Treatment of experimental esophagogastric myotomy with bone marrow mesenchymal stem cells in a rat model

Docking Proteins Upregulate IL-1β Expression in Lower Esophageal Sphincter Muscle in Esophageal Achalasia

Background/Objectives: Esophageal achalasia is an archetypal esophageal motility disorder characterized by abnormal peristalsis of the esophageal body and impaired lower esophageal sphincter (LES) relaxation. Methods: In this study, the mRNA expression of docking proteins 1 and 2 (DOK1 and DOK2, respectively) were analyzed and the mechanisms underlying achalasia onset were investigated. Results:DOK1 and DOK2 mRNA levels significantly increased in the LES of patients with achalasia. Moreover, significant correlations were observed between IL-1β and DOK1, IL-1β and DOK2, ATG16L1 and DOK1, and HSV1-miR-H1-3p and DOK2 expression levels. However, a correlation between ATG16L1 and DOK2 or between HSV-miR-H1-3p and DOK1 expression was not observed. In addition, a positive correlation was observed between patient age and DOK1 expression. Microarray analysis revealed a significant decrease in the expression of hsa-miR-377-3p and miR-376a-3p in the LES muscle of patients with achalasia. Conclusions: These miRNAs possessed sequences targeting DOK. The upregulation of DOK1 and DOK2 expression induces IL-1β expression in the LES of achalasia patients, which may contribute to the development of esophageal motility disorder.

Glutamate regulates gliosis of BMSCs to promote ENS regeneration through α-KG and H3K9/H3K27 demethylation

Background

There is a lack of effective therapies for enteric nervous system (ENS) injury. Our previous study showed that transplanted bone marrow-derived mesenchymal stem cells (BMSCs) play a “glia-like cells” role in initiating ENS regeneration in denervated mice. Cellular energy metabolism is an important factor in maintaining the biological characteristics of stem cells. However, how cellular energy metabolism regulates the fate of BMSCs in the ENS-injured microenvironment is unclear.

Methods

The biological characteristics, energy metabolism, and histone methylation levels of BMSCs following ENS injury were determined. Then, glutamate dehydrogenase 1 (Glud1) which catalyzes the oxidative deamination of glutamate to α-KG was overexpressed (OE) in BMSCs. Further, OE-Glud1 BMSCs were targeted–transplanted into the ENS injury site of denervated mice to determine their effects on ENS regeneration.

Results

In vitro, in the ENS-injured high-glutamate microenvironment, the ratio of α-ketoglutarate (α-KG) to succinate (P < 0.05), the histone demethylation level (P < 0.05), the protein expression of glial cell markers (P < 0.05), and the gene expression of Glud1 (P < 0.05) were significantly increased. And the binding of H3K9me3 to the GFAP, S100B, and GDNF promoter was enhanced (P < 0.05). Moreover, α-KG treatment increased the monomethylation and decreased the trimethylation on H3K9 (P < 0.01) and H3K27 (P < 0.05) in BMSCs and significantly upregulated the protein expression of glial cell markers (P < 0.01), which was reversed by the α-KG competitive inhibitor D-2-hydroxyglutarate (P < 0.05). Besides, overexpression of Glud1 in BMSCs exhibited increases in monomethylation and decreases in trimethylation on H3K9 (P < 0.05) and H3K27 (P < 0.05), and upregulated protein expression of glial cell markers (P < 0.01). In vivo, BMSCs overexpressing Glud1 had a strong promotion effect on ENS regeneration in denervated mice through H3K9/H3K27 demethylation (P < 0.05), and upregulating the expression of glial cell protein (P < 0.05).

Conclusions

BMSCs overexpressing Glud1 promote the expression of glial cell markers and ENS remodeling in denervated mice through regulating intracellular α-KG and H3K9/H3K27 demethylation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-022-02936-7.

CD44 fucosylation on bone marrow-derived mesenchymal stem cells enhances homing and promotes enteric nervous system remodeling in diabetic mice

Background

Diabetes can cause extensive enteric nervous system (ENS) injuries and gastrointestinal motility disorder. In developing possible treatments, researchers have engaged in tissue regeneration engineering with the very promising bone marrow-derived mesenchymal stem cells (BMSCs). However, BMSCs have poor homing ability to the targeted tissues after intravenous injection. Thus, we aimed to investigate whether enhancing the expression of E-selectin ligand on BMSCs could improve their homing ability and subsequently influence their role in ENS remodeling in diabetic mice.

Methods

First, we constructed the fucosylation modification of CD44 on BMSCs through a fucosyltransferase VII (FTVII) system to generate a Hematopoietic Cell E-/L-selectin Ligand (HCELL) property, a fucosylated sialyllactosaminyl glycovariant of CD44 that potently binds E-selectin. Next, FTVII-modified and unmodified BMSCs labeled with green fluorescent protein (GFP) were injected into diabetic mice through the tail vein to compare their homing ability to the gastrointestinal tract and their effect on ENS remodeling, respectively. A bioluminescent imaging system was used to evaluate the homing ability of GFP-labeled BMSCs with and without FTVII modification, to the gastrointestinal tract. Gastrointestinal motility was assessed by gastrointestinal transient time, defecation frequency, stool water content and colon strips contractility. Immunofluorescence staining and western blotting were used to assess the expression levels of protein gene product 9.5 (PGP9.5), glial fibrillary acidic protein (GFAP) and glial cell line-derived neurotrophic factor (GDNF).

Results

The FTVII-mediated α(1,3)-fucosylation modification of CD44 on BMSCs generated a HCELL property. Bioluminescent imaging assays showed that FTVII-modified BMSCs had enhanced homing ability to gastrointestinal tract, mainly to the colon, 24 h after injection through the tail vein. Compared with diabetic mice, FTVII-modified BMSCs significantly promoted the gastrointestinal motility and the ENS remodeling, including intestinal peristalsis (P < 0.05), increased feces excretion (P < 0.05) and the water content of the feces (P < 0.05), restored the spontaneous contraction of the colon (P < 0.05), and upregulated the protein expression levels of PGP9.5 (P < 0.01), GFAP (P < 0.001), and GDNF (P < 0.05), while unmodified BMSCs did not (P > 0.05).

Conclusions

CD44 fucosylation modification on murine BMSCs promotes homing ability to the gastrointestinal tract and ENS remodeling in diabetic mice.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13578-021-00632-2.

Imaging of extracellular vesicles derived from human bone marrow mesenchymal stem cells using fluorescent and magnetic labels

Background

Mesenchymal stem cells have been shown therapeutic in various neurological disorders. Recent studies support the notion that the predominant mechanism by which MSCs act is through the release of extracellular vesicles (EVs). EVs seem to have similar therapeutic activity as their cellular counterparts and may represent an interesting alternative standalone therapy for various diseases. The aim of the study was to optimize the method of EV imaging to better understand therapeutic effects mediated by EVs.

Methods

The fluorescent lipophilic stain PKH26 and superparamagnetic iron oxide nanoparticles conjugated with rhodamine (Molday ION Rhodamine B™) were used for the labeling of vesicles in human bone marrow MSCs (hBM-MSCs). The entire cycle from intracellular vesicles to EVs followed by their uptake by hBM-MSCs has been studied. The identity of vesicles has been proven by antibodies against: anti-CD9, -CD63, and -CD81 (tetraspanins). NanoSight particle tracking analysis (NTA), high-resolution flow cytometric analysis, transmission electron microscopy (TEM), ELYRA PS.1 super-resolution microscopy, and magnetic resonance imaging (MRI) were used for the characterization of vesicles.

Results

The PKH26 and Molday ION were exclusively localized in intracellular vesicles positively stained for EV markers: CD9, CD63, and CD81. The isolated EVs represent heterogeneous population of various sizes as confirmed by NTA. The TEM and MRI were capable to show successful labeling of EVs using ION. Co-culture of EVs with hBM-MSCs revealed their uptake by cells in vitro, as visualized by the co-localization of PKH26 or Molday ION with tetraspanins inside hBM-MSCs.

Conclusion

PKH26 and Molday ION seem to be biocompatible with EVs, and the labeling did not interfere with the capability of EVs to re-enter hBM-MSCs during co-culture in vitro. Magnetic properties of IONs provide an additional advantage for the imaging of EV using TEM and MRI.

Local injection of bone marrow progenitor cells for the treatment of anal sphincter injury: in-vitro expanded versus minimally-manipulated cells

Background

Anal incontinence is a disabling condition that adversely affects the quality of life of a large number of patients, mainly with anal sphincter lesions. In a previous experimental work, in-vitro expanded bone marrow (BM)-derived mesenchymal stem cells (MSC) were demonstrated to enhance sphincter healing after injury and primary repair in a rat preclinical model. In the present article we investigated whether unexpanded BM mononuclear cells (MNC) may also be effective.

Methods

Thirty-two rats, divided into groups, underwent sphincterotomy and repair (SR) with primary suture of anal sphincters plus intrasphincteric injection of saline (CTR), or of in-vitro expanded MSC, or of minimally manipulated MNC; moreover, the fourth group underwent sham operation. At day 30, histologic, morphometric, in-vitro contractility, and functional analysis were performed.

Results

Treatment with both MSC and MNC improved muscle regeneration and increased contractile function of anal sphincters after SR compared with CTR (p < 0.05). No significant difference was observed between the two BM stem cell types used. GFP-positive cells (MSC and MNC) remained in the proximity of the lesion site up to 30 days post injection.

Conclusions

In the present study we demonstrated in a preclinical model that minimally manipulated BM-MNC were as effective as in-vitro expanded MSC for the recovery of anal sphincter injury followed by primary sphincter repair. These results may serve as a basis for improving clinical applications of stem cell therapy in human anal incontinence treatment.

Application of mesenchymal stem cells in digestive system diseases

Mesenchymal stem cells (MSCs) have the capacity of multipotent differentiation and the property of immunomodulation. MSCs have been widely used in digestive system disease research because of their advantageous characteristics such as homing to areas of inflammation or tumour tissue, anti-inflammation, high plasticity, absence of immunologic rejection, being easy to be isolated, and being convenient for the expression of exogenous genes. In this article, we will review the application of mesenchymal stem cells in digestive system diseases including caustic esophagus injury, reflux esophagitis, gastric ulcer, radioactive intestinal injury, severe acute pancreatitis, inflammatory bowel disease, nonalcoholic steatohepatitis, acute liver failure, hepatic fibrosis, autoimmune liver diseases, liver cirrhosis, esophageal cancer, gastric cancer, colon cancer, liver cancer, and pancreatic cancer.