Gastric Electrical Stimulation Increases the Proliferation of Interstitial Cells of Cajal and Alters the Enteric Nervous System in Diabetic Rats

Electroacupuncture at ST36 ameliorates gastric dysmotility in rats with diabetic gastroparesis via the nucleus tractus solitarius-vagal axis

BACKGROUND

Diabetic gastroparesis (DGP), characterized by delayed gastric emptying and impaired motility, poses significant therapeutic challenges due to its complex neural and molecular pathophysiology. Emerging evidence suggests that electroacupuncture (EA) at ST36 modulates gastrointestinal function; however, the precise neuromolecular pathways underlying its efficacy in DGP remain incompletely defined.

AIM

To elucidate the neural mechanisms underlying EA at ST36 improving DGP gastric motility through the nucleus tractus solitarius (NTS)-vagal axis.

METHODS

The DGP model was established via a single high-dose intraperitoneal injection of 2% streptozotocin combined with an 8-week high-sugar/high-fat diet. Interventions included EA at ST36, pharmacological modulation [choline acetyltransferase (ChAT) agonist polygalacic acid (PA) and inhibitor antagonist alpha-NETA], and subdiaphragmatic vagotomy. Post-intervention observations included body weight and blood glucose levels. Gastric emptying was evaluated using phenol red assays, gastric slow-wave recordings, and dynamic positron emission tomography-computed tomography imaging. Histopathological analysis (hematoxylin-eosin staining) and molecular assessments (Western blot, immunofluorescence) were performed to quantify gastric smooth muscle-associated factors [neuronal nitric oxide synthase (nNOS), cluster of differentiation 117 (C-kit), stem cell factor (SCF)] and vagal targets [ChAT, α7 nicotinic acetylcholine receptor (α7nAChR)] in the ST36 acupoint region, L4-L6 spinal segments, and NTS. Gastrointestinal peptides [gastrin (Gas), motilin (MLT) and vasoactive intestinal peptide (VIP)] were measured via enzyme-linked immunosorbent assay.

RESULTS

The study found that EA significantly increased the rate of gastric emptying, restored the slow-wave rhythms of the stomach, and improved the architecture of the smooth muscles in the stomach. This was evidenced by a reduction in inflammatory infiltration and an increase in the expression of nNOS, C-kit, and SCF. Mechanistically, EA activated vagal targets (ChAT and α7nAChR) at ST36, transmitting signals via spinal segments L4-L6 to the NTS, subsequently regulating gastrointestinal peptides (Gas, MLT, VIP) and restoring interstitial cells of Cajal (ICCs) function via subdiaphragmatic vagal efferent pathways. It is crucial to note that subdiaphragmatic vagotomy led to the abrogation of EA-induced enhancements in gastric motility and ICC recovery, thereby confirming the indispensable role of vagal efferent signalling.

CONCLUSION

EA provides a novel molecular mechanism for improving gastrointestinal motility in DGP via a peripheral stimulation (ST36), spinal afferent (L4-L6), brainstem integration (NTS), vagal efferent (gastric) circuit.

Systematic review of translational insights: Neuromodulation in animal models for Diabetic Peripheral Neuropathy

Diabetic Peripheral Neuropathy (DPN) is a prevalent and debilitating complication of diabetes, affecting a significant proportion of the diabetic population. Neuromodulation, an emerging therapeutic approach, has shown promise in the management of DPN symptoms. This systematic review aims to synthesize and analyze the current advancements in neuromodulation techniques for the treatment of DPN utilizing studies with preclinical animal models. A comprehensive search was conducted across multiple databases, including PubMed, Scopus, and Web of Science. Inclusion criteria were focused on studies utilizing preclinical animal models for DPN that investigated the efficacy of various neuromodulation techniques, such as spinal cord stimulation, transcranial magnetic stimulation, and peripheral nerve stimulation. The findings suggest that neuromodulation significantly alleviated pain symptoms associated with DPN. Moreover, some studies reported improvements in nerve conduction velocity and reduction in nerve damage. The mechanisms underlying these effects appeared to involve modulation of pain pathways and enhancement of neurotrophic factors. However, the review also highlights the variability in methodology and stimulation parameters across studies, highlighting the need for standardization in future research. Additionally, while the results are promising, the translation of these findings from animal models to human clinical practice requires careful consideration. This review concludes that neuromodulation presents a potentially effective therapeutic strategy for DPN, but further research is necessary to optimize protocols and understand the underlying molecular mechanisms. It also emphasizes the importance of bridging the gap between preclinical findings and clinical applications to improve the management of DPN in diabetic patients.

Gastric and sacral electrical stimulation for motility disorders-A clinical perspective

BACKGROUND

Electrical stimulation of the gut has been investigated in recent decades with a view to treating various gastro-intestinal motility disorders including, among others, gastric electrical stimulation to relieve nausea and vomiting associated with gastroparesis and sacral neuromodulation to treat fecal incontinence and/or constipation. Although their symptomatic efficacy has been ascertained by randomized controlled trials, their mechanisms of action are not fully understood.

PURPOSE

This review summarizes the past year's literature on the mechanisms of action of gut electrical stimulation therapies, including their impact on the gut-brain axis.

Common Pathophysiological Mechanisms and Treatment of Diabetic Gastroparesis

Diabetic gastroparesis (DGP) is a common complication of diabetes mellitus, marked by gastrointestinal motility disorder, a delayed gastric emptying present in the absence of mechanical obstruction. Clinical manifestations include postprandial fullness and epigastric discomfort, bloating, nausea, and vomiting. DGP may significantly affect the quality of life and productivity of patients. Research on the relationship between gastrointestinal dynamics and DGP has received much attention because of the increasing prevalence of DGP. Gastrointestinal motility disorders are closely related to a variety of factors including the absence and destruction of interstitial cells of Cajal, abnormalities in the neuro-endocrine system and hormone levels. Therefore, this study will review recent literature on the mechanisms of DGP and gastrointestinal motility disorders as well as the development of prokinetic treatment of gastrointestinal motility disorders in order to give future research directions and identify treatment strategies for DGP.

Effects of Electrical Stimulation of the Cell: Wound Healing, Cell Proliferation, Apoptosis, and Signal Transduction

Electrical stimulation of the cell can have a number of different effects depending on the type of cell being stimulated. In general, electrical stimulation can cause the cell to become more active, increase its metabolism, and change its gene expression. For example, if the electrical stimulation is of low intensity and short duration, it may simply cause the cell to depolarize. However, if the electrical stimulation is of high intensity or long duration, it may cause the cell to become hyperpolarized. The electrical stimulation of cells is a process by which an electrical current is applied to cells in order to change their function or behavior. This process can be used to treat various medical conditions and has been shown to be effective in a number of studies. In this perspective, the effects of electrical stimulation on the cell are summarized.