Collagen posttranslational processing is crucial for its proper assembly and function. Disruption of collagen processing leads to tissue development and structure disorders like osteogenesis imperfecta (OI). OI-related collagen processing machinery includes prolyl 3-hydroxylase 1 (P3H1), peptidyl-prolyl cis-trans isomerase B (PPIB), and cartilage-associated protein (CRTAP), with their structural organization and mechanism unclear. We determine cryo-EM structures of the P3H1/CRTAP/PPIB complex. The active sites of P3H1 and PPIB form a face-to-face bifunctional reaction center, indicating a coupled modification mechanism. The structure of the P3H1/CRTAP/PPIB/collagen peptide complex reveals multiple binding sites, suggesting a substrate interacting zone. Unexpectedly, a dual-ternary complex is observed, and the balance between ternary and dual-ternary states can be altered by mutations in the P3H1/PPIB active site and the addition of PPIB inhibitors. These findings provide insights into the structural basis of collagen processing by P3H1/CRTAP/PPIB and the molecular pathology of collagen-related disorders.

The adhesion receptor vascular endothelial (VE)-cadherin transduces an array of signals that modulate crucial lymphatic cell behaviors including permeability and cytoskeletal remodeling. Consequently, VE-cadherin must interact with a multitude of intracellular proteins to exert these functions. Yet, the full protein interactome of VE-cadherin in endothelial cells remains a mystery. Here, we use proximity proteomics to illuminate how the VE-cadherin interactome changes during junctional reorganization from dis-continuous to continuous junctions, triggered by the lymphangiogenic factor adrenomedullin. These analyses identified interactors that reveal roles for ADP ribosylation factor 6 (ARF6) and the exocyst complex in VE-cadherin trafficking and recycling. We also identify a requisite role for VE-cadherin in the in vitro and in vivo control of secretion of reelin-a lymphangiocrine glycoprotein with recently appreciated roles in governing heart development and injury repair. This VE-cadherin protein interactome shines light on mechanisms that control adherens junction remodeling and secretion from lymphatic endothelial cells.

OBJECTIVE: To analyze the association between fibulin-2 and Ki-67 index with histopathological grade and other clinicopathological factors in patients with meningioma among the Minangkabau ethnic group.
METHODS: This cross-sectional observational study uses 50 specimens comprising 25 low-risk meningioma cases and 25 high-risk meningioma cases obtained at three anatomical pathology laboratories in Padang, West Sumatra, Indonesia, between 2019 and 2022. All samples were stained using an immunohistochemistry procedure with Ki-67 and fibulin-2. The chi-square test was used to assess IBM SPSS statistics version 26 for Windows was used to assess the association of Ki-67 and fibulin-2 with the histopathological grade. The p-value of <0.05 was considered significant.
RESULTS: We found a significant association between Ki-67 (p = 0.013) or fibulin-2 (p = 0.001) expression with histopathological grade of meningioma. High histopathological grade has high expression of Ki-67 and fibulin-2, with Odds ratio (OR) of 13.500 (1.556-117.137) and 10.028 (2,738-36,722), respectively. Fibulin-2 expression was also associated with the age of patients (p = 0.020). The low age group (<50) has high expression of fibulin-2 (OR 0.196 (0.056-0.691).  Conclusion: Ki-67 and fibulin-2 were associated with the histopathological grade of meningioma, while fibulin-2 is also associated with age in the Minangkabau ethnic group.

We present the results of the first study of a large cohort of patients with inherited retinal dystrophies (IRD) performed for the Polish population using whole-exome sequencing (WES) in the years 2016-2019. Moreover, to facilitate such diagnostic analyses and enable future application of gene therapy and genome editing for IRD patients, a Polish genomic reference database (POLGENOM) was created based on whole-genome sequences of healthy Polish Caucasian nonagenarians and centenarians. The newly constructed database served as a control, providing a comparison for variant frequencies in the Polish population. The diagnostic yield for the selected group of IRD patients reached 64.9%. The study uncovered the most common pathogenic variants in ABCA4 and USH2A in the European population, along with several novel causative variants. A significant frequency of the ABCA4 complex haplotype p.(Leu541Pro; Ala1038Val) was observed, as well as that of the p.Gly1961Glu variant. The first VCAN causative variant NM_004385.5:c.4004-2A>G in Poland was found and described. Moreover, one of the first patients with the RPE65 causative variants was identified, and, in consequence, could receive the dedicated gene therapy. The availability of the reference POLGENOM database enabled comprehensive variant characterisation during the NGS data analysis, confirming the utility of a population-specific genomic database for enhancing diagnostic accuracy. Study findings suggest the significance of genetic testing in elder patients with unclear aetiology of eye diseases. The combined approach of NGS and the reference genomic database can improve the diagnosis, management, and future treatment of IRDs.

Ribonucleotide reductase (RNR) is the rate-limiting enzyme in the synthesis of deoxyribonucleotides and the target of multiple chemotherapy drugs, including gemcitabine. We previously identified that inhibition of RNR in Ewing sarcoma tumors upregulates the expression levels of multiple members of the activator protein-1 (AP-1) transcription factor family, including c-Jun and c-Fos, and downregulates the expression of c-Myc. However, the broader functions and downstream targets of AP-1, which are highly context- and cell-dependent, are unknown in Ewing sarcoma tumors. Consequently, in this work, we used genetically defined models, transcriptome profiling, and gene-set -enrichment analysis to identify that AP-1 and EWS-FLI1, the driver oncogene in most Ewing sarcoma tumors, reciprocally regulate the expression of multiple extracellular-matrix proteins, including fibronectins, integrins, and collagens. AP-1 expression in Ewing sarcoma cells also drives, concurrent with these perturbations in gene and protein expression, changes in cell morphology and phenotype. We also identified that EWS-FLI1 dysregulates the expression of multiple AP-1 proteins, aligning with previous reports demonstrating genetic and physical interactions between EWS-FLI1 and AP-1. Overall, these results provide novel insights into the distinct, EWS-FLI1-dependent features of Ewing sarcoma tumors and identify a novel, reciprocal regulation of extracellular-matrix components by EWS-FLI1 and AP-1.

Throughout the isolation process, human islets are subjected to destruction of the islet basement membrane (BM) and reduced oxygen supply. Reconstruction of the BM represents an option to improve islet function and survival post-transplant and may particularly be relevant for islet encapsulation devices and scaffolds. In the present study, we assessed whether Perlecan, used alone or combined with the BM proteins (BMPs) Collagen-IV and Laminin-521, has the ability to protect isolated human islets from hypoxia-induced damage. Islets isolated from the pancreas of seven different organ donors were cultured for 4-5 days at 2% oxygen in plain CMRL (sham-treated controls) or in CMRL supplemented with BMPs used either alone or in combination. Postculture, islets were characterized regarding survival, in vitro function and production of chemokines and reactive oxygen species (ROS). Individually added BMPs significantly doubled islet survival and increased in vitro function. Combining BMPs did not provide a synergistic effect. Among the tested BMPs, Perlecan demonstrated the significantly strongest inhibitory effect on chemokine and ROS production when compared with sham-treatment (p < 0.001). Perlecan may be useful to improve islet survival prior to and after transplantation. Its anti-inflammatory potency should be considered to optimise encapsulation and scaffolds to protect isolated human islets post-transplant.

The main component of human skin is a collagen-rich extracellular matrix (ECM), known as the matrisome. The matrisome is essential for maintaining the structural integrity and mechanical properties of the skin. Recently, we reported notable decreases in matrisome proteins in natural aging and photoaging human skin. This study aims to investigate the mRNA expression of the core matrisome proteins in human skin, comparing young versus aged and sun-protected versus sun-exposed skin by quantitative real-time PCR and immunostaining. Our findings reveal a notable decrease in core matrisome transcription in aged skin. The mRNA expression of the core matrisome, such as collagen 1A1 (COL1A1), decorin, and dermatopontin, is significantly reduced in aged skin compared to its young skin. Yet, the majority of collagen mRNA expression levels of aged sun-exposed skin are similar to those found in young sun-exposed skin. This discrepancy is primarily attributable to a substantial decrease in collagen transcription in young sun-exposed skin, suggesting early molecular changes in matrisome transcription due to sun exposure, which preceded the emergence of clinical signs of photoaging. These findings shed light on the mRNA transcript profile of major matrisome proteins and their alterations in naturally aged and photoaged human skin, offering valuable insights into skin matrisome biology.

UNASSIGNED: Inflammation-induced remodelling of gestational tissues that underpins spontaneous preterm birth (sPTB, delivery < 37 weeks\' gestation) may vary by race and context. To explore relationships between markers of these pathological processes, we (a) characterised the cervicovaginal fluid (CVF) cytokine profiles of pregnant South African women at risk of PTB; (b) determined CVF matrix-metalloproteinase-9 (MMP-9) and its regulator tissue inhibitor of metalloproteinase-1 (TIMP-1); and (c) explored the predictive potential of these markers for sPTB.
UNASSIGNED: The concentrations of 10 inflammatory cytokines and MMP-9 and TIMP-1 were determined by ELISA in CVF samples from 47 non-labouring women at high risk of PTB. We studied CVF sampled at three gestational time points (GTPs): GTP1 (20-22 weeks, n = 37), GTP2 (26-28 weeks, n = 40), and GTP3 (34-36 weeks, n = 29) and analysed for changes in protein concentrations and predictive capacities (area under the ROC curve (AUC) and 95% confidence interval (CI)) for sPTB.
UNASSIGNED: There were 11 (GTP1), 13 (GTP2), and 6 (GTP3) women who delivered preterm within 85.3 ± 25.9, 51.3 ± 15.3, and 11.8 ± 7.5 (mean ± SD) days after assessment, respectively. At GTP1, IL-8 was higher (4-fold, p = 0.02), whereas GM-CSF was lower (~1.4-fold, p = 0.03) in the preterm compared with term women with an average AUC = 0.73. At GTP2, IL-1β (18-fold, p < 0.0001), IL-8 (4-fold, p = 0.03), MMP-9 (17-fold, p = 0.0007), MMP-9/TIMP-1 ratio (9-fold, p = 0.004), and MMP-9/GM-CSF ratio (87-fold, p = 0.005) were higher in preterm compared with term women with an average AUC = 0.80. By contrast, IL-10 was associated with term delivery with an AUC (95% CI) = 0.75 (0.55-0.90). At GTP3, IL-1β (58-fold, p = 0.0003), IL-8 (12-fold, p = 0.002), MMP-9 (296-fold, p = 0.03), and TIMP-1 (35-fold, p = 0.01) were higher in preterm compared with term women with an average AUC = 0.85. Elevated IL-1β was associated with delivery within 14 days of assessment with AUC = 0.85 (0.67-0.96). Overall, elevated MMP-9 at GTP3 had the highest (13.3) positive likelihood ratio for distinguishing women at risk of sPTB. Lastly, a positive correlation between MMP-9 and TIMP-1 at all GTPs (ρ ≥ 0.61, p < 0.01) for women delivering at term was only observed at GTP1 for those who delivered preterm (ρ = 0.70, p < 0.03).
UNASSIGNED: In this cohort, sPTB is associated with gestation-dependent increase in pro-inflammatory cytokines, decreased IL-10 and GM-CSF, and dysregulated MMP-9-TIMP-1 interaction. Levels of cytokine (especially IL-1β) and ECM remodelling proteins rise significantly in the final 2 weeks before the onset of labour when sPTB is imminent. The signalling mechanisms for these ECM remodelling observations remain to be elucidated.

OBJECTIVE: The aim of this study was to investigate the role and molecular mechanism of proline/arginine-rich end leucine-rich repeat protein (PRELP), a secreted protein in extracellular matrix, in oral squamous cell carcinoma (OSCC) progression.
METHODS: PRELP expression in OSCC was analyzed in the Gene Set Enrichment (GSE) 138206, GSE37991, and GSE23558 datasets as well as cell lines. Also, PRELP expression and its relationship with prognosis and immune infiltration in head and neck squamous cell carcinoma (HNSCC) were confirmed by bioinformatics analysis. The proliferation, apoptosis, invasion, epithelial-to-mesenchymal transition (EMT) and NF-κB activation were detected after alteration of PRELP expression in OSCC cells using CCK-8, EdU, flow cytometry, Transwell, real-time PCR, immunofluorescence and Western blot. Additionally, an NF-κB inhibitor PDTC was used to confirm the regulation mechanism of PRELP.
RESULTS: The expression of PRELP in OSCC tissues, cells and in HNSCC samples was low. HNSCC patients with higher PRELP expression was associated with longer overall survival. A positive correlation between PRELP expression and immune cell infiltration was found in HNSCC. Upregulation of PRELP inhibited, whereas PRELP silencing promoted, the proliferation, invasion and EMT of OSCC cells. Also, overexpression of PRELP promoted cell apoptosis. Mechanistically, PRELP suppressed p65 phosphorylation and nuclear translocation. And PDTC treatment partially reversed the influences of PRELP knockdown on the malignant behaviors in OSCC cells.
CONCLUSIONS: PRELP suppressed OSCC progression via inactivation of the NF-κB pathway. Targeting PRELP may be a potential approach for OSCC treatment.

OBJECTIVE: This study aims to elucidate the genetic causes of congenital hypogonadotropic hypogonadism (CHH), a rare genetic disorder resulting in GnRH deficiency, in six families from Pakistan.
METHODS: Eighteen DNA samples from six families underwent genome sequencing followed by standard evaluation for pathogenic single nucleotide variants (SNVs) and small indels. All families were subsequently analyzed for pathogenic copy number variants (CNVs) using CoverageMaster.
RESULTS: Novel pathogenic homozygous SNVs in known CHH genes were identified in four families: two families with variants in GNRHR, and two others harboring KISS1R variants. Subsequent investigation of CNVs in the remaining two families identified novel unique large deletions in ANOS1.
CONCLUSIONS: A combined, systematic analysis of single nucleotide and CNVs helps to improve the diagnostic yield for variants in patients with CHH.