Concise Review: Cellular Therapies: The Potential to Regenerate and Restore Tolerance in Immune-Mediated Intestinal Diseases

Engineering and loading therapeutic extracellular vesicles for clinical translation: A data reporting frame for comparability

Extracellular vesicles (EVs) have emerged as new drug delivery systems as well as a regenerative cell-free effectors going beyond academic research to reach industrial research and development (R&D). Many proof-of-concept studies are now published describing the delivery of drugs, nanoparticles or biologics among which nucleic acids, proteins, viruses, etc. Their main interests rely on their intrinsic biocompatibility, targeting capabilities and biological activities. The possibility of loading EVs with exogenous therapeutic drug/nanoparticles or imaging tracers opens up the perspectives to extend EV therapeutic properties and enable EV tracking. Clinical translation is still hampered by the difficulty to produce and load EVs with large scale, efficient and cGMP methods. In this review, we critically discuss important notions related to EV engineering and the methods available with a particular focus on technologies fitted for clinical translation. Besides, we provide a tentative data reporting frame in order to support comparability and standardization in the field.

Rapid Magneto-Sonoporation of Adipose-Derived Cells

By permeabilizing the cell membrane with ultrasound and facilitating the uptake of iron oxide nanoparticles, the magneto-sonoporation (MSP) technique can be used to instantaneously label transplantable cells (like stem cells) to be visualized via magnetic resonance imaging in vivo. However, the effects of MSP on cells are still largely unexplored. Here, we applied MSP to the widely applicable adipose-derived stem cells (ASCs) for the first time and investigated its effects on the biology of those cells. Upon optimization, MSP allowed us to achieve a consistent nanoparticle uptake (in the range of 10 pg/cell) and a complete membrane resealing in few minutes. Surprisingly, this treatment altered the metabolic activity of cells and induced their differentiation towards an osteoblastic profile, as demonstrated by an increased expression of osteogenic genes and morphological changes. Histological evidence of osteogenic tissue development was collected also in 3D hydrogel constructs. These results point to a novel role of MSP in remote biophysical stimulation of cells with focus application in bone tissue repair.

Refractory Celiac Disease Type II: A Case Report and Literature Review

We present an unusual case of 68-year-old male, who presented with acute abdomen, ulcerative jejunitis with perforation, and 2 months later with perforation of the sigmoid colon. We will also discuss difficulties in the delay in diagnosis of refractory celiac disease (RCD), specifically the atypical presentation, multiple surgeries, the consecutive failure of distinct therapeutic options, and multiple complications that occurred within the 3 months since first presentation.

Systematic review with meta-analysis: Safety and efficacy of local injections of mesenchymal stem cells in perianal fistulas

Perianal fistulas in Crohn's disease (CD) represent a highly debilitating and difficult‐to‐treat condition. Given emerging supportive evidence, we conducted a systematic review and meta‐analysis of all trials/observational studies to establish the safety and efficacy of local injections of mesenchymal stem cells (MSCs). The PRISMA‐P statement was applied for planning and reporting, and MEDLINE, EMBASE, Web of Science, Cochrane, CINAHL, ClinicalTrials.gov database, and ECCO 2017 proceedings were searched for published observational studies and one‐arm and randomized clinical trials (RCTs). Safety was assessed in terms of acute local/systemic events, long‐term events, and relatedness with MSC treatment. Efficacy was evaluated in terms of external and/or radiological closure of fistula tracks. After a review of 211 citations, 23 studies, including 696 participants, were evaluated. Four were RCTs with a total of 483 patients. Overall, fistula closure occurred in 80% of MSC‐treated patients. In RCTs, this rate was 64% in the MSC arm and 37% in the control arm (relative risk (RR) = 1.54). Radiological response occurred in 83% of MSC‐treated patients. Treatment‐related adverse events occurred in 1% of MSC‐treated patients, with severe treatment‐related adverse events reaching 0% over a median follow‐up of 6 months. In RCTs, treatment‐related adverse events occurred in 13% in the MSC arm and 24% in the control arm (RR = 0.65). The relapse rate was 0. These results suggest that a local MSC injection is safe and efficacious. Further clinical trials with standardized end‐points are required to ensure the timely implementation of this new therapy in the management of perianal CD.

Systematic Exposition of Mesenchymal Stem Cell for Inflammatory Bowel Disease and Its Associated Colorectal Cancer

Mesenchymal stem cells (MSCs) therapy has been applied to a wide range of diseases with excessive immune response, including inflammatory bowel disease (IBD), owing to its powerful immunosuppression and its ability to repair tissue lesions. Different sources of MSCs show different therapeutic properties. Engineering managements are able to enhance the immunomodulation function and the survival of MSCs involved in IBD. The therapeutic mechanism of MSCs in IBD mainly focuses on cell-to-cell contact and paracrine actions. One of the promising therapeutic options for IBD can focus on exosomes of MSCs. MSCs hold promise for the treatment of IBD-associated colorectal cancer because of their tumor-homing function and chronic inflammation inhibition. Encouraging results have been obtained from clinical trials in IBD and potential challenges caused by MSCs therapy are getting solved. This review can assist investigators better to understand the research progress for enhancing the efficacy of MSCs therapy involved in IBD and CAC.

Endoscopic Transplantation of Mesenchymal Stem Cell Sheets in Experimental Colitis in Rats

Owing to the recent progress in regenerative medicine technology, clinical trials that harnessed the regeneration and immune modulation potentiality of stem cells for treating IBD have shown promising results. We investigated the feasibility and utility of intraluminal endoscopic transplantation of rat MSC sheets in murine models of experimental colitis for targeted delivery of stem cells to lesions. We isolated adipose-derived mesenchymal stem cells (AD-MSC) and bone marrow-derived mesenchymal stem cells (BM-MSC) from EGFP-transgenic rats and fabricated the cells in sheet forms using temperature-responsive culture dishes. The MSC sheets were endoscopically transplanted to the inflamed area in electrocoagulation and DNBS colitis model. The effect of the transplantation was verified using endoscopic scoring and histological analysis. In the electrocoagulation model, the AD-MSC group showed significantly decreased ulcer size in the transplanted regions. In the DNBS colitis model, the AD-MSC group showed decreased inflammation and colitis in the transplanted regions. Histologic analysis showed that the MSC sheets had successfully attached to the inflamed mucosa in both the electrocoagulation and DNBS colitis model. Our results show that endoscopic transplantation of MSC sheets could be a new effective mode of stem cell therapy for IBD treatment.

Above the Epitranscriptome: RNA Modifications and Stem Cell Identity

Sequence databases and transcriptome-wide mapping have revealed different reversible and dynamic chemical modifications of the nitrogen bases of RNA molecules. Modifications occur in coding RNAs and noncoding-RNAs post-transcriptionally and they can influence the RNA structure, metabolism, and function. The result is the expansion of the variety of the transcriptome. In fact, depending on the type of modification, RNA molecules enter into a specific program exerting the role of the player or/and the target in biological and pathological processes. Many research groups are exploring the role of RNA modifications (alias epitranscriptome) in cell proliferation, survival, and in more specialized activities. More recently, the role of RNA modifications has been also explored in stem cell biology. Our understanding in this context is still in its infancy. Available evidence addresses the role of RNA modifications in self-renewal, commitment, and differentiation processes of stem cells. In this review, we will focus on five epitranscriptomic marks: N6-methyladenosine, N1-methyladenosine, 5-methylcytosine, Pseudouridine (Ψ) and Adenosine-to-Inosine editing. We will provide insights into the function and the distribution of these chemical modifications in coding RNAs and noncoding-RNAs. Mainly, we will emphasize the role of epitranscriptomic mechanisms in the biology of naïve, primed, embryonic, adult, and cancer stem cells.

Mesenchymal Stem Cells to Treat Crohn's Disease with Fistula

Crohn's disease, which mainly affects the gastrointestinal tract, is a refractory inflammatory disease that has clinical manifestations of abdominal pain, fever, bowel obstruction, and diarrhea with blood or mucus. Together, these symptoms can severely impair a patient's quality of life. Besides the common complication of intestinal obstruction, fistulas, particularly anorectal fistulas, are common in Crohn's disease patients. Since radical surgical cures can be difficult to achieve and relapse is common, Crohn's disease patients often seek other effective treatments in addition to surgery. Stem-cell therapies have recently been proposed as a method to address the challenges and prospective medical needs of Crohn's disease patients in general and those with fistulas. Several studies suggest that mesenchymal stem cells (MSCs) could improve Crohn's disease and Crohn's fistula. Moreover, studies concerning MSC transplantation or local rejection of stem cells derived from bone marrow or adipose tissue-derived stem cells have assessed stem cell-based treatments for refractory Crohn's disease. Many patients in these studies are now in remission. A number of clinical trials for refractory Crohn's disease have also evaluated transplantation of autologous or allogenic MSCs and showed that MSCs can be safely administered to Crohn's disease patients, with some achieving positive clinical responses.

[Mesenchymal stem/stroma cells : Therapeutic potential in the treatment of autoimmune diseases]

Mesenchymal stem and stromal cells (MSC) are propagated for the treatment of autoimmune and autoinflammatory processes. These cells can be relatively easily obtained from various tissues. The MSC feature anti-inflammatory and immunosuppressive properties in vitro as well as in animal models. Initial reports on the clinical application of MSC for various diseases are available, some with promising results and so far no reported toxicity; however, data from phase III studies are still lacking and crucial questions are still unanswered. The MSC preparations used are heterogeneous and also differ depending on the source and it is unclear whether autologous (own) or allogeneic (foreign) MSC are more suitable for therapeutic use. Long-term consequences, such as possible malignant transformation and possible endogenous tumor growth stimulation cannot be completely excluded. Ultimately, these questions can only be answered through randomized controlled trials for defined clinical indications with defined MSC.

Mesenchymal stromal cell-based therapy: Regulatory and translational aspects in gastroenterology

The past decade has witnessed an outstanding scientific production focused towards the possible clinical applications of mesenchymal stromal cells (MSCs) in autoimmune and chronic inflammatory diseases. This raised the need of novel standards to adequately address quality, efficacy and safety issues of this advanced therapy. The development of a streamlined regulation is currently hampered by the complexity of analyzing dynamic biological entities rather than chemicals. Although numerous pieces of evidence show efficacy in reducing intestinal inflammation, some inconsistencies between the mechanisms of action of rodent vs human MSCs suggest caution before assigning translational value to preclinical studies. Preliminary evidence from clinical trials showed efficacy of MSCs in the treatment of fistulizing Crohn's disease (CD), and preparations of heterologous MSCs for CD treatment are currently tested in ongoing clinical trials. However, safety issues, especially in long-term treatment, still require solid clinical data. In this regard, standardized guidelines for appropriate dosing and methods of infusion could enhance the likelihood to predict more accurately the number of responders and the duration of remission periods. In addition, elucidating MSC mechanisms of action could lead to novel and more reliable formulations such as those derived from the MSCs themselves (e.g., supernatants).