Impairment of Tissue-Resident Mesenchymal Stem Cells in Chronic Ulcerative Colitis and Crohn's Disease

Comparison of the value of adipose tissues in abdomen and lumbar vertebra for predicting disease activity in Crohn's disease: A preliminary study based on CSE-MRI

BACKGROUND

To compare the value of adipose tissues in abdomen and lumbar vertebra for predicting Crohn's disease (CD) activity based on chemical shift encoded magnetic resonance imaging (CSE-MRI).

METHODS

84 CD patients were divided into remission, mild, and moderate-severely groups based on CD activity index (CDAI). Differences in different adipose parameters [subcutaneous adipose tissue (SAT), visceral adipose tissue (VAT), mesenteric fat index (MFI), and bone marrow fat fraction (BMFF)] and blood inflammatory indicators among three groups, as well as the correlation of above parameters and CDAI were analyzed. The areas under the receiver-operating characteristic curves (AUCs) for the parameters selected by multivariate logistic regression analysis for predicting active CD were calculated.

RESULTS

There were no significant differences in VAT and MFI among three groups (both P > 0.05). The cross-sectional areas of SAT in moderate-severe group were significantly lower than those in remission group (P = 0.014). BMFF values of remission group were significantly higher than those in the mild and moderate-severe groups (both P < 0.001). BMFF was negatively correlated with CDAI (r = -0.595, P < 0.001). SAT exhibited no significant correlation with CDAI. Erythrocyte sedimentation rate (ESR) and BMFF were the independent predictors of CDAI. Both combined had a higher diagnostic efficacy for active CD with an AUC of 0.895.

CONCLUSIONS

BMFF is the best marker for predicting CD activity in fat parameters of abdomen and lumbar vertebra based on CSE-MRI. The model based on BMFF and ESR has a high efficiency in predicting active CD.

TRIAL REGISTRATION

No. 22 K164 (Registered 18-07-2022).

Increased Activity of MAPKAPK2 within Mesenchymal Cells as a Target for Inflammation-Associated Fibrosis in Crohn's Disease

BACKGROUND

Mesenchymal stromal cells are suggested to play a critical role in Crohn's disease [CD]-associated fibrosis. MAPKAPK2 [MK2] has emerged as a potential therapeutic target to reduce inflammation in CD. However, the cell-specific pattern of phospho-MK2 activation and its role in CD-associated fibrosis are unknown. The objectives of this study were to evaluate cell-specific changes in MK2 activity between predominantly inflammatory CD vs CD with fibrotic complications and define the role of stromal cell-specific MK2 activation in CD-associated fibrosis.

METHODS

CD tissue, CD tissue-derived mesenchymal stromal cells known as myo-/fibroblasts [CD-MFs], and fibroblast-specific MK2 conditional knockout [KO] mice were used.

RESULTS

In the inflamed area of predominantly inflammatory CD, high MK2 activity was equally distributed between mesenchymal and haematopoietic cells. By contrast, in CD with fibrotic complications, high MK2 activity was mostly associated with mesenchymal stromal cells. Using ex vivo CD tissue explants and an IL-10KO murine colitis model, we demonstrated that pro-fibrotic responses are significantly reduced by treatment with the MK2 inhibitor PF-3644022. Inhibition of MK2 activity in primary cultures of CD-MFs significantly reduced basal and TGF-β1-induced profibrotic responses. Using fibroblast-specific MK2 knockout mice in chronic dextran saline sulphate colitis, we demonstrated that fibroblast intrinsic MK2 signalling is among the key processes involved in the chronic inflammation-induced profibrotic responses.

CONCLUSIONS

Our data suggest that activation of MK2 within fibroblasts contributes to the chronic inflammation-induced fibrosis in CD and that targeting MK2 has potential for the development of novel therapeutic approaches for fibrosis in CD.

Advancements in hydrogel-based drug delivery systems for the treatment of inflammatory bowel disease: a review

Inflammatory bowel disease (IBD) is a chronic disorder that affects millions of individuals worldwide. However, current drug therapies for IBD are plagued by significant side effects, low efficacy, and poor patient compliance. Consequently, there is an urgent need for novel therapeutic approaches to alleviate IBD. Hydrogels, three-dimensional networks of hydrophilic polymers with the ability to swell and retain water, have emerged as promising materials for drug delivery in the treatment of IBD due to their biocompatibility, tunability, and responsiveness to various stimuli. In this review, we summarize recent advancements in hydrogel-based drug delivery systems for the treatment of IBD. We first identify three pathophysiological alterations that need to be addressed in the current treatment of IBD: damage to the intestinal mucosal barrier, dysbiosis of intestinal flora, and activation of inflammatory signaling pathways leading to disequilibrium within the intestines. Subsequently, we discuss in depth the processes required to prepare hydrogel drug delivery systems, from the selection of hydrogel materials, types of drugs to be loaded, methods of drug loading and drug release mechanisms to key points in the preparation of hydrogel drug delivery systems. Additionally, we highlight the progress and impact of the hydrogel-based drug delivery system in IBD treatment through regulation of physical barrier immune responses, promotion of mucosal repair, and improvement of gut microbiota. In conclusion, we analyze the challenges of hydrogel-based drug delivery systems in clinical applications for IBD treatment, and propose potential solutions from our perspective.

Stromal Cell Regulation of Intestinal Inflammatory Fibrosis

Intestinal inflammatory fibrosis is a severe consequence of inflammatory bowel diseases (IBDs). There is currently no cure for the treatment of intestinal fibrosis in IBD. Although inflammation is necessary for triggering fibrosis, the anti-inflammatory agents used to treat IBD are ineffective in preventing the progression of intestinal fibrosis and stricture formation once initiated, suggesting that inflammatory signals are not the sole drivers of fibrosis progression once it is established. Among multiple mechanisms involved in the initiation and progression of intestinal fibrosis in IBD, stromal cells play critical roles in mediating the process. In this review, we summarize recent progress on how stromal cells regulate intestinal fibrosis in IBD and how they are regulated by focusing on immune regulation and gut microbiota. We also outline the challenges moving forward in the field.

Biomarkers prediction and immune landscape in ulcerative colitis: Findings based on bioinformatics and machine learning

BACKGROUND

Ulcerative colitis (UC) presents diagnostic and therapeutic difficulties. The primary objective of this study is to identify efficacious biomarkers for diagnosis and treatment, as well as acquire a deeper understanding of the immuneological characteristics associated with the disease.

METHODS

Datasets relating to UC were obtained from GEO database. Among these, three datasets were merged to create a metadata for bioinformatics analysis and machine learning. Additionally, one dataset specifically utilized for external validation. Least absolute shrinkage and selection operator (LASSO) and random forest (RF) were employed to screen signature genes. The artificial neural network (ANN) model and receiver operating characteristic (ROC) curve were used to assess the diagnostic performance of signature genes. The single sample gene set enrichment analysis (ssGSEA) was applied to reveal the immune landscape. Finally, the relationship between the signature genes, immune infiltration, and clinical characteristics was investigated through correlation analysis.

RESULT

By intersecting the result of LASSO, RF and WGCNA, 8 signature genes were identified, including S100A8, IL-1B, CXCL1, TCN1, MMP10, GREM1, DUOX2 and SLC6A14. The biological progress of this gene mostly encompasses acute inflammatory response, aggregation and chemotaxis of leukocyte, and response to lipopolysaccharide by mediating IL-17 signaling pathway, NF-kappa B signaling pathway, TNF signaling pathway, NOD-like receptor signaling pathway. Immune infiltration analysis shows 25 immune cells are significantly elevated in UC samples. Moreover, these signature genes exhibit a strong correlation with various immune cells and a mild to moderate correlation with the Mayo score.

CONCLUSION

S100A8, IL-1B, CXCL1, TCN1, MMP10, GREM1, DUOX2 and SLC6A14 have been identified as credible potential biomarkers for the diagnosis and therapy of UC. The immune response mediated by these signature biomarkers plays a crucial role in the occurrence and advancement of UC by means of the reciprocal interaction between the signature biomarkers and immune-infiltrated cells.

Effects of mesenchymal stem cells on Treg cells in rats with colitis

The aim was to investigate the therapeutic effect of bone marrow mesenchymal stem cells (BM-MSC) on dextran sulfate sodium (DSS) induced colitis in rats and its effect on regulatory T cells (Treg). A model of DSS-induced colitis was established. BM-MSC was isolated and cultured to observe the efficacy of BM-MSC on colitis, including general vital signs, weight changes, colonic length changes, colonic histopathological changes, and colonic tissue MPO activity. The expression of inflammatory factors (IFN-γ, IL-4, IL-17, TGF-β) in colonic tissues was measured by real-time PCR. The amount of CD4 + CD25 + Treg was detected by flow cytometry. Real-time PCR was used to detect Foxp3+mRNA in CD4 + CD25 + Treg, western to detect Foxp3+protein expression in CD4 + CD25 + Treg, and ELISA was used to detect IL-35 and IL-10 cytokines in CD4 + CD25 + Treg culture supernatant. Results show that intravenous injection of BM-MSC significantly improved the clinical manifestations and histopathological changes in rats with experimental DSS colitis; significantly down-regulated the expression of inflammatory factors IFN-γ, IL-4, and IL-17 and up-regulated the expression of TGF-β in colon tissues; BM-MSC also increased the number of CD4+CD25+Foxp3+Treg and enhanced the function of CD4+CD25+Foxp3+Treg in colon tissues, and up-regulated the expression of IL-35. In conclusion, BM-MSC has a certain therapeutic effect on DSS-induced colitis. It can improve the general signs of colitis rats and reduce intestinal injury and inflammatory response. The immunoregulatory effect of BM-MSC is achieved by enhancing the function of CD4+CD25+Foxp3+Treg and up-regulating the secretion of immunosuppressive inflammatory factors.

Cellular microenvironment: a key for tuning mesenchymal stem cell senescence

Mesenchymal stem cells (MSCs) possess the ability to self-renew and differentiate into multiple cell types, making them highly suitable for use as seed cells in tissue engineering. These can be derived from various sources and have been found to play crucial roles in several physiological processes, such as tissue repair, immune regulation, and intercellular communication. However, the limited capacity for cell proliferation and the secretion of senescence-associated secreted phenotypes (SASPs) pose challenges for the clinical application of MSCs. In this review, we provide a comprehensive summary of the senescence characteristics of MSCs and examine the different features of cellular microenvironments studied thus far. Additionally, we discuss the mechanisms by which cellular microenvironments regulate the senescence process of MSCs, offering insights into preserving their functionality and enhancing their effectiveness.

Therapeutic effects and potential mechanisms of endoscopic submucosal injection of mesenchymal stem cells on chronic atrophic gastritis

Previous studies have demonstrated the rejuvenating and restorative actions of mesenchymal stem cells (MSCs) in multiple diseases, but their role in reversing chronic atrophic gastritis (CAG) is not well understood owing to their low efficiency in homing to the stomach. In this work, we investigated the therapeutic effect of umbilical cord-derived MSCs (UC-MSCs) on CAG by endoscopic submucosal injection and preliminarily explored possible mechanisms in vitro. MSCs and normal saline (NS) were injected into the submucosa of the stomach in randomly grouped CAG rabbits. Therapeutic effects on serum indices and histopathology of the gastric mucosa were analyzed in vivo at 30 and 60 days after MSCs injection. GES-1 cells were co-cultured with MSCs in vitro using a Transwell system and cell viability, proliferation, and migration ability were detected. Additionally, in view of the potential mechanisms, the relative protein expression levels of apoptosis, autophagy and inflammation in vitro were explored by Western Blotting. We found that submucosal injection of MSCs up-regulated serum indices (G-17, PGI and PGI/PGII) and alleviated histopathological damage to the gastric mucosa in CAG rabbits. Co-culture of GES-1 cells with MSCs improved cell viability, proliferation, and migration ability, while suppressing apoptosis. We also observed a reduction in the expression of apoptosis indicators, including Bax and cleaved caspase-3, in GES-1 cells after co-culture with MSCs in vitro. Our findings suggest that submucosal injection of MSCs is a promising approach for reversing CAG, and attenuating apoptosis plays a potential role in this process.

Creating a Surgical Biobank: The Hershey Medical Center Experience

BACKGROUND

Tissue harvesting at the time of surgery offers surgeons and scientists a unique opportunity to discover and better understand disease pathophysiology. Tissue biobanking presents challenges in patient consents, specimen collection, preparation, and storage, but the potential for scientific discovery justifies the effort. Although the number of tissue biobanks is increasing worldwide, information regarding necessary infrastructure, process flow, and management of expected obstacles is lacking.

OBJECTIVE

To provide a framework and motivation for clinician scientists intending to start an intestinal tissue biobank under their direction.

DATA SOURCES

The Carlino Family Inflammatory Bowel and Colorectal Diseases Biobank is housed at the Milton S. Hershey Medical Center.

STUDY SELECTION

Review.

INTERVENTION

Implementation of a surgical tissue biobank at a large tertiary care institution.

MAIN OUTCOME MEASURES

Assess critical challenges and obstacles over the years as well as keys to the success of the program.

RESULTS

Over 2 decades, the institutional biobank grew from an IBD biobank to one which now incorporates thousands of surgical specimens representing numerous colorectal diseases. This was done through a process of refinement focusing on patient recruitment and an efficient consenting and specimen management process. The biobank's success is further insured by institutional, external, and philanthropic support; scientific collaborations; and sharing of biological specimens with other groups of dedicated researchers.

LIMITATIONS

This is a single-center experience in collecting surgically resected colorectal specimens.

CONCLUSIONS

Surgical specimen biobanks are essential in studying disease cause using genomics, transcriptomics, and proteomic technologies. Therefore, surgeons, clinicians, and scientists should build biobanks at their institutions to promote further scientific discovery and improve specimen diversity.

Short-Term Clinical Response and Changes in the Fecal Microbiota and Metabolite Levels in Patients with Crohn's Disease After Stem Cell Infusions

Recent studies have shown a close relationship between the gut microbiota and Crohn's disease (CD). This study aimed to determine whether mesenchymal stem cell (MSC) treatment alters the gut microbiota and fecal metabolite pathways and to establish the relationship between the gut microbiota and fecal metabolites. Patients with refractory CD were enrolled and received 8 intravenous infusions of MSCs at a dose of 1.0 × 106 cells/kg. The MSC efficacy and safety were evaluated. Fecal samples were collected, and their microbiomes were analyzed by 16S rDNA sequencing. The fecal metabolites at baseline and after 4 and 8 MSC infusions were identified by liquid chromatography-mass spectrometry (LC--MS). A bioinformatics analysis was conducted using the sequencing data. No serious adverse effects were observed. The clinical symptoms and signs of patients with CD were substantially relieved after 8 MSC infusions, as revealed by changes in weight, the CD activity index (CDAI) score, C-reactive protein (CRP) level, and erythrocyte sedimentation rate (ESR). Endoscopic improvement was observed in 2 patients. A comparison of the gut microbiome after 8 MSC treatments with that at baseline showed that the genus Cetobacterium was significantly enriched. Linoleic acid was depleted after 8 MSC treatments. A possible link between the altered Cetobacterium abundance and linoleic acid metabolite levels was observed in patients with CD who received MSCs. This study enabled an understanding of both the gut microbiota response and bacterial metabolites to obtain more information about host-gut microbiota metabolic interactions in the short-term response to MSC treatment.

Recent developments on BMPs and their antagonists in inflammatory bowel diseases

Inflammatory bowel diseases (IBDs), including ulcerative colitis, and Crohn's disease, are intestinal disorders characterized by chronic relapsing inflammation. A large proportion of patients with IBD will progress to develop colitis-associated colorectal cancer due to the chronic intestinal inflammation. Biologic agents that target tumour necrosis factor-α, integrin α4β7, and interleukin (IL)12/23p40 have been more successful than conventional therapies in treating IBD. However, drug intolerance and loss of response are serious drawbacks of current biologics, necessitating the development of novel drugs that target specific pathways in IBD pathogenesis. One promising group of candidate molecules are bone morphogenetic proteins (BMPs), members of the TGF-β family involved in regulating morphogenesis, homeostasis, stemness, and inflammatory responses in the gastrointestinal tract. Also worth examining are BMP antagonists, major regulators of these proteins. Evidence has shown that BMPs (especially BMP4/6/7) and BMP antagonists (especially Gremlin1 and follistatin-like protein 1) play essential roles in IBD pathogenesis. In this review, we provide an updated overview on the involvement of BMPs and BMP antagonists in IBD pathogenesis and in regulating the fate of intestinal stem cells. We also described the expression patterns of BMPs and BMP antagonists along the intestinal crypt-villus axis. Lastly, we synthesized available research on negative regulators of BMP signalling. This review summarizes recent developments on BMPs and BMP antagonists in IBD pathogenesis, which provides novel insights into future therapeutic strategies.

Stem Cell Therapy in Inflammatory Bowel Disease: A Review of Achievements and Challenges

Inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), is a group of chronic inflammatory diseases of the gastrointestinal tract. Repeated inflammation can lead to complications, such as intestinal fistula, obstruction, perforation, and bleeding. Unfortunately, achieving durable remission and mucosal healing (MH) with current treatments is difficult. Stem cells (SCs) have the potential to modulate immunity, suppress inflammation, and have anti-apoptotic and pro-angiogenic effects, making them an ideal therapeutic strategy to target chronic inflammation and intestinal damage in IBD. In recent years, hematopoietic stem cells (HSCs) and adult mesenchymal stem cells (MSCs) have shown efficacy in treating IBD. In addition, numerous clinical trials have evaluated the efficiency of MSCs in treating the disease. This review summarizes the current research progress on the safety and efficacy of SC-based therapy for IBD in both preclinical models and clinical trials. We discuss potential mechanisms of SC therapy, including tissue repair, paracrine effects, and the promotion of angiogenesis, immune regulation, and anti-inflammatory effects. We also summarize current SC engineering strategies aimed at enhancing the immunosuppressive and regenerative capabilities of SCs for treating intestinal diseases. Additionally, we highlight current limitations and future perspectives of SC-related therapy for IBD.

Characterization of Intestinal Mesenchymal Stromal Cells From Patients With Inflammatory Bowel Disease for Autologous Cell Therapy

Therapy with mesenchymal stromal cells (MSCs) has shown promise in inflammatory bowel disease-leveraging their immunosuppressive and regenerative properties. However, the potential immunogenic complications of allogenic MSCs sourced from different tissues raise concern. Thus, we assessed the fitness and functionality of autologous intestinal MSCs as a potential platform for cellular therapy. Mucosal biopsy-derived MSCs from Crohn's disease (n = 11), ulcerative colitis (n = 12), and controls (n = 14) were analyzed by microscopy and flow cytometry for doubling-time, morphology, differentiation potential, and immunophenotype. Gene expression, cell-subtype composition, along with surface marker and secretome changes after IFN-γ priming were measured by bulk and single-cell RNA sequencing coupled with a 30-plex Luminex panel. MSCs expanded ex vivo demonstrate canonical MSC markers, similar growth kinetics, and tripotency regardless of the patient phenotype. Global transcription patterns were similar at baseline though inflammatory bowel disease (IBD) rectal MSCs showed changes in select immunomodulatory genes. IFN-γ priming resulted in upregulation of shared immunoregulatory genes (particularly in PD-1 signaling) and overrode the transcriptional differences observed at baseline. Furthermore, MSCs secrete key immunomodulatory molecules at baseline and in response to IFN-γ including CXCL10, CXCL9, and MCP-1. Overall, MSCs from IBD patients have normal transcriptional and immunomodulatory properties with therapeutic potential and can be sufficiently expanded.

Essential immune functions of fibroblasts in innate host defense

The term fibroblast has been used generally to describe spindle-shaped stromal cells of mesenchymal origin that produce extracellular matrix, establish tissue structure, and form scar. Current evidence has found that cells with this morphology are highly heterogeneous with some fibroblastic cells actively participating in both innate and adaptive immune defense. Detailed analysis of barrier tissues such as skin, gut, and lung now show that some fibroblasts directly sense pathogens and other danger signals to elicit host defense functions including antimicrobial activity, leukocyte recruitment, and production of cytokines and lipid mediators relevant to inflammation and immunosuppression. This review will synthesize current literature focused on the innate immune functions performed by fibroblasts at barrier tissues to highlight the previously unappreciated importance of these cells in immunity.

The Therapeutic Efficacy of Adipose Tissue-Derived Mesenchymal Stem Cell Conditioned Medium on Experimental Colitis Was Improved by the Serum From Colitis Rats

Adipose derived mesenchymal stem cells (AD-MSCs) have shown therapeutic potential in treatments of inflammatory bowel disease (IBD). Due to the harsh host environment and poor survival of the cells, controversy concerning the homing, proliferation and differentiation of MSCs in lesion tissue still remains. It has been reported that conditioned media from MSCs could improve the colitis, whereas the therapeutic efficiency could be significantly elevated by the stimulation of pro-cytokines. In this study, we pre-treated the adipose derived MSCs with the serum from colitis rats and then the activated conditioned media (CM-AcMSC) were collected. To compare the therapeutic effects of CM-MSC and CM-AcMSC on IBD, we constructed dextran sodium sulphate (DSS)-induced colitis rat models. The colitis was induced in rats by administrating 5% DSS in drinking water for 10 days, and the disease symptoms were recorded daily. The colon histopathological changes were observed by different staining methods (H&E and PAS). The expression levels of MUC2 and tight junctions (TJs) were determined by RT-qPCR. The levels of inflammatory cytokines were analyzed by ELISA and western blot analysis. Our findings suggested that CM-AcMSC was more effective in ameliorating the clinical features and histological damage scores. Treatment with CM-AcMSC significantly increased the expression of MUC2 and TJs and suppressed the production of pro-inflammatory cytokines in colonic tissues of colitis rats. The inhibitory effects of CM-AcMSC on inflammatory responses of colitis rats were mediated by NF-κB signaling pathway. These results suggested that pre-activation of MSCs with serum from colitis rats could promote the production of paracrine factors and improve the therapeutic effects of conditioned medium on colitis rats.

Wogonin Strengthens the Therapeutic Effects of Mesenchymal Stem Cells in DSS-Induced Colitis via Promoting IL-10 Production

Inflammatory bowel diseases (IBD) are prevalent and debilitating diseases; their clinical remedy is desperately unmet. Mesenchymal stem cells (MSCs) are pluripotent stem cells with multiple immunomodulatory effects, which are attributed to their efficacy in the IBD rodent model. Optimization of MSC regimes in IBD is a crucial step for their further clinical application. Wogonin is a flavonoid-like compound, which showed extensive immunomodulatory and adjuvant effects. This research is aimed at investigating whether and how Wogonin boosted the therapeutic efficiency of MSCs on DSS-induced colitis. Our results showed that the MSC treatment with Wogonin significantly alleviated the intestinal inflammation in IBD mice by increased IL-10 expression. In vitro experiments, Wogonin obviously raised the IL-10 production and ROS levels of MSCs in a dose-dependent manner. Meanwhile, western blot data suggested Wogonin improves the IL-10 production by inducing transcript factor HIF-1α expression via AKT/GSK3β signal pathway. Finally, the favorable effects of Wogonin on MSCs were confirmed by IL-10 blockade experiment in vivo. Together, our results suggested that Wogonin significantly increased the IL-10 production and enhanced the therapeutic effects of MSCs in DSS-induced colitis. This work suggested Wogonin as a novel optimal strategy for MSC clinical application.