Schwann cells in the subcutaneous adipose tissue have neurogenic potential and can be used for regenerative therapies.

Stem cell therapies for nervous system disorders are hindered by a lack of accessible autologous sources of neural stem cells (NSCs). In this study, neural crest-derived Schwann cells are found to populate nerve fiber bundles (NFBs) residing in mouse and human subcutaneous adipose tissue (SAT). NFBs containing Schwann cells were harvested from mouse and human SAT and cultured in vitro. During in vitro culture, SAT-derived Schwann cells remodeled NFBs to form neurospheres and exhibited neurogenic differentiation potential. Transcriptional profiling determined that the acquisition of these NSC properties can be attributed to dedifferentiation processes in cultured Schwann cells. The emerging population of cells were termed SAT-NSCs because of their considerably distinct gene expression profile, cell markers, and differentiation potential compared to endogenous Schwann cells existing in vivo. SAT-NSCs successfully engrafted to the gastrointestinal tract of mice, migrated longitudinally and circumferentially within the muscularis, differentiated into neurons and glia, and exhibited neurochemical coding and calcium signaling properties consistent with an enteric neuronal phenotype. These cells rescued functional deficits associated with colonic aganglionosis and gastroparesis, indicating their therapeutic potential as a cell therapy for gastrointestinal dysmotility. SAT can be harvested easily and offers unprecedented accessibility for the derivation of autologous NSCs from adult tissues. Evidence from this study indicates that SAT-NSCs are not derived from mesenchymal stem cells and instead originate from Schwann cells within NFBs. Our data describe efficient isolation procedures for mouse and human SAT-NSCs and suggest that these cells have potential for therapeutic applications in gastrointestinal motility disorders.

Tamoxifen administration alters gastrointestinal motility in mice.

BACKGROUND: Tamoxifen is widely used for Cre-estrogen receptor-mediated genomic recombination in transgenic mouse models to mark cells for lineage tracing and to study gene function. However, recent studies have highlighted off-target effects of tamoxifen in various tissues and cell types when used for induction of Cre recombination. Despite the widespread use of these transgenic Cre models to assess gastrointestinal (GI) function, the effect of tamoxifen exposure on GI motility has not been described. METHODS: We examined the effects of tamoxifen on GI motility by measuring total GI transit, gastric emptying, small intestinal transit, and colonic contractility in wild-type adult mice. KEY RESULTS: We observed a significant delay in total GI transit in tamoxifen-treated mice, with unaltered gastric emptying, accelerated small intestinal transit, and abnormal colonic motility. CONCLUSION: Our findings highlight the importance of considering GI motility alterations induced by tamoxifen when designing protocols that utilize tamoxifen as a Cre-driver for studying GI function.

Enteric mesenchymal cells support the growth of postnatal enteric neural stem cells.

Interplay between embryonic enteric neural stem cells (ENSCs) and enteric mesenchymal cells (EMCs) in the embryonic gut is essential for normal development of the enteric nervous system. Disruption of these interactions underlies the pathogenesis of intestinal aganglionosis in Hirschsprung disease (HSCR). ENSC therapy has been proposed as a possible treatment for HSCR, but whether the survival and development of postnatal-derived ENSCs similarly rely on signals from the mesenchymal environment is unknown and has important implications for developing protocols to expand ENSCs for cell transplantation therapy. Enteric neural crest-derived cells (ENCDCs) and EMCs were cultured from the small intestine of Wnt1-Rosa26-tdTomato mice. EMCs promoted the expansion of ENCDCs 9.5-fold by inducing ENSC properties, including expression of Nes, Sox10, Sox2, and Ngfr. EMCs enhanced the neurosphere-forming ability of ENCDCs, and this persisted after withdrawal of the EMCs. These effects were mediated by paracrine factors and several ligands known to support neural stem cells were identified in EMCs. Using the optimized expansion procedures, neurospheres were generated from small intestine of the Ednrb-/- mouse model of HSCR. These ENSCs had similar proliferative and migratory capacity to Ednrb+/+ ENSCs, albeit neurospheres contained fewer neurons. ENSCs derived from Ednrb-/- mice generated functional neurons with similar calcium responses to Ednrb+/+ ENSCs and survived after transplantation into the aganglionic colon of Ednrb-/- recipients. EMCs act as supporting cells to ENSCs postnatally via an array of synergistically acting paracrine signaling factors. These properties can be leveraged to expand autologous ENSCs from patients with HSCR mutations for therapeutic application.

Pan-enteric neuropathy and dysmotility are present in a mouse model of short-segment Hirschsprung disease and may contribute to post-pullthrough morbidity.

PURPOSE: Hirschsprung disease (HSCR) is characterized by distal intestinal aganglionosis. While surgery is lifesaving, gastrointestinal (GI) motility disorders persist in many patients. Our objective was to determine whether enteric nervous system (ENS) abnormalities exist in the ganglionated portions of the GI tract far proximal to the aganglionic region and whether these are associated with GI dysmotility. METHODS: Using Ednrb-null mice, a model of HSCR, immunohistochemical analysis was performed to evaluate quantitatively ENS structure in proximal colon, small intestine, and stomach. Gastric emptying and intestinal transit were measured in vivo and small and large bowel contractility was assessed by spatiotemporal mapping ex vivo. RESULTS: Proximal colon of HSCR mice had smaller ganglia and decreased neuronal fiber density, along with a marked reduction in migrating motor complexes. The distal small intestine exhibited significantly fewer ganglia and decreased neuronal fiber density, and this was associated with delayed small intestinal transit time. Finally, in the stomach of HSCR mice, enteric neuronal packing density was increased and gastric emptying was faster. CONCLUSIONS: ENS abnormalities and motility defects are present throughout the ganglionated portions of the GI tract in Ednrb-deficient mice. This may explain the GI morbidity that often occurs following pull-through surgery for HSCR.

Treatment of psychogenic nonepileptic seizures (PNES) using video telehealth.

OBJECTIVE: Previous studies have shown the effectiveness of manual-based treatment for psychogenic nonepileptic seizures (PNES), but access to mental health care still remains a problem, especially for patients living in areas without medical professionals who treat conversion disorder. Thus, we evaluated patients treated with cognitive behavioral therapy-informed psychotherapy for seizures with clinical video telehealth (CVT). We evaluated neuropsychiatric and seizure treatment outcomes in veterans diagnosed with PNES seen remotely via telehealth. We hypothesized that seizures and comorbidities will improve with treatment. METHODS: This was a single-arm, prospective, observational, cohort, consecutive outpatient study. Patients with video-electroencephalography-confirmed PNES (n = 32) documented their seizure counts daily and comorbid symptoms prospectively over the course of treatment. Treatment was provided using a 12-session manual-based psychotherapy treatment given once per week, via CVT with a clinician at the Providence Veterans Affairs Medical Center. RESULTS: The primary outcome, seizure reduction, was 46% (P = .0001) per month over the course of treatment. Patients also showed significant improvements in global functioning (Global Assessment of Functioning, P = < .0001), quality of life (Quality of Life in Epilepsy Inventory-31, P = .0088), and health status scales (Short Form 36 Health Survey, P < .05), and reductions in both depression (Beck Depression Inventory-II, P = .0028) and anxiety (Beck Anxiety Inventory, P = .0013) scores. SIGNIFICANCE: Patients with PNES treated remotely with manual-based seizure therapy decreased seizure frequency and comorbid symptoms and improved functioning using telehealth. These results suggest that psychotherapy via telehealth for PNES is a viable option for patients across the nation, eliminating one of the many barriers of access to mental health care.

Examination of Potential Differences in Reporting of Sensitive Psychosocial Measures via Diagnostic Evaluation Using Computer Video Telehealth.

OBJECTIVE: The authors compared baseline characteristics and reporting of psychosocial measures among veterans with seizures who were evaluated in-clinic or remotely via computer video telehealth (CVT). It was hypothesized that the CVT group would report less trauma history, drug use, and comorbid symptoms compared with veterans seen in-clinic. METHODS: A cross-sectional design was used to compare 72 veterans diagnosed with psychogenic nonepileptic seizures (PNES) or concurrent mixed epilepsy and PNES who were consecutively evaluated by a single clinician at the Providence Veterans Affairs Medical Center (PVAMC) Neuropsychiatric Clinic. In-clinic evaluations of veterans were performed at the PVAMC Neuropsychiatric Clinic (N=16), and remote evaluations of veterans referred to the VA National TeleMental Health Center were performed via CVT (N=56). All 72 patients were given comprehensive neuropsychiatric evaluations by direct interview, medical examination, and medical record review. Veterans' reporting of trauma and abuse history, drug use, and psychiatric comorbidities was assessed, along with neurologic and psychiatric variables. RESULTS: No significant differences were found between veterans evaluated in-clinic or remotely with regard to baseline characteristics and reporting of potentially sensitive information, including trauma and abuse history, substance use, and comorbid symptoms. CONCLUSIONS: Veterans with PNES evaluated via telehealth did not appear to withhold sensitive or personal information compared with those evaluated in-clinic, suggesting that CVT may be a comparable alternative for conducting evaluations. Baseline evaluations are used to determine treatment suitability, and telehealth allows clinicians to gain access to important information that may improve or inform care.

Hypoganglionosis in the gastric antrum causes delayed gastric emptying.

BACKGROUND: Enteric nervous system (ENS) abnormalities have been implicated in delayed gastric emptying but studies exploring potential treatment options are limited by the lack of an experimental animal model. We examined the ENS abnormalities in the mouse stomach associated with aging, developed a novel model of gastroparesis, and established a new approach to measure gastric emptying. METHODS: A modified gastric emptying assay was developed, validated in nNOS -/- mice, and tested in mice at multiple ages. Age-related changes in ENS structure were analyzed by immunohistochemistry. Gastric aganglionosis was generated in Wnt1-iDTR mice using focal administration of diphtheria toxin (DT) into the anterior antral wall. KEY RESULTS: Older mice (>5 months) exhibit hypoganglionosis in the gastric antrum and a decreased proportion of nNOS neurons as compared to younger mice (age 5-7 weeks). This was associated with a significant age-dependent decrease in liquid and solid gastric emptying. A novel model of gastric antrum hypoganglionosis was established using neural crest-specific expression of diphtheria toxin receptor. In this model, a significant reduction in liquid and solid gastric emptying is observed. CONCLUSIONS & INFERENCES: Older mice exhibit delayed gastric emptying associated with hypoganglionosis and a reduction in nNOS-expressing neurons in the antrum. The causal relationship between antral hypoganglionosis and delayed gastric emptying was verified using a novel experimental model of ENS ablation. This study provides new information regarding the pathogenesis of delayed gastric emptying and provides a robust model system to study this disease and develop novel treatments.

Enteric neuronal cell therapy reverses architectural changes in a novel diphtheria toxin-mediated model of colonic aganglionosis.

Hirschsprung disease (HSCR) is characterized by absence of the enteric nervous system (ENS) in the distal bowel. Despite removal of the aganglionic segment, gastrointestinal (GI) problems persist. Cell therapy offers potential treatment but use of genetic models is limited by their poor survival. We have developed a novel model of aganglionosis in which enteric neural crest-derived cells (ENCDCs) express diphtheria toxin (DT) receptor. Local DT injection into the colon wall results in focal, specific, and sustained ENS ablation without altering GI transit or colonic contractility, allowing improved survival over other aganglionosis models. Focal ENS ablation leads to increased smooth muscle and mucosal thickness, and localized inflammation. Transplantation of ENCDCs into this region leads to engraftment, migration, and differentiation of enteric neurons and glial cells, with restoration of normal architecture of the colonic epithelium and muscle, reduction in inflammation, and improved survival.