Human adipose stem cell-derived extracellular nanovesicles for treatment of chronic liver fibrosis

Human Adipose Tissue-Derived Stromal Cells Ameliorate Adriamycin-Induced Nephropathy by Promoting Angiogenesis

This study is to investigate the therapeutical effect and mechanisms of human-derived adipose mesenchymal stem cells (ADSC) in relieving adriamycin (ADR)-induced nephropathy (AN). SD rats were separated into normal group, ADR group, ADR+Losartan group (20 mg/kg), and ADR + ADSC group. AN rats were induced by intravenous injection with adriamycin (8 mg/kg), and 4 d later, ADSC (2 × 105 cells/mouse) were administrated twice with 2 weeks interval time (i.v.). The rats were euthanized after the 6 weeks' treatment. Biochemical indicators reflecting renal injury, such as blood urea nitrogen (BUN), neutrophil gelatinase alpha (NGAL), serum creatinine (Scr), inflammation, oxidative stress, and pro-fibrosis molecules, were evaluated. Results demonstrated that we obtained high qualified ADSCs for treatment determined by flow cytometry, and ADSCs treatment significantly ameliorated renal injuries in DN rats by decreasing BUN, Scr and NGAL in peripheral blood, as well as renal histopathological injuries, especially protecting the integrity of podocytes by immunofluorescence. Furthermore, ADSCs treatment also remarkably reduced the renal inflammation, oxidative stress, and fibrosis in DN rats. Preliminary mechanism study suggested that the ADSCs treatment significantly increased renal neovascularization via enhancing proangiogenic VEGF production. Pharmacodynamics study using in vivo imaging confirmed that ADSCs via intravenous injection could accumulate into the kidneys and be alive at least 2 weeks. In a conclusion, ADSC can significantly alleviate ADR-induced nephropathy, and mainly through reducing oxidative stress, inflammation and fibrosis, as well as enhancing VEGF production.

Smart Microneedle Arrays Integrating Cell-Free Therapy and Nanocatalysis to Treat Liver Fibrosis

Liver fibrosis is a chronic pathological condition lacking specific clinical treatments. Stem cells, with notable potential in regenerative medicine, offer promise in treating liver fibrosis. However, stem cell therapy is hindered by potential immunological rejection, carcinogenesis risk, efficacy variation, and high cost. Stem cell secretome-based cell-free therapy offers potential solutions to address these challenges, but it is limited by low delivery efficiency and rapid clearance. Herein, an innovative approach for in situ implantation of smart microneedle (MN) arrays enabling precisely controlled delivery of multiple therapeutic agents directly into fibrotic liver tissues is developed. By integrating cell-free and platinum-based nanocatalytic combination therapy, the MN arrays can deactivate hepatic stellate cells. Moreover, they promote excessive extracellular matrix degradation by more than 75%, approaching normal levels. Additionally, the smart MN arrays can provide hepatocyte protection while reducing inflammation levels by ≈70-90%. They can also exhibit remarkable capability in scavenging almost 100% of reactive oxygen species and alleviating hypoxia. Ultimately, this treatment strategy can effectively restrain fibrosis progression. The comprehensive in vitro and in vivo experiments, supplemented by proteome and transcriptome analyses, substantiate the effectiveness of the approach in treating liver fibrosis, holding immense promise for clinical applications.

Bone mesenchymal stem cells improve cholestatic liver fibrosis by targeting ULK1 to regulate autophagy through PI3K/AKT/mTOR pathway

Cholestatic liver disease (CLD) is a severe disease, which can progress to liver cirrhosis, even liver cancer. Hepatic stellate cells (HSCs) activation plays a crucial role in CLD development. Bone mesenchymal stem cells (BMSCs) treatment was demonstrated to be beneficial in liver diseases. However, the therapeutic effect and mechanism of BMSCs on CLD are poorly known. In the present study, we investigated the therapeutic effects and underlying mechanisms of BMSCs transplantation in mouse models of bile duct ligation-induced cholestatic liver fibrosis (CLF). The results revealed that BMSCs significantly improved liver function and reduced the formation of fibrosis after portal vein transplantation. Mechanistically, after coculturing BMSCs and HSCs, we identified that BMSCs alleviated starvation-induced HSCs activation. Further, BMSCs inhibited HSCs activation by decreasing autophagy, and PI3K/AKT/mTOR pathway was involved in the regulation. More importantly, ULK1 is identified as the main autophagy-related gene regulated by BMSCs in HSCs autophagy. Overexpression of ULK1 reversed the suppression of HSCs autophagy by BMSCs. Collectively, our results provide a theoretical basis for BMSCs targeting ULK1 to attenuate HSCs autophagy and activation and suggest that BMSCs or ULK1 may be an alternative therapeutic approach/target for the treatment of CLF.

The clinical manifestations and molecular pathogenesis of radiation fibrosis

Advances in radiation techniques have enabled the precise delivery of higher doses of radiotherapy to tumours, while sparing surrounding healthy tissues. Consequently, the incidence of radiation toxicities has declined, and will likely continue to improve as radiotherapy further evolves. Nonetheless, ionizing radiation elicits tissue-specific toxicities that gradually develop into radiation-induced fibrosis, a common long-term side-effect of radiotherapy. Radiation fibrosis is characterized by an aberrant wound repair process, which promotes the deposition of extensive scar tissue, clinically manifesting as a loss of elasticity, tissue thickening, and organ-specific functional consequences. In addition to improving the existing technologies and guidelines directing the administration of radiotherapy, understanding the pathogenesis underlying radiation fibrosis is essential for the success of cancer treatments. This review integrates the principles for radiotherapy dosimetry to minimize off-target effects, the tissue-specific clinical manifestations, the key cellular and molecular drivers of radiation fibrosis, and emerging therapeutic opportunities for both prevention and treatment.

Liver fibrosis: pathological features, clinical treatment and application of therapeutic nanoagents

Liver fibrosis is a reversible damage-repair response, the pathological features of which mainly include damage to hepatocytes, sinusoid capillarization, hepatic stellate cells activation, excessive accumulation of extracellular matrix and inflammatory response. Although some treatments (including drugs and stem cell therapy) for these pathological features have been shown to be effective, more clinical trials are needed to confirm their effectiveness. In recent years, nanomaterials-based therapies have emerged as an innovative and promising alternative to traditional drugs, being explored for the treatment of liver fibrosis diseases. Natural nanomaterials (including extracellular vesicles) and synthetic nanomaterials (including inorganic nanomaterials and organic nanomaterials) are developed to facilitate drug targeting delivery and combination therapy. In this review, the pathological features of liver fibrosis and the current anti-fibrosis drugs in clinical trials are briefly introduced, followed by a detailed introduction of the therapeutic nanoagents for the precise delivery of anti-fibrosis drugs. Finally, the future development trend in this field is discussed.

Mesenchymal Stem Cell-Derived Exosomes in Various Chronic Liver Diseases: Hype or Hope?

Chronic liver conditions are associated with high mortality rates and have a large adverse effect on human well-being as well as a significant financial burden. Currently, the only effective treatment available for the effects of liver failure and cirrhosis resulting from the progression of several chronic liver diseases is liver transplantation carried out at the original location. This implies that developing novel and effective treatments is imperative. Regenerative medicine has long been associated with stem cell therapy. Mesenchymal stem cells (MSCs), a type of cell with great differentiation potential, have become the preferred source for stem cell therapy. According to recent studies, MSCs' paracrine products-rather than their capacity for differentiation-play a significant therapeutic effect. MSC exosomes, a type of extracellular vesicle (MSC-EV), came into view as the paracrine substances of MSCs. According to research, MSC exosomes can maintain tissue homeostasis, which is necessary for healthy tissue function. All tissues contain them, and they take part in a variety of biological activities that support cellular activity and tissue regeneration in order to preserve tissue homeostasis. The outcomes support the use of MSCs and the exosomes they produce as a therapeutic option for a range of diseases. This review provides a brief overview of the source of MSC-EVs and outlines their physiological roles and biochemical capabilities. The elucidation of the role of MSC-EVs in the recovery and repair of hepatic tissues, as well as their contribution to maintaining tissue homeostasis, is discussed in relation to different chronic liver diseases. This review aims to provide new insights into the unique roles that MSC-EVs play in the treatment of chronic liver diseases.

Delivering Relaxin Plasmid by Polymeric Metformin Lipid Nanoparticles for Liver Fibrosis Treatment

BACKGROUND

Liver fibrosis usually progresses to liver cirrhosis and even results in hepatocellular carcinoma, which accounts for one million deaths annually worldwide. To date, anti-liver fibrosis drugs for clinical treatment have not yet been approved. Nowadays, as a natural regulator, Relaxin (RLX) has received increased attention because the expression of RLX could deactivate the activation of hepatic stellate cells (aHSCs) and resolve liver fibrosis. However, its application in treatment is limited due to the short half-life in circulation and low accumulation within the target organ.

METHODS

To address these problems, a kind of polymeric metformin (PolyMet)-loaded relaxin plasmid (pRLX) core-membrane lipid nanoparticle (PolyMet-pRLX-LNPs, PRLNP) was prepared. Here, PolyMet was used as a carrier to replace the traditional polymer polyethylene diene (PEI), which is of higher toxicity, to prolong the circulation time of pRLX in vivo. Then, the antifibrotic ability of PRLNP to overcome liver fibrosis was carried out in C57BL/6 mice. It is worth mentioning that this is the first time to investigate the potential of PRLNP in carbon tetrachloride-induced liver fibrosis.

RESULTS

The results showed that PRLNP effectively downregulated fibrosis-related biomarkers such as alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Meanwhile, histopathological examinations also showed low collagen accumulation, revealing that PRLNP could histologically and functionally alleviate liver fibrosis. In addition, no significant difference in serum biochemical value between the PRLNP and the normal group, suggesting the safety profile of PRLNP.

CONCLUSION

This research proposed a novel non-toxic treatment method for liver fibrosis with a nanosystem to effectively treat liver fibrosis.

New era of mesenchymal stem cell-based medicine: basis, challenges and prospects

Stem cells of mesenchymal origin (MSC) arouse special interest due to their regenerative, anti-inflammatory, anti-apoptotic, anti-oxidative stress, antitumor or antimicrobial properties. However, its implementation in the clinic runs into drawbacks of cell therapy (immunological incompatibility, tumor formation, possible transmission of infections, entry into cellular senescence, difficult evaluation of safety, dose and potency; complex storage conditions, high economic cost or impractical clinical use). Considering that the positive effects of MSC are due, to a large extent, to the paracrine effects mediated by the set of substances they secrete (growth factors, cytokines, chemokines or microvesicles), the in vitro obtaining of these biological products makes possible a medicine cell-free regenerative therapy without the drawbacks of cell therapy. However, this new therapeutic innovation implies challenges, such as the recognition of the biological heterogeneity of MSC and the optimization and standardization of their secretome.

Mesenchymal stromal/stem cells and their extracellular vesicles in liver diseases: insights on their immunomodulatory roles and clinical applications

Liver disease is a leading cause of mortality and morbidity that is rising globally. Liver dysfunctions are classified into acute and chronic diseases. Various insults, including viral infections, alcohol or drug abuse, and metabolic overload, may cause chronic inflammation and fibrosis, leading to irreversible liver dysfunction. Up to now, liver transplantation could be the last resort for patients with end-stage liver disease. However, liver transplantation still faces unavoidable difficulties. Mesenchymal stromal/stem cells (MSCs) with their broad ranging anti-inflammatory and immunomodulatory properties can be effectively used for treating liver diseases but without the limitation that are associated with liver transplantation. In this review, we summarize and discuss recent advances in the characteristics of MSCs and the potential action mechanisms of MSCs-based cell therapies for liver diseases. We also draw attention to strategies to potentiate the therapeutic properties of MSCs through pre-treatments or gene modifications. Finally, we discuss progress toward clinical application of MSCs or their extracellular vesicles in liver diseases.

Extracellular vesicles: a rising star for therapeutics and drug delivery

Extracellular vesicles (EVs) are nano-sized, natural, cell-derived vesicles that contain the same nucleic acids, proteins, and lipids as their source cells. Thus, they can serve as natural carriers for therapeutic agents and drugs, and have many advantages over conventional nanocarriers, including their low immunogenicity, good biocompatibility, natural blood-brain barrier penetration, and capacity for gene delivery. This review first introduces the classification of EVs and then discusses several currently popular methods for isolating and purifying EVs, EVs-mediated drug delivery, and the functionalization of EVs as carriers. Thereby, it provides new avenues for the development of EVs-based therapeutic strategies in different fields of medicine. Finally, it highlights some challenges and future perspectives with regard to the clinical application of EVs.

Pooled Analysis of Mesenchymal Stromal Cell-Derived Extracellular Vesicle Therapy for Liver Disease in Preclinical Models

Background: Although increasing preclinical studies have emphasized the benefits of exosome-related therapies, the efficacy of mesenchymal stromal cell (MSC)-derived extracellular vesicles (EV) for liver injury is unclear. In this work, a pooled analysis was conducted to explore the overall effect of MSC-EV in animal models. Methods: A systematic search of the PubMed, EMBASE, Web of Science, and Cochrane Library databases was performed, from initiation to February 2022, for preclinical studies with liver disease models. The treatment outcomes were evaluated based on liver function, histological analysis, and inflammatory cytokines. Results: After screening, 39 studies were included. Pooled analyses demonstrated that MSC-EV therapy significantly improved liver functions (ALB, ALT, AST, ALP, and γ-GT), promoted the repair of injured liver tissue (damaged area, Ishak’s score), reduced inflammatory factors (TNF-α, IL-1β, IL-6, and IFN-γ), and increased an anti-inflammatory cytokine (IL-10) compared to the placebo control group. Subgroup analyses indicated that MSC-EV had therapeutic effects on liver fibrosis (n = 16), acute liver injury (n = 11), non-alcoholic fatty liver disease (n = 3), autoimmune hepatitis (n = 4), and hepatic ischemia-reperfusion injury (n = 6). Additionally, the therapeutic effect of EV was comparable to that of MSCs. Conclusion: MSC-EV have therapeutic potential for acute and chronic liver diseases.

Exosomes derived from human adipose mesenchymal stem cells ameliorate hepatic fibrosis by inhibiting PI3K/Akt/mTOR pathway and remodeling choline metabolism

Liver fibrosis is a chronic liver disease with the presence of progressive wound healing response caused by liver injury. Currently, there are no approved therapies for liver fibrosis. Exosomes derived from human adipose mesenchymal stem cells (hADMSCs-Exo) have displayed a prominent therapeutic effect on liver diseases. However, few studies have evaluated therapeutic effect of hADMSCs-Exo in liver fibrosis and cirrhosis, and its precise mechanisms of action remain unclear. Herein, we investigated anti-fibrotic efficacy of hADMSCs-Exo in vitro and in vivo, and identified important metabolic changes and the detailed mechanism through transcriptomic and metabolomic profiling. We found hADMSCs-Exo could inhibit the proliferation of activated hepatic stellate cells through aggravating apoptosis and arresting G1 phase, effectively inhibiting the expression of profibrogenic proteins and epithelial-to-mesenchymal transition (EMT) in vitro. Moreover, it could significantly block collagen deposition and EMT process, improve liver function and reduce liver inflammation in liver cirrhosis mice model. The omics analysis revealed that the key mechanism of hADMSCs-Exo anti-hepatic fibrosis was the inhibition of PI3K/AKT/mTOR signaling pathway and affecting the changes of metabolites in lipid metabolism, and mainly regulating choline metabolism. CHPT1 activated by hADMSCs-Exo facilitated formation and maintenance of vesicular membranes. Thus, our study indicates that hADMSCs-Exo can attenuate hepatic stellate cell activation and suppress the progression of liver fibrosis, which holds the significant potential of hADMSCs-Exo for use as extracellular nanovesicles-based therapeutics in the treatment of liver fibrosis and possibly other intractable chronic liver diseases.

Exosomes Derived from BMMSCs Mitigate the Hepatic Fibrosis via Anti-Pyroptosis Pathway in a Cirrhosis Model

Researchers increasingly report the therapeutic effect of exosomes derived from rat bone marrow mesenchymal stem cells (Exos-rBMMSC) on liver disease, while the optimal dose of Exos-rBMMSC in liver cirrhotic treatment has not been reported. In this study, we aimed to explore the efficacy and dose of Exos-rBMMSC in a hepatic cirrhosis rat model. The therapeutic effects of a low dose, medium dose and high dose of Exos-rBMMSC were assessed by liver function tests and histopathology. After four-weeks of Exos-rBMMSC therapy, pyroptosis-related expression levels in the medium dose and the high dose Exos-rBMMSC groups were significantly decreased compared to those in the liver cirrhosis group (p < 0.05). The hepatic function assay and histopathology results showed significant improvement in the medium dose and the high dose Exos-rBMMSCs groups. The localization of PKH67-labeled Exos-rBMMSC was verified microscopically, and these particles were coexpressed with the PCNA, NLRP3, GSDMD and Caspase-1. Our results demonstrated that Exos-rBMMSC accelerated hepatocyte proliferation and relieved liver fibrosis by restraining hepatocyte pyroptosis. More importantly, we confirmed that the high dose of Exos-rBMMSC may be the optimal dose for liver cirrhosis, which is conducive to the application of Exos-rBMMSC as a promising cell-free strategy.

Hair follicle-MSC-derived small extracellular vesicles as a novel remedy for acute pancreatitis

BACKGROUND

Hair follicle-derived mesenchymal stem cell (HF-MSC)-based therapies protect against acute pancreatitis (AP). However, accumulating evidence suggests that MSC-based therapy mainly involves the secretion of MSC-derived small extracellular vesicles (MSC-sEVs) through paracrine effects. Thus, the present research investigated the therapeutic effect of HF-MSC-sEVs in AP and the underlying mechanisms.

METHODS

SEVs were purified from cultured HF-MSC supernatant. The effects of sEVs in vitro were analyzed on caerulein-simulated pancreatic acinar cells (PACs). The therapeutic potential of sEVs in vivo was examined in a caerulein-induced AP model. The organ distribution of sEVs in mice was determined by near-infrared fluorescence (NIRF) imaging. Serum specimens and pancreatic tissues were collected to analyze the inhibition of inflammation and pyroptosis in vivo, as well as the appropriate infusion route: intraperitoneal (i.p.) or intravenous (i.v.) injection.

RESULTS

HF-MSC-sEVs were taken up by PACs and improved cell viability in vitro. In vivo, sEVs were abundant in the pancreas, and the indicators of pancreatitis, including amylase, lipase, the inflammatory response, myeloperoxidase (MPO) expression and histopathology scores, in sEV-treated mice were markedly improved compared with those in the AP group, especially via tail vein injection. Furthermore, we revealed that sEVs observably downregulated the levels of crucial pyroptosis proteins in both PACs and AP tissue.

CONCLUSIONS

We innovatively demonstrated that HF-MSC-sEVs could alleviate inflammation and pyroptosis in PACs in AP, suggesting a refreshing cell-free remedy for AP.

Dissolving microneedles for long-term storage and transdermal delivery of extracellular vesicles

Extracellular vesicles (EVs) have shown great potential in disease diagnosis and treatment; however, their clinical applications remain challenging due to their unsatisfactory long-term stability and the lack of effective delivery strategies. In this study, we prepared human adipose stem cell-derived EV (hASC-EV)-loaded hyaluronic acid dissolving microneedles (EV@MN) to investigate the feasibility of EVs for their clinical applications. The biological activities of the EVs in this formulation were maintained for more than six months under mild storage conditions, especially at temperatures lower than 4 °C. Moreover, the EV@MN enabled precise and convenient intradermal delivery for sustained release of EVs in the dermis layer. Therefore, EV@MN significantly improved the biological functions of hASC-EVs on dermal fibroblasts by promoting syntheses of proteins for the extracellular matrix such as collagen and elastin, enhancing fibroblast proliferation, and regulating the phenotype of fibroblast, compared with other administration methods. This research revealed a possible and feasible formulation for the clinical application of EVs.

Regulation of in vivo fate of exosomes for therapeutic applications: New frontier in nanomedicines

The significance of exosomes as intercellular messengers in a range of biological phenomena has hugely inspired many researchers to use them for disease diagnosis and treatment. Likewise, since the adoption of exosomes as new tools for our research, I aspired to address relevant delivery challenges with my expertise in the field of nanomedicine to develop better exosome-related therapies. In particular, innately therapeutic and exogenous drug-loaded exosomes should be located at the target site, whereas pathological exosomes or their biogenesis pathways should be targeted to control them. Reflecting recent preclinical efforts in my research group to meet such needs, the related previous work history, and initial accomplishments for regulating the in vivo fate of exosomes are covered in this contribution to the Orations-New Horizons of the Journal of Controlled Release, along with our ambitions for future developments in the field.

Therapeutic potential of stem cell and melatonin on the reduction of CCl4-induced liver fibrosis in experimental mice model

Liver fibrosis is initial stage of any chronic liver disease and its end stage is develops into cirrhosis. Chronic liver diseases are a crucial global health issue and the cause of approximately 2 million deaths per year worldwide. Cirrhosis is currently the 11th most common cause of death globally. Mesenchymal stem cell (MSCs) treatment is the best way to treat acute and chronic liver disease. The aim of this study is to improve the therapeutic potential of MSCs combined with melatonin (MLT) to overcome CCl4-induced liver fibrosis and also investigate the individual impact of melatonin and MSCs against CCl4-induced liver impairment in animal model. Female BALB/c mice were used as CCL4-induced liver fibrotic animal model. Five groups of animal model were made; negative control, Positive control, CCl4+MSCs treated group, CCl4+MLT treated group and CCl4+MSCs+MLT treated group. Cultured MSCs from mice bone marrow were transplanted to CCl4-induced liver injured mice model, individually as well as together with melatonin. Two weeks after MSCs and MLT administration, all groups of mice were sacrificed for examination. Morphological and Histopathological results showed that combined therapy of MSCs+MLT showed substantial beneficial impact on CCl4-induced liver injured model, compared with MSCs and MLT individually. Biochemically, considerable reduction was observed in serum bilirubin and ALT levels of MLT+MSC treated mice, compared to other groups. PCR results shown down-regulation of Bax and up-regulation of Bcl-xl and Albumin, confirm a significant therapeutic effect of MSCs+MLT on CCI4-induced liver fibrosis. From the results, it is concluded that combined therapy of MSCs and MLT show strong therapeutic effect on CCL4-induced liver fibrosis, compared with MSCs and MLT individually.

Delivery of Stem Cell Secretome for Therapeutic Applications

Intensive studies on stem cell therapy reveal that benefits of stem cells attribute to the paracrine effects. Hence, direct delivery of stem cell secretome to the injured site shows the comparative therapeutic efficacy of living cells while avoiding the potential limitations. However, conventional systemic administration of stem cell secretome often leads to rapid clearance in vivo. Therefore, a variety of different biomaterials are developed for sustained and controllable delivery of stem cell secretome to improve therapeutic efficiency. In this review, we first introduce current approaches for the preparation and characterization of stem cell secretome as well as strategies to improve their therapeutic efficacy and production. The up-to-date delivery platforms are also summarized, including nanoparticles, injectable hydrogels, microneedles, and scaffold patches. Meanwhile, we discuss the underlying therapeutic mechanism of stem cell secretome for the treatment of various diseases. In the end, future opportunities and challenges are proposed.

Stem Cell-Derived Extracellular Vesicle-Bearing Dermal Filler Ameliorates the Dermis Microenvironment by Supporting CD301b-Expressing Macrophages

Hyaluronic acid-based hydrogels (Hyal-Gels) have the potential to reduce wrinkles by physically volumizing the skin. However, they have limited ability to stimulate collagen generation, thus warranting repeated treatments to maintain their volumizing effect. In this study, stem cell-derived extracellular vesicle (EV)-bearing Hyal-Gels (EVHyal-Gels) were prepared as a potential dermal filler, ameliorating the dermis microenvironment. No significant differences were observed in rheological properties and injection force between Hyal-Gels and EVHyal-Gels. When locally administered to mouse skin, Hyal-Gels significantly extended the biological half-life of EVs from 1.37 d to 3.75 d. In the dermis region, EVHyal-Gels induced the overexpression of CD301b on macrophages, resulting in enhanced proliferation of fibroblasts. It was found that miRNAs, such as let-7b-5p and miR-24-3p, were significantly involved in the change of macrophages toward the CD301b^hi phenotype. The area of the collagen layer in EVHyal-Gel-treated dermis was 2.4-fold higher than that in Hyal-Gel-treated dermis 4 weeks after a single treatment, and the collagen generated by EVHyal-Gels was maintained for 24 weeks in the dermis. Overall, EVHyal-Gels have the potential as an antiaging dermal filler for reprogramming the dermis microenvironment.

An anti-DR5 antibody-curcumin conjugate for the enhanced clearance of activated hepatic stellate cells

Anti-death receptor 5 (DR5) antibody is a potential therapeutic agent for liver fibrosis because it exhibits anti-fibrotic effects by inducing the apoptosis of activated hepatic stellate cells (HSCs), which are responsible for hepatic fibrogenesis. However, the clinical applications of anti-DR5 antibodies have been limited by their low agonistic activity against DR5. In this study, an anti-DR5 antibody-curcumin conjugate (DCC) was prepared to investigate its effect on the clearance of activated HSCs. The DCC was synthesized through a coupling reaction between a maleimide-functionalized curcumin derivative and a thiolated anti-DR5 antibody. No significant differences were observed in the uptake behaviors of activated HSCs between the bare anti-DR5 antibodies and DCC. Owing to the antioxidant and anti-inflammatory effects of curcumin, DCC-treated HSCs produced much lower levels of reactive oxygen species and inducible nitric oxide synthase than the bare anti-DR5 antibody-treated HSCs. Additionally, the anti-fibrotic effects of DCC on activated HSCs were more prominent than those of the bare anti-DR5 antibodies, as demonstrated by the immunocytochemical analysis of α-smooth muscle actin. DCC preferentially accumulated in the liver after its systemic administration to mice with liver fibrosis. Thus, DCC may serve as a potential therapeutic agent for treating liver fibrosis.

Application of adipose-derived stem cells in treating fibrosis

Fibrosis is the hyperactivation of fibroblasts that results in excessive accumulation of extracellular matrix, which is involved in numerous pathological changes and diseases. Adipose-derived stem cells (ASCs) are promising seed cells for regenerative medicine due to their bountiful source, low immunogenicity and lack of ethical issues. Their anti-fibrosis, immunomodulation, angiogenesis and other therapeutic effects have made them suitable for treating fibrosis-related diseases. Here, we review the literature on ASCs treating fibrosis, elaborate and discuss their mechanisms of action, changes in disease environment, ways to enhance therapeutic effects, as well as current preclinical and clinical studies, in order to provide a general picture of ASCs treating fibrotic diseases.

The Role of MSC in Wound Healing, Scarring and Regeneration

Tissue repair and regeneration after damage is not completely understood, and current therapies to support this process are limited. The wound healing process is associated with cell migration and proliferation, extracellular matrix remodeling, angiogenesis and re-epithelialization. In normal conditions, a wound will lead to healing, resulting in reparation of the tissue. Several risk factors, chronic inflammation, and some diseases lead to a deficient wound closure, producing a scar that can finish with a pathological fibrosis. Mesenchymal stem/stromal cells (MSCs) are widely used for their regenerative capacity and their possible therapeutically potential. Derived products of MSCs, such as exosomes or extravesicles, have shown a therapeutic potential similar to MSCs, and these cell-free products may be interesting in clinics. MSCs or their derivative products have shown paracrine beneficial effects, regulating inflammation, modifying the fibroblast activation and production of collagen and promoting neovascularization and re-epithelialization. This review describes the effects of MSCs and their derived products in each step of the wound repair process. As well, it reviews the pre-clinical and clinical use of MSCs to benefit in skin wound healing in diabetic associated wounds and in pathophysiological fibrosis.

Application of Modified Mesenchymal Stem Cells Transplantation in the Treatment of Liver Injury

Acute and chronic hepatitis, cirrhosis, and other liver diseases pose a serious threat to human health; however, liver transplantation is the only reliable treatment for the terminal stage of liver diseases. Previous researchers have shown that mesenchymal stem cells (MSCs) are characterized by differentiation and paracrine effects, as well as anti-oxidative stress and immune regulation functions. When MSCs are transplanted into animals, they migrate to the injured liver tissue along with the circulation, to protect the liver and alleviate the injury through the paracrine, immune regulation and other characteristics, making mesenchymal stem cell transplantation a promising alternative therapy for liver diseases. Although the efficacy of MSCs transplantation has been confirmed in various animal models of liver injury, many researchers have also proposed various pretreatment methods to improve the efficacy of mesenchymal stem cell transplantation, but there is still lack a set of scientific methods system aimed at improving the efficacy of transplantation therapy in scientific research and clinical practice. In this review, we summarize the possible mechanisms of MSCs therapy and compare the existing methods of MSCs modification corresponding to the treatment mechanism, hoping to provide as a reference to help future researchers explore a safe and simple transplantation strategy.

Vitamin A-coupled stem cell-derived extracellular vesicles regulate the fibrotic cascade by targeting activated hepatic stellate cells in vivo

Allogeneic transplantation of mesenchymal stem cell-derived extracellular vesicles (EVs) offers great potential for treating liver fibrosis. However, owing to their intrinsic surface characteristics, bare EVs are non-specifically distributed in the liver tissue after systemic administration, leading to limited therapeutic efficacy. To target activated hepatic stellate cells (HSCs), which are responsible for hepatic fibrogenesis, vitamin A-coupled small EVs (V-EVs) were prepared by incorporating vitamin A derivative into the membrane of bare EVs. No significant differences were found in the particle size and morphology between bare and V-EVs. In addition, surface engineering of EVs did not affect the expression of surface marker proteins (e.g., CD63 and CD9), as demonstrated by flow cytometry. Owing to the surface incorporation of vitamin A, V-EVs were selectively taken up by activated HSCs via receptor-mediated endocytosis. When systemically administered to mice with liver fibrosis, V-EVs effectively targeted activated HSCs in the liver tissue, resulting in reversal of the fibrotic cascade. Consequently, even at a 10-fold lower dose, V-EVs exhibited comparable anti-fibrotic effects to those of bare EVs, substantiating their therapeutic potential for liver fibrosis.

ADSC Exosomes Mediate lncRNA-MIAT Alleviation of Endometrial Fibrosis by Regulating miR-150-5p

Background

Secondary infertility remains a major complication of endometrial fibrosis in women. The use of exosomes from adipose-derived mesenchymal stem cells (ADSCs) has shown promising results for the treatment of endometrial fibrosis. However, the mechanisms of action of ADSC-exosome (ADSC-Exo) therapy remain unclear.

Materials and Methods

An endometrial fibrosis model was established in mice treated with alcohol and endometrial epithelial cells (ESCs) treated with TGF-β1. ADSCs were isolated from Sprague Dawley (SD) rats, and exosomes were isolated from ADSCs using ExoQuick reagent. Exosomes were identified by transmission electron microscopy (TEM), NanoSight, and Western blot analysis. The expression level of lncRNA-MIAT was detected by qPCR analysis. Western blot analysis was carried out to determine the protein levels of fibrosis markers (TGFβR1, α-SMA, and CK19). A dual-luciferase reporter gene assay was used to verify the relationship between target genes. The endometrial tissues of the endometrial fibrosis model were stained with HE and Masson’s trichrome.

Results

ADSCs and ADSC-Exos were successfully isolated, and the expression level of lncRNA-MIAT was significantly down-regulated in endometrial tissue and the TGF-β1-induced ESC injury model, whereas ADSC-Exos increased the expression of lncRNA-MIAT in the TGF-β1-induced ESC model. Functionally, ADSC-Exo treatment repressed endometrial fibrosis in vivo and in vitro by decreasing the expression of hepatic fibrosis markers (α-SMA and TGFβR1) and increasing the expression of CK19. Moreover, miR-150-5p expression was repressed by lncRNA-MIAT in the TGF-β1-induced ESC injury model. The miR-150-5p mimic promoted TGF-β1-induced ESC fibrosis.

Conclusion

ADSC-Exos mediate lncRNA-MIAT alleviation of endometrial fibrosis by regulating miR-150-5p, which suggests that lncRNA-MIAT from ADSC-Exos may be a viable treatment for endometrial fibrosis.

Metabolically engineered stem cell–derived exosomes to regulate macrophage heterogeneity in rheumatoid arthritis

Despite the remarkable advances in therapeutics for rheumatoid arthritis (RA), a large number of patients still lack effective countermeasures. Recently, the reprogramming of macrophages to an immunoregulatory phenotype has emerged as a promising therapeutic strategy for RA. Here, we report metabolically engineered exosomes that have been surface-modified for the targeted reprogramming of macrophages. Qualified exosomes were readily harvested from metabolically engineered stem cells by tangential flow filtration at a high yield while maintaining their innate immunomodulatory components. When systemically administered into mice with collagen-induced arthritis, these exosomes effectively accumulated in the inflamed joints, inducing a cascade of anti-inflammatory events via macrophage phenotype regulation. The level of therapeutic efficacy obtained with bare exosomes was achievable with the engineered exosomes of 10 times less dose. On the basis of the boosted nature to reprogram the synovial microenvironment, the engineered exosomes display considerable potential to be developed as a next-generation drug for RA.

Cell Therapy and Bioengineering in Experimental Liver Regenerative Medicine: In Vivo Injury Models and Grafting Strategies

Purpose of Review

To describe experimental liver injury models used in regenerative medicine, cell therapy strategies to repopulate damaged livers and the efficacy of liver bioengineering.

Recent Findings

Several animal models have been developed to study different liver conditions. Multiple strategies and modified protocols of cell delivery have been also reported. Furthermore, using bioengineered liver scaffolds has shown promising results that could help in generating a highly functional cell delivery system and/or a whole transplantable liver.

Summary

To optimize the most effective strategies for liver cell therapy, further studies are required to compare among the performed strategies in the literature and/or innovate a novel modifying technique to overcome the potential limitations. Coating of cells with polymers, decellularized scaffolds, or microbeads could be the most appropriate solution to improve cellular efficacy. Besides, overcoming the problems of liver bioengineering may offer a radical treatment for end-stage liver diseases.

Exosomes derived from human adipose mesenchymal stem cells attenuate hypertrophic scar fibrosis by miR-192-5p/IL-17RA/Smad axis

BACKGROUND

Hypertrophic scar (HS) is a fibro-proliferative disorder of dermis after burn or trauma and usually leads to esthetic disfiguration and functionary impairment for patients. Emerging evidences demonstrated ADSC-Exo could alleviate the visceral fibrosis, but little attention had been paid to its role in skin fibrosis. In the study, we would explore the effect of ADSC-Exo on HS and investigated the exact mechanism underlying the properties.

METHODS

ADSC-Exo were isolated, identified, and internalized by HS-derived fibroblasts (HSFs). The effect of ADSC-Exo on the proliferation and migration of HSFs were detected by flow cytometry and Ki67 immunofluorescence staining, or scratch and trans-wells assays, respectively. RT-PCR, immunoblotting, immunofluorescence, and immunohistochemistry staining were used to evaluate the expression of IL-17RA, Col1, Col3, α-SMA, SIP1, and p-Smad2/p-Smad3 in HSFs stimulated with ADSC-Exo, miR-192-5p mimics, or inhibitors, IL-17RA siRNA and their negative controls. Digital morphology, H&E, Masson's trichrome staining, and immunohistochemistry staining were performed to measure the effect of ADSC-Exo and Lv-IL-17RA shRNA on excisional wound of BALB/c mice.

RESULTS

The verified ADSC-Exo effectively inhibited the proliferation and migration of HSFs, decreased the expression of Col1, Col3, α-SMA, IL-17RA, and p-Smad2/p-Smad3 and increased the levels of SIP1 in HSFs. Besides, the mice in ADSC-Exo-treated group demonstrated faster wound healing and less collagen deposition. Furthermore, miR-192-5p was highly expressed in ADSC-Exo and ADSC-Exosomal miR-192-5p ameliorated hypertrophic scar fibrosis. Meanwhile, miR-192-5p targeted the expression of IL-17RA to decrease the pro-fibrotic proteins levels. Moreover, IL-17RA was overexpressed in HS and HSFs, and knockdown IL-17RA alleviated the expression of Col1, Col3, α-SMA, and p-Smad2/p-Smad3 and increased the expression of SIP1 in HSFs. Most importantly, IL-17RA silence also facilitated wound healing, attenuated collagen production, and modulated Smad pathway in HSFs.

CONCLUSIONS

This study illustrated ADSC-Exo attenuated the deposition of collagen, the trans-differentiation of fibroblasts-to-myofibroblasts, and the formation of hypertrophic scar by in vitro and in vivo experiments. ADSC-Exosomal miR-192-5p targeted IL-17RA to regulate Smad pathway in hypertrophic scar fibrosis. ADSC-Exo could be a promising therapeutic strategy for clinical treatment of hypertrophic scar and the anti-fibrotic properties could be achieved by miR-192-5p/IL-17RA/Smad axis.

Mesenchymal Stem Cells as a Cornerstone in a Galaxy of Intercellular Signals: Basis for a New Era of Medicine

Around 40% of the population will suffer at some point in their life a disease involving tissue loss or an inflammatory or autoimmune process that cannot be satisfactorily controlled with current therapies. An alternative for these processes is represented by stem cells and, especially, mesenchymal stem cells (MSC). Numerous preclinical studies have shown MSC to have therapeutic effects in different clinical conditions, probably due to their mesodermal origin. Thereby, MSC appear to play a central role in the control of a galaxy of intercellular signals of anti-inflammatory, regenerative, angiogenic, anti-fibrotic, anti-oxidative stress effects of anti-apoptotic, anti-tumor, or anti-microbial type. This concept forces us to return to the origin of natural physiological processes as a starting point to understand the evolution of MSC therapy in the field of regenerative medicine. These biological effects, demonstrated in countless preclinical studies, justify their first clinical applications, and draw a horizon of new therapeutic strategies. However, several limitations of MSC as cell therapy are recognized, such as safety issues, handling difficulties for therapeutic purposes, and high economic cost. For these reasons, there is an ongoing tendency to consider the use of MSC-derived secretome products as a therapeutic tool, since they reproduce the effects of their parent cells. However, it will be necessary to resolve key aspects, such as the choice of the ideal type of MSC according to their origin for each therapeutic indication and the implementation of new standardized production strategies. Therefore, stem cell science based on an intelligently designed production of MSC and or their derivative products will be able to advance towards an innovative and more personalized medical biotechnology.

Regenerative effect of mesenteric fat stem cells on ccl4-induced liver cirrhosis, an experimental study

Background

Liver cirrhosis is a chronic disease in which normal liver tissue is replaced by fibrous tissue, leads to liver malfunction. Although transplantation is the most certain cure, stem cell therapies are shedding light on efforts to regenerate cirrhotic liver. The purpose of this study was to evaluate the regenerative potential of mesenteric fat stem cells in CCL4-induced liver cirrhosis in an animal model.

Methods

Thirty rats were treated with the mixture of CCL4 and olive oil intraperitoneally by a dose of 0.2 ml (0.1 ml CCL4 and 0.1 ml olive oil) every other day for 16 weeks till cirrhosis signs appeared. Fifteen rats were randomly selected as control group. Others treated by mesenteric fat derived mesenchymal stem cells transferred into the liver parenchyma.

Results

After 5 weeks, rats received stem cells had improved clinically by increased movements, appetite, improvement in overall behavior and decreased abdomen size. Histopathologically, liver cells showed state of regeneration and forming new colonies.

Conclusion

Liver cirrhosis was induced. The mesenchymal stem cells derived from mesenteric adipose tissue could improve hepatic status of the rats, as cirrhotic livers were regenerated back into normal appearing parenchyma. Rats' clinical behavior also reached healthy status.

Adipose Tissue Fibrosis: Mechanisms, Models, and Importance

Increases in adipocyte volume and tissue mass due to obesity can result in inflammation, further dysregulation in adipose tissue function, and eventually adipose tissue fibrosis. Like other fibrotic diseases, adipose tissue fibrosis is the accumulation and increased production of extracellular matrix (ECM) proteins. Adipose tissue fibrosis has been linked to decreased insulin sensitivity, poor bariatric surgery outcomes, and difficulty in weight loss. With the rising rates of obesity, it is important to create accurate models for adipose tissue fibrosis to gain mechanistic insights and develop targeted treatments. This article discusses recent research in modeling adipose tissue fibrosis using in vivo and in vitro (2D and 3D) methods with considerations for biomaterial selections. Additionally, this article outlines the importance of adipose tissue in treating other fibrotic diseases and methods used to detect and characterize adipose tissue fibrosis.

Obtaining hepatocytes by transdifferentiation of multipotent mesenchymal stromal cells by genetic engineering

Therapy of liver failure is a common and insufficiently resolved problem. One of the options for its solution it is a liver transplantation. However, this method has a number of drawbacks, which include a limited number of donors and transplant rejection. The use of autologous hepatocytes would allow significant progress to solve the problem under discussion. The work considers a method that allowed obtaining autologous hepatocytes by transdifferentiation of multipotent mesenchymal stromal cells using genetic engineering methods.