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).

Notochordal cells (NCs) present in the nucleus pulposus (NP) of the developing human intervertebral disc (IVD) disappear during the first decade of life. This loss coincides with the onset of IVD degeneration, therefore these cells are hypothesized to be important in NP homeostasis. Putative NC-derived (CD24+) and progenitor (TIE2+/GD2+) cell sub-populations have previously been identified in the adult human NP, but their characteristics have yet to be compared. Here, we used CD24, TIE2 and GD2 to identify and then isolate discrete cell sub-populations to assess cell phenotype.
CD24, GD2 and TIE2 positivity was assessed in a cohort of human pediatric and adult NP samples across a range of ages and histological degeneration grades using immunohistochemistry and flow cytometry. FACS sorting was used to isolate different cell sub-populations (CD24+/GD2+; CD24+/GD2-; CD24-/GD2+; CD24-/GD2-). Cell phenotype was assessed using qPCR for known NC and NP markers as well as catabolic genes.
CD24+ and GD2+ cells were localized in all samples, irrespective of age or degeneration grade, while TIE2+ cell number was consistently very low. The same positivity trend was confirmed using flow cytometry. A small CD24+/GD2+ sub-population was present and maintained marker expression with time in culture. CD24+ subpopulations showed a significantly higher expression of NC markers than the CD24- subpopulations and unsorted samples, suggesting a healthier phenotype in the CD24+ cells. GD2 did not appear to influence gene expression.
This study provides a better understanding of different cell sub-populations present in the adult NP, with identification of CD24+/GD2+ cells that are maintained with aging and degeneration. Healthy, NC-like phenotypic profiles appeared reliant on CD24, rather than GD2. The study highlights the importance of studying discrete cell sub-populations, especially CD24+ NP cells to better understand their role in NP homeostasis.
© 2024 The Author(s). JOR Spine published by Wiley Periodicals LLC on behalf of Orthopaedic Research Society.

Vascular cognitive impairment(VCI) ranks as the second most prevalent type of dementia.Increasing evidence has shown that inflammation and multi-faceted neuro-immune interactions integrate systemic and central inflammatory pathways, thereby inducing vascular tissue injury and contributing to the development of vascular cognitive impairment (VCI).V-type immunoglobulin-like suppressor of T cell activation (VISTA) is an Negative checkpoint regulators(NCR) that is associated with CNS homeostasis, interactions with peripheral immunity and CNS inflammation.The primary objective of this study was to seek the correlation between VISTA and VCI in patients with cardiovascular risk factors.Our secondary objective was to explore the potential of VISTA as a biomarker for VCI.
We enrolled individuals with cardiovascular risk factors in this cross-sectional study research and categorized them into two groups: without cognitive impairment (control) and with cognitive impairment (VCI). VISTA expression in peripheral blood mononuclear cells (PBMCs) was analyzed using relative quantitative polymerase chain reaction. VISTA expression was identified in monocyte subsets using flow cytometry. We use Enzyme linked immunosorbent assay to detect inflammatory factors in serum.
In PBMC in patients with VCI, the expression of VSIR was significantly reduced. In contrast to controls, fasting glucose, fibrosis, and the levels of interleukin 6 (IL-6) in VCI patients were noticeably higher, and uric acid levels were significantly lower. Vsir mRNA expression in PBMCs correlated negatively with IL-6 levels, Trail Making Test B scores, and Hachinski scores and positively with Boston Naming Test scores. In intermediate monocytes, flow cytometry showed reduced Vsir expression, which was connected with VCI. The percentage of intermediate monocytes, uric acid, and the VISTA mean fluorescence intensity on intermediate monocytes were shown to be independent factors to VCI by multivariate logistic regression analysis.
Decreased VISTA promotes the occurrence of VCI in patients with cardiovascular risk factors by promoting monocytes toward the proinflammatory intermediate monocyte subset. VISTA may serve as a potential biomarker for distinguishing VCI in individuals with cardiovascular risk factors.
© 2024 Liu and Chi.

Human Cytomegalovirus (HCMV) infection can result in either productive or latent infection, the latter being the basis for the virus life-long persistence. Intriguingly, monocytes, which support latent infection, become permissive to productive infection upon differentiation to macrophages. However, the molecular factors explaining these differentiation-driven differences are not fully understood and have been so far attributed to chromatin-mediated repression of the viral genome. Here, by using metabolic labeling of newly synthesized RNA early in monocyte and macrophage infection, we discover a major early block in viral gene expression, and viral transcripts are barely detected in infected monocytes. By unbiasedly analyzing the changes between monocytes and their differentiated counterparts, we reveal that the levels of several cell surface proteins involved in HCMV entry are upregulated upon monocyte to macrophage differentiation, and correspondingly we uncover HCMV entry into monocytes compared to macrophages is extremely inefficient. Remarkably, ectopic expression of a canonical HCMV entry receptor in monocytes facilitates productive infection of these cells, demonstrating that given efficient viral entry, monocytes, like macrophages, have the capacity to support productive infection. Among the cell surface proteins that are upregulated upon monocyte differentiation are several integrins, which we show play an important role in HCMV entry into macrophages, partially explaining the differences in viral entry. Overall, our findings reveal that a previously unrecognized major barrier for productive infection in monocytes is entry, adding a critical layer to the paradigm of HCMV latency.

Type I interferons (IFN-I) are implicated in exacerbation of tuberculosis (TB), but the mechanisms are unclear. Mouse macrophages infected with Mycobacterium tuberculosis (Mtb) produce IFN-I, which contributes to their death. Here we investigate whether the same is true for human monocyte-derived macrophages (MDM). MDM prepared by a conventional method markedly upregulate interferon-stimulated genes (ISGs) upon Mtb infection, while MDM prepared to better restrict Mtb do so much less. A mixture of antibodies inhibiting IFN-I signaling prevents ISG induction. Surprisingly, secreted IFN-I are undetectable until nearly two days after ISG induction. These same antibodies do not diminish Mtb-infected MDM death. MDM induce ISGs in response to picogram/mL levels of exogenous IFN-I while depleting similar quantities from the medium. Exogenous IFN-I increase the proportion of dead MDM. We speculate that Mtb-infected MDM produce and respond to minute levels of IFN-I, and that only some of the resultant signaling is susceptible to neutralizing antibodies. Many types of cells may secrete IFN-I in patients with TB, where IFN-I is likely to promote the death of infected macrophages.
© 2024. The Author(s).