BMSCs Promote Differentiation of Enteric Neural Precursor Cells to Maintain Neuronal Homeostasis in Mice With Enteric Nerve Injury

Circadian rhythm disruption modulates enteric neural precursor cells differentiation leading to gastrointestinal motility dysfunction via the NR1D1/NF-κB axis

OBJECTIVES

Circadian rhythm disruption (CRD) is implicated with numerous gastrointestinal motility diseases, with the enteric nervous system (ENS) taking main responsibility for the coordination of gastrointestinal motility. The purpose of this study is to explore the role of circadian rhythms in ENS remodeling and to further elucidate the underlying mechanisms.

METHODS

First, we established a jet-lagged mice model by advancing the light/dark phase shift by six hours every three days for eight weeks. Subsequent changes in gastrointestinal motility and the ENS were then assessed. Additionally, a triple-transgenic mouse strain (Nestin-creERT2 × Ngfr-DreERT2: DTRGFP) was utilized to track the effects of CRD on the differentiation of enteric neural precursor cells (ENPCs). RNA sequencing was also performed to elucidate the underlying mechanism.

RESULTS

Compared to the control group, CRD significantly accelerated gastrointestinal motility, evidenced by faster intestinal peristalsis (P < 0.01), increased fecal output (P < 0.01), and elevated fecal water content (P < 0.05), as well as enhanced electrical field stimulation induced contractions (P < 0.05). These effects were associated with an increase in the number of glial cells and nitrergic neurons in the colonic myenteric plexus. Additionally, ENPCs in the colon showed a heightened differentiation into glial cells and nitrergic neurons. Notably, the NR1D1/nuclear factor-kappaB (NF-κB) axis played a crucial role in the CRD-mediated changes in ENPCs differentiation. Supplementation with NR1D1 agonist or NF-κB antagonist was able to restore gastrointestinal motility and normalize the ENS in jet-lagged mice.

CONCLUSIONS

CRD regulates the differentiation of ENPCs through the NR1D1/NF-κB axis, resulting in dysfunction of the ENS and impaired gastrointestinal motility in mice.

Distribution, contribution and regulation of nestin+ cells

BACKGROUND

Nestin is an intermediate filament first reported in neuroepithelial stem cells. Nestin expression could be found in a variety of tissues throughout all systems of the body, especially during tissue development and tissue regeneration processes.

AIM OF REVIEW

This review aimed to summarize and discuss current studies on the distribution, contribution and regulation of nestin+ cells in different systems of the body, to discuss the feasibility ofusing nestin as a marker of multilineage stem/progenitor cells, and better understand the potential roles of nestin+ cells in tissue development, regeneration and pathological processes.

KEY SCIENTIFIC CONCEPTS OF REVIEW

This review highlights the potential of nestin as a marker of multilineage stem/progenitor cells, and as a key factor in tissue development and tissue regeneration. The article discussed the current findings, limitations, and potential clinical implications or applications of nestin+ cells. Additionally, it included the relationship of nestin+ cells to other cell populations. We propose potential future research directions to encourage further investigation in the field.

Abscisic acid ameliorates d-galactose -induced aging in mice by modulating AMPK-SIRT1-p53 pathway and intestinal flora

Abscisic acid (ABA) is a plant hormone with various biological activities. Aging is a natural process accompanied by cognitive and physiological decline, and aging and its associated diseases pose a serious threat to public health, but its mechanisms remain insufficient. Therefore, the purpose of this study was to investigate the ameliorative effects of ABA on d-galactose (D-Gal)-induced aging in mice and to delve into its molecular mechanisms. Aging model was es-tablished by theintraperitoneal injection of D-Gal. We evaluated the oxidative stress by measuring superoxide dismutase (SOD), malondialdehyde (MDA), catalase (CAT) levels in serum. Proteins content in brain were determined by Western blot. D-Gal-induced brain damage was monitored by measuring the levels of acetylcholinesterase (AChE) content and hematoxylin-eosin staining (H&E). To evaluate the effects of ABA on aging, we measured the gut microbiota. The results demonstrated that ABA increased SOD, CAT and AChE, decreased MDA level. H&E staining showed that ABA could improve D-Gal-induced damage. In addition, ABA regulated the B-cell-lymphoma-2 (BCL-2) family and Phosphatidylinositol 3-kinase/Protein kinase B (PI3K/AKT) signaling pathway, while further regulating the acetylation of p53 protein by modulating the AMPK pathway and activating SIRT1 protein, thereby inhibiting the apoptosis of brain neurons and thus regulating the aging process. Interestingly, ABA improved the ratio of intestinal bacteria involved in regulating multiple metabolic pathways in the aging process, such as Bacteroides, Firmicutes, Lactobacillus and Ak-kermansia. In conclusion, the present study suggests that ABA may be responsible for improving and delaying the aging process by enhancing antioxidant activity, anti-apoptosis and regulating intestinal flora.

L-Fucose promotes enteric nervous system regeneration in type 1 diabetic mice by inhibiting SMAD2 signaling pathway in enteric neural precursor cells

BACKGROUND

Diabetes can lead to extensive damage to the enteric nervous system (ENS), causing gastrointestinal motility disorders. However, there is currently a lack of effective treatments for diabetes-induced ENS damage. Enteric neural precursor cells (ENPCs) closely regulate the structural and functional integrity of the ENS. L-Fucose, is a dietary sugar that has been showed to effectively ameliorate central nervous system injuries, but its potential for ameliorating ENS damage and the involvement of ENPCs in this process remains uncertain.

METHODS

Genetically engineered mice were generated for lineage tracing of ENPCs in vivo. Using diabetic mice in vivo and high glucose-treated primary ENPCs in vitro, the effects of L-Fucose on the injured ENS and ENPCs was evaluated by assessing gastrointestinal motility, ENS structure, and the differentiation of ENPCs. The key signaling pathways in regulating neurogenesis and neural precursor cells properties, transforming growth factor-β (TGF-β) and its downstream signaling pathways were further examined to clarify the potential mechanism of L-Fucose on the injured ENS and ENPCs.

RESULTS

L-Fucose improved gastrointestinal motility in diabetic mice, including increased defecation frequency (p < 0.05), reduced total gastrointestinal transmission time (p < 0.001) and bead expulsion time (p < 0.05), as well as enhanced spontaneous contractility and electric field stimulation-induced contraction response in isolated colonic muscle strips (p < 0.001). The decrease in the number of neurons and glial cells in the ENS of diabetic mice were reversed by L-Fucose treatment. More importantly, L-Fucose treatment significantly promoted the proportion of ENPCs differentiated into neurons and glial cells both in vitro and in vivo, accompanied by inhibiting SMAD2 phosphorylation.

CONCLUSIONS

L-Fucose could promote neurogenesis and gliogenesis derived from ENPCs by inhibiting the SMAD2 signaling, thus facilitating ENS regeneration and gastrointestinal motility recovery in type 1 diabetic mice. Video Abstract.