Membrane proteins are integral components of cellular membranes, accounting for approximately 30% of the mammalian proteome and serving as targets for 60% of FDA-approved drugs. They are critical to both physiological functions and disease mechanisms. Their functional protein-protein interactions form the basis for many physiological processes, such as signal transduction, material transport, and cell communication. Membrane protein interactions are characterized by membrane environment dependence, spatial asymmetry, weak interaction strength, high dynamics, and a variety of interaction sites. Therefore, in situ analysis is essential for revealing the structural basis and kinetics of these proteins. This paper introduces currently available in situ analytical techniques for studying membrane protein interactions and evaluates the characteristics of each. These techniques are divided into two categories: label-based techniques (e.g., co-immunoprecipitation, proximity ligation assay, bimolecular fluorescence complementation, resonance energy transfer, and proximity labeling) and label-free techniques (e.g., cryo-electron tomography, in situ cross-linking mass spectrometry, Raman spectroscopy, electron paramagnetic resonance, nuclear magnetic resonance, and structure prediction tools). Each technique is critically assessed in terms of its historical development, strengths, and limitations. Based on the authors’ relevant research, the paper further discusses the key issues and trends in the application of these techniques, providing valuable references for the field of membrane protein research. Label-based techniques rely on molecular tags or antibodies to detect proximity or interactions, offering high specificity and adaptability for dynamic studies. For instance, proximity ligation assay combines the specificity of antibodies with the sensitivity of PCR amplification, while proximity labeling enables spatial mapping of interactomes. Conversely, label-free techniques, such as cryo-electron tomography, provide near-native structural insights, and Raman spectroscopy directly probes molecular interactions without perturbing the membrane environment. Despite advancements, these methods face several universal challenges: (1) indirect detection, relying on proximity or tagged proxies rather than direct interaction measurement; (2) limited capacity for continuous dynamic monitoring in live cells; and (3) potential artificial influences introduced by labeling or sample preparation, which may alter native conformations. Emerging trends emphasize the multimodal integration of complementary techniques to overcome individual limitations. For example, combining in situ cross-linking mass spectrometry with proximity labeling enhances both spatial resolution and interaction coverage, enabling high-throughput subcellular interactome mapping. Similarly, coupling fluorescence resonance energy transfer with nuclear magnetic resonance and artificial intelligence (AI) simulations integrates dynamic structural data, atomic-level details, and predictive modeling for holistic insights. Advances in AI, exemplified by AlphaFold’s ability to predict interaction interfaces, further augment experimental data, accelerating structure-function analyses. Future developments in cryo-electron microscopy, super-resolution imaging, and machine learning are poised to refine spatiotemporal resolution and scalability. In conclusion, in situ analysis of membrane protein interactions remains indispensable for deciphering their roles in health and disease. While current technologies have significantly advanced our understanding, persistent gaps highlight the need for innovative, integrative approaches. By synergizing experimental and computational tools, researchers can achieve multiscale, real-time, and perturbation-free analyses, ultimately unraveling the dynamic complexity of membrane protein networks and driving therapeutic discovery.

ObjectiveJunctophilin-2 (JPH2) is an essential structural protein that maintains junctional membrane complexes (JMCs) in cardiomyocytes by tethering the plasma membrane to the sarcoplasmic reticulum, thereby facilitating excitation-contraction (E-C) coupling. Mutations in JPH2 have been associated with hypertrophic cardiomyopathy (HCM), but the molecular mechanisms governing its membrane-binding properties and the functional relevance of its membrane occupation and recognition nexus (MORN) repeat motifs remain incompletely understood. This study aimed to elucidate the structural basis of JPH2 membrane association and its implications for HCM pathogenesis. MethodsA recombinant N-terminal fragment of mouse JPH2 (residues1-440), encompassing the MORN repeats and an adjacent helical region, was purified under near-physiological buffer conditions.X-ray crystallography was employed to determine the structure of the JPH2 MORN-Helix domain. Sequence conservation analysis across species and junctophilin isoforms was performed to assess the evolutionary conservation of key structural features. Functional membrane-binding assays were conducted using liposome co-sedimentation and cell-based localization studies in COS7 and HeLa cells. In addition, site-directed mutagenesis targeting positively charged residues and known HCM-associated mutations, including R347C, was used to evaluate their effects on membrane interaction and subcellular localization. ResultsThe crystal structure of the mouse JPH2 MORN-Helix domain was resolved at 2.6 Å, revealing a compact, elongated architecture consisting of multiple tandem MORN motifs arranged in a curved configuration, forming a continuous hydrophobic core stabilized by alternating aromatic residues. A C-terminal α-helix further reinforced structural integrity. Conservation analysis identified the inner groove of the MORN array as a highly conserved surface, suggesting its role as a protein-binding interface. A flexible linker segment enriched in positively charged residues, located adjacent to the MORN motifs, was found to mediate direct electrostatic interactions with negatively charged phospholipid membranes. Functional assays demonstrated that mutation of these basic residues impaired membrane association, while the HCM-linked R347C mutation completely abolished membrane localization in cellular assays, despite preserving the overall MORN-Helix fold in structural modeling. ConclusionThis study provides structural insight into the membrane-binding mechanism of the cardiomyocyte-specific protein JPH2, highlighting the dual roles of its MORN-Helix domain in membrane anchoring and protein interactions. The findings clarify the structural basis for membrane targeting via a positively charged linker and demonstrate that disruption of this interaction—such as that caused by the R347C mutation—likely contributes to HCM pathogenesis. These results not only enhance current understanding of JPH2 function in cardiac E-C coupling but also offer a structural framework for future investigations into the assembly and regulation of JMCs in both physiological and disease contexts.

Objective To investigate the prevalence status and influencing factors of metabolic syndrome (MS) in adult patients with hypopituitarism (HP) during hospitalization. Methods The data of adult HP patients who received treatment in the hospital were collected from March 2021 to March 2024. The prevalence status of MS in adult HP patients was counted, and logistic regression analysis was adopted to analyze the influencing factors of MS in adult HP patients. Results Among the 308 adult HP patients in this study, 121 cases developed MS and 187 cases did not develop MS, and they were included in the MS group (n=148) and the non-MS group (n=232). The incidence of MS in adult HP patients was 38.95% (148/380). Compared with the non-MS group, the levels of high-density lipoprotein cholesterol, serum total cholesterol and low-density lipoprotein cholesterol in the MS group were higher, the waist circumference was larger, and the growth hormone was lower (P<0.05). After logistic regression analysis, it was found that high-density lipoprotein cholesterol (OR=1.069, 95%CI: 1.010-1.132, P=0.021), total serum cholesterol (OR=1.065, 95%CI: 1.014-1.119, P=0.012), low-density lipoprotein cholesterol (OR=1.055, 95%CI: 1.005-1.108, P=0.031), waist circumference (OR=1.063, 95%CI: 1.006-1.123, P=0.030) and growth hormone (OR=1.077, 95%CI: 1.019-1.138, P=0.009) could independently affect the occurrence of MS in adult HP patients (P<0.05). Conclusion Adult HP patients during hospitalization are often complicated with MS. High-density lipoprotein cholesterol, serum total cholesterol, low-density lipoprotein cholesterol, waist circumference, and growth hormone are factors affecting the occurrence of MS in adult HP patients.

Objective To investigate the prevalence of Schistosoma japonicum infections in wild rodents in schistosomiasis-endemic areas of China, so as to provide insights into formulation of technical guidelines for monitoring of and the precise control strategy for S. japonicum infections in wild rodents during the elimination phase. Methods Two administrative villages where schistosomiasis was historically highly prevalent were selected each from Dongzhi County, Anhui Province, and Duchang County, Jiangxi Province as study villages. Wild rodents were captured from study villages with baited traps or cages at night in June and September, 2021. The number of rodents captured was recorded, and the rodent species was characterized based on morphologi-cal characteristics. Liver tissues were sampled from captured rodents for macroscopical observation of the presence of egg granu- lomas, and S. japonicum infection was detected simultaneously using liver tissue homogenate microscopy, examinations of mesenteric tissues for parasites, and modified Kato-Katz thick smear technique (Kato-Katz technique). A positive S. japonicum infection was defined as detection of S. japonicum eggs or adult worms by any of these methods. The rate of wild rodent capture and prevalence of S. japonicum infections in wild rodents were compared in different study villages and at different time periods, and the detection of S. japonicum infections in wild rodents was compared by different assays. Results The overall rate of wild ro- dent capture was 8.28% (237/2 861) in Dongzhi County, and the wild rodent capture rates were 9.24% (133/1 439) and 7.31% (104/1 422) in two study villages (χ² = 3.503, P = 0.061), and were 8.59% (121/1 409) and 7.99% (116/1 452) in June and September, 2021, respectively (χ² = 0.337, P = 0.561). The overall rate of wild rodent capture was 3.72% (77/2 072) in Duchang County, and the wild rodent capture rates were 6.91% (67/970) and 0.91% (10/1 102) in two study villages (χ² = 51.901, P < 0.001), and were 4.13% (39/945) and 3.37% (38/1 127) in June and September, 2021, respectively (χ² = 0.815, P = 0.365). Rattus norvegicus was the predominant rodent species captured in both counties, accounting for 70.04% (166/237) of all captured wild rodents in Dongzhi County and 88.31% (68/77) in Duchang County. No S. japonicum infection was detected in wild rodents captured in Duchang County. Nevertheless, the overall prevalence of S. japonicum infections was 51.05% (121/237) in wild rodents captured in Dongzhi County, with prevalence rates of 50.38% (67/133) and 51.92% (54/104) in two study villages (χ² = 0.098, P = 0.755), and 54.31% (63/116) and 47.93% (58/121) in September and June, 2021, respectively (χ² = 0.964, P = 0.326). Of 237 wild rodents captured in Dongzhi County, there were 140 (59.07%) rodents with visible hepatic egg granulomas, 117 (49.47%) tested positive for S. japonicum eggs by liver tissue homogenate microscopy, 34 (14.35%) tested positive for S. japonicum eggs with Kato-Katz technique; however, no adult S. japonicum worms were detected in mesenteric tissues. In addition, hepatic egg granulomas were found in all wild rodents tested positive for S. japonicum eggs with liver tissue homogenate microscopy. Conclusions The rate of wild rodent capture and prevalence of S. japonicum infection in wild rodents vary greatly in schistosomiasis-endemic areas of China, and the prevalence of S. japonicum infection is slightly higher in wild rodents captured in autumn than in summer. Liver tissue is recommended as the preferred sample for surveillance of S. japonicum infection in wild rodents, and a combination of macroscopical observation of hepatic egg granulomas and liver tissue homogenate microscopy may be a standard method for surveillance of S. japonicum infection in wild rodents.

BACKGROUND: The potential impact of pre-existing coronary artery stenosis (CAS) on right ventricular (RV) function during acute pulmonary embolism (PE) episodes remains underexplored. This study aimed to investigate the association between pre-existing CAS and RV dysfunction in patients with acute PE. METHODS: In this multicenter, case-control study, 89 cases and 176 controls matched for age were enrolled at three study centers (Peking Union Medical College Hospital, Fuwai Hospital, and the Second Affiliated Hospital of Harbin Medical University) from January 2016 to December 2020. The cases were patients with acute PE with CAS, and the controls were patients with acute PE without CAS. Coronary artery assessment was performed using coronary computed tomographic angiography. CAS was defined as ≥50% stenosis of the lumen diameter in any coronary vessel >2.0 mm in diameter. Conditional logistic regression analysis was used to evaluate the association between CAS and RV dysfunction. RESULTS: The percentages of RV dysfunction (19.1% [17/89] vs. 44.6% [78/176], P <0.001) and elevated systolic pulmonary artery pressure (sPAP) (19.3% [17/89] vs. 39.5% [68/176], P = 0.001) were significantly lower in the case group than those in the control group. In the multivariable logistic regression model, CAS was independently and negatively associated with RV dysfunction (adjusted odds ratio [OR]: 0.367; 95% confidence interval [CI]: 0.185-0.728; P = 0.004), and elevated sPAP (OR: 0.490; 95% CI: 0.252-0.980; P = 0.035), respectively. CONCLUSIONS Pre-existing CAS was significantly and negatively associated with RV dysfunction and elevated sPAP in patients with acute PE. This finding provides new insights into RV dysfunction in patients with acute PE with pre-existing CAS.
Humans ; Pulmonary Embolism/complications* ; Case-Control Studies ; Male ; Ventricular Dysfunction, Right/physiopathology* ; Female ; Middle Aged ; Aged ; Coronary Stenosis/complications* ; Logistic Models ; Adult

INTRODUCTION: Lecanemab has shown promise in treating early Alzheimer's disease (AD), but its safety and efficacy in Chinese populations remain unexplored. This study aimed to evaluate the safety and 6-month clinical outcomes of lecanemab in Chinese patients with mild cognitive impairment (MCI) or mild AD. METHODS: In this single-arm, real-world study, participants with MCI due to AD or mild AD received biweekly intravenous lecanemab (10 mg/kg). The study was conducted at Hainan Branch, Ruijin Hospital Shanghai Jiao Tong University School of Medicine. Patient enrollment and baseline assessments commenced in November 2023. Safety assessments included monitoring for amyloid-related imaging abnormalities (ARIA) and other adverse events. Clinical and biomarker changes from baseline to 6 months were evaluated using cognitive scales (mini-mental state examination [MMSE], montreal cognitive assessment [MoCA], clinical dementia rating-sum of boxes [CDR-SB]), plasma biomarker analysis, and advanced neuroimaging. RESULTS: A total of 64 patients were enrolled in this ongoing real-world study. Safety analysis revealed predominantly mild adverse events, with infusion-related reactions (20.3%, 13/64) being the most common. Of these, 69.2% (9/13) occurred during the initial infusion and 84.6% (11/13) did not recur. ARIA-H (microhemorrhages/superficial siderosis) and ARIA-E (edema/effusion) were observed in 9.4% (6/64) and 3.1% (2/64) of participants, respectively, with only two symptomatic cases (one ARIA-E presenting with headache and one ARIA-H with visual disturbances). After 6 months of treatment, cognitive scores remained stable compared to baseline (MMSE: 22.33 ± 5.58 vs . 21.27 ± 4.30, P = 0.733; MoCA: 16.38 ± 6.67 vs . 15.90 ± 4.78, P = 0.785; CDR-SB: 2.30 ± 1.65 vs . 3.16 ± 1.72, P = 0.357), while significantly increasing plasma amyloid-β 42 (Aβ42) (+21.42%) and Aβ40 (+23.53%) levels compared to baseline. CONCLUSIONS: Lecanemab demonstrated a favorable safety profile in Chinese patients with early AD. Cognitive stability and biomarker changes over 6 months suggest potential efficacy, though high dropout rates and absence of a control group warrant cautious interpretation. These findings provide preliminary real-world evidence for lecanemab's use in China, supporting further investigation in larger controlled studies. REGISTRATION ClinicalTrials.gov , NCT07034222.
Humans ; Alzheimer Disease/drug therapy* ; Male ; Female ; Aged ; Middle Aged ; Cognitive Dysfunction/drug therapy* ; Aged, 80 and over ; Amyloid beta-Peptides/metabolism* ; Biomarkers ; East Asian People