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.

Forsythia suspensa is a traditional Chinese medicine and a commonly used landscaping plant. Its dried fruit is used in medicine for its functions of clearing heat, removing toxins, reducing swelling, dissipating masses, and dispersing wind and heat. It possesses extremely high medicinal and economic value. However, the genetic differentiation and diversity of its wild populations remain unclear. In this study, chloroplast genome sequences were obtained from 15 wild individuals of F. suspensa using high-throughput sequencing technology. The sequence characteristics and intraspecific variations were analyzed. The results were as follows:(1) The full length of the F. suspensa chloroplast genome ranged from 156 184 to 156 479 bp, comprising a large single-copy region, a small single-copy region, and two inverted repeat regions. The chloroplast genome encoded a total of 132 genes, including 87 protein-coding genes, 37 tRNA genes, and 8 rRNA genes.(2) A total of 166-174 SSR loci, 792 SNV loci, and 63 InDel loci were identified in the F. suspensa chloroplast genome, indicating considerable genetic variation among individuals.(3) Population structure analysis revealed that F. suspensa could be divided into five or six groups. Both the population structure analysis and phylogenetic reconstruction results indicated significant genetic variation within the wild populations of F. suspensa, with no obvious correlation between intraspecific genetic differentiation and geographical distribution. This study provides new insights into the genetic diversity and differentiation within F. suspensa species and offers additional references for the conservation of species diversity and the utilization of germplasm resources in wild F. suspensa.
Genome, Chloroplast ; Forsythia/classification* ; Phylogeny ; Genetic Variation ; Chloroplasts/genetics* ; Microsatellite Repeats

The genome tagging project (GTP) plays a pivotal role in addressing a critical gap in the understanding of protein functions. Within this framework, we successfully generated a human influenza hemagglutinin-tagged sperm-specific protein 411 (HA-tagged Ssp411) mouse model. This model is instrumental in probing the expression and function of Ssp411. Our research revealed that Ssp411 is expressed in the round spermatids, elongating spermatids, elongated spermatids, and epididymal spermatozoa. The comprehensive examination of the distribution of Ssp411 in these germ cells offers new perspectives on its involvement in spermiogenesis. Nevertheless, rigorous further inquiry is imperative to elucidate the precise mechanistic underpinnings of these functions. Ssp411 is not detectable in metaphase II (MII) oocytes, zygotes, or 2-cell stage embryos, highlighting its intricate role in early embryonic development. These findings not only advance our understanding of the role of Ssp411 in reproductive physiology but also significantly contribute to the overarching goals of the GTP, fostering groundbreaking advancements in the fields of spermiogenesis and reproductive biology.
Animals ; Female ; Humans ; Male ; Mice ; Spermatids/metabolism* ; Spermatogenesis/physiology* ; Spermatozoa/metabolism* ; Thioredoxins/genetics*

BACKGROUND: The clinical impact of post-percutaneous coronary intervention (PCI) quantitative flow ratio (QFR) in patients treated with PCI for chronic total occlusion (CTO) was still undetermined. METHODS: All CTO vessels treated with successful anatomical PCI in patients from PANDA III trial were retrospectively measured for post-PCI QFR. The primary outcome was 2-year vessel-oriented composite endpoints (VOCEs, composite of target vessel-related cardiac death, target vessel-related myocardial infarction, and ischemia-driven target vessel revascularization). Receiver operator characteristic curve analysis was conducted to identify optimal cutoff value of post-PCI QFR for predicting the 2-year VOCEs, and all vessels were stratified by this optimal cutoff value. Cox proportional hazards models were employed to calculate the hazard ratio (HR) with 95% CI. RESULTS: Among 428 CTO vessels treated with PCI, 353 vessels (82.5%) were analyzable for post-PCI QFR. 31 VOCEs (8.7%) occurred at 2 years. Mean value of post-PCI QFR was 0.92 ± 0.13. Receiver operator characteristic curve analysis shown the optimal cutoff value of post-PCI QFR for predicting 2-year VOCEs was 0.91. The incidence of 2-year VOCEs in the vessel with post-PCI QFR < 0.91 (n = 91) was significantly higher compared with the vessels with post-PCI QFR ≥ 0.91 (n = 262) (22.0% vs. 4.2%, HR = 4.98, 95% CI: 2.32-10.70). CONCLUSIONS Higher post-PCI QFR values were associated with improved prognosis in the PCI practice for coronary CTO. Achieving functionally optimal PCI results (post-PCI QFR value ≥ 0.91) tends to get better prognosis for patients with CTO lesions.

OBJECTIVES: This study aimed to investigate the impact of foam macrophages (FMs) on the intracellular survival of Mycobacterium tuberculosis (MTB) and identify the molecular mechanisms influencing MTB survival. METHODS: An in vitro FM model was established using oleic acid induction. Transcriptomic and metabolomic analyses were conducted to identify the key molecular pathways involved in FM-mediated MTB survival. RESULTS: Induced FMs effectively restricted MTB survival. Transcriptomic and metabolomic profiling revealed distinct changes in gene and metabolite expression in FMs during MTB infection compared with normal macrophages. Integrated analyses identified significant alterations in the cyclic adenosine monophosphate (cAMP) signaling pathway, indicating that its activation contributes to the FM-mediated restriction of MTB survival. CONCLUSIONS FMs inhibit MTB survival. The cAMP signaling pathway is a key contributor. These findings enhance the understanding of the role of FMs in tuberculosis progression, suggest potential targets for host-directed therapies, and offer new directions for developing diagnostic and therapeutic strategies against tuberculosis.
Mycobacterium tuberculosis/physiology* ; Transcriptome ; Metabolomics ; Foam Cells/microbiology* ; Humans ; Metabolome ; Tuberculosis/microbiology* ; Gene Expression Profiling

Objective To investigate the effect of vascular endothelial growth factor(VEGF)on the expression of genes related to ovarian steroid synthesis in mice and its underlying mechanism.Methods A transgenic mouse model with tetracycline-reversible regulation of VEGF expression was used,and the genotype of mice was identified by polymerase chain reaction(PCR).Twenty mice were divided into normal VEGF expression group(Dox+,n=10)and VEGF expression inhibition group(Dox-,n=10)by feeding them doxycycline.Western blotting was used to detect the expression of VEGF protein in ovarian tissues.Fluorescence quantitative PCR was used to detect the mRNA expression of VEGF,KDR and genes known to play roles in follicle development,such as follicle-stimulating hormone(FSH)and inhibin B(INHBB).HE staining was used to observe changes in ovarian tissue.Total RNA was extracted from mouse ovarian tissues for transcriptome sequencing,and the relevant differential genes were analyzed by FPKM and log2FC values.Results Compared with the Dox+group,the mRNA and protein levels of VEGF in the Dox-group significantly reduced,and the mRNA levels of KDR also significantly decreased(P<0.05).HE staining results showed that compared with the Dox+group,follicular development was impaired and atresia follicles appeared in the Dox-group.Sequencing analysis identified that significant differences in follicular development-related genes and steroid synthesis-related genes between the two groups(P<0.05).Enrichment analysis showed that VEGF in mouse ovaries mainly regulates ovarian steroidogenesis and other pathways.Fluorescence quantitative PCR results demonstrated that compared with the Dox+group,the follicular development-related genes(INHBB and FSHR)in the ovarian tissues of the Dox-group were significantly up-regulated(P<0.05),whereas the key genes of steroid synthesis(StAR,CYP11A1,3β-HSD)were significantly down-regulated(P<0.05).The quantitative results were basically consistent with the sequencing results.Conclusion Mice with inhibited VEGF exhibited ovarian follicular dysplasia,potentially due to the mechanism whereby VEGF inhibition downregulated the expression of genes associated with steroid synthesis,such as FSH and INHBB,thereby obstructing cholesterol metabolism.

Objective To investigate the value of the human chorionic gonadotropin(hCG)stimulation test in the diagnosis of disorder of sexual development(DSD)in children.Methods A retrospective analysis was conducted on 132 children with DSD.According to the karyotype,they were divided into three groups:46,XX group(n=10),46,XY group(n=87),and sex chromosome abnormality group(n=35).The above groups were compared in terms of sex hormone levels before and after hCG stimulation test,and the morphological manifestation of the impact of testicular tissue on the results of the hCG stimulation test was analyzed.Results There was no significant difference in the multiple increase of testosterone after stimulation among the three groups(P>0.05).In the 46,XY group,the children with 5α-reductase type 2 deficiency had a testosterone-to-dihydrotestosterone ratio higher than that of the 46,XY DSD children with other causes.Morphological analysis showed that DSD children with testicular tissue demonstrated a significantly higher multiple increase in testosterone after stimulation compared to children without testicular tissue(P<0.05).Conclusions The hCG stimulation test has an important value in assessing the presence and function of testicular interstitial cells in children with different types of DSD,and it is recommended to perform the hCG stimulation test for DSD children with unclear gonadal type.[Chinese Journal of Contemporary Pediatrics,2024,26(2):158-163]

Objective:To study the magnetic resonance imaging (MRI) and clinical manifestations of intraspinal echinococcosis.Methods:The general conditions, MRI and clinical manifestations of 23 patients with intraspinal echinococcosis diagnosed by pathology at the First Affiliated Hospital of Xinjiang Medical University from September 2011 to May 2023 were retrospectively analyzed.Results:There were 10 males and 13 females of the 23 patients with intraspinal echinococcosis. The age of the patients was (44.1 ± 13.9) years old, with a median age of 41 years old and a range of 25 to 72 years old. Eleven patients (47.8%) had a history of echinococcosis in the spine or other parts of the body. Among the 23 patients with intraspinal echinococcosis, 12 cases (52.2%) involved thoracic segment, 6 cases (26.1%) involved lumbar segment, 1 case (4.3%) involved sacral segment, 1 case (4.3%) involved thoracolumbar segment, 2 cases (8.7%) involved lumbosacral segment, and 1 case (4.3%) involved cervical and lumbar segment. There were 2 cases (8.7%) involving the intramedullary, 9 cases (39.1%) involving the extramedullary subdural, and 12 cases (52.2%) involving the extramedullary epidural. At the same time, 18 cases (78.3%) involved adjacent vertebral bodies, accessories or surrounding soft tissues. Intramedullary cystic echinococcosis was characterized by multiple nodules at the lower end of the spinal cord and the cauda equina nerve on MRI, with equal or low signal on T1WI, slightly high signals on T2WI and short time of inversion recovery (STIR), accompanied by small vesicles with high signal on T2WI. Intramedullary alveolar echinococcosis was characterized by nodular T1WI signals, slightly lower signals on T2WI and STIR, and circular enhancement on enhanced scan. Extramedullary subdural echinococcosis was mostly manifested as oval small vesicles with low signal on T1WI and high signal on T2WI, with a grape string-like appearance, and the capsular wall with low signal on T2WI could be seen at the edge. Extramedullary epidural echinococcosis was manifested as slightly low signal on T1WI, high signals on T2WI and STIR, accompanied by single or multiple small vesicles with high signal on T2WI, and compression of the dural sac. The clinical manifestations were chest and back, lumbosacral pain in 21 cases (91.3%), and lower limb dysfunction in 6 cases (26.1%).Conclusions:Intraspinal echinococcosis is relatively rare compared with other sites. When MRI features are clear, typical clinical manifestations are present, or there is a history of echinococcosis in other sites, intraspinal echinococcosis should be considered.

Objective:To investigate the function and underlying mechanism of cysteine and glycine-rich protein 2(CSRP2)in neuroblastoma(NB).Methods:The correlation between the expression level of CSRP2 mRNA and the prognosis of NB children in NB clinical samples was analyzed in R2 Genomics Analysis and Visualization Platform.The small interfering RNA(siRNA)targeting CSRP2 or CSRP2 plasmid were transfected to NB cell lines SK-N-BE(2)and SH-SY5Y.Cell proliferation was observed by crystal violet staining and real-time cellular analysis.The ability of colony formation of NB cells was ob-served by colony-forming unit assay.Immunofluorescence assay was used to detect the expression of the proliferation marker Ki-67.Flow cytometry analysis for cell cycle proportion was used with cells stained by propidium iodide(PI).Annexin V/7AAD was used to stain cells and analyze the percentage of cell apoptosis.The ability of cell migration was determined by cell wound-healing assay.The level of protein and mRNA expression of CSRP2 in NB primary tumor and NB cell lines were detected by Western blot and quantitative real-time PCR(RT-qPCR).Results:By analyzing the NB clinical sample databases,it was found that the expression levels of CSRP2 in high-risk NB with 3/4 stages in international neuroblas-toma staging system(INSS)were significantly higher than that in low-risk NB with 1/2 INSS stages.The NB patients with high expression levels of CSRP2 were shown lower overall survival rate than those with low expression levels of CSRP2.We detected the protein levels of CSRP2 in the NB samples by Western blot,and found that the protein level of CSRP2 in 3/4 INSS stages was significantly higher than that in 1/2 INSS stages.Knockdown of CSRP2 inhibited cell viability and proliferation of NB cells.Overexpression of CSRP2 increased the proliferation of NB cells.Flow cytometry showed that the proportion of sub-G1,G0/G1 and S phase cells and Annexin V positive cells were increased after CSRP2 deficiency.In the cell wound-healing assay,the healing rate of NB cells was significantly attenuated after knockdown of CSRP2.Further mechanism studies showed that the proportion of the proliferation marker Ki-67 and the phospho-rylation levels of extracellular signal-regulated kinases 1/2(ERK1/2)were significantly decreased after CSRP2 knockdown.Conclusion:CSRP2 is highly expressed in high-risk NB with 3/4 INSS stages,and the expression levels of CSRP2 are negatively correlated with the overall survival of NB patients.CSRP2 significantly increased the proliferation and cell migration of NB cells and inhibited cell apoptosis via the activation of ERK1/2.All these results indicate that CSRP2 promotes the progression of NB by activating ERK1/2,and this study will provide a potential target for high-risk NB therapy.