As a major component of intracellular trafficking, the coat protein complex II (COPII) is indispensable for cellular function during embryonic development and throughout life. The 4 SEC24 proteins (A-D) are essential COPII components involved in cargo selection and packaging. A human disorder corresponding to alterations of SEC24 function is currently known only for SEC24D. Here, we reported that biallelic loss of SEC24C leads to a syndrome characterized by primary microcephaly, brain anomalies, epilepsy, hearing loss, liver dysfunction, anemia, and cataracts in an extended consanguineous family with 4 affected individuals. We showed that knockout of sec24C in zebrafish recapitulated important aspects of the human phenotype. SEC24C-deficient fibroblasts displayed alterations in the expression of several COPII components as well as impaired anterograde trafficking to the Golgi, indicating a severe impact on COPII function. Transcriptome analysis revealed that SEC24C deficiency also affected the proteasome and autophagy pathways. Moreover, a shift in the N-glycosylation pattern and deregulation of the N-glycosylation pathway suggested a possible secondary alteration of protein glycosylation, linking the described disorder with the congenital disorders of glycosylation.

Human menstrual blood-derived stem cells (MenSCs), a major class of mesenchymal stem cells (MSCs), modulate intercellular signals via paracrine factors. Previous studies found that MenSC-derived secretomes exert protective effects against liver fibrosis. However, the underlying mechanisms of these observations remain unclear.
Extracellular Matrix Protein 1 (ECM1), identified in MenSCs culture medium using mass spectrometry, was employed to stably overexpress ECM1-HA or silence in MenSCs using lentiviral vectors. These genetically engineered cells were either intravenously injected into the carbon tetrachloride (CCl4)-induced liver fibrosis mice or co-cultured with hepatic stellate cells (HSCs)-LX-2. The interaction between ECM1 and low-density lipoprotein receptor-related protein 1α (LRP1α) was confirmed using Co-Immunoprecipitation (Co-ip), Duolink Proximity Ligation Assays (PLA) and pull-down. LRP1 deficient mice were generated via intravenous administration of adeno-associated-virus-8. The downstream molecular mechanisms were characterized by non-target metabolomics and multiplex immunohistochemical staining. RNA sequencing was performed to evaluate the genetic alterations in various genes within the MenSCs.
MenSC-secreted ECM1 exhibits potential to ameliorate liver fibrosis by inactivating HSCs, improving liver functions, and reducing collagen deposition in both cellular and mouse model of the CCl4-induced liver fibrosis. Mechanistically, a novel interaction was identified that ECM1 directly bound to cell surface receptor LRP1α. Notably, the antifibrotic efficacy of MenSC was negated in LRP1-deficient cells and mice. Moreover, the ECM1-LRP1 axis contributed to the alleviation of liver fibrosis by suppressing AKT/mTOR while activating the FoxO1 signaling pathway, thereby facilitating pyrimidine and purine metabolism. Additionally, ECM1-modified MenSCs regulate the transcription of intrinsic cytokine genes, further mitigating liver fibrosis.
These findings highlight an extensive network of ECM1-LRP1 interaction, which serve as a link for providing promising insights into the mechanism of MenSC-based drug development for liver fibrosis. Our study also potentially presents novel avenues for clinical antifibrotic therapy.
© 2025. The Author(s).

Aim: This study aims to investigate the effects of large extracellular vesicles (EVs) induced by pluripotent stem cell-derived mesenchymal stem cells on lower limb ischemic disease and explore its potential mechanisms. Materials & methods: The pathology of muscles was accessed by H&E staining and immunofluorescence staining. In vitro, we conducted wound-healing assay, tube formation assay, RT qPCR, ELISA, RNA sequencing and proteomic analysis. Results: iMSCs-lEVs alleviated the injury of ischemic lower limb and promoted the recovery of lower limb function. In vitro, iMSCs-lEVs promoted the proliferation, migration, and angiogenesis of HMEC-1 cells by regulating the ERK/MAPK signing pathway. Conclusion: This study demonstrated that iMSCs-lEVs promoted endothelial cell angiogenesis via the ERK/MAPK signaling pathway, thereby improving function after lower limb ischemic injury.

Radiotherapy (RT) is one of three major treatments for malignant tumors, and one of its most common side effects is skin and soft tissue injury. However, the treatment of these remains challenging. Several studies have shown that mesenchymal stem cell (MSC) treatment enhances skin wound healing. In this study, we extracted human dermal fibroblasts (HDFs) and adipose-derived stem cells (ADSCs) from patients and generated an in vitro radiation-induced skin injury model with HDFs to verify the effect of conditioned medium derived from adipose-derived stem cells (ADSC-CM) and extracellular vesicles derived from adipose-derived stem cells (ADSC-EVs) on the healing of radiation-induced skin injury. The results showed that collagen synthesis was significantly increased in wounds treated with ADSC-CM or ADSC-EVs compared with the control group, which promoted the expression of collagen-related genes and suppressed the expression of inflammation-related genes. These findings indicated that treatment with ADSC-CM or ADSC-EVs suppressed inflammation and promoted extracellular matrix deposition; treatment with ADSC-EVs also promoted fibroblast proliferation. In conclusion, these results demonstrate the effectiveness of ADSC-CM and ADSC-EVs in the healing of radiation-induced skin injury.

Mesenchymal stromal/stem cells (MSCs) possess immunoregulatory properties and their regulatory functions represent a potential therapy for acute lung injury (ALI). However, uncertainties remain with respect to defining MSCs-derived immunomodulatory pathways. Therefore, this study aimed to investigate the mechanism underlying the enhanced effect of human recombinant bone morphogenic protein-2 (rhBMP-2) primed ES-MSCs (MSCBMP2) in promoting Tregs in ALI mice. MSC were preconditioned with 100 ng/ml rhBMP-2 for 24 h, and then administrated to mice by intravenous injection after intratracheal injection of 1 mg/kg LPS. Treating MSCs with rhBMP-2 significantly increased cellular proliferation and migration, and cytokines array reveled that cytokines release by MSCBMP2 were associated with migration and growth. MSCBMP2 ameliorated LPS induced lung injury and reduced myeloperoxidase activity and permeability in mice exposed to LPS. Levels of inducible nitric oxide synthase were decreased while levels of total glutathione and superoxide dismutase activity were further increased via inhibition of phosphorylated STAT1 in ALI mice treated with MSCBMP2. MSCBMP2 treatment increased the protein level of IDO1, indicating an increase in Treg cells, and Foxp3+CD25+ Treg of CD4+ cells were further increased in ALI mice treated with MSCBMP2. In co-culture assays with MSCs and RAW264.7 cells, the protein level of IDO1 was further induced in MSCBMP2. Additionally, cytokine release of IL-10 was enhanced while both IL-6 and TNF-α were further inhibited. In conclusion, these findings suggest that MSCBMP2 has therapeutic potential to reduce massive inflammation of respiratory diseases by promoting Treg cells.
Copyright © 2023. The Korean Association of Immunologists.