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.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.
3.Mechanisms by which aerobic and resistance exercises improve obesity-related cognitive impairment
Yu LIU ; Senlin LEI ; Jintao ZHOU ; Hui LIU ; Xianhui LI
Chinese Journal of Tissue Engineering Research 2026;30(5):1171-1183
BACKGROUND:Obesity is not only related to metabolic diseases such as diabetes and cardiovascular disease,but also closely related to the increased risk of cognitive decline,dementia and other neurodegenerative diseases.Studies have found that aerobic exercise and resistance exercise can help improve obesity-related cognitive impairment,but their therapeutic effects and related mechanisms of action are still unclear.OBJECTIVE:To explore the protective effects of aerobic and resistance exercises on the nervous center of obesity-related cognitive impairment mice.METHODS:Forty-eight 8-week-old C57BL/6J wild-type male mice were randomly divided into four groups:a control group was fed normally for 20 weeks;a high fat group was fed with high fat diet(60%fat energy)for 20 weeks;an aerobic exercise group was fed with 12 weeks of high-fat diet followed by 8 weeks of aerobic exercise;and a resistance exercise group was fed with 12 weeks of high-fat diet followed by 8 weeks of resistance exercise.After the exercise intervention,body mass was weighed,insulin tolerance and glucose tolerance were tested to evaluate insulin resistance,and cognitive function of mice in each group was detected by new object recognition experiment and Y-maze experiment.The morphology of hippocampal and cortical tissue cells was observed by hematoxylin-eosin staining.The mRNA relative expression levels of tumor necrosis factor-α and interleukin-6 were detected by real-time fluorescence quantitative PCR,and the protein expressions of Bax,Bcl-2,nuclear factor-κB,Cleaved Caspase-1,Caspase-3,synapsin 1 and brain-derived neurotrophic factor were detected by western blot.RESULTS AND CONCLUSION:(1)Compared with the control group,the body mass of mice increased in the high-fat group(P<0.05),accompanied by insulin resistance and cognitive dysfunction,the expression levels of nuclear factor-κB,Bax,Caspase-3,Cleaved Caspase-1 in the hippocampus were significantly increased(P<0.05),the expression levels of brain-derived neurotrophic factor,synapsin 1and Bcl-2 proteins were significantly decreased(P<0.05),Bcl-2/Bax ratio was significantly decreased(P<0.05),and the mRNA levels of inflammatory cytokines,tumor necrosis factor-α and interleukin-6,were significantly up-regulated(P<0.05).(2)Compared with the high-fat group,the above indexes were significantly improved in the aerobic exercise group(P<0.05),while in the resistance exercise group,the body mass of mice was significantly decreased,the levels of inflammatory cytokines tumor necrosis factor-α and interleukin-6 mRNA were significantly decreased(P<0.05),the protein expression of Caspase-3 was significantly decreased(P<0.05),and the protein expression of brain-derived neurotrophic factor was significantly up-regulated(P<0.05),but no significant changes were observed in the other indexes(P>0.05).In conclusion,long-term exercise can reduce insulin resistance,down-regulate the expression of nuclear factor-κB pathway,weaken inflammatory response,inhibit neuronal apoptosis and improve synaptic plasticity,resulting in neuroprotective effects,and effectively alleviate obesity-related cognitive dysfunction in obese mice.The therapeutic effect of aerobic exercise is superior to that of resistance exercise.
4.Volatile Component Differences in Xihuangwan Prepared with Natural and Artificial Musk Based on Non-targeted and Targeted Metabolomics
Jing WANG ; Fangzhu XU ; Li MENG ; Qizhen ZHU ; Huanjun ZHAO ; Caina YU ; Xuelian CHEN ; Hui GAO ; Zimin YUAN
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(8):194-201
ObjectiveHeadspace solid-phase microextraction-gas chromatography-mass spectrometry(HS-SPME-GC-MS) and GC-triple quadrupole MS(GC-QqQ-MS) in combination with non-targeted and targeted metabolomics were employed to systematically analyze the chemical composition differences of Xihuangwan prepared with natural musk and artificial musk, and establish an identification system for them. MethodsThe volatile components of 9 batches of Xihuangwan samples from 8 manufacturers were analyzed by HS-SPME-GC-MS non-targeted metabolomics, and identified by comparing their MS data with the National Institute of Standards and Technology(NIST) spectral library. Orthogonal partial least squares-discriminant analysis(OPLS-DA) was used to identify differential volatile components of Xihuangwan prepared with natural musk and artificial musk. Additionally, GC-QqQ-MS targeted metabolomics was applied to quantify the levels of α-pinene, β-elemene, muscone, dehydroepiandrosterone, bornyl acetate, and octyl acetate in 27 batches of samples from 9 manufacturers. Cluster analysis, principal component analysis(PCA), and partial least squares-discriminant analysis(PLS-DA) were conducted to further explore the differences in volatile components between Xihuangwan samples prepared with natural musk and artificial musk. ResultsNon-targeted metabolomics identified 291 volatile compounds in Xihuangwan, including alkanes, esters, alkanes, alcohols, ketones, naphthalenes and others. OPLS-DA analysis revealed distinct separation between Xihuangwan samples containing artificial musk(A1, C1, D1, E1, F1, G1, I1) and those containing natural musk(H1, H3). A total of 30 differential metabolites were identified. The relative contents of these 30 differential metabolites were visualized using a radar chart, revealing significant differences in the levels of octanol, borneol acetate and muscone. Cluster analysis and PCA results from targeted metabolomics indicated that Xihuangwan could be classified into two distinct groups:one composed of natural musk(H1, H3) and the other of artificial musk, sample H2. PLS-DA identified muscone, octyl acetate, and dehydroepiandrosterone as key differential volatile components. Although no significant difference was observed in the content of octyl acetate between the two groups, statistically significant differences were found for muscone and dehydroepiandrosterone(P<0.05). ConclusionMuscone and dehydroepiandrosterone can be used for the differentiation of Xihuangwan samples containing natural musk from those containing artificial musk. This study systematically and comprehensively analyzed the differences in the types and contents of major volatile components in Xihuangwan prepared with natural musk and artificial musk, providing a scientific basis for quality evaluation and control of Xihuangwan.
5.Volatile Component Differences in Xihuangwan Prepared with Natural and Artificial Musk Based on Non-targeted and Targeted Metabolomics
Jing WANG ; Fangzhu XU ; Li MENG ; Qizhen ZHU ; Huanjun ZHAO ; Caina YU ; Xuelian CHEN ; Hui GAO ; Zimin YUAN
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(8):194-201
ObjectiveHeadspace solid-phase microextraction-gas chromatography-mass spectrometry(HS-SPME-GC-MS) and GC-triple quadrupole MS(GC-QqQ-MS) in combination with non-targeted and targeted metabolomics were employed to systematically analyze the chemical composition differences of Xihuangwan prepared with natural musk and artificial musk, and establish an identification system for them. MethodsThe volatile components of 9 batches of Xihuangwan samples from 8 manufacturers were analyzed by HS-SPME-GC-MS non-targeted metabolomics, and identified by comparing their MS data with the National Institute of Standards and Technology(NIST) spectral library. Orthogonal partial least squares-discriminant analysis(OPLS-DA) was used to identify differential volatile components of Xihuangwan prepared with natural musk and artificial musk. Additionally, GC-QqQ-MS targeted metabolomics was applied to quantify the levels of α-pinene, β-elemene, muscone, dehydroepiandrosterone, bornyl acetate, and octyl acetate in 27 batches of samples from 9 manufacturers. Cluster analysis, principal component analysis(PCA), and partial least squares-discriminant analysis(PLS-DA) were conducted to further explore the differences in volatile components between Xihuangwan samples prepared with natural musk and artificial musk. ResultsNon-targeted metabolomics identified 291 volatile compounds in Xihuangwan, including alkanes, esters, alkanes, alcohols, ketones, naphthalenes and others. OPLS-DA analysis revealed distinct separation between Xihuangwan samples containing artificial musk(A1, C1, D1, E1, F1, G1, I1) and those containing natural musk(H1, H3). A total of 30 differential metabolites were identified. The relative contents of these 30 differential metabolites were visualized using a radar chart, revealing significant differences in the levels of octanol, borneol acetate and muscone. Cluster analysis and PCA results from targeted metabolomics indicated that Xihuangwan could be classified into two distinct groups:one composed of natural musk(H1, H3) and the other of artificial musk, sample H2. PLS-DA identified muscone, octyl acetate, and dehydroepiandrosterone as key differential volatile components. Although no significant difference was observed in the content of octyl acetate between the two groups, statistically significant differences were found for muscone and dehydroepiandrosterone(P<0.05). ConclusionMuscone and dehydroepiandrosterone can be used for the differentiation of Xihuangwan samples containing natural musk from those containing artificial musk. This study systematically and comprehensively analyzed the differences in the types and contents of major volatile components in Xihuangwan prepared with natural musk and artificial musk, providing a scientific basis for quality evaluation and control of Xihuangwan.
6.Facilitators and barriers to work-related musculoskeletal disorder prevention behaviors among healthcare professionals: A comprehensive review
Haijing MA ; Su’e YUAN ; Hui ZHU ; Yujia CHEN ; Ping SONG ; Huiqin YU ; Yunxia LI
Journal of Environmental and Occupational Medicine 2026;43(3):387-394
Work-related musculoskeletal disorders (WMSDs) represent a significant occupational health challenge among healthcare professionals globally, posing substantial threats to physical and mental well-being as well as work sustainability. Adopting preventive behaviors—including ergonomic postural adjustments, optimized work-rest scheduling, proper use of protective and assistive equipment, and regular physical activity—is essential for mitigating the risk of WMSDs. Guided by the social ecological model, the review synthesized current evidence on the determinants of WMSDs preventive behaviors across four levels: intrapersonal characteristics, work environment conditions, interpersonal support, and policy/institutional factors. The findings suggest that higher educational attainment, favorable health-related behavioral patterns, optimized ergonomic work environments, adoption of supportive collaborative systems, strong organizational support, as well as policy safeguards facilitate preventive behavior adoption. Conversely, limited prevention-related knowledge, low risk perception, insufficient physical activity, excessive workload, lack of appropriate protective equipment, inadequate ergonomic training, a prevailing culture of presenteeism, and inadequate policy implementation constitute significant barriers. Multi-dimensional intervention strategies targeting these determinants are warranted to enhance preventive behaviors, reduce the risk of WMSDs, and strengthen occupational health protection for healthcare professionals.
7.Mechanisms by which aerobic and resistance exercises improve obesity-related cognitive impairment
Yu LIU ; Senlin LEI ; Jintao ZHOU ; Hui LIU ; Xianhui LI
Chinese Journal of Tissue Engineering Research 2026;30(5):1171-1183
BACKGROUND:Obesity is not only related to metabolic diseases such as diabetes and cardiovascular disease,but also closely related to the increased risk of cognitive decline,dementia and other neurodegenerative diseases.Studies have found that aerobic exercise and resistance exercise can help improve obesity-related cognitive impairment,but their therapeutic effects and related mechanisms of action are still unclear.OBJECTIVE:To explore the protective effects of aerobic and resistance exercises on the nervous center of obesity-related cognitive impairment mice.METHODS:Forty-eight 8-week-old C57BL/6J wild-type male mice were randomly divided into four groups:a control group was fed normally for 20 weeks;a high fat group was fed with high fat diet(60%fat energy)for 20 weeks;an aerobic exercise group was fed with 12 weeks of high-fat diet followed by 8 weeks of aerobic exercise;and a resistance exercise group was fed with 12 weeks of high-fat diet followed by 8 weeks of resistance exercise.After the exercise intervention,body mass was weighed,insulin tolerance and glucose tolerance were tested to evaluate insulin resistance,and cognitive function of mice in each group was detected by new object recognition experiment and Y-maze experiment.The morphology of hippocampal and cortical tissue cells was observed by hematoxylin-eosin staining.The mRNA relative expression levels of tumor necrosis factor-α and interleukin-6 were detected by real-time fluorescence quantitative PCR,and the protein expressions of Bax,Bcl-2,nuclear factor-κB,Cleaved Caspase-1,Caspase-3,synapsin 1 and brain-derived neurotrophic factor were detected by western blot.RESULTS AND CONCLUSION:(1)Compared with the control group,the body mass of mice increased in the high-fat group(P<0.05),accompanied by insulin resistance and cognitive dysfunction,the expression levels of nuclear factor-κB,Bax,Caspase-3,Cleaved Caspase-1 in the hippocampus were significantly increased(P<0.05),the expression levels of brain-derived neurotrophic factor,synapsin 1and Bcl-2 proteins were significantly decreased(P<0.05),Bcl-2/Bax ratio was significantly decreased(P<0.05),and the mRNA levels of inflammatory cytokines,tumor necrosis factor-α and interleukin-6,were significantly up-regulated(P<0.05).(2)Compared with the high-fat group,the above indexes were significantly improved in the aerobic exercise group(P<0.05),while in the resistance exercise group,the body mass of mice was significantly decreased,the levels of inflammatory cytokines tumor necrosis factor-α and interleukin-6 mRNA were significantly decreased(P<0.05),the protein expression of Caspase-3 was significantly decreased(P<0.05),and the protein expression of brain-derived neurotrophic factor was significantly up-regulated(P<0.05),but no significant changes were observed in the other indexes(P>0.05).In conclusion,long-term exercise can reduce insulin resistance,down-regulate the expression of nuclear factor-κB pathway,weaken inflammatory response,inhibit neuronal apoptosis and improve synaptic plasticity,resulting in neuroprotective effects,and effectively alleviate obesity-related cognitive dysfunction in obese mice.The therapeutic effect of aerobic exercise is superior to that of resistance exercise.
8.Analysis of T7 RNA Polymerase: From Structure-function Relationship to dsRNA Challenge and Biotechnological Applications
Wei-Chen NING ; Yu HUA ; Hui-Ling YOU ; Qiu-Shi LI ; Yao WU ; Yun-Long LIU ; Zhen-Xin HU
Progress in Biochemistry and Biophysics 2025;52(9):2280-2294
T7 RNA polymerase (T7 RNAP) is one of the simplest known RNA polymerases. Its unique structural features make it a critical model for studying the mechanisms of RNA synthesis. This review systematically examines the static crystal structure of T7 RNAP, beginning with an in-depth examination of its characteristic “thumb”, “palm”, and “finger” domains, which form the classic “right-hand-like” architecture. By detailing these structural elements, this review establishes a foundation for understanding the overall organization of T7 RNAP. This review systematically maps the functional roles of secondary structural elements and their subdomains in transcriptional catalysis, progressively elucidating the fundamental relationships between structure and function. Further, the intrinsic flexibility of T7 RNAP and its applications in research are also discussed. Additionally, the review presents the structural diagrams of the enzyme at different stages of the transcription process, and through these diagrams, it provides a detailed description of the complete transcription process of T7 RNAP. By integrating structural dynamics and kinetics analyses, the review constructs a comprehensive framework that bridges static structure to dynamic processes. Despite its advantages, T7 RNAP has a notable limitation: it generates double-stranded RNA (dsRNA) as a byproduct. The presence of dsRNA not only compromises the purity of mRNA products but also elicits nonspecific immune responses, which pose significant challenges for biotechnological and therapeutic applications. The review provides a detailed exploration of the mechanisms underlying dsRNA formation during T7 RNAP catalysis, reviews current strategies to mitigate this issue, and highlights recent progress in the field. A key focus is the semi-rational design of T7 RNAP mutants engineered to minimize dsRNA generation and enhance catalytic performance. Beyond its role in transcription, T7 RNAP exhibits rapid development and extensive application in fields, including gene editing, biosensing, and mRNA vaccines. This review systematically examines the structure-function relationships of T7 RNAP, elucidates the mechanisms of dsRNA formation, and discusses engineering strategies to optimize its performance. It further explores the engineering optimization and functional expansion of T7 RNAP. Furthermore, this review also addresses the pressing issues that currently need resolution, discusses the major challenges in the practical application of T7 RNAP, and provides an outlook on potential future research directions. In summary, this review provides a comprehensive analysis of T7 RNAP, ranging from its structural architecture to cutting-edge applications. We systematically examine: (1) the characteristic right-hand domains (thumb, palm, fingers) that define its minimalistic structure; (2) the structure-function relationships underlying transcriptional catalysis; and (3) the dynamic transitions during the complete transcription cycle. While highlighting T7 RNAP’s versatility in gene editing, biosensing, and mRNA vaccine production, we critically address its major limitation—dsRNA byproduct formation—and evaluate engineering solutions including semi-rationally designed mutants. By synthesizing current knowledge and identifying key challenges, this work aims to provide novel insights for the development and application of T7 RNAP and to foster further thought and progress in related fields.
9.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.
10.Effect of Tongdu Tiaoshen acupuncture on hippocampal neuronal ferroptosis in depression rats based on SLC7A11/GPX4 pathway.
Tingting QIAN ; Ling ZOU ; Zhi GAO ; Yu WU ; Yanbiao ZHAO ; Nan LI ; Hui LIU ; Meixiang SUN ; Peiyang SUN
Chinese Acupuncture & Moxibustion 2025;45(8):1120-1127
OBJECTIVE:
To observe the effects of Tongdu Tiaoshen acupuncture (acupuncture for unblocking the obstruction in the governor vessel and regulating the spirit) on the depression-like behavior and the hippocampal neuronal ferroptosis mediated by solute carrier family 7 member 11 (SLC7A11)/glutathione peroxidase 4 (GPX4) pathway in depression rats, and explore the mechanism of this therapy for depression.
METHODS:
Of 30 male SD rats of SPF grade, 24 rats were selected. According to the random number table, they were divided into a normal group (n=8) and a modeling group (n=16). The rats in the modeling group were subjected to chronic unpredictable mild stress (CUMS) for 28 consecutive days to establish depression model. After modeling, 16 successfully-modeled rats were randomly divided into a model group and an acupuncture group, 8 rats in each one. In the acupuncture group, Tongdu Tiaoshen acupuncture was applied to "Dazhui"(GV14), "Shuigou" (GV26), "Baihui" (GV20) and "Shenting" (GV24). This intervention measure was deliveredonce a day, continuously for 6 days. The intervention discontinued on day 7, and was completed in 4 weeks. Before and after modeling, and after intervention completion, the behavioristics detection was performed using sucrose preference experiment and open field experiment. After intervention, using hematoxylin-eosin (HE) and Nissl staining, the morphology of hippocampal neurons was observed; with Western blot method, the protein expression of GPX4, SLC7A11, Ferritin and acyl-CoA synthetase long-chain family 4 (ACSL4) in hippocampal tissues was detected; with the real-time fluorescence quantitative PCR adopted, the mRNA expression of GPX4, SLC7A11, Ferritin and ACSL4 was detected; and using colorimetry, the hippocampal iron content was determined.
RESULTS:
After modeling, the sucrose preference rates, the total distance of movement, the standing times and the boxes of horizontal crossing in the model group and the acupuncture group were lower than those in the normal group (P<0.01). After the intervention, the sucrose preference rates, the total distance of movement, the standing times and the boxes of horizontal crossing in the acupuncture group were higher than those in the model group (P<0.01, P<0.05). Compared with the normal group, the number of necrotic cells increased and the number of Nissl bodies decreased in the model group; and when compared with the model group, the neuronal pyknosis and necrosis were ameliorated, the cells were arranged more regularly, the neuronal structure was clear, the matrix was dense, the blood vessels were enriched and the number of Nissl bodies increased in the acupuncture group. In comparison with the normal group, the relative expression of protein and mRNA of hippocampal GPX4, SLC7A11 decreased (P<0.01), it increased in the expression of hippocampal Ferritin and ACSL4 (P<0.01) in the model group. When compared with the model group, in the acupuncture group, the relative expression of protein and mRNA of hippocampal GPX4, SLC7A11 was elevated (P<0.01, P<0.05), it was dropped for hippocampal Ferritin and ACSL4 (P<0.01). In the model group, the hippocampal iron content was elevated when compared with that in the normal group (P<0.01); and it was reduced in the acupuncture group when compared with that in the model group (P<0.05).
CONCLUSION
Tongdu Tiaoshen acupuncture attenuates depression-like behaviors in the depression rats, which may be related to regulating SLC7A11/GPX4 pathway and inhibiting neuronal ferroptosis in the hippocampus.
Animals
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Ferroptosis
;
Male
;
Hippocampus/cytology*
;
Rats, Sprague-Dawley
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Rats
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Depression/enzymology*
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Phospholipid Hydroperoxide Glutathione Peroxidase/genetics*
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Acupuncture Therapy
;
Neurons/metabolism*
;
Humans
;
Acupuncture Points
;
Amino Acid Transport System y+/genetics*
;
Glutathione Peroxidase/genetics*

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