Mesenchymal Stromal Cell Secretome for Therapeutic Application in Skin Wound Healing: A Systematic Review of Preclinical Studies.

Non-healing skin wounds remain a challenge in the healthcare system. In this sense, it is suggested that the secretome of mesenchymal stromal cells (MSCs) can be effective as a therapeutic strategy for regenerative medicine. Therefore, this systematic review aimed to determine the effects of treatment with a secretome derived from MSCs on the healing of skin wounds in a preclinical model of rodents (mice and rats). Studies were systematically retrieved from 6 databases and gray literature that provided 1,172 records, of which 25 met the inclusion criteria for qualitative analysis. Results revealed substantial heterogeneity among studies concerning experimental designs and methodologies, resulting in a high risk of bias. Together, the selected studies reported that treatment improved wound healing by (1) accelerating wound closure and improving skin repair quality; (2) reducing inflammation by decreasing the number of cells and inflammatory cytokines, accompanied by polarization of the M2 macrophage; (3) complete re-epithelialization and epidermal reorganization; (4) neovascularization promoted by proliferation of endothelial cells (CD34+) and increased levels of pro-angiogenic mediators; (5) better scar quality promoted by increased expression of collagen types I and III, as well as improved deposition and remodeling of collagen fibers. In conclusion, despite the need for alignment of methodological protocols and transparent reports in future studies, results show that the secretome of MSCs from different tissue sources corresponds to a promising tool of regenerative medicine for the treatment of skin wounds.

Administration of mesenchymal stem cells from adipose tissue at the hip joint of dogs with osteoarthritis: A systematic review.

This systematic review aimed to determine the effects of intra-articular administration of mesenchymal stem cells from adipose tissue in dogs with hip joint osteoarthritis (OA). Clinical trials were systematically reviewed, using PubMed, EMBASE, Cochrane Library, LILACS, Web of Science, Scopus, Open Grey, Google Scholar, and ProQuest Dissertation and Thesis without publication year restrictions. References were screened and selected based on predefined eligibility criteria by two independent reviewers, according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Clinical outcomes were assessed quantitatively using clinical pain scores, physical examination, imaging examination, questionnaire responses, pain in manipulation, gait analysis, range of joint motion, and adverse effects. The risk of bias was assessed using the Joanna Briggs Institute Critical Appraisal Checklist. Out of 1483 articles, six met the inclusion criteria for qualitative analysis, with two randomized controlled trials and four before-and-after studies. All studies reported significantly better clinical outcomes in the adipose tissue stem cells (ADSC) group with improvements in pain and function and decreased evidence of hip OA. The risk of bias was categorized as high in the before-and-after studies and moderate to high in the randomized studies. The studies were considered heterogeneous owing to clinical results and methodology. Because of this heterogeneity, it was not possible to perform meta-analysis. Assessments of ADSC reports yielded positive clinical effects that showed improvements in pain and function and decreased evidence of hip osteoarthritis. More high-level, larger-cohort dog studies that utilize standardized protocols are needed.

FGF2 Stimulates the Growth and Improves the Melanocytic Commitment of Trunk Neural Crest Cells.

Neural crest cells (NCCs) comprise a population of multipotent progenitors and stem cells at the origin of the peripheral nervous system (PNS) and melanocytes of skin, which are profoundly influenced by microenvironmental factors, among which is basic fibroblast growth factor 2 (FGF2). In this work, we further investigated the role of this growth factor in quail trunk NC morphogenesis and demonstrated its huge effect in NCC growth mainly by stimulating cell proliferation but also reducing cell death, despite that NCC migration from the neural tube explant was not affected. Moreover, following FGF2 treatment, reduced expression of the early NC markers Sox10 and FoxD3 and improved proliferation of HNK1-positive NCC were observed. Since these markers are involved in the regulation of glial and melanocytic fate of NC, the effect of FGF2 on NCC differentiation was investigated. Therefore, in the presence of FGF2, increased proportions of NCCs positives to the melanoblast marker Mitf as well as NCCs double stained to Mitf and BrdU were recorded. In addition, treatment with FGF2, followed by differentiation medium, resulted in increased expression of melanin and improved proportion of melanin-pigmented melanocytes without alteration in the glial marker Schwann myelin protein (SMP). Taken together, these data further reveal the important role of FGF2 in NCC proliferation, survival, and differentiation, particularly in melanocyte development. This is the first demonstration of FGF2 effects in melanocyte commitment of NC and in the proliferation of Mitf-positive melanoblasts. Elucidating the differentiation process of embryonic NCCs brings us a step closer to understanding the development of the PNS and then undertaking the search for advanced technologies to prevent, or treat, injuries caused by NC-related disorders, also known as neurocristopathies.

Prion protein binding to HOP modulates the migration and invasion of colorectal cancer cells.

Colorectal cancer (CRC) is one of the most frequently diagnosed malignancies. The generation of conventional treatments has improved, but approximately 50 % of patients with CRC who undergo potentially curative surgery ultimately relapse and die, usually as a consequence of metastatic disease. Our previous findings showed that engagement of the cellular prion protein (PrP(C)) to its ligand HSP70/90 heat shock organizing protein (HOP) induces proliferation of glioblastomas. In addition, PrP(C) has been described as an important modulator of colorectal tumor growth. Here, we investigated the biological relevance of the PrP(C)-HOP interaction in CRC cells. We demonstrate that HOP induced the migration and invasion of CRC cell lines in a PrP(C)-dependent manner and that phosphorylation of the ERK1/2 pathway is a downstream mediator of these effects. Additionally, we show that a HOP peptide with the ability to bind PrP(C) and abolish the PrP(C)-HOP interaction inhibited the migration and invasion of CRC cells. Together, these data indicate that the disruption of the PrP(C)-HOP complex could be a potential therapeutic target for modulating the migratory and invasive cellular properties that lead to metastatic CRC.

Interações proteína príon e seus ligantes STI1 e laminina: possíveis implicações na doença de Alzheimer / Interactions of the prion protein and its ligands STI1 and laminin: possible implications for Alzheimer’s disease

A Doença de Alzheimer (DA) é uma demência progressiva que tem como principais características a disfunção sináptica e a neurodegeneração em áreas específicas do cérebro, que levam a um quadro grave de perda de memória e outras habilidades cognitivas. Uma das principais características neuropatológicas é a deposiçãode placas amiloides extracelulares, que contêm principalmente o peptídeo beta-amiloide (Aβ), que é formado por um processamento alterado da proteína precursora amiloide (APP). Os oligômeros formados por Aβ (AβO) são considerados os elementos tóxicos mais importantes deste processo, esses se ligam às sinapses e estão estreitamente relacionados com a patogênese da DA. Recentemente, foi descrito que a proteína príon celular (PrPC) é um receptor para AβO, porém, os mecanismos envolvidos nesta interação e de que forma esta pode estar relacionada à DA ainda não foram elucidados. PrPC é uma glicoproteína ancorada à membrana plasmática que interage com diversos ligantes, como a proteína de matriz extracelular laminina e a co-chaperona STI1 (Stress Inducible Protein 1). Estas interações induzem neuroproteção, neuritogênese e modulam a formação de memória. Deste modo, torna-se interessante verificar um possível efeito neuroprotetor dos ligantes de PrPC contra a toxicidade produzida pelos AβO. Utilizando culturas neuronais, observamos que os tratamentos com AβO levam uma diminuição nos níveis da proteína sináptica sinaptofisina (Syp), devido a um aumento da degradação..

Alzheimer's disease (AD) is a progressive dementia mainly characterized by synaptic dysfunction and neurodegeneration in specific areas of the brain, leading to severe memory loss, and others cognitive inabilities. One of the main neuropathological characteristics is the formation of extracellular amyloid plaques, which mainly contain beta-amyloid peptide (Aβ). This peptide is formed by an alteration in the processing of the amyloid precursor protein (APP). The Aβ oligomers (AβO) are considered the major toxic components within this process where they bind to synapses and are closely related to the pathogenesis of the AD. Recently, it was reported that PrPC is a receptor for AβO, however, the mechanisms involved in this interaction and how this may be related to AD have not yet been elucidated. The cellular prion protein (PrPC) is a glycoprotein anchored to the plasma membrane that interacts with several ligands such as the co-chaperone STI1 (Stress inducible protein 1) and the extracellular matrix protein laminin. These interactions induce neuroprotection, neuritogenesis, and modulate memory formation. Therefore, it becomes interesting to verify a possible neuroprotective effect of PrPC ligands against the toxicity induced by AβO. We observed that the treatment of neuronal cultures with AβO lead to a decrease in the levels of synaptic protein synaptophysin (Syp) due to an increase of Syp degradation by the proteasome...

Epidermal growth factor (EGF) promotes the in vitro differentiation of neural crest cells to neurons and melanocytes.

Proliferation of neural crest (NC) stem cells and their subsequent differentiation into different neural cell types are key early events in the development of the peripheral nervous system. Soluble growth factors present at the sites where NC cells migrate are critical to the development of NC derivatives in each part of the body. In the present study, we further investigate the effect of microenvironmental factors on quail trunk NC development. We show for the first time that EGF induces differentiation of NC to the neuronal and melanocytic phenotypes, while fibroblast growth factor 2 (FGF2) promotes NC differentiation to Schwann cells. In the presence of both EGF and FGF2, the neuronal differentiation predominates. Our results suggest that FGF2 stimulates gliogenesis, while EGF promotes melanogenesis and neurogenesis. The combination of both growth factors stimulates neurogenesis. These findings suggest that these two growth factors may play an important role in the fate decision of NC progenitors and in the development of the peripheral nervous system.