (e.g., different lighting angles or surface appearance). ConclusionNeurons in the pigeon MVL maintain a consistent neural encoding pattern for different stereoscopic shapes, unaffected by illumination or surface appearance. This ensures stable object recognition by pigeons in changing visual environments. Our findings provide new physiological evidence for understanding how birds achieve stable perception (“invariant neural representations”) while coping with variations in the visual field.
6.Risk and protective factors associated with adolescent depression in Singapore: a systematic review.
Wei Sheng GOH ; Jun Hao Norman TAN ; Yang LUO ; Sok Hui NG ; Mohamed Sufyan Bin Mohamed SULAIMAN ; John Chee Meng WONG ; Victor Weng Keong LOH
Singapore medical journal 2025;66(1):2-14
INTRODUCTION:
Adolescent depression is prevalent, and teen suicide rates are on the rise locally. A systemic review to understand associated risk and protective factors is important to strengthen measures for the prevention and early detection of adolescent depression and suicide in Singapore. This systematic review aims to identify the factors associated with adolescent depression in Singapore.
METHODS:
A systematic search on the following databases was performed on 21 May 2020: PubMed, EMBASE and PsycINFO. Full texts were reviewed for eligibility, and the included studies were appraised for quality using the Newcastle Ottawa Scale. Narrative synthesis of the finalised articles was performed through thematic analysis.
RESULTS:
In total, eight studies were included in this review. The four factors associated with adolescent depression identified were: (1) sociodemographic factors (gender, ethnicity); (2) psychological factors, including childhood maltreatment exposure and psychological constructs (hope, optimism); (3) coexisting chronic medical conditions (asthma); and (4) lifestyle factors (sleep inadequacy, excessive internet use and pathological gaming).
CONCLUSION
The identified factors were largely similar to those reported in the global literature, except for sleep inadequacy along with conspicuously absent factors such as academic stress and strict parenting, which should prompt further research in these areas. Further research should focus on current and prospective interventions to improve mental health literacy, targeting sleep duration, internet use and gaming, and mitigating the risk of depression in patients with chronic disease in the primary care and community setting.
Humans
;
Singapore/epidemiology*
;
Adolescent
;
Risk Factors
;
Depression/etiology*
;
Protective Factors
;
Male
;
Female
;
Life Style
;
Suicide
7.Mental health-related presentations to a tertiary emergency department during the COVID-19 pandemic.
Elijah Gin LIM ; Ashley Ern Hui HOW ; Julian Zhong Hui LEE ; Sameera GANTI ; Eunizar OMAR
Singapore medical journal 2025;66(12):645-650
INTRODUCTION:
The coronavirus disease 2019 (COVID-19) pandemic has caused significant mental distress in populations globally. At the frontline of the pandemic, emergency departments (EDs) are the prime setting to observe the effects of the pandemic on the mental health of the population. We aimed to describe the trend of mental health-related ED attendances at an acute hospital in Singapore before and during the various stages of the COVID-19 pandemic.
METHODS:
This is a retrospective, descriptive study of patients who presented to the ED between 1 January 2019 and 31 December 2020. Patients diagnosed with mental health-related systematised nomenclature of medicine who visited the ED during this period were identified and were placed into mental health diagnosis categories for analysis. A comparison was made between patients who presented before the pandemic (2019) and during the pandemic (2020).
RESULTS:
During the study periods, we identified 1,421 patients, of whom 27 were excluded due to non-mental health-related diagnoses, leaving 1,394 patients for analysis. There was a 36.7% increase in mental health-related ED presentations from 2019 to 2020. The proportion of higher-acuity mental health-related ED attendances and number of suicide attempts also increased.
CONCLUSION
Our study described an increase in the proportion of high-acuity mental health-related ED attendances during the COVID-19 pandemic. Emergency physicians must be cognisant of the effects of the pandemic on mental health. Further research should be conducted to better equip the healthcare system for handling all aspects of the pandemic.
Humans
;
COVID-19/psychology*
;
Emergency Service, Hospital/statistics & numerical data*
;
Retrospective Studies
;
Singapore/epidemiology*
;
Male
;
Female
;
Adult
;
Middle Aged
;
Mental Disorders/diagnosis*
;
Mental Health
;
SARS-CoV-2
;
Tertiary Care Centers
;
Pandemics
;
Aged
;
Suicide, Attempted/statistics & numerical data*
;
Young Adult
;
Adolescent
8.Frontiers in subclinical atherosclerosis and the latest in early life preventive cardiology.
Mayank DALAKOTI ; Ching Kit CHEN ; Ching-Hui SIA ; Kian-Keong POH
Singapore medical journal 2025;66(3):141-146
Subclinical atherosclerosis underlies most cardiovascular diseases, manifesting before clinical symptoms and representing a key focus for early prevention strategies. Recent advancements highlight the importance of early detection and management of subclinical atherosclerosis. This review underscores that traditional risk factor levels considered safe, such as low-density lipoprotein cholesterol (LDL-C) and glycated haemoglobin (HbA1c), may still permit the development of atherosclerosis, suggesting a need for stricter thresholds. Early-life interventions are crucial, leveraging the brain's neuroplasticity to establish lifelong healthy habits. Preventive strategies should include more aggressive management of LDL-C and HbA1c from youth and persist into old age, supported by public health policies that promote healthy environments. Emphasising early education on cardiovascular health can fundamentally shift the trajectory of cardiovascular disease prevention and optimise long-term health outcomes.
Humans
;
Atherosclerosis/diagnosis*
;
Risk Factors
;
Cardiovascular Diseases/prevention & control*
;
Cholesterol, LDL/blood*
;
Glycated Hemoglobin
;
Cardiology/trends*
;
Heart Disease Risk Factors

Result Analysis
Print
Save
E-mail