Cytokine Profile and Anti-Inflammatory Activity of a Standardized Conditioned Medium Obtained by Coculture of Monocytes and Mesenchymal Stromal Cells (PRS CK STORM).

Intercellular communication between monocytes/macrophages and cells involved in tissue regeneration, such as mesenchymal stromal cells (MSCs) and primary tissue cells, is essential for tissue regeneration and recovery of homeostasis. Typically, in the final phase of the inflammation-resolving process, this intercellular communication drives an anti-inflammatory immunomodulatory response. To obtain a safe and effective treatment to counteract the cytokine storm associated with a disproportionate immune response to severe infections, including that associated with COVID-19, by means of naturally balanced immunomodulation, our group has standardized the production under GMP-like conditions of a secretome by coculture of macrophages and MSCs. To characterize this proteome, we determined the expression of molecules related to cellular immune response and tissue regeneration, as well as its possible toxicity and anti-inflammatory potency. The results show a specific molecular pattern of interaction between the two cell types studied, with an anti-inflammatory and regenerative profile. In addition, the secretome is not toxic by itself on human PBMC or on THP-1 monocytes and prevents lipopolysaccharide (LPS)-induced growth effects on those cell types. Finally, PRS CK STORM prevents LPS-induced TNF-A and IL-1Β secretion from PBMC and from THP-1 cells at the same level as hydrocortisone, demonstrating its anti-inflammatory potency.

Intra-articular infiltration of adipose-derived stromal vascular fraction cells slows the clinical progression of moderate-severe knee osteoarthritis: hypothesis on the regulatory role of intra-articular adipose tissue.

BACKGROUND: The infiltration of the stromal vascular fraction (SVF) of autologous adipose tissue to treat osteoarthritis has been used for several years demonstrating its safety and noticeable efficacy. This article presents clinical data from patients afftected by moderate and severe knee osteoarthritis demonstrating safety and clinical efficacy of the treatment when this autologous cell product is injected in the knee joint and patients evaluated post-operatively after 1 year. However, what do we know about the mechanism that underlies this clinical improvement? This article proposes, for the first time in our opinion, a hypothesis of the mode of action that involves structural and molecular interactions between SVF and infrapatellar fat pad (IFP). As consequence, there would be a re-education of intra-articular adipose tissue, which we consider a key player for the clinical effect observed in the mid and long term mainly due to immuno-regulatory mechanisms. METHODS: This is a retrospective and not controlled study that evaluated 50 patients (100 joints) ranging from 50 to 89 years old, separated by age cohorts. Clinical efficacy was assessed using the Lequesne, WOMAC, and VAS scales, by ultrasound control and quantification of the biochemical profiles of synovial fluid. RESULTS: There were no serious adverse effects. All the indexes studied showed a significant clinical improvement after 1-year follow-up for all ages and OA degree groups. This finding was correlated with the ultrasound observations and biochemical data, which show a marked decrease in catabolic and pro-inflammatory molecules (MMP-2, IL-1B, IL-6, and IL-8) and significant increase for anabolic and anti-inflammatory molecules (IGF-1 and IL-10). CONCLUSIONS: We conclude that intra-articular SVF infiltration for knee OA treatment is safe and effective during 1 year. We propose that applied SVF cells cause a cascade of molecular and structural events that, through complex interactions between IFP and SVF, re-educating the intra-articular fatty tissue towards a homeostatic, protective, and anti-inflammatory function, which will ultimately promote the restructuring and regeneration of damaged tissues.

Adipose-derived stem cells are a source for cell therapy of the corneal stroma.

Most corneal diseases affect corneal stroma and include immune or infectious diseases, ecstatic disorders, traumatic scars, and corneal dystrophies. Cell-based therapy is a promising therapeutic approach to overcome the current disadvantages of corneal transplantation. We intended to search for a cell source to repopulate and regenerate corneal stroma. We investigated the ability of human processed lipoaspirate derived (PLA) cells to regenerate corneal stroma in experimental animals. In the first set of experiments, we tested the biosafety and immunogenicity of human PLA stem cells transplanted into the corneal stroma of rabbits. No immune response was elicited even though we used immune-competent animals. PLA cells survived up to 10 weeks post-transplant, maintained their shape, and remained intermingled in the stroma without disrupting its histological pattern. Interestingly, transparency was preserved even 10 weeks after the transplant, when PLA cells formed a discontinuous layer in the stroma. In the second set of experiments, regeneration of the corneal stroma by PLA cells was assessed, creating a niche by partial ablation of the stroma. After 12 weeks, human cells were disposed following a multilayered pattern and differentiated into functional keratocytes, as assessed by the expression of aldehyde-3-dehydrogenase and cornea-specific proteoglycan keratocan. Based on our results, we believe that adipose-derived adult stem cells can be a cell source for stromal regeneration and repopulation in diseased corneas. The low health impact of the surgical procedure performed to obtain the PLA cells provides this cell source with an additional beneficial feature for its possible future autologous use in human patients.

Adipose-derived mesenchymal stem cells slow disease progression of acute-on-chronic liver failure.

A serious complication of chronic hepatic insufficiency is acute-on-chronic liver failure, a recognized syndrome characterized by acute decompensation of cirrhosis and organ/system failure. We investigated the use of adipose-derived mesenchymal stem cells (AD-MSCs) in an experimental model of acute-on-chronic liver failure, developed by microsurgical extrahepatic cholestasis in rats. Rats undergoing microsurgical extrahepatic cholestasis were treated by intraparenchymal liver injection of human or rat AD-MSCs, undifferentiated or previously differentiated in vitro toward the hepatocyte lineage. The groups treated with rat AD-MSCs showed less ascites, lower hepato- and splenomegaly, less testicular atrophy, and an improvement in serum biochemical hepatic parameters. There was also an improvement in histological liver changes, in which the area of fibrosis and bile duct proliferation were significantly decreased in the group treated with predifferentiated rat AD-MSCs. In conclusion, an isograft of hepatocyte-predifferentiated AD-MSCs injected intraparenchymally 2 weeks after microsurgery in extrahepatic cholestatic rats prevents secondary complications of acute-on-chronic hepatic failure. These data support the potential use of autologous AD-MSCs in the treatment of human cholestasis, and specifically of newborn biliary atresia, which could be beneficial for patients awaiting transplant.

Coupling inflammation with evo-devo.

Inflammation integrates diverse mechanisms that are associated not only with pathological conditions, such as cardiovascular diseases, type 2 diabetes, obesity, neurodegenerative diseases and cancer, but also with physiological processes like reproduction i.e. oogenesis and embryogenesis as well as aging. In the current review we firstly propose that the inflammatory response could recapitulate the phylogenia. In this way, highly conserved inflammatory mechanisms that play a main role in the evolutive development of different animal species, both invertebrates as well as vertebrates, are identified. Therefore, we also hypothesize that inflammation could represent a key tool used by nature to modulate organisms according to the environmental conditions in which these develop. Thus, inflammation could be the pathway by which the environmental factors could be related to the evolutionary development. If so, the diverse human chronic inflammatory diseases that nowadays the Western society suffer would represent the way for adapting to the abrupt changes in their lifestyle. Nonetheless, the distribution of the different pathological conditions varies in terms of intensity and magnitude among Western country populations depending on their genetic polymorphism. In this case, it should be considered that this set of diseases, distributed between all the individuals that constitute the Westernized society, would represent a true Social Inflammatory Syndrome whose final result is its remodeling. In this context, the use of inflammation by the Western society could represent the camouflaged expression of efficient mechanisms of evolution and development. In addition, if the different types of the inflammatory response involved in these diverse chronic pathological conditions could trace the biochemical origins of life, perhaps inflammation could represent an archaeological tool of unsuspected usefulness for understanding our own origin.

Short and long term fate of human AMSC subcutaneously injected in mice.

AIM: To study the ability of human adipose-derived mesenchymal stem cells (AMSCs) to survive over the short and long term, their biodistribution and their biosafety in vivo in tumor-prone environments. METHODS: We subcutaneously injected human AMSCs from different human donors into immunodeficient SCID mice over both short- (2 and 4 mo) and long- (17 mo) term in young, and aged tumor-prone mice. Presence of human cells was studied by immunohistochemistry and polymerase chain reaction analysis in all organs of injected mice. RESULTS: Subcutaneously injected AMSCs did not form teratomas at any time point. They did not migrate but remained at the site of injection regardless of animal age, and did not fuse with host cells in any organ examined. AMSCs survived in vivo for at least 17 mo after injection, and differentiated into fibroblasts of the subdermic connective tissue and into mature adipocytes of fat tissue, exclusively at the site of injection. CONCLUSION: Our results support the assertion that AMSC may be safe candidates for therapy when injected subcutaneously because of their long term inability to form teratomas.

Epiblast-derived stem cells in embryonic and adult tissues.

Pluripotent cells can be isolated from the mammalian inner cell mass (ICM) of the embryo at the blastocyst stage, and maintained in culture as undifferentiated, embryonic stem cells (ES). These cells are an important model of mammalian development in vitro and are the focus of a great deal of research for their use in Cell Therapy. In vivo, shortly after the blastocyst stage, the ICM segregates into two layers: the hypoblast which will give rise to the yolk sac, and the epiblast. Epiblast stem cells, like ES cells, are pluripotent. The epiblast will differentiate very early into germ cell progenitors, the primordial germ cells (PGC). PGCs can give rise to embryonal carcinoma cells, the pluripotent stem cells of testicular tumors. During normal embryo development, PGCs migrate into the aorta-gonad-mesonephros region (AGM). Interestingly, this region also harbors the first wave of embryonic hematopoiesis. Subsequent waves of hematopoiesis involve AGM-hematopoietic stem cell (HSC) colonization of the fetal liver, thymus, spleen and ultimately, for adult hematopoiesis, the bone marrow (BM). The BM is also source of mesenchymal stem cells (MSCs). It is accepted that the AGM region cells give rise to the mesothelial cells which are the embryonic precursors of the HSC and MSC of the BM. Recent identification of a subpopulation of cells with markers typical of PGCs in the adult BM, which are capable of differentiating into HSCs, suggests that HSCs originate from a common precursor of PGCs and HSCs derived from the epiblast. Several groups have described the presence of stem cells with the same markers in epidermis, bronchial epithelium, pancreas, retina, hair follicle, heart and dental pulp among, other organs. This presence supports the hypothesis that during early development, epiblast/germ line-derived cells are deposited in various organs which persist into adulthood. The question remains whether these pluripotent stem cells are only developmental remnants or if they continuously contribute to the renewal of tissues, and thus can be reactivated for tissue regeneration without the need for stem cell transplantation for human cell therapies.