Exosomes from umbilical cord mesenchymal stromal cells promote the collagen production of fibroblasts from pelvic organ prolapse.

BACKGROUND: Pelvic organ prolapse (POP) involves pelvic organ herniation into the vagina due to pelvic floor tissue laxity, and vaginal structure is an essential factor. In POP, the vaginal walls exhibit abnormal collagen distribution and decreased fibroblast levels and functions. The intricate etiology of POP and the prohibition of transvaginal meshes in pelvic reconstruction surgery present challenges in targeted therapy development. Human umbilical cord mesenchymal stromal cells (hucMSCs) present limitations, but their exosomes (hucMSC-Exo) are promising therapeutic tools for promoting fibroblast proliferation and extracellular matrix remodeling. AIM: To investigate the effects of hucMSC-Exo on the functions of primary vaginal fibroblasts and to elucidate the underlying mechanism involved. METHODS: Human vaginal wall collagen content was assessed by Masson's trichrome and Sirius blue staining. Gene expression differences in fibroblasts from patients with and without POP were assessed via RNA sequencing (RNA-seq). The effects of hucMSC-Exo on fibroblasts were determined via functional experiments in vitro. RNA-seq data from fibroblasts exposed to hucMSC-Exo and microRNA (miRNA) sequencing data from hucMSC-Exo were jointly analyzed to identify effective molecules. RESULTS: In POP, the vaginal wall exhibited abnormal collagen distribution and reduced fibroblast 1 quality and quantity. Treatment with 4 or 6 µg/mL hucMSC-Exo suppressed inflammation in POP group fibroblasts, stimulated primary fibroblast growth, and elevated collagen I (Col1) production in vitro. High-throughput RNA-seq of fibroblasts treated with hucMSC-Exo and miRNA sequencing of hucMSC-Exo revealed that abundant exosomal miRNAs downregulated matrix metalloproteinase 11 (MMP11) expression. CONCLUSION: HucMSC-Exo normalized the growth and function of primary fibroblasts from patients with POP by promoting cell growth and Col1 expression in vitro. Abundant miRNAs in hucMSC-Exo targeted and downregulated MMP11 expression. HucMSC-Exo-based therapy may be ideal for safely and effectively treating POP.

Quercetin antagonized advanced glycated end products induced apoptosis and functional inhibition of fibroblasts from the prolapsed uterosacral ligament.

The altered behaviors and functions of pelvic floor fibroblasts are pathophysiological changes of pelvic organ prolapse (POP). Our previous study showed that advanced glycated end products (AGEs) accumulated in the pelvic tissues of POP and induced fibroblast apoptosis. The study was designed to investigate whether quercetin antagonize AGEs-induced apoptosis and functional inhibition of fibroblasts. The uptake of 5-ethynyl-2'-deoxyuridine (EdU) was evaluated for cell proliferation. Flow cytometric analysis was applied for cell apoptosis. Intracellular reactive oxygen species (ROS) content was determined by the fluorescence of dichlorofluorescein (DCF). The contractility of fibroblasts was measured by collagen gel contraction assay. The expressions of extracellular matrix (ECM) related genes and the expression of miR-4429 and caspase-3 were quantified by qPCR. The expressions of phosphatase and tensin homolog (PTEN), phosphoinositide 3-kinase (PI3K), serine-threonine kinase (Akt), and phosphorylated Akt (p-Akt) were analyzed by Western Blot. The down-regulation of miR-4429 was achieved by cell transfection. Quercetin antagonized AGEs-induced apoptosis, proliferation inhibition, and ROS increase in fibroblasts. Quercetin did not alleviate AGEs-induced contractile impairment of fibroblasts. Quercetin reduced the gene expressions of lysyl oxidase like protein 1 (LOXL1)and matrix metallopeptidase 1 (MMP1), and increased the gene expressions of lysyl oxidase (LOX) and fibrillin 2 (FBN2) in fibroblasts. Quercetin reversed AGEs-induced upregulation of PTEN and downregulation of PI3K, P-Akt, and miR-4429 in fibroblasts. The inhibitory effect of quercetin on AGEs-induced fibroblast apoptosis was inhibited by downregulating the expression of miR-4429. In conclusion, quercetin antagonized AGEs-induced apoptosis and functional inhibition of fibroblasts from the prolapsed uterosacral ligament. And inhibiting AGEs-induced down-regulation of miR-4429/PTEN/PI3K/Akt pathway was the mechanism underlying the antagonistic effect of quercetin on AGEs-induced apoptosis.

Exosomes derived from mesenchymal stromal cells: a promising treatment for pelvic floor dysfunction.

Pelvic floor dysfunction (PFDs), which include pelvic organ prolapse (POP), stress urinary incontinence (SUI) and anal incontinence (AI), are common degenerative diseases in women that have dramatic effects on quality of life. The pathology of PFDs is based on impaired pelvic connective tissue supportive strength due to an imbalance in extracellular matrix (ECM) metabolism, the loss of a variety of cell types, such as fibroblasts, muscle cells, peripheral nerve cells, and oxidative stress and inflammation in the pelvic environment. Fortunately, exosomes, which are one of the major secretions of mesenchymal stromal cells (MSCs), are involved in intercellular communication and the modulation of molecular activities in recipient cells via their contents, which are bioactive proteins and genetic factors such as mRNAs and miRNAs. These components modify fibroblast activation and secretion, facilitate ECM modelling, and promote cell proliferation to enhance pelvic tissue regeneration. In this review, we focus on the molecular mechanisms and future directions of exosomes derived from MSCs that are of great value in the treatment of PFD.

CD106/VCAM-1 distinguishes a fibroblast subpopulation with high colony-forming capacity and distinct protein expression from the uterosacral ligament.

Background: Pelvic organ prolapse (POP) is a common degenerative disease in women which may diminish quality of life. Investigating the pathological changes of the uterosacral ligament, including the functional changes of fibroblasts, is critical to understanding the pathophysiology of POP. This study was designed to isolate CD106-positive (CD106+) fibroblasts from the human uterosacral ligament and assess the function and expression of this subpopulation. Methods: We separated CD106+ fibroblasts and CD106 negative (CD106-) fibroblasts by fluorescence-activated cell sorting (FACS) and cultured them for subsequent experiments. Flow cytometric analysis was used to test the sorting efficiency, CD106 expression, and typical mesenchymal stem cell (MSC) phenotype marker expression. A colony-forming unit (CFU) assay was applied to evaluate the colony-forming ability of the fibroblasts. Trilineage differentiation capacities were assessed after in vitro induction. The protein levels of vimentin, fibroblast specific protein-1 (FSP-1), collagen I (COL 1), matrix metallopeptidase-1 (MMP-1), and α-smooth muscle actin (α-SMA) were detected by western blot analysis. The expression of CD106 was verified by flow cytometric analysis and immunohistochemistry (IHC) in the POP and non-POP groups. Results: The CD106+ fibroblasts were isolated with a purity of (93.50±3.91)%. The CD106+ fibroblasts exhibited higher colony-forming capacity than that of CD106- fibroblasts, but neither of them showed adipogenic or osteogenic differentiation similar to that of MSCs. The protein levels of MMP-1 and α-SMA were lower, and the level of COL 1 was higher in the CD106+ fibroblasts than in the CD106- fibroblasts. In addition, we observed a decreased expression of CD106 in the POP group compared with the non-POP group. Conclusions: Our results suggest that CD106+ fibroblasts possess a high colony-forming capacity and distinct protein expression, and this subpopulation is reduced in POP.

Advanced glycation end products (AGEs) downregulate the miR-4429/PTEN axis to promote apoptosis of fibroblasts in pelvic organ prolapse.

Background: Pelvic organ prolapse (POP) is a common degenerative disease among females. We previously reported that advanced glycation end products (AGEs), compounds derived from nonenzymatic glycoxidation reactions, accumulated in the human vaginal wall and impaired the function of fibroblasts in the pathogenesis of POP. This study investigated the apoptosis induced by AGEs in human uterosacral ligament fibroblasts and the underlying mechanism. Methods: Human uterosacral ligament fibroblasts were cultured and identified. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis was performed to identify the expression of miR-4429, phosphatase and tensin homolog (PTEN), and caspase-3. Flow cytometric analysis was applied to detect the apoptosis rate of fibroblasts. Dual-luciferase reporter assay was performed to verify the relationship between miR-4429 and PTEN. The overexpression of miR-4429 and the inhibition of PTEN were achieved by cell transfections. Western blot analysis was used to detect the protein levels of PTEN, phosphoinositide 3-kinase (PI3K), and protein kinase B (Akt). Results: The AGEs promoted fibroblast apoptosis both in the POP and the non-POP groups. The expression of PTEN increased in fibroblasts from the POP group or fibroblasts treated with AGEs. It was confirmed that miR-4429 interacted with PTEN messenger RNA (mRNA), and the expression level of miR-4429 was reduced in fibroblasts from the POP group or fibroblasts treated with AGEs. Further, overexpression of miR-4429 alleviated increased PTEN expression and fibroblast apoptosis induced by AGEs. Similarly, inhibition of PTEN expression alleviated increased fibroblast apoptosis induced by AGEs. In addition, the protein expressions of PI3K and phosphorylated Akt were reduced in fibroblasts exposed to AGEs. Conclusions: We proposed that AGEs induced fibroblast apoptosis by regulating the miR-4429/PTEN/PI3K/Akt pathway in POP. Our results revealed a novel mechanism by which AGEs contributed to the molecular pathological alteration in POP.

Lovastatin Prevents Depressive Behaviors and Increased Hippocampal Neurogenesis in Streptozotocin-Induced Diabetic Mice.

Depression is a progressive and chronic syndrome and commonly related to several neuropsychiatric comorbidities, of which depression is the most studied. Population-based studies have suggested a positive role of statins in ameliorating depression risk. However, the role of statins in the treatment of diabetes-related depression has not been well examined. Herein, we investigated the effects of lovastatin (LOV) on depressive phenotypes in streptozotocin-induced diabetic mice. The data suggested that the treatment of LOV at 10 or 20 mg/kg for 3 weeks markedly prevented diabetes-associated depressive behaviors reflected by better performance in the sucrose preference test, tail suspension test, and novelty-suppressed feeding test. The study further showed that these treatments improved the hippocampal neurogenesis as evidenced by increased bromodeoxyuridine-positive cells in the dentate gyrus with higher expression of mature brain-derived neurotrophic factor and increased phosphorylation of cAMP-response element-binding protein. As expected, diabetic mice treated with LOV showed significant improvement of hyperlipidemia rather than hyperglycemia. These results suggest that LOV may be employed as a drug for the treatment of diabetes-related depression.