Mesenchymal stromal cells: promising treatment for liver cirrhosis

Liver ischemia reperfusion injury: Mechanisms, cellular pathways, and therapeutic approaches

Liver ischemia-reperfusion injury (LIRI) is a critical challenge in liver transplantation, resection, and trauma surgeries, leading to significant hepatic damage due to oxidative stress, inflammation, and mitochondrial dysfunction. This review explores the cellular and molecular mechanisms underlying LIRI, focusing on ATP depletion, mitochondrial dysfunction, and the involvement of reactive oxygen species (ROS). Inflammatory pathways, including the activation of nuclear factor-kappa B (NF-κB) and the NLRP3 inflammasome, as well as pro-inflammatory cytokines such as TNF-α and IL-1β, play a crucial role in exacerbating tissue damage. Various types of cell death, including necrosis, apoptosis, necroptosis, pyroptosis, ferroptosis and cuproptosis are also discussed. Therapeutic interventions targeting these mechanisms, such as antioxidants, anti-inflammatories, mitochondrial protectors, and signaling modulators, have shown promise in pre-clinical studies. However, translating these findings into clinical practice faces challenges due to the limitations of animal models and the complexity of human responses. Emerging therapies, such as RNA-based treatments, genetic editing, and stem cell therapies, offer potential breakthroughs in LIRI management. This review highlights the need for further research and the development of innovative therapeutic approaches to improve clinical outcomes.

Extracellular vesicles from mesenchymal stem cells improve liver injury in rats with mild liver damage. Underlying mechanisms and role of TGFβ

Preventing the progression of liver damage to fibrosis would be beneficial for patients with steatotic liver disease (SLD). Mesenchymal stem cells (MSC) are a promising therapy for SLD and derived extracellular vesicles (EVs) could even improve the treatment's efficacy and safety. However, the mechanisms of MSC-EVs beneficial effects are not well known. It has been suggested that modifying the EVs cargo could improve their beneficial effects. The aims of this study were to assess if MSC-EVs reduce liver damage in a rat model of mild liver damage; to analyze the underlying mechanisms and to assess if silencing TGFβ enhances the beneficial effects of MSC-EVs. CCl4 was injected three times per week during four weeks to induce mild liver damage. EVs from human adipocyte MSC and from TGFβ-depleted MSC (siTGFβ-MSC-EVs) were injected in the tail vein. Steatosis, fibrosis, liver inflammation, macrophage infiltration and liver content of fibrotic markers, DAMPs, cytokines and bile acids were analyzed. Normal MSC-EVs reduce the CCL2 increase in liver, macrophage infiltration and the increases in the fibrosis markers collagen I and α-SMA. Treatment with siTGFβ-MSC-EVs, in addition, reduces liver steatosis, the increase of bile acids (mainly TCA), and DAMP HMGB1 levels, inducing a larger reduction of collagen I in liver of CCl4 rats. Treatment with MSCs-EVs effectively reduces early liver damage. Silencing of TGFβ in MSCs enhances the beneficial effects by additional mechanisms. Early treatment with MSC-EVs, especially after silencing TGFβ, could improve liver damage in SLD patients.

Human placental extract improves liver cirrhosis in mice with regulation of macrophages and senescent cells

Introduction

Cirrhosis is a disease with poor prognosis that requires the development of a novel therapeutic approach alternative to liver transplantation. In this study, we focused on the placenta and aimed to clarify the effects of human placental extract (HPE) on cirrhosis.

Methods

A mouse model of carbon tetrachloride-induced cirrhosis was used to evaluate the effect of HPE administration subcutaneously and compared with the control group (n = 8 for each group). In vitro and in vivo, real time-PCR and immunostaining were performed for HPE mechanistic analysis. Spatial transcriptomics was also performed for detailed analysis of the effect of HPE on cirrhosis.

Results

HPE administration improved serum ALT levels compared to control mice. Furthermore, there was a decrease in the number of senescent cells in the liver and the mRNA levels of secrete senescence-associated secretory phenotype factors and Cdkn2a (p16). In vitro, HPE induced macrophage polarization to the anti-inflammatory M2 phenotype. Spatial transcriptomics was also performed to analyze the underlying anti-inflammatory mechanism. The results showed that HPE strongly polarized macrophages to the M2 phenotype, especially in macrophage-rich regions in the liver. Gene expression pathway analysis using spatial transcriptomics also revealed the possibility of improving senescent cell-derived inflammation via mitochondrial function.

Conclusions

HPE improves serum ALT levels via anti-inflammatory mechanisms in macrophages and senescent cells. HPE serves as a novel agent for cirrhosis treatment.

Progress of mesenchymal stem cells affecting extracellular matrix metabolism in the treatment of female stress urinary incontinence

Stress urinary incontinence (SUI) is a prevalent pelvic floor dysfunction in women post-pregnancy. Currently, conservative treatment options have low success rates, while surgical interventions often result in multiple complications. The altered state of the extracellular matrix (ECM) is a pivotal factor in the onset of various diseases and likely plays a significant role in the pathogenesis of SUI, particularly through changes in collagen and elastin levels. Recent advances in mesenchymal stem cells (MSCs) therapy have shown considerable promise in treating SUI by modulating ECM remodeling, thereby enhancing the supportive tissues of the female pelvic floor. MSCs exhibit substantial potential in enhancing urethral sphincter function, modulating connective tissue architecture, and stimulating fibroblast activity. They play a pivotal role in the reconstruction and functional recovery of the ECM by influencing various signaling pathways, including TGF-β/SMAD, JAK/STAT, Wnt/β-catenin, PI3K/AKT, and ERK/MAPK. We have reviewed the advancements in MSC-mediated ECM metabolism in SUI and, by integrating the functions of ECM in other diseases and how MSCs can ameliorate conditions through their impact on ECM metabolism, we have projected the future trajectory of SUI treatment development.

Association between lactate-to-albumin ratio and all-cause mortality in cirrhosis patients: Analysis of the MIMIC-IV database

OBJECTIVE

This study evaluates the predictive value of the lactate/albumin ratio (LAR) for all-cause mortality in cirrhosis patients.

DESIGN

Retrospective observational study.

SETTING

Intensive care unit (ICU).

PATIENTS OR PARTICIPANTS

626 first-time ICU-admitted cirrhosis patients in the USA (MIMIC-IV v2.2).

INTERVENTIONS

None.

MAIN VARIABLES OF INTEREST

LAR index, 28-day, and 90-day all-cause mortality.

RESULTS

Of 626 patients (60.86% male), 27.80% and 39.14% died within 28 and 90 days, respectively. Multivariate Cox analysis showed a significant association between higher LAR and mortality. Adjusted for confounders, elevated LAR increased the 28-day mortality risk [HR: 1.31 (1.21-1.42), P < 0.001]. A restricted cubic spline analysis revealed non-linear relationships between LAR and mortality. For 28-day mortality, the inflection point was 1.583: below this, HR was 2.29 (95% CI: 1.61-3.27, P < 0.001); above, HR was 1.16 (95% CI: 1.02-1.31, P = 0.021; P = 0.002). For 90-day mortality, the inflection point was 1.423: below, HR was 1.60 (95% CI: 1.04-2.47, P = 0.033); above, HR was 0.94 (95% CI: 0.75-1.16, P = 0.542; P = 0.012).

CONCLUSIONS

LAR predicts 28-day and 90-day mortality with a segmented effect. An LAR ≥1.583 signals high 28-day mortality risk, necessitating intensified monitoring and potential ICU admission. For 90-day mortality, LAR near 1.423 serves as an early warning for high-risk patients and guides interventions. Continuous LAR monitoring aids management, but prospective studies are needed to confirm clinical utility.

Focal adhesion kinase promotes aerobic glycolysis in hepatic stellate cells via the cyclin D1/c-Myc/MCT-1 pathway to induce liver fibrosis

Hepatic stellate cells (HSCs) transdifferentiate into myofibroblasts during liver fibrosis and exhibit increased glycolysis. Phosphorylated focal adhesion kinase (FAK) (pY397-FAK) promotes monocarboxylate transporter 1 (MCT-1) expression in HSCs to increase aerobic glycolysis and cause liver fibrosis. A combined multiomics analysis of C57BL/6 mice with tetrachloromethane (CCl4)-induced liver fibrosis was performed to identify the downstream FAK signaling pathway. The effect of the FAK inhibitor PF562271 on CCl4-induced liver fibrosis was explored by immunofluorescence of liver tissues. The migration, proliferation and aerobic glycolysis of LX-2 cells after stimulation and activation by transforming growth factor beta-1 (TGF-β1) or suppression by PF562271 was assessed in vitro. Multiomics analysis of a successfully generated CCl4-induced liver fibrosis mouse model was performed. FAK and cyclin D1 were significantly enriched in mice with CCl4-induced liver fibrosis. In vivo, the MCT-1 and alpha smooth muscle actin (α-SMA) levels were increased in mice with CCl4-induced liver fibrosis, and MCT-1 and α-SMA expression decreased after PF562271 treatment. In vitro, PF562271 alleviated TGF-β1-induced LX-2 activation. LX-2 cells showed diminished migration, proliferation, and aerobic glycolysis after PF562271 intervention. FAK promotes aerobic glycolysis in LX-2 cells through the cyclin D1/c-Myc/MCT-1 pathway, thereby increasing liver fibrosis.

A comprehensive evaluation system for ultrasound-guided infusion of human umbilical cord-derived MSCs in liver cirrhosis patients

BACKGROUND

Infusion of mesenchymal stem cells (MSCs) via portal vein is one of the main ways for MSCs transplantation to treat liver cirrhosis (LC). As the tissue of LC showed diffuse fibrosis and thickened Glission sheath, the soft pig-tail catheter, or central venous catheter can not successfully insert the portal vein. Thus, our study used an improved method and performed a relatively comprehensive system to evaluate the effect for human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) transplantation.

METHOD

Fifteen patients with hepatitis B-related cirrhosis were enrolled in the study, and we performed hUC-MSCs transplantation via portal vein by using an 16-G needle and 0.035-inch guide wire combined with 7FR "retentional metal stiffner trocar" of pig-tail catheter under the guidance of contrast-enhanced ultrasound. Serum liver function, fibrotic indicators, tissue stiffness, coagulation function, and hemodynamics were measured at weeks 4, 12, and 24 after MSCs transplantation. Liver biopsy was performed before and 24 weeks after hUC-MSCs transplantation.

RESULT

After hUC-MSCs transplantation, the prothrombin time was lower than before. The levels of hyaluronic acid and IV-C(Type IV collagen) in fibrotic indicators were significantly reduced, and the Young's modulus was also decreased. Moreover, liver biopsy showed that the lytic necrosis of hepatocyte was decreased. In liver hemodynamics, the portal vein diameter was decreased after hUC-MSCs transplantation.

CONCLUSION

hUC-MSCs transplantation can alleviate liver damage caused by LC. The improved "retentional metal stiffner trocar" of pig-tail catheter was safe and effective in the infusion of hUC-MSCs transplantation, which is worth promoting in clinical practice.

Mesenchymal stem cell therapy as a game-changer in liver diseases: review of current clinical trials

Chronic liver diseases, including cirrhosis and liver failure, remain formidable challenges due to their complex progression and limited therapeutic options. Mesenchymal stem cell (MSC) therapy has emerged as a game-changing approach, leveraging its potent immunomodulatory, anti-fibrotic, and regenerative capabilities, along with the ability to transdifferentiate into hepatocytes. This review delves into the latest advances in MSC-based treatments for chronic and end-stage liver diseases, as highlighted in current clinical trials. MSCs derived from bone marrow and umbilical cord have shown remarkable promise in reversing liver damage, improving liver function, and providing hope for patients who do not respond to conventional therapies. When administered through hepatic, portal, or peripheral veins, MSCs have significantly improved liver histology, reduced fibrosis, and restored functional capacity. Furthermore, MSC-derived materials, such as extracellular vesicles and exosomes, are emerging as cutting-edge tools for treating liver failure and mitigating post-transplant complications. While autologous MSC-derived hepatocytes hold promise for non-fatal cirrhosis, allogeneic MSCs are being applied in more severe conditions, including liver failure and transplantation cases. Despite these promising early outcomes, larger trials and long-term studies are essential to fully harness MSCs as a transformative, off-the-shelf alternative to liver transplantation, heralding a new era in regenerative liver therapies.

Application of mesenchymal stem cells in liver fibrosis and regeneration

Liver transplantation remains the most effective treatment for end-stage liver disease (ESLD), but it is fraught with challenges such as immunosuppression, high risk and cost, and donor shortage. In recent years, stem cell transplantation has emerged as a promising new strategy for ESLD treatment, with mesenchymal stem cells (MSCs) gaining significant attention because of their unique properties. MSCs can regulate signaling pathways, including hepatocyte growth factor/c-Met, Wnt/beta (β)-catenin, Notch, transforming growth factor-β1/Smad, interleukin-6/Janus kinase/signal transducer and activator of transcription 3, and phosphatidylinositol 3-kinase/PDK/Akt, thereby influencing the progression of liver fibrosis and regeneration. As a promising stem cell type, MSCs offer numerous advantages in liver disease treatment, including low immunogenicity; ease of acquisition; unlimited proliferative ability; pluripotent differentiation potential; immunomodulatory function; and anti-inflammatory, antifibrotic, and antiapoptotic biological characteristics. This review outlines the mechanisms by which MSCs reverse liver fibrosis and promote liver regeneration. MSCs are crucial in reversing liver fibrosis and repairing liver damage through the secretion of growth factors, regulation of signaling pathways, and modulation of immune responses. MSCs have shown good therapeutic effects in preclinical and clinical studies, providing new strategies for liver disease treatment. However, challenges still exist in the clinical application of MSCs, including low differentiation efficiency and limited sources. This review provides a reference for MSC application in liver disease treatment. With the continuous progress in MSC research, MSCs are expected to achieve breakthroughs in liver disease treatment, thereby improving patient treatment outcomes.

Branched-chain amino acids and their metabolites decrease human and rat hepatic stellate cell activation

BACKGROUND

End-stage liver diseases (ESLDs) are a significant global health challenge due to their high prevalence and severe health impacts. Despite the severe outcomes associated with ESLDs, therapeutic options remain limited. Targeting the activation of hepatic stellate cells (HSCs), key drivers of extracellular matrix accumulation during liver injury presents a novel therapeutic approach. In ESLDs patients, branched-chain amino acids (BCAAs, leucine, isoleucine and valine) levels are decreased, and supplementation has been proposed to attenuate liver fibrosis and improve regeneration. However, their effects on HSCs require further investigation.

OBJECTIVE

To evaluate the efficacy of BCAAs and their metabolites, branched-chain α-keto acids (BCKAs), in modulating HSCs activation in human and rat models.

METHODS

Primary HSCs from rats and cirrhotic and non-cirrhotic human livers, were cultured and treated with BCAAs or BCKAs to assess their effects on both preventing (from day 1 of isolation) and reversing (from day 7 of isolation) HSCs activation.

RESULTS

In rat HSCs, leucine and BCKAs significantly reduced fibrotic markers and cell proliferation. In human HSCs, the metabolite of isoleucine decreased cell proliferation around 85% and increased the expression of branched-chain ketoacid dehydrogenase. The other metabolites also showed antifibrotic effects in HSCs from non-cirrhotic human livers.

CONCLUSION

BCAAs and their respective metabolites inhibit HSC activation with species-specific responses. Further research is needed to understand how BCAAs influence liver fibrogenesis. BCKAs supplementation could be a strategic approach for managing ESLDs, considering the nutritional status and amino acid profiles of patients.

Novel insights into the role of immunomodulatory extracellular vesicles in the pathogenesis of liver fibrosis

Liver fibrosis, a chronic and long-term disease, can develop into hepatocellular carcinoma (HCC) and ultimately lead to liver failure. Early diagnosis and effective treatment still face significant challenges. Liver inflammation leads to liver fibrosis through continuous activation of hepatic stellate cells (HSCs) and the accumulation of immune cells. Intracellular communication among various immune cells is important for mediating the inflammatory response during fibrogenesis. Extracellular vesicles (EVs), which are lipid bilayer membrane-enclosed particles naturally secreted by cells, make great contributions to cell-cell communication and the transport of bioactive molecules. Nearly all the cells that participate in liver fibrosis release EVs loaded with lipids, proteins, and nucleic acids. EVs from hepatocytes, immune cells and stem cells are involved in mediating the inflammatory microenvironment of liver fibrosis. Recently, an increasing number of extracellular vesicle-based clinical applications have emerged, providing promising cell-free diagnostic and therapeutic tools for liver fibrosis because of their crucial role in immunomodulation during pathogenesis. The advantages of extracellular vesicle-based therapies include stability, biocompatibility, low cytotoxicity, and minimal immunogenicity, which highlight their great potential for drug delivery and specific treatments for liver fibrosis. In this review, we summarize the complex biological functions of EVs in the inflammatory response in the pathogenesis of liver fibrosis and evaluate the potential of EVs in the diagnosis and treatment of liver fibrosis.

Advancements and challenges in stem cell transplantation for regenerative medicine

Stem cell transplantation has emerged as a promising avenue in regenerative medicine, potentially facilitating tissue repair in degenerative diseases and injuries. This review comprehensively examines recent developments and challenges in stem cell transplantation. It explores the identification and isolation of various stem cell types, including embryonic, induced pluripotent, and adult stem cells derived from multiple sources. Additionally, the review highlights the tissue-specific applications of these stem cells, focusing on bone and cartilage regeneration, treatment of neurological disorders, and management of hematological conditions. Future advancements and effective resolution of current challenges will be crucial in fully realizing the potential of stem cell transplantation in regenerative medicine. With responsible and ethical practices, the field can potentially transform disease and injury treatment, ultimately improving the quality of life for countless individuals.

Progress of mesenchymal stem cells (MSCs) & MSC-Exosomes combined with drugs intervention in liver fibrosis

Liver fibrosis is an intrahepatic chronic damage repair response caused by various reasons such as alcoholic liver, fatty liver, viral hepatitis, autoimmune diseases, etc., and is closely related to the progression of liver disease. Currently, the mechanisms of liver fibrosis and its treatment are hot research topics in the field of liver disease remedy. Mesenchymal stem cells (MSCs) are a class of adult stem cells with self-renewal and multidirectional differentiation potential, which can ameliorate fibrosis through hepatic-directed differentiation, paracrine effects, and immunomodulation. However, the low inner-liver colonization rate, low survival rate, and short duration of intervention after stem cell transplantation have limited their wide clinical application. With the intensive research on liver fibrosis worldwide, it has been found that MSCs and MSCs-derived exosomes combined with drugs have shown better intervention efficiency than utilization of MSCs alone in many animal models of liver fibrosis. In this paper, we review the interventional effects and mechanisms of mesenchymal stem cells and their exosomes combined with drugs to alleviate hepatic fibrosis in vivo in animal models in recent years, which will provide new ideas to improve the efficacy of mesenchymal stem cells and their exosomes in treating hepatic fibrosis in the clinic.

Beneficial Effect of Rapamycin on Liver Fibrosis in a Mouse Model (C57bl/6 Mouse)

BACKGROUND

Liver fibrosis is a chronic inflammatory disease that progresses and has a high mortality rate. This study was performed to investigate the protective effect of rapamycin on experimentally induced chronic liver injury in mice models using both biochemical parameters of liver function enzymes.

METHODS

Twenty-four mice were divided randomly into 4 equal groups: [1] the normal group, n = 6; [2] the liver fibrosis (LF) group, n = 6; [3] the LF with the treatment of rapamycin group, n = 6; [4] the LF with the treatment of silimaryn, n = 6.

RESULTS

In the group receiving oral administration of rapamycin, aspartate aminotransferase, alanine aminotransferase, urea, and creatinine were found to significantly decrease compared to the liver fibrosis group. Rapamycin, in the orally administered group, demonstrated a statistically significant decrease in the expression of interleukin (IL) 10, IL-1B, inducible nitric oxide synthase, and tumor necrosis factor alpha compared to the liver fibrosis group.

CONCLUSIONS

In this study, we explored the potential therapeutic effects of rapamycin on liver fibrosis in an animal model.

Apoptotic Extracellular Vesicles Induced Endothelial Cell-Mediated Autologous Stem Cell Recruitment Dominates Allogeneic Stem Cell Therapeutic Mechanism for Bone Repair

Although stem cell therapy is proved to be a promising strategy for bone repair and regeneration, transplanted allogeneic stem cells generally suffer from unfavorable apoptosis instead of differentiation into osteocytes. How the apoptotic stem cells promote bone regeneration still needs to be uncovered. In this work, we found that apoptotic extracellular vesicles released by allogeneic stem cells are critical mediators for promoting bone regeneration. Based on the results of in vivo experiments, a mechanism of apoptotic stem cells determined autologous stem cell recruitment and enhance osteogenesis was proposed. The nanoscaled apoptotic extracellular vesicles released from transplanted stem cells were endocytosed by vascular endothelial cells and preferentially distribute at endoplasmic reticular region. The oxidized phosphatidylcholine enriched in the vesicles activated the endoplasmic reticulum stress and triggered the reflective elevation of adhesion molecules, which induced the recruitment of autologous stem cells located in the blood vessels, transported them into the defect region, and promoted osteogenesis and bone repair. These findings not only reveal the mechanism of stem cell therapy of bone defects but also provide a cue for investigation of the biological process of stem cell therapy for other diseases and develop stem cell therapeutic strategies.

Fucoxanthin Enhances the Antifibrotic Potential of Placenta-derived Mesenchymal Stem Cells in a CCl4-induced Mouse Model of Liver

BACKGROUND

The effectiveness of fucoxanthin (Fx) in liver diseases has been reported due to its anti-inflammatory and antifibrotic effects. Mesenchymal stem cells (MSCs)-based therapy has also been proposed as a promising strategy for liver fibrosis treatment. Recent studies have shown that the co-administration of MSCs and drugs demonstrates a pronounced effect on liver fibrosis.

AIM

This study aimed to determine the therapeutic potential of placenta-derived MSCs (PD-MSCs) in combination with Fx to treat liver fibrosis and evaluate their impact on the main links of liver fibrosis pathogenesis.

METHODS

After PD-MSCs isolation and identification, outbred ICR/CD1 mice were divided into five groups: Control group, CCl4 group (CCl4), Fx group (CCl4+Fx), PD-MSCs group (CCl4+MSCs) and cotreatment group (CCl4+MSCs+Fx). Biochemical histopathological investigations were performed. Semiquantitative analysis of the alpha-smooth muscle actin (α-SMA+), matrix metalloproteinases (MMP-9+, MMP-13+), tissue inhibitor of matrix metalloproteinases-1 (TIMP-1+) areas, and the number of positive cells in them were studied by immunohistochemical staining. Transforming growth factor-beta (TGF-β), hepatic growth factor (HGF), procollagen-1 (COL1α1) in liver homogenate and proinflammatory cytokines in blood serum were determined using an enzyme immunoassay.

RESULTS

Compared to the single treatment with PD-MSCs or Fx, their combined administration significantly reduced liver enzyme activity, the severity of liver fibrosis, the proinflammatory cytokine levels, TGF-β level, α-SMA+, TIMP-1+ areas and the number of positive cells in them, and increased HGF level, MMP-13+, and MMP-9+ areas.

CONCLUSION

Fx enhanced the therapeutic potential of PD-MSCs in CCl4-induced liver fibrosis, but more investigations are necessary to understand the mutual impact of PD-MSCs and Fx.

Therapeutic potential of stem cells in regeneration of liver in chronic liver diseases: Current perspectives and future challenges

The deposition of extracellular matrix and hyperplasia of connective tissue characterizes chronic liver disease called hepatic fibrosis. Progression of hepatic fibrosis may lead to hepatocellular carcinoma. At this stage, only liver transplantation is a viable option. However, the number of possible liver donors is less than the number of patients needing transplantation. Consequently, alternative cell therapies based on non-stem cells (e.g., fibroblasts, chondrocytes, keratinocytes, and hepatocytes) therapy may be able to postpone hepatic disease, but they are often ineffective. Thus, novel stem cell-based therapeutics might be potentially important cutting-edge approaches for treating liver diseases and reducing patient' suffering. Several signaling pathways provide targets for stem cell interventions. These include pathways such as TGF-β, STAT3/BCL-2, NADPH oxidase, Raf/MEK/ERK, Notch, and Wnt/β-catenin. Moreover, mesenchymal stem cells (MSCs) stimulate interleukin (IL)-10, which inhibits T-cells and converts M1 macrophages into M2 macrophages, producing an anti-inflammatory environment. Furthermore, it inhibits the action of CD4+ and CD8+ T cells and reduces the activity of TNF-α and interferon cytokines by enhancing IL-4 synthesis. Consequently, the immunomodulatory and anti-inflammatory capabilities of MSCs make them an attractive therapeutic approach. Importantly, MSCs can inhibit the activation of hepatic stellate cells, causing their apoptosis and subsequent promotion of hepatocyte proliferation, thereby replacing dead hepatocytes and reducing liver fibrosis. This review discusses the multidimensional therapeutic role of stem cells as cell-based therapeutics in liver fibrosis.

Advancements in the pathogenesis of hepatic osteodystrophy and the potential therapeutic of mesenchymal stromal cells

Hepatic osteodystrophy (HOD) is a metabolically associated bone disease mainly manifested as osteoporosis with the characteristic of bone loss induced by chronic liver disease (CLD). Due to its high incidence in CLD patients and increased risk of fracture, the research on HOD has received considerable interest. The specific pathogenesis of HOD has not been fully revealed. While it is widely believed that disturbance of hormone level, abnormal secretion of cytokines and damage of intestinal barrier caused by CLD might jointly affect the bone metabolic balance of bone formation and bone absorption. At present, the treatment of HOD is mainly to alleviate the bone loss by drug treatment, but the efficacy and safety are not satisfactory. Mesenchymal stromal cells (MSCs) are cells with multidirectional differentiation potential, cell transplantation therapy based on MSCs is an emerging therapeutic approach. This review mainly summarized the pathogenesis and treatment of HOD, reviewed the research progress of MSCs therapy and the combination of MSCs and scaffolds in the application of osteoporotic bone defects, and discussed the potential and limitations of MSCs therapy, providing theoretical basis for subsequent studies.

Human umbilical cord mesenchymal stem cells inhibit liver fibrosis via the microRNA-148a-5p/SLIT3 axis

BACKGROUND

Human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) have garnered considerable attention as prospective modalities of treatment for liver fibrosis (LF). The inhibition of hepatic stellate cell (HSC) activation underlies the anti-fibrotic effects of hUC-MSCs. However, the precise mechanism by which hUC-MSCs impede HSC activation remains unclarified. We aimed to elucidate the intrinsic mechanisms underlying the therapeutic effects of hUC-MSCs in LF patients.

METHODS

Mice with liver cirrhosis induced by carbon tetrachloride (CCl4) were used as experimental models and administered hUC-MSCs via tail-vein injection. The alterations in inflammation and fibrosis were evaluated through histopathological examinations. RNA sequencing (RNA-seq) and bioinformatics analysis were then conducted to investigate the therapeutic mechanism of hUC-MSCs. Finally, an in-vitro experiment involving the co-cultivation of hUC-MSCs or hUC-MSC-derived exosomes (MSC-Exos) with LX2 cells was performed to validate the potential mechanism underlying the hepatoprotective effects of hUC-MSCs in LF patients.

RESULTS

hUC-MSC therapy significantly improved liver function and alleviated LF in CCl4-induced mice. High-throughput RNA-Seq analysis identified 1142 differentially expressed genes that were potentially involved in mediating the therapeutic effects of hUC-MSCs. These genes play an important role in regulating the extracellular matrix. miRNA expression data (GSE151098) indicated that the miR-148a-5p level was downregulated in LF samples, but restored following hUC-MSC treatment. miR-148a-5p was delivered to LX2 cells by hUC-MSCs via the exosome pathway, and the upregulated expression of miR-148a-5p significantly suppressed the expression of the activated phenotype of LX2 cells. SLIT3 was identified within the pool of potential target genes regulated by miR-148a-5p. Furthermore, hUC-MSC administration upregulated the expression of miR-148a-5p, which played a crucial role in suppressing the expression of SLIT3, thereby palliating fibrosis.

CONCLUSIONS

hUC-MSCs inhibit the activation of HSCs through the miR-148a-5p/SLIT3 pathway and are thus capable of alleviating LF.

Potential Therapeutic Use of Stem Cells for Prion Diseases

Prion diseases are neurodegenerative disorders that are progressive, incurable, and deadly. The prion consists of PrPSc, the misfolded pathogenic isoform of the cellular prion protein (PrPC). PrPC is involved in a variety of physiological functions, including cellular proliferation, adhesion, differentiation, and neural development. Prion protein is expressed on the membrane surface of a variety of stem cells (SCs), where it plays an important role in the pluripotency and self-renewal matrix, as well as in SC differentiation. SCs have been found to multiply the pathogenic form of the prion protein, implying their potential as an in vitro model for prion diseases. Furthermore, due to their capability to self-renew, differentiate, immunomodulate, and regenerate tissue, SCs are prospective cell treatments in many neurodegenerative conditions, including prion diseases. Regenerative medicine has become a new revolution in disease treatment in recent years, particularly with the introduction of SC therapy. Here, we review the data demonstrating prion diseases' biology and molecular mechanism. SC biology, therapeutic potential, and its role in understanding prion disease mechanisms are highlighted. Moreover, we summarize preclinical studies that use SCs in prion diseases.

Application of 3D Bioprinting in Liver Diseases

Liver diseases are the primary reason for morbidity and mortality in the world. Owing to a shortage of organ donors and postoperative immune rejection, patients routinely suffer from liver failure. Unlike 2D cell models, animal models, and organoids, 3D bioprinting can be successfully employed to print living tissues and organs that contain blood vessels, bone, and kidney, heart, and liver tissues and so on. 3D bioprinting is mainly classified into four types: inkjet 3D bioprinting, extrusion-based 3D bioprinting, laser-assisted bioprinting (LAB), and vat photopolymerization. Bioinks for 3D bioprinting are composed of hydrogels and cells. For liver 3D bioprinting, hepatic parenchymal cells (hepatocytes) and liver nonparenchymal cells (hepatic stellate cells, hepatic sinusoidal endothelial cells, and Kupffer cells) are commonly used. Compared to conventional scaffold-based approaches, marked by limited functionality and complexity, 3D bioprinting can achieve accurate cell settlement, a high resolution, and more efficient usage of biomaterials, better mimicking the complex microstructures of native tissues. This method will make contributions to disease modeling, drug discovery, and even regenerative medicine. However, the limitations and challenges of this method cannot be ignored. Limitation include the requirement of diverse fabrication technologies, observation of drug dynamic response under perfusion culture, the resolution to reproduce complex hepatic microenvironment, and so on. Despite this, 3D bioprinting is still a promising and innovative biofabrication strategy for the creation of artificial multi-cellular tissues/organs.

Immunomodulatory role of mesenchymal stem cell therapy in liver fibrosis

Liver fibrosis is a fibrogenic and inflammatory process that results from hepatocyte injury and is characterized by hepatic architectural distortion and resultant loss of liver function. There is no effective treatment for advanced fibrosis other than liver transplantation, but it is limited by expensive costs, immune rejection, and postoperative complications. With the development of regenerative medicine in recent years, mesenchymal stem cell (MSCs) transplantation has become the most promising treatment for liver fibrosis. The underlying mechanisms of MSC anti-fibrotic effects include hepatocyte differentiation, paracrine, and immunomodulation, with immunomodulation playing a central role. This review discusses the immune cells involved in liver fibrosis, the immunomodulatory properties of MSCs, and the immunomodulation mechanisms of MSC-based strategies to attenuate liver fibrosis. Meanwhile, we discuss the current challenges and future directions as well.

Curcumin Nanofiber PCL/PLGA/Collagen Enhanced the Therapeutic Efficacy of Mesenchymal Stem Cells against Liver Fibrosis in Animal Model and Prevented its Recurrence

The aim of this study is preconditioning of hBM-MSCs using curcumin modified nanomembrane to optimize therapy of hepatic fibrosis and preventing its recurrence. Methods: The nanomembrane was prepared by electrospinning technique and characterized using conventional method (cur^- nanoscaffold and cur⁺ nanoscaffold). Kinetic release of curcumin was also measured by spectrophotometry. MSCs were isolated from human bone marrow (hBM-MSCs) and cultured on the both nanoscaffolds. We evaluated the in-vivo effect of hBM-MSCs from both nanoscaffold cultures (cur^- nanoscaffold/hMSCs and cur⁺ nanoscaffold/MSCs) on liver fibrosis from its effective and preventive points and we assessed the mechanisms of these effects as in vitro studies as cell proliferation, its effect on hepatogenic differentiation, its effect on paracrine release of hBM-MSCs and in-vivo studying the effect on cell migration, survival, engraftment, fate of transplanted cells, modifying the fibrogenic and inflammatory microenvironments. Results: The results of animal model showed that single injection of preconditioning of hBM-MSCs using curcumin modified nanoscaffold ameliorate the fibrosis and prevent its recurrence until 24 weeks of therapy in contrast to improvement but not ameliorative effect of hBM-MSCs/ curcumin negative nanoscaffold which recurred progressively after 12 weeks of therapy. These effects of curcumin modified nanoscaffold were results from its highly efficacy on cell proliferation, in-vitro and in-vivo hepatogenic differentiation, increasing cell migration, engraftment and survival in the inflammatory microenvironment which was markedly improved by down regulation of inflammatory mediators and upregulation of anti-oxidant factors. Conclusion: hBM-MSCs cultured on the prepared curcumin nanomembrane in this study is promising in regenerative therapy for ameliorating the hepatic fibrosis and to prevent its recurrence.

Co-expression of fibrotic genes in inflammatory bowel disease; A localized event?

Introduction

Extracellular matrix turnover, a ubiquitous dynamic biological process, can be diverted to fibrosis. The latter can affect the intestine as a serious complication of Inflammatory Bowel Diseases (IBD) and is resistant to current pharmacological interventions. It embosses the need for out-of-the-box approaches to identify and target molecular mechanisms of fibrosis.

Methods and results

In this study, a novel mRNA sequencing dataset of 22 pairs of intestinal biopsies from the terminal ileum (TI) and the sigmoid of 7 patients with Crohn's disease, 6 with ulcerative colitis and 9 control individuals (CI) served as a validation cohort of a core fibrotic transcriptomic signature (FIBSig), This signature, which was identified in publicly available data (839 samples from patients and healthy individuals) of 5 fibrotic disorders affecting different organs (GI tract, lung, skin, liver, kidney), encompasses 241 genes and the functional pathways which derive from their interactome. These genes were used in further bioinformatics co-expression analyses to elucidate the site-specific molecular background of intestinal fibrosis highlighting their involvement, particularly in the terminal ileum. We also confirmed different transcriptomic profiles of the sigmoid and terminal ileum in our validation cohort. Combining the results of these analyses we highlight 21 core hub genes within a larger single co-expression module, highly enriched in the terminal ileum of CD patients. Further pathway analysis revealed known and novel inflammation-regulated, fibrogenic pathways operating in the TI, such as IL-13 signaling and pyroptosis, respectively.

Discussion

These findings provide a rationale for the increased incidence of fibrosis at the terminal ileum of CD patients and highlight operating pathways in intestinal fibrosis for future evaluation with mechanistic and translational studies.