Exosomes Secreted from Amniotic Membrane Contribute to Its Anti-Fibrotic Activity

Effects of a human amniotic membrane extract on ARPE-19 cells

BACKGROUND

Human Amniotic Membrane (hAM) is endowed with several biological activities and might be considered an optimal tool in surgical treatment for different ophthalmic pathologies. We pioneered the surgical use of hAM to treat retinal pathologies such as macular holes, tears, and retinal detachments, and to overcome photoreceptor damage in age-related macular degeneration. Although hAM contributed to improved outcomes, the mechanisms of its effects are not yet fully understood. The characterization and explanation of the effects of hAM would allow the adoption of this new natural product in different retinal pathologies, operative contexts, and hAM formulations. At this end, we studied the properties of a hAM extract (hAME) on the ARPE-19 cells.

METHODS AND RESULTS

A non-denaturing sonication-based technique was developed to obtain a suitable hAME. Viability, proliferation, apoptosis, oxidative stress, and epithelial-mesenchymal transition (EMT) were studied in hAME-treated ARPE-19 cells. The hAME was able to increase ARPE-19 cell viability even in the presence of oxidative stress (H2O2, TBHP). Moreover, hAME prevented the expression of EMT features, such as EMT-related proteins, fibrotic foci formation, and migration induced by different cytokines.

CONCLUSIONS

Our results demonstrate that the hAME retains most of the properties observed in the whole tissue by others. The hAME, other than providing a manageable research tool, could represent a cost-effective and abundant drug to treat retinal pathologies in the future.

Novel Functional Dressing Materials for Intraoral Wound Care

Intraoral wounds represent a particularly challenging category of mucosal and hard tissue injuries, characterized by the unique structures, complex environment, and distinctive healing processes within the oral cavity. They have a common occurrence yet frequently inflict significant inconvenience and pain on patients, causing a serious decline in the quality of life. A variety of novel functional dressings specifically designed for the moist and dynamic oral environment have been developed and realized accelerated and improved wound healing. Thoroughly analyzing and summarizing these materials is of paramount importance in enhancing the understanding and proficiently managing intraoral wounds. In this review, the particular processes and unique characteristics of intraoral wound healing are firstly described. Up-to-date knowledge of various forms, properties, and applications of existing products are then intensively discussed, which are categorized into animal products, plant extracts, natural polymers, and synthetic products. To conclude, this review presents a comprehensive framework of currently available functional intraoral wound dressings, with an aim to provoke inspiration of future studies to design more convenient and versatile materials.

Cryopreserved amniotic membrane in chronic nonhealing wounds: a series of case reports

A case series of the use of amniotic membrane (AM) for treating chronic nonhealing wounds. It presents five cases of polymorbid patients with a total of nine chronic nonhealing wounds. The patient group consisted of four men and one woman with various comorbidities, aged 45-72 years. The mean initial wound size was 15.8 cm2, and the mean time from the onset of the wound to the first application of AM was 122 weeks. The wounds were caused by chronic venous insufficiency and/or peripheral arterial disease. Wounds were treated in a standardized protocol. AM was applied weekly in the first month and then every two weeks. Photo documentation of the wound and microbiological colonization was carried out at each visit. In three out of five patients, the AM treatment effectively promoted healing up to complete wound closure. In two cases, the wounds stayed unhealed despite numerous AM applications. Pain relief was noted in all patients. The success of the treatment was closely tied to patient factors, such as adherence to the prescribed treatment regimen and individual patient characteristics. In some cases, treatment failure was observed, possibly due to underlying comorbidities, wound parameters, or poor patient compliance. AM treatment has the potential to become a viable treatment option for these nonhealing wounds. However, the effectiveness of the treatment may be influenced by various patient factors and the underlying cause of the wound. Therefore, it is crucial to have an individualized treatment plan that considers these particular factors.

Enhancing antimicrobial activity and reducing cytotoxicity of silver nanoparticles through gelatin nanoparticles

Aim: To develop a novel stabilizing agent for silver nanoparticles (AgNPs) with the aim of enhancing its antibacterial efficacy against wound associated pathogens while mitigating their cytotoxic effect on human cells. Materials & methods: In this study, monodispersed gelatin nanoparticles were synthesized to stabilize AgNPs. The stability, antibacterial activity and biocompatibility of the gelatin-stabilized AgNPs (Gel-AgNPs) were compared with citrate-stabilized AgNPs (citrate-AgNPs) or silver ions. Results & conclusion: Gelatin-stabilized AgNPs showed significantly better antibacterial activities compared with citrate-stabilized AgNPs against both Gram-positive and Gram-negative bacteria. These Gel-AgNPs showed significantly lower cytotoxicity to human dermal fibroblasts compared with Ag+. These findings provided the first evidence substantiating a novel functionality of gelatin nanoparticles in both stabilizing and enhancing the activity of AgNPs.

Exosomes from adipose-derived mesenchymal stem cells improve liver fibrosis by regulating the miR-20a-5p/TGFBR2 axis to affect the p38 MAPK/NF-κB pathway

OBJECTIVE

Human adipose-derived mesenchymal stem cell exosomes (ADSC-Exos) are active constituents for treating liver fibrosis. This paper attempted to preliminarily explain the functional mechanism of ADSC-Exos in liver fibrosis through the p38 MAPK/NF-κB pathway.

METHODS

The cell models of hepatic fibrosis were established by inducing LX-2 cells with TGF-β1. Mouse models of liver fibrosis were established by treating mice with CCl4. The in vivo and in vitro models of liver fibrosis were treated with ADSC-Exos. ADSCs were identified by flow cytometry/Alizarin red/oil red O/alcian blue staining. ADSC-Exos were identified by transmission electron microscopy, nanoparticle tracking analysis, and Western blot. LX-2 cell proliferation/viability were evaluated by MTT/BrdU assays. Exosomes were tracked in vivo and body weight changes in mice were monitored. Hepatic pathological changes were observed by HE/Masson staining. α-SMA/collagen I levels in liver tissues were assessed by immunohistochemistry. HA/PIIINP concentrations were measured using the magnetic particle chemiluminescence method. Liver function was assessed using an automatic analyzer. miR-20a-5p level was measured by RT-qPCR. The mRNA levels of fibrosis markers were determined by RT-qPCR, and their protein levels and levels of MAPK/NF-κB pathway-related proteins, as well as TGFBR2 protein level were measured by Western blot. The P65 nuclear expression in mouse liver tissues was quantified by immunofluorescence.

RESULTS

ADSC-Exos suppressed TGF-β1-induced LX-2 cell proliferation and fibrosis and reduced mRNA and protein levels of fibrosis markers in vitro. ADSC-Exos ameliorated liver fibrosis by inhibiting the p38 MAPK/NF-κB pathway activation. ADSC-Exos inhibited activation of the p38 MAPK/NF-κB pathway via regulating the miR-20a-5p/TGFBR2 axis. The in vivo experiment asserted that ADSC-Exos were mainly distributed in the liver, and ADSC-Exos relieved liver fibrosis in mice, which was evidenced by alleviating decreased body weight, reducing collagen and enhancing liver function, and repressed the activation of the p38 MAPK/NF-κB pathway via the miR-20a-5p/TGFBR2 axis.

CONCLUSION

ADSC-Exos attenuated liver fibrosis by suppressing the activation of the p38 MAPK/NF-κB pathway via the miR-20a-5p/TGFBR2 axis.

The Truth Is Out There: Biological Features and Clinical Indications of Extracellular Vesicles from Human Perinatal Stem Cells

The potential of perinatal tissues to provide cellular populations to be used in different applications of regenerative medicine is well established. Recently, the efforts of researchers are being addressed regarding the evaluation of cell products (secreted molecules or extracellular vesicles, EVs) to be used as an alternative to cellular infusion. The data regarding the effective recapitulation of most perinatal cells' properties by their secreted complement point in this direction. EVs secreted from perinatal cells exhibit key therapeutic effects such as tissue repair and regeneration, the suppression of inflammatory responses, immune system modulation, and a variety of other functions. Although the properties of EVs from perinatal derivatives and their significant potential for therapeutic success are amply recognized, several challenges still remain that need to be addressed. In the present review, we provide an up-to-date analysis of the most recent results in the field, which can be addressed in future research in order to overcome the challenges that are still present in the characterization and utilization of the secreted complement of perinatal cells and, in particular, mesenchymal stromal cells.

Amniotic Membrane and Its Derivatives: Novel Therapeutic Modalities in Liver Disorders

The liver is a vital organ responsible for metabolic and digestive functions, protein synthesis, detoxification, and numerous other necessary functions. Various acute, chronic, and neoplastic disorders affect the liver and hamper its biological functions. Most of the untreated liver diseases lead to inflammation and fibrosis which develop into cirrhosis. The human amniotic membrane (hAM), the innermost layer of the fetal placenta, is composed of multiple layers that include growth-factor rich basement membrane, epithelial and mesenchymal stromal cell layers. hAM possesses distinct beneficial anti-fibrotic, anti-inflammatory and pro-regenerative properties via the secretion of multiple potent trophic factors and/or direct differentiation into hepatic cells which place hAM-based therapies as potential therapeutic strategies for the treatment of chronic liver diseases. Decellularized hAM is also an ideal scaffold for liver tissue engineering as this biocompatible niche provides an excellent milieu for cell proliferation and hepatocytic differentiation. Therefore, the current review discusses the therapeutic potential of hAM and its derivatives in providing therapeutic solutions for liver pathologies including acute liver failure, metabolic disorders, liver fibrosis as well as its application in liver tissue engineering.

Bovine Fibroblast-Derived Extracellular Matrix Promotes the Growth and Preserves the Stemness of Bovine Stromal Cells during In Vitro Expansion

Cultivated meat is a fast-growing research field and an industry with great potential to overcome the limitations of traditional meat production. Cultivated meat utilizes cell culture and tissue engineering technologies to culture a vast number of cells in vitro and grow/assemble them into structures mimicking the muscle tissues of livestock animals. Stem cells with self-renewal and lineage-specific differentiation abilities have been considered one of the key cell sources for cultivated meats. However, the extensive in vitro culturing/expansion of stem cells results in a reduction in their abilities to proliferate and differentiate. Extracellular matrix (ECM) has been used as a culturing substrate to support cell expansion for cell-based therapies in regenerative medicine due to its resemblance to the native microenvironment of cells. In this study, the effect of the ECM on the expansion of bovine umbilical cord stromal cells (BUSC) in vitro was evaluated and characterized. BUSCs with multi-lineage differentiation potentials were isolated from bovine placental tissue. Decellularized ECM prepared from a confluent monolayer of bovine fibroblasts (BF) is free of cellular components but contains major ECM proteins such as fibronectin and type I collagen and ECM-associated growth factors. Expansion of BUSC on ECM for three passages (around three weeks) resulted in about 500-fold amplification, while cells were amplified less than 10-fold when cultured on standard tissue culture plates (TCP). Moreover, the presence of ECM reduced the requirement for serum in the culture medium. Importantly, the cells amplified on ECM retained their differentiation abilities better than cells cultured on TCP. The results of our study support the notion that monolayer cell-derived ECM may be a strategy to expand bovine cells in vitro effectively and efficiently.

An electrospun scaffold functionalized with a ROS-scavenging hydrogel stimulates ocular wound healing

Ocular alkali burn is a serious ophthalmic emergency. Highly penetrative alkalis cause strong inflammatory responses leading to persistent epithelial defects, acute corneal perforation and severe scarring, and thereby persistent pain, loss of vision and cicatricial sequelae. Early and effective anti-inflammation management is vital in reducing the severity of injury. In this study, a double network biomaterial was prepared by compounding electrospinning nanofibres of thioketal-containing polyurethane (PUTK) with a reactive oxygen species (ROS)-scavenging hydrogel (RH) fabricated by crosslinking poly(poly(ethylene glycol) methyl ether methacrylate-co-glycidyl methacrylate) with thioketal diamine and 3,3'-dithiobis(propionohydrazide). The developed PUTK/RH patch exhibited good transparency, high tensile strength and increased hydrophilicity. Most importantly, it demonstrated strong antioxidant activity against H₂O₂ and 2,2-di(4-tert-octylphenyl)-1-picryl-hydrazyl (DPPH). Next, a rat corneal alkali burn model was established, and the PUTK/RH patch was transplanted on the injured cornea. Reduced inflammatory cell infiltration was revealed by confocal microscopy, and lower expression levels of genes relative to inflammation, vascularization and scarring were identified by qRT-PCR and western blot. Fluorescein sodium dyeing, hematoxylin and eosin (H&E) staining and immunohistochemical staining confirmed that the PUTK/RH patch could accelerate corneal wound healing by inhibiting inflammation, promoting epithelial regeneration and decreasing scar formation. STATEMENT OF SIGNIFICANCE: Ocular alkali burn is a serious ophthalmic emergency, characterized with persistent inflammation and irreversible vision loss. Oxidative stress is the main pathological process at the acute inflammatory stage, during which combined use of glucocorticoids and amniotic membrane transplantation is the most widely accepted treatment. In this study, we fabricated a polyurethane electrospun nanofiber membrane functionalized with a ROS-scavenging hydrogel. This composite patch could be a promising amniotic membrane substitute, possessing with a transparent appearance, elasticity and anti-inflammation effect. It could be easily transplanted onto the alkali-burned corneas, resulting in a significant inhibition of stromal inflammation and accelerating the recovery of corneal transparency. The conception of ROS-scavenging wound patch may offer a new way for ocular alkali burn.

Proteomic and miRNA Profiles of Exosomes Derived from Myometrial Tissue in Laboring Women

Myometrial contraction is essential for successful delivery. Recent studies have highlighted the vital roles of tissue-derived exosomes in disease diagnostic, prognostic, and therapeutic applications; however, the characteristics of uterine myometrium-derived exosomes are unclear. Here, we successfully isolated exosomes from myometrial tissues, human myometrial smooth muscle cells (HMSMCs), and human umbilical vein endothelial cells (HUVECs), then performed quantitative liquid chromatography-tandem mass spectrometry and miRNA sequencing to investigate the cargo of the exosomes. Fifty-two proteins and five miRNAs were differentially expressed (DE) in term non-labor and term labor myometrium-derived exosomes. Among them, seven proteins (SERPINE1, THBS1, MGAT1, VIM, FGB, FGG, and VWF) were differentially expressed both in the myometrial exosomes and tissues, three miRNAs (miR-363-3p, miR-203a-3p, and miR-205-5p) target 13 DE genes. The top three miRNA derived from HMSMCs (miR-125b-1-3p, miR-337-5p, and miR-503-5p) and HUVECs (miR-663a, miR-4463, and miR-3622a-5p) were identified. Two proteins, GJA1 and SLC39A14, exist in female blood exosomes and are highly expressed in HMSMCs exosomes, are also upregulated in the laboring myometrium, which verified increased in laboring blood samples, might be novel potential biomarkers for myometrial activation. The proteomic and miRNA profile of exosomes derived from laboring myometrium revealed some molecules in the exosomes that affect the intercellular communication and the function of the myometrium.

A decellularized flowable placental connective tissue matrix supports cellular functions of human tenocytes in vitro

Purpose

Injectable connective tissue matrices (CTMs) may promote tendon healing, given their minimally invasive properties, structural and biochemical extracellular matrix components, and capacity to fill irregular spaces. The purpose of this study is to evaluate the effects of placental CTMs on the cellular activities of human tenocytes. Decellularization, the removal of cells, cell fragments, and DNA from CTMs, has been shown to reduce the host’s inflammatory response. Therefore, the authors hypothesize that a decellularized CTM will provide a more cell-friendly matrix to support tenocyte functions.

Methods

Three human placental CTMs were selected for comparison: AmnioFill® (A-CTM), a minimally manipulated, non-viable cellular particulate, BioRenew™ (B-CTM), a liquid matrix, and Interfyl® (I-CTM), a decellularized flowable particulate. Adhesion and proliferation were evaluated using cell viability assays and tenocyte migration using a transwell migration assay. Gene expression of tenocyte markers, cytokines, growth factors, and matrix metalloprotease (MMP) in tenocytes were assessed using quantitative polymerase chain reaction.

Results

Although A-CTM supported more tenocyte adhesion, I-CTM promoted significantly more tenocyte proliferation compared with A-CTM and B-CTM. Unlike A-CTM, tenocyte migration was higher in I-CTM than the control. The presence of I-CTM also prevented the loss of tenocyte phenotype, attenuated the expression of pro-inflammatory cytokines, growth factors, and MMP, and promoted the expression of antifibrotic growth factor, TGFβ3.

Conclusion

Compared with A-CTM and B-CTM, I-CTM interacted more favorably with human tenocytes in vitro. I-CTM supported tenocyte proliferation with reduced de-differentiation and attenuation of the inflammatory response, suggesting that I-CTM may support tendon healing and regeneration in vivo.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40634-022-00509-4.