Therapeutic effects of CXCL9-overexpressing human umbilical cord mesenchymal stem cells on liver fibrosis in rats

Chemical reprogramming culture for the expansion of salivary gland epithelial basal progenitor cells

BACKGROUND

Salivary gland (SG) hypofunction presents a significant clinical challenge with limited treatment options. SG epithelial cells offer a promising approach due to their intrinsic tissue specificity and regenerative potential. However, the lack of efficient culture methods has hindered their clinical use.

METHODS

This study presents a chemical reprogramming culture (CRC) system that utilizes a combination of three small molecules for the long-term two-dimensional culture of human SG epithelial progenitor cells. We characterized the cultured cells, measured their organoid-forming efficiencies, and assessed their differentiation potential. To evaluate the therapeutic efficacy of the SG basal progenitor cells (SG-BPCs), we administered them into a mouse model with radiation-induced SG hypofunction and assessed the functional recovery.

RESULTS

By utilizing optimal concentrations of the small molecules Y-27632, A83-01, and LDN193189, the SG epithelial cells achieved over 50 population doubling levels (PD) within 80 d, surpassing the Hayflick limit. β-galactosidase and Terminal deoxynucleotidyl transferase dUTP nick end labeling staining confirmed that these small molecules inhibited cellular senescence and apoptosis, respectively. The cells expressed SG basal ductal cell markers KRT5, KRT19, and SOX9, with increased expression levels observed from PD5 to PD40. Notably, these expanded cells were able to differentiate into various SG cell types, including acinar and myoepithelial cells, indicating that SG-basal progenitor cells (SG-BPCs) were selectively proliferated using our CRC method. To assess the therapeutic potential of the expanded SG-BPCs, they were administered to mice with radiation-induced SG hypofunction. The treatment successfully restored SG function.

CONCLUSION

Our findings demonstrate that our CRC system is an effective method for the long-term culture of SG-BPCs. This advancement holds significant promise for the development of SG epithelial progenitor-based therapies to treat SG hypofunction.

Thermosensitive and injectable chitosan-based hydrogel embedding umbilical cord mesenchymal stem cells for β-cell repairing in type 2 diabetes mellitus

A thermosensitive and injectable hydrogel composed of chitosan (CS), chitosan biguanide hydrochloride (CSG) and collagen (CO) could embed umbilical cord mesenchymal stem cells (UC-MSCs), then was applied for the type 2 diabetes mellitus (T2DM) treatment in vivo. UC-MSCs could adhere well on CS/CSG/CO hydrogel surface and cell division could be clearly observed. Especially, UC-MSCs maintained alive till they grew in CS/CSG/CO hydrogel for 8 days, while the amount of UC-MSCs was limited due to the steric hindrance in hydrogel. To T2DM mice contrastive treatment by intraperitoneal injection for thirteen weeks, UC-MSCs + Hydrogel group could improve the impaired glucose tolerance, maintain glucose homeostasis in vivo, and restore islet morphology for T2DM mice. The immunofluorescence staining and western blot experiments further displayed that both the nuclear antigen Ki67 for cell proliferation and pancreatic duodenal homeobox-1 (Pdx1) expression in UC-MSCs + Hydrogel group were significantly higher than the expressions in untreated T2DM group and treated UC-MSCs + PBS group, which indicated that UC-MSCs + Hydrogel elevated β cell transcriptional activity. Moreover, the positivity rates of iNOS and CD163 in UC-MSCs + Hydrogel group were generally decreased and increased, respectively, compared to those in untreated T2DM group and treated UC-MSCs + PBS group. It displayed that UC-MSCs + Hydrogel could reduce M1 macrophage expression and increase M2 macrophage polarization in T2DM mice.

Pretreatment with Inflammatory Factors Altered the Secretome of Human Amniotic Epithelial Cells

Human amniotic epithelial cells (hAECs) are novel and promising therapeutic agents for patients suffering from degenerative diseases. Studies have demonstrated that the therapeutic effects of hAECs mainly depend on their paracrine components. Currently, appropriate pretreatment is a widely confirmed strategy for enhancing the repair potential of stem cells; however, the effect of proinflammatory factor pretreatment on hAECs and their secretome is still unclear. In this study, we used the well-characterized proinflammatory factors tumor necrosis factor alpha (TNF-α) and interferon gamma (IFN-γ) to stimulate hAECs and analyzed the effect of TNF-α and IFN-γ on hAECs, including gene expression profile, paracrine proteins, and microRNAs (miRNAs) in exosomes. Results showed that TNF-α and IFN-γ pretreatment improved the viability of hAECs but inhibited the proliferation of hAECs. TNF-α and IFN-γ pretreatment altered the gene expression profile of hAECs, and upregulated differentially expressed genes were predominantly enriched in biological adhesion, antioxidant activity, and response to IFN-beta. In addition, TNF-α and IFN-γ pretreatment enhanced the paracrine secretion of cytokines by hAECs. The upregulated differentially expressed proteins were mainly enriched in tissue remodeling proteins and cytokine-cytokine receptor. Notably, the expression of miRNAs in exosomes from hAECs was also changed by TNF-α and IFN-γ pretreatment. The target genes of upregulated exosomal miRNAs substantially contributed to the response to stimulus, metabolic pathways, and PI3K-Akt signaling pathway. Our findings improve our understanding of the biological characteristics of hAECs after proinflammatory factor pretreatment and provide novel insights to strengthen and optimize the therapeutic potential of hAECs and their secretome in regenerative medicine.

TC14012 enhances the anti-fibrosis effects of UC-MSCs on the liver by reducing collagen accumulation and ameliorating inflammation

BACKGROUND

Mesenchymal stem cells (MSCs) are attracting attention as a promising cell-based therapy for the treatment of liver fibrosis or cirrhosis. However, the strategies and potential mechanisms of MSCs therapy need further investigation. The CXCL12/CXCR4/CXCR7 chemokine axis is well known to regulate cell migration and is involved in the regulation of liver fibrosis. This study aims to treat MSCs with a CXCR7-specific agonist to evaluate its therapeutic effects on hepatic fibrosis and potential mechanisms.

METHODS

TC14012, a potent agonist of CXCR7, has been used to pretreat human umbilical cord-derived MSCs (UC-MSCs) and assess its effect on proliferation, apoptosis, migration, immunoregulation, and gene regulatory network. Then, CCl4-induced liver fibrosis mice models were used to evaluate the therapeutic effect and mechanism of TC14012-treated UC-MSCs for treating hepatic fibrosis.

RESULTS

TC14012 increased CXCR7 expression in UC-MSCs. Notably, co-culture of liver sinusoidal endothelial cells (LSEC) with TC14012-pretreated UC-MSCs increased CXCR7 expression in LSEC. Additionally, TC14012 promoted cell migration and mediated the immunoregulation of UC-MSCs. Compared to UC-MSCs without TC14012 pretreatment, UC-MSCs treated with TC14012 ameliorated live fibrosis by restoring CXCR7 expression, reducing collagen fibril accumulation, inhibiting hepatic stellate cells activation, and attenuating the inflammatory response.

CONCLUSION

This study suggests that TC14012 pretreatment can enhance the therapeutic effects of UC-MSCs on liver fibrosis, mainly by promoting the migration and immunoregulation of MSCs.

Enhancing mesenchymal stem cell survival and homing capability to improve cell engraftment efficacy for liver diseases

Although mesenchymal stem cell (MSC) transplantation provides an alternative strategy for end-stage liver disease (ESLD), further widespread application of MSC therapy is limited owing to low cell engraftment efficiency. Improving cell engraftment efficiency plays a critical role in enhancing MSC therapy for liver diseases. In this review, we summarize the current status and challenges of MSC transplantation for ESLD. We also outline the complicated cell-homing process and highlight how low cell engraftment efficiency is closely related to huge differences in extracellular conditions involved in MSC homing journeys ranging from constant, controlled conditions in vitro to variable and challenging conditions in vivo. Improving cell survival and homing capabilities enhances MSC engraftment efficacy. Therefore, we summarize the current strategies, including hypoxic priming, drug pretreatment, gene modification, and cytokine pretreatment, as well as splenectomy and local irradiation, used to improve MSC survival and homing capability, and enhance cell engraftment and therapeutic efficiency of MSC therapy. We hope that this review will provide new insights into enhancing the efficiency of MSC engraftment in liver diseases.

The antibacterials ciprofloxacin, trimethoprim and sulfadiazine modulate gene expression, biomarkers and metabolites associated with stress and growth in gilthead sea bream (Sparus aurata)

The high consumption and subsequent input of antibacterial compounds in marine ecosystems has become a worldwide problem. Their continuous presence in these ecosystems allows a direct interaction with aquatic organisms and can cause negative effects over time. The objective of the present study was to evaluate the effects of exposure to three antibacterial compounds of high consumption and presence in marine ecosystems (Ciprofloxacin CIP, Sulfadiazine SULF and Trimethoprim TRIM) on the physiology of the gilthead sea bream, Sparus aurata. Plasma parameters, enzymatic biomarkers of oxidative stress and damage and expression of genes related to stress and growth were assessed in exposed S. aurata specimens. For this purpose, sea bream specimens were exposed to individual compounds at concentrations of 5.2 ± 2.1 μg L^-1 for CIP, 3.8 ± 2.7 μg L^-1 for SULF and 25.7 ± 10.8 μg L^-1 for TRIM during 21 days. Exposure to CIP up-regulated transcription of genes associated with the hypothalamic-pituitary-thyroid (HPT) (thyrotropin-releasing hormone, trh) and hypothalamic-pituitary-interrenal (HPI) axes (corticotropin-releasing hormone-binding protein, crhbp) in the brain, as well as altering several hepatic stress biomarkers (catalase, CAT; glutathione reductase, GR; and lipid peroxidation, LPO). Similar alterations at the hepatic level were observed after exposure to TRIM. Overall, our study indicates that S. aurata is vulnerable to environmentally relevant concentrations of CIP and TRIM and that their exposure could lead to a stress situation, altering the activity of antioxidant defense mechanisms as well as the activity of HPT and HPI axes.