1.Hippocampal Extracellular Matrix Protein Laminin β1 Regulates Neuropathic Pain and Pain-Related Cognitive Impairment.
Ying-Chun LI ; Pei-Yang LIU ; Hai-Tao LI ; Shuai WANG ; Yun-Xin SHI ; Zhen-Zhen LI ; Wen-Guang CHU ; Xia LI ; Wan-Neng LIU ; Xing-Xing ZHENG ; Fei WANG ; Wen-Juan HAN ; Jie ZHANG ; Sheng-Xi WU ; Rou-Gang XIE ; Ceng LUO
Neuroscience Bulletin 2025;41(12):2127-2147
Patients suffering from nerve injury often experience exacerbated pain responses and complain of memory deficits. The dorsal hippocampus (dHPC), a well-defined region responsible for learning and memory, displays maladaptive plasticity upon injury, which is assumed to underlie pain hypersensitivity and cognitive deficits. However, much attention has thus far been paid to intracellular mechanisms of plasticity rather than extracellular alterations that might trigger and facilitate intracellular changes. Emerging evidence has shown that nerve injury alters the microarchitecture of the extracellular matrix (ECM) and decreases ECM rigidity in the dHPC. Despite this, it remains elusive which element of the ECM in the dHPC is affected and how it contributes to neuropathic pain and comorbid cognitive deficits. Laminin, a key element of the ECM, consists of α-, β-, and γ-chains and has been implicated in several pathophysiological processes. Here, we showed that peripheral nerve injury downregulates laminin β1 (LAMB1) in the dHPC. Silencing of hippocampal LAMB1 exacerbates pain sensitivity and induces cognitive dysfunction. Further mechanistic analysis revealed that loss of hippocampal LAMB1 causes dysregulated Src/NR2A signaling cascades via interaction with integrin β1, leading to decreased Ca2+ levels in pyramidal neurons, which in turn orchestrates structural and functional plasticity and eventually results in exaggerated pain responses and cognitive deficits. In this study, we shed new light on the functional capability of hippocampal ECM LAMB1 in the modulation of neuropathic pain and comorbid cognitive deficits, and reveal a mechanism that conveys extracellular alterations to intracellular plasticity. Moreover, we identified hippocampal LAMB1/integrin β1 signaling as a potential therapeutic target for the treatment of neuropathic pain and related memory loss.
Animals
;
Laminin/genetics*
;
Hippocampus/metabolism*
;
Neuralgia/metabolism*
;
Cognitive Dysfunction/etiology*
;
Male
;
Peripheral Nerve Injuries/metabolism*
;
Extracellular Matrix/metabolism*
;
Integrin beta1/metabolism*
;
Pyramidal Cells/metabolism*
;
Signal Transduction
2.Ras Guanine Nucleotide-Releasing Protein-4 Inhibits Erythropoietin Production in Diabetic Mice with Kidney Disease by Degrading HIF2A
Junmei WANG ; Shuai HUANG ; Li ZHANG ; Yixian HE ; Xian SHAO ; A-Shan-Jiang A-NI-WAN ; Yan KONG ; Xuying MENG ; Pei YU ; Saijun ZHOU
Diabetes & Metabolism Journal 2025;49(3):421-435
Background:
In acute and chronic renal inflammatory diseases, the activation of inflammatory cells is involved in the defect of erythropoietin (EPO) production. Ras guanine nucleotide-releasing protein-4 (RasGRP4) promotes renal inflammatory injury in type 2 diabetes mellitus (T2DM). Our study aimed to investigate the role and mechanism of RasGRP4 in the production of renal EPO in diabetes.
Methods:
The degree of tissue injury was observed by pathological staining. Inflammatory cell infiltration was analyzed by immunohistochemical staining. Serum EPO levels were detected by enzyme-linked immunosorbent assay, and EPO production and renal interstitial fibrosis were analyzed by immunofluorescence. Quantitative real-time polymerase chain reaction and Western blotting were used to detect the expression of key inflammatory factors and the activation of signaling pathways. In vitro, the interaction between peripheral blood mononuclear cells (PBMCs) and C3H10T1/2 cells was investigated via cell coculture experiments.
Results:
RasGRP4 decreased the expression of hypoxia-inducible factor 2-alpha (HIF2A) via the ubiquitination–proteasome degradation pathway and promoted myofibroblastic transformation by activating critical inflammatory pathways, consequently reducing the production of EPO in T2DM mice.
Conclusion
RasGRP4 participates in the production of renal EPO in diabetic mice by affecting the secretion of proinflammatory cytokines in PBMCs, degrading HIF2A, and promoting the myofibroblastic transformation of C3H10T1/2 cells.
3.Adolescent self-harm and suicide attempts: An analysis of emergency department presentations in Singapore.
Darren Kai Siang CHONG ; Vicknesan Jeyan MARIMUTTU ; Pei Shan HOE ; Chu Shan Elaine CHEW ; Angelina Su Yin ANG
Annals of the Academy of Medicine, Singapore 2025;54(2):78-86
INTRODUCTION:
The rising rate of adolescent suicide, and the burden of self-harm and mental health disorders, pose significant threats to Singapore's future health outcomes and human potential. This study sought to examine the risk profile and healthcare utilisation patterns of Singaporean adolescents who presented to the emergency department (ED) for suicidal or self-harm behaviour.
METHOD:
A retrospective review of medical records for patients aged 10 to 19 years who visited Singapore's KK Women's and Children's Hospital ED for suicidal or self-harm attempts from January to December 2021 was conducted.
RESULTS:
A total of 221 patients were identified, with a predominance of female patients (85.5%) over males (14.5%). The mean age was 14.2 ± 1.4 years. Intentional drug overdose (52.0%) was the most commonly used method. Significantly more females presented for intentional paracetamol overdose (46.6% versus [vs] 28.1%, P=0.049), whereas jumping from a height was more common among males (18.8% vs 5.8%, P=0.022). The most frequently observed mental health challenges were stress-related and emotional coping difficulties (50.7%), followed by mood and anxiety symptoms (53.4%). A history of self-harm and suicidal behaviours were the most common psychosocial risk factors. Within the year prior to their ED presentation, 15.4% had accessed healthcare services for mild medical ailments, 19.5% for medically unexplained symptoms, and 17.2% for previous self-harm or suicide attempts.
CONCLUSION
Most cases involved psychosocial and emotional regulation difficulties, some of which displayed sex-specific patterns, rather than complex psychiatric disorders. The identified predictive factors can help inform Singapore's National Mental Health and Well-being Strategy, to guide targeted and transdiagnostic interventions in schools and community settings.
Humans
;
Adolescent
;
Singapore/epidemiology*
;
Female
;
Male
;
Suicide, Attempted/psychology*
;
Emergency Service, Hospital/statistics & numerical data*
;
Self-Injurious Behavior/psychology*
;
Retrospective Studies
;
Child
;
Young Adult
;
Drug Overdose/epidemiology*
;
Risk Factors
;
Acetaminophen/poisoning*
;
Patient Acceptance of Health Care/statistics & numerical data*
;
Sex Factors
4.Singapore consensus statements on the management of obstructive sleep apnoea.
Leong Chai LEOW ; Chuen Peng LEE ; Sridhar VENKATESWARAN ; Michael Teik Chung LIM ; Oon Hoe TEOH ; Ruth CHANG ; Yam Cheng CHEE ; Khai Beng CHONG ; Ai Ping CHUA ; Joshua GOOLEY ; Hong Juan HAN ; Nur Izzianie KAMARUDDIN ; See Meng KHOO ; Lynn Huiting KOH ; Shaun Ray Han LOH ; Kok Weng LYE ; Mark IGNATIUS ; Yingjuan MOK ; Jing Hao NG ; Thun How ONG ; Chu Qin PHUA ; Rui Ya SOH ; Pei Rong SONG ; Adeline TAN ; Alvin TAN ; Terry TAN ; Jenny TANG ; David TAY ; Jade TAY ; Song Tar TOH ; Serene WONG ; Chiang Yin WONG ; Mimi YOW
Annals of the Academy of Medicine, Singapore 2025;54(10):627-643
INTRODUCTION:
Obstructive sleep apnoea (OSA) is common in Singapore, with moderate to severe OSA affecting around 30% of residents. These consensus statements aim to provide scientifically grounded recommendations for the management of OSA, standar-dise the management of OSA in Singapore and promote multidisciplinary collaboration.
METHOD:
An expert panel, which was convened in 2024, identified several areas of OSA management that require guidance. The expert panel reviewed the current literature and developed consensus statements, which were later independently voted on using a 3-point Likert scale (agree, neutral or disagree). Consensus (total ratings of agree and neutral) was set a priori at ≥80% agreement. Any statement not reaching consensus was excluded.
RESULTS:
The final consensus included 49 statements that provide guidance on the screening, diagnosis and management of adults with OSA. Additionally, 23 statements on the screening, diagnosis and management of paediatric OSA achieved consensus. These 72 consensus statements considered not only the latest clinical evidence but also the benefits and harms, resource implications, feasibility, acceptability and equity impact of the recommendations.
CONCLUSION
The statements presented in this paper aim to guide clinicians based on the most updated evidence and collective expert opinion from sleep specialists in Singapore. These recommendations should augment clinical judgement rather than replace it. Management decisions should be individualised, taking into account the patient's clinical characteristics, as well as patient and caregiver concerns and preferences.
Humans
;
Sleep Apnea, Obstructive/diagnosis*
;
Singapore
;
Consensus
;
Adult
6.Ras Guanine Nucleotide-Releasing Protein-4 Inhibits Erythropoietin Production in Diabetic Mice with Kidney Disease by Degrading HIF2A
Junmei WANG ; Shuai HUANG ; Li ZHANG ; Yixian HE ; Xian SHAO ; A-Shan-Jiang A-NI-WAN ; Yan KONG ; Xuying MENG ; Pei YU ; Saijun ZHOU
Diabetes & Metabolism Journal 2025;49(3):421-435
Background:
In acute and chronic renal inflammatory diseases, the activation of inflammatory cells is involved in the defect of erythropoietin (EPO) production. Ras guanine nucleotide-releasing protein-4 (RasGRP4) promotes renal inflammatory injury in type 2 diabetes mellitus (T2DM). Our study aimed to investigate the role and mechanism of RasGRP4 in the production of renal EPO in diabetes.
Methods:
The degree of tissue injury was observed by pathological staining. Inflammatory cell infiltration was analyzed by immunohistochemical staining. Serum EPO levels were detected by enzyme-linked immunosorbent assay, and EPO production and renal interstitial fibrosis were analyzed by immunofluorescence. Quantitative real-time polymerase chain reaction and Western blotting were used to detect the expression of key inflammatory factors and the activation of signaling pathways. In vitro, the interaction between peripheral blood mononuclear cells (PBMCs) and C3H10T1/2 cells was investigated via cell coculture experiments.
Results:
RasGRP4 decreased the expression of hypoxia-inducible factor 2-alpha (HIF2A) via the ubiquitination–proteasome degradation pathway and promoted myofibroblastic transformation by activating critical inflammatory pathways, consequently reducing the production of EPO in T2DM mice.
Conclusion
RasGRP4 participates in the production of renal EPO in diabetic mice by affecting the secretion of proinflammatory cytokines in PBMCs, degrading HIF2A, and promoting the myofibroblastic transformation of C3H10T1/2 cells.
7.Ras Guanine Nucleotide-Releasing Protein-4 Inhibits Erythropoietin Production in Diabetic Mice with Kidney Disease by Degrading HIF2A
Junmei WANG ; Shuai HUANG ; Li ZHANG ; Yixian HE ; Xian SHAO ; A-Shan-Jiang A-NI-WAN ; Yan KONG ; Xuying MENG ; Pei YU ; Saijun ZHOU
Diabetes & Metabolism Journal 2025;49(3):421-435
Background:
In acute and chronic renal inflammatory diseases, the activation of inflammatory cells is involved in the defect of erythropoietin (EPO) production. Ras guanine nucleotide-releasing protein-4 (RasGRP4) promotes renal inflammatory injury in type 2 diabetes mellitus (T2DM). Our study aimed to investigate the role and mechanism of RasGRP4 in the production of renal EPO in diabetes.
Methods:
The degree of tissue injury was observed by pathological staining. Inflammatory cell infiltration was analyzed by immunohistochemical staining. Serum EPO levels were detected by enzyme-linked immunosorbent assay, and EPO production and renal interstitial fibrosis were analyzed by immunofluorescence. Quantitative real-time polymerase chain reaction and Western blotting were used to detect the expression of key inflammatory factors and the activation of signaling pathways. In vitro, the interaction between peripheral blood mononuclear cells (PBMCs) and C3H10T1/2 cells was investigated via cell coculture experiments.
Results:
RasGRP4 decreased the expression of hypoxia-inducible factor 2-alpha (HIF2A) via the ubiquitination–proteasome degradation pathway and promoted myofibroblastic transformation by activating critical inflammatory pathways, consequently reducing the production of EPO in T2DM mice.
Conclusion
RasGRP4 participates in the production of renal EPO in diabetic mice by affecting the secretion of proinflammatory cytokines in PBMCs, degrading HIF2A, and promoting the myofibroblastic transformation of C3H10T1/2 cells.
8.Ras Guanine Nucleotide-Releasing Protein-4 Inhibits Erythropoietin Production in Diabetic Mice with Kidney Disease by Degrading HIF2A
Junmei WANG ; Shuai HUANG ; Li ZHANG ; Yixian HE ; Xian SHAO ; A-Shan-Jiang A-NI-WAN ; Yan KONG ; Xuying MENG ; Pei YU ; Saijun ZHOU
Diabetes & Metabolism Journal 2025;49(3):421-435
Background:
In acute and chronic renal inflammatory diseases, the activation of inflammatory cells is involved in the defect of erythropoietin (EPO) production. Ras guanine nucleotide-releasing protein-4 (RasGRP4) promotes renal inflammatory injury in type 2 diabetes mellitus (T2DM). Our study aimed to investigate the role and mechanism of RasGRP4 in the production of renal EPO in diabetes.
Methods:
The degree of tissue injury was observed by pathological staining. Inflammatory cell infiltration was analyzed by immunohistochemical staining. Serum EPO levels were detected by enzyme-linked immunosorbent assay, and EPO production and renal interstitial fibrosis were analyzed by immunofluorescence. Quantitative real-time polymerase chain reaction and Western blotting were used to detect the expression of key inflammatory factors and the activation of signaling pathways. In vitro, the interaction between peripheral blood mononuclear cells (PBMCs) and C3H10T1/2 cells was investigated via cell coculture experiments.
Results:
RasGRP4 decreased the expression of hypoxia-inducible factor 2-alpha (HIF2A) via the ubiquitination–proteasome degradation pathway and promoted myofibroblastic transformation by activating critical inflammatory pathways, consequently reducing the production of EPO in T2DM mice.
Conclusion
RasGRP4 participates in the production of renal EPO in diabetic mice by affecting the secretion of proinflammatory cytokines in PBMCs, degrading HIF2A, and promoting the myofibroblastic transformation of C3H10T1/2 cells.
9.Construction and Identification of a Macrophage-specific Colgalt1 Gene Knockout Mouse Model
Pei-Pei QIU ; Xiao-Jiao SUN ; WANG-LEI ; Zhi-Qi WANG ; Chu-Xiao YI ; Zhen-Ming LIU ; Ji-Guo ZHANG
Chinese Journal of Biochemistry and Molecular Biology 2025;41(8):1214-1222
Aberrant expression of Colgalt1 is closely associated with tumorigenesis and tumor progres-sion;however,the mechanism by which it regulates macrophages to influence tumor development remains poorly understood.This study aimed to establish a macrophage-specific Colgalt1 gene knockout mouse model to delve into the mechanisms through which Colgalt1 modulates macrophage function and subse-quently affects the occurrence and progression of tumor-related diseases.Initially,Colgalt1flox+mice were generated using gene editing techniques,followed by crossing with Lyz2-Cre+mice,which exhibit tissue-specific expression in the myeloid lineage(including monocytes and mature macrophages).Through this strategy,mice with the genotype Colgalt1-/-Lyz2-Cre+were successfully obtained,achieving conditional knockout of the Colgalt1 gene in macrophages.Colgalt1flox/flox Lyz2-Cre-mice were used as control.PCR and agarose gel electrophoresis were employed to identify the Flox and Cre genotypes of the knockout mice.RT-qPCR and Western Blot techniques were utilized to detect the expression levels of Colgalt1 in BMDMs from knockout mice at both the mRNA and protein levels,respectively.Western Blot results re-vealed a significant downregulation of Colgaltl expression in BMDMs from knockout mice compared to controls(P<0.01).RT-qPCR results demonstrated a significant reduction in Colgalt1 mRNA levels in BMDMs from knockout mice compared to contro1s(P<0.001),while no significant differences in Col-galt1 mRNA expression were observed in liver,lung,or spleen tissues between the two groups.Addition-ally,immunohistochemistry was employed to detect Colgalt1 expression in liver-specific macrophages,re-vealing an absence of Colgalt l-positive staining in liver macrophages from knockout mice.HE staining was used to observe cellular morphology in liver tissues from both groups of mice,showing no significant differences in cellular morphology or obvious pathological changes in tissues and organs.Moreover,the o-verall survival of the mice was not affected.Finally,RT-qPCR was used to assess the expression of mac-rophage-related inflammatory factors in BMDMs from both groups of mice.The results indicated that com-pared to controls,knockout mice exhibited downregulated expression of TNF-α(P<0.05)and signifi-cantly upregulated expression of IL-10(P<0.01),Arginase1(P<0.001),and CD206(P<0.001)in BMDMs,suggesting an anti-inflammatory trend and M2 polarization of macrophages following Colgalt 1 knockout.In summary,this study successfully established a macrophage-specific Colgalt1 gene knockout mouse model,providing a more reliable experimental animal model for in-depth exploration of the specific roles of Colgalt1 in macrophage functional regulation and the pathogenesis of tumor-related diseases.This model holds promise for identifying novel therapeutic targets and strategies for tumors and other diseases.
10.Clinical Analysis of Torque Teno Virus Infection after Hematopoi-etic Stem Cell Transplantation in Children
Ye-Ping SHENG ; Ling-Jun KONG ; Pei-Pei CHU ; Ya-Lin XIA ; Chen-Tao SHEN ; Jie-Fan SUN
Journal of Experimental Hematology 2025;33(6):1784-1789
Objective:To investigate the incidence,clinical characteristics,and complications of Torque teno virus(TTV)in children after hematopoietic stem cell transplantation(HSCT).Methods:A total of 40 children with hematological diseases who underwent HSCT were selected,and metagenomic next-generation sequencing(mNGS)technology was used to detect the gene sequences of pathogenic microorganisms in the blood.Combined with clinical data,the characteristics of TTV infection were analyzed.Results:Among the 40 pediatric patients post-HSCT,the TTV positive rate was 42.5%(17/40).There were no statistically significant differences between the TTV-positive group and the TTV-negative group in sex,age,white blood cell count(WBC),red blood cell count(RBC),hemoglobin,platelet count,neutrophil count,lymphocyte count,and high-sensitivity C-reactive protein(all P>0.05).The incidence of TTV infection was significantly higher in children who underwent haploidentical HSCT and in those with bone marrow stem cells(BMSC)as the transplant source(P<0.05).However,there were no significant differences in the TTV infection rate among patients with different disease types,different HLA matching statuses,or different engraftment times of neutrophils and platelets(all P>0.05).Among 17 children infected with TTV,13(76.5%)had co-infections with other viruses,mainly including cytomegalovirus(58.8%,10/17),human polyomavirus(41.2%,7/17),and Epstein-Barr virus(17.6%,3/17).In children with TTV infection,the most common complications were sepsis(82.4%),graft-versus-host disease(GVHD)(70.6%),pulmonary infection(41.2%),and hemorrhagic cystitis(17.6%).The incidence of GVHD in the TTV-positive group was significantly higher than that in the TTV-negative group(P<0.05).Conclusion:TTV infection is common in children undergoing HSCT,and it is prone to be complicated with cytomegalovirus infection and GVHD,which has an important influence on the clinical outcomes.

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