Cbl and Cbl-b ubiquitin ligases are essential for intestinal epithelial stem cell maintenance.

Receptor tyrosine kinases (RTKs) control stem cell maintenance vs. differentiation decisions. Casitas B-lineage lymphoma (CBL) family ubiquitin ligases are negative regulators of RTKs, but their stem cell regulatory roles remain unclear. Here, we show that Lgr5+ intestinal stem cell (ISC)-specific inducible Cbl-knockout (KO) on a Cblb null mouse background (iDKO) induced rapid loss of the Lgr5 Hi ISCs with transient expansion of the Lgr5 Lo transit-amplifying population. LacZ-based lineage tracing revealed increased ISC commitment toward enterocyte and goblet cell fate at the expense of Paneth cells. Functionally, Cbl/Cblb iDKO impaired the recovery from radiation-induced intestinal epithelial injury. In vitro, Cbl/Cblb iDKO led to inability to maintain intestinal organoids. Single-cell RNA sequencing in organoids identified Akt-mTOR (mammalian target of rapamycin) pathway hyperactivation upon iDKO, and pharmacological Akt-mTOR axis inhibition rescued the iDKO defects. Our results demonstrate a requirement for Cbl/Cblb in the maintenance of ISCs by fine-tuning the Akt-mTOR axis to balance stem cell maintenance vs. commitment to differentiation.

Exploring the impact of pediatric short bowel syndrome on parent well-being using a disease-specific pilot survey.

BACKGROUND: Children with short bowel syndrome (SBS) have complex care needs, most of which are met in the home by family caregivers who may experience a range of stressors unique to this experience. Prior research suggests that parents of children with SBS have poorer health-related quality of life than peers parenting children without health needs, but the mechanisms shaping parent outcomes are understudied. METHODS: A pilot survey was developed using a community-driven research design to measure the impact of disease-specific items on parent-perceived well-being. The cross-sectional survey, which included both closed-ended and open-ended items, was distributed to a convenience sample of parents of children with SBS. Quantitative and qualitative data were integrated for a mixed-methods analysis of how individual items impacted parent well-being. RESULTS: Twenty parents completed the survey. Sleep interruptions, lack of support and resources, and psychological stressors and their mental health implications were more frequently reported as stressors than logistics related to caregiving (e.g., managing therapies and preparing specialized meals). CONCLUSION: The impact of a child's SBS on parent well-being may stem mainly from three interconnected domains: poor sleep and its consequences, lack of access to support and resources, and a range of psychological stressors that affect parent mental health. Understanding the mechanisms through which SBS shapes parent well-being is a necessary first step for developing targeted interventions to support parents and provide family-centered care.

Cbl and Cbl-b Ubiquitin Ligases are Essential for Intestinal Epithelial Stem Cell Maintenance.

Among the signaling pathways that control the stem cell self-renewal and maintenance vs. acquisition of differentiated cell fates, those mediated by receptor tyrosine kinase (RTK) activation are well established as key players. CBL family ubiquitin ligases are negative regulators of RTKs but their physiological roles in regulating stem cell behaviors are unclear. While hematopoietic Cbl/Cblb knockout (KO) leads to a myeloproliferative disease due to expansion and reduced quiescence of hematopoietic stem cells, mammary epithelial KO led to stunted mammary gland development due to mammary stem cell depletion. Here, we examined the impact of inducible Cbl/Cblb double-KO (iDKO) selectively in the Lgr5-defined intestinal stem cell (ISC) compartment. Cbl/Cblb iDKO led to rapid loss of the Lgr5 Hi ISC pool with a concomitant transient expansion of the Lgr5 Lo transit amplifying population. LacZ reporter-based lineage tracing showed increased ISC commitment to differentiation, with propensity towards enterocyte and goblet cell fate at the expense of Paneth cells. Functionally, Cbl/Cblb iDKO impaired the recovery from radiation-induced intestinal epithelial injury. In vitro , Cbl/Cblb iDKO led to inability to maintain intestinal organoids. Single cell RNAseq analysis of organoids revealed Akt-mTOR pathway hyperactivation in iDKO ISCs and progeny cells, and pharmacological inhibition of the Akt-mTOR axis rescued the organoid maintenance and propagation defects. Our results demonstrate a requirement for Cbl/Cblb in the maintenance of ISCs by fine tuning the Akt-mTOR axis to balance stem cell maintenance vs. commitment to differentiation.

Surgical considerations in the management of short bowel syndrome.

Patients with short bowel syndrome (SBS) are optimally managed in centers of expertise with dedicated multidisciplinary intestinal failure (IF) teams. Over the life of a patient with SBS, many different surgical concerns may arise requiring intervention. These can range from reasonably simple procedures, such as the creation or maintenance of gastrostomy tube and enterostomies, to complex reconstructions of multiple enterocutaneous fistulas or the performance of intestine-containing transplants. This review will cover the development of a surgeon's role on the IF team; common surgical issues arising in patients with SBS, with a focus on decision-making rather than technique; and, finally, a brief overview of transplantation and some related decision-making issues.

Optimizing transition from pediatric to adult care in short bowel syndrome and intestinal failure.

As the majority of children with short bowel syndrome (SBS) and intestinal failure (IF) are now surviving into adulthood, there is a paradigm shift from short-term management to long-term outcomes and a growing need to focus on healthcare transition (HCT). It is imperative that adolescents and young adults with SBS and IF receive disease education, empowerment, and support as they navigate the transition from pediatric to adult care. Furthermore, both pediatric and adult healthcare providers who manage these patients should be aware of the challenges faced by this population, barriers to their HCT, and strategies to overcome them. This article reviews the literature on HCT in children with chronic illnesses, discusses barriers to HCT in SBS/IF, identifies the important constituents of the transition process in SBS/IF, and provides recommendations for the successful and smooth transition of the pediatric patient to the adult healthcare environment. Structured and multicomponent HCT programs should become the standard of care to ensure uninterrupted high-quality care across the life span for patients with SBS/IF.

Case presentation and panel discussion: Transitions in care.

There is evidence that significant quality problems arise as patients transitions in care from one setting to another. Attention to nutrition during transitions of care is important to avoid complication. During the American Society for Parenteral and Enteral Nutrition 2022 preconference course, nutrition during transition of care from pediatric to adult care, from the intensive care unit to the hospital floors and from the hospital to home was addressed.

Cholecystectomy prior to short bowel syndrome does not alter nutritional prognosis.

BACKGROUND: Previous cholecystectomy is common in patients with short bowel syndrome (SBS). An intact gallbladder is beneficial in preventing cirrhosis in SBS patients, but the nutritional consequences of cholecystectomy are largely unknown. Our aim was to evaluate the effect of pre-SBS cholecystectomy on need for chronic parenteral nutrition (PN). METHODS: We reviewed 485 adults with SBS: 267 underwent cholecystectomy prior to SBS and 218 patients had an intact gallbladder. Demographic data, intestinal anatomy, and nutritional outcome were compared. RESULTS: Pre-SBS cholecystectomy patients were more likely to have had postoperative SBS and BMI >35. Intestinal remnant length and anatomy type and performance of surgical rehabilitation procedures within the first year were similar. Overall, there was no significant difference in the need for PN > 1year between the two groups. There was also no significant difference in the need for PN > 1year in any specific subgroup of intestinal remnant length or intestinal anatomy. CONCLUSIONS: Cholecystectomy performed prior to the development of SBS does not influence the nutritional prognosis of SBS, regardless of the intestinal remnant length and anatomy type.

Characteristics of chronic intestinal failure in the USA based on analysis of claims data.

BACKGROUND: This study investigated the prevalence, characteristics, and management of patients with chronic intestinal failure (CIF) in the United States in 2012-2020, based on parenteral support (PS) prescription claims and healthcare utilization. METHODS: Patients with CIF were identified from the Integrated DataVerse® claims database if they had at least two PS prescriptions within 6 months and a relevant diagnosis. Analysis included prevalence and characteristics of patients with CIF, their travel distance to receive PS prescriptions, and the distribution of PS providers and their prescribing history. RESULTS: Up to 24,048 patients with CIF were identified, equivalent to 75 patients per million. CIF affected people of all ages, being more prevalent in women than in men. Many providers signed PS orders for small patient groups over short time periods, whereas few providers signed PS orders for large patient groups long term, indicating a lack of centralization. The distribution of PS providers suggested a disparity in healthcare coverage in rural vs urban areas, leading to patients traveling considerable distances to receive PS prescriptions. This may be exacerbated by a decline of providers with expertise in CIF and nutrition. CONCLUSIONS: Healthcare disparities for patients with CIF have likely been obscured by the lack of CIF-specific diagnostic and procedure codes, obliging providers to code for their patients under other codes. Effective policy changes, including centralized care, revision of reimbursement models, and expansion of nutrition-focused education in addition to the newly introduced International Classification of Diseases codes, are needed to provide the best care for patients.

A beautiful struggle: Parent-perceived impact of short bowel syndrome on child and family wellbeing.

BACKGROUND: Despite considerable improvements in outcomes for children with short bowel syndrome (SBS), many clinicians remain pessimistic about long-term quality of life (QoL) for this population. METHODS: The validated FaMM tool was used to measure parent-perceived impact of the child's condition on child and family life. Partnered disease-specific survey questions relevant to child's overall wellbeing and family function were additionally completed and reported. The cross-sectional surveys were distributed to a convenience sample of parents of children with SBS. Child and family wellbeing were described and compared across child age group and involvement of an intestinal rehabilitation program (IRP). Multivariate regression analyses investigated associations between outcomes and IRP management. Open-ended responses were analyzed to investigate perceived impact of the child's SBS on the parent. RESULTS: Seventeen parents completed both surveys; 71% perceived child QoL as higher today than what they had originally been told to expect. Child daily life and family difficulty scores suggest parents perceived both to be fairly "normal". While acknowledging effort invested in condition management, parents perceived high competence in managing their child's condition; 56% perceived personal growth resulting from their child's SBS journey. IRP management was associated with better child daily life (4.11, p = 0.015), family difficulty (-4.85, p = 0.048), and family management ability (4.28, p = 0.014) scores. CONCLUSIONS: Many parents perceive child and family life with SBS to be fairly "normal", manage their child's care with great competence, and report personal growth because of their child's SBS journey. Additional research inclusive of diverse patient and parent backgrounds is warranted. LEVEL OF EVIDENCE: prognosis study; Level IV.

Glucocorticoids Improve Enteral Feeding Tolerance in Pediatric Short Bowel Syndrome With Chronic Intestinal Inflammation.

OBJECTIVES: A group of short bowel syndrome (SBS) patients developed chronic intestinal inflammation while struggling weaning off parenteral nutrition (PN). They did not respond to standard management of SBS and food allergy. We treated them with glucocorticoids and described the outcome. METHODS: Our study is a retrospective descriptive study. We reviewed records from the intestinal rehabilitation program from 2006 to 2017. We identified 15 patients whose lab values, pathology results, and clinic notes were reviewed. RESULTS: We had more patients (n = 10) with diagnosis of gastroschisis, and more female patients (n = 9). Seven patients weaned off PN with median treatment duration of 5 months, 5 of which remained on budesonide for significant period of time (median: 7.5 months). One of these 7 patients relapsed, as the patient resumed glucocorticoids because of recurrence of chronic intestinal inflammation. Six of 15 children had significant eosinophils in their initial biopsy, 5 of these children weaned off PN whereas 1 child's gastrointestinal (GI) bleeding stopped. Four patients were not able to decrease PN calorie. Two of these patients' GI bleeding stopped, the other 2 had normalized histology. CONCLUSIONS: For SBS children with histologically confirmed chronic intestinal inflammation, glucocorticoids may help promote enteral feeding tolerance. Glucocorticoids regimen should be chosen individually. Patients are more likely to respond if initial histology has significant eosinophilic infiltration. Patients may need to remain on glucocorticoids for over 6 months.

Safety Findings in Pediatric Patients During Long-Term Treatment With Teduglutide for Short-Bowel Syndrome-Associated Intestinal Failure: Pooled Analysis of 4 Clinical Studies.

BACKGROUND: This analysis assessed combined safety data from 4 clinical studies of teduglutide in pediatric patients with short-bowel syndrome-associated intestinal failure (SBS-IF). METHODS: Safety data from teduglutide-treated patients in 4 clinical trials were pooled. The completed 12-week and 24-week phase 3 core studies (NCT01952080/EudraCT 2013-004588-30 and NCT02682381/EudraCT 2015-002252-27) enrolled children aged 1-17 years with SBS-IF. Patients could elect to enroll in ongoing open-label extensions (NCT02949362/EudraCT 2016-000863-17 and NCT02954458/EudraCT 2016-000849-30). Interim data from ongoing studies were included. RESULTS: Safety data are reported for 89 pediatric patients treated with teduglutide for a median (range) of 51.7 (5.0-94.7) weeks. Adverse events (AEs) were reported in all patients; the most common were vomiting (51.7%), pyrexia (43.8%), upper respiratory tract infection (41.6%), and cough (33.7%). Thirty-five patients (39.3%) had AEs considered related to teduglutide treatment; abdominal pain and vomiting were most frequent (5.6% each). Three serious AEs in 3 patients (3.4%) were considered related to teduglutide treatment: ileus, d-lactic acidosis, and gastrointestinal obstruction due to hard stools. All 3 events resolved. One cecal polyp was detected, which was not biopsied or found on repeat colonoscopy. No cases of neoplasia occurred. CONCLUSION: Based on integrated data from 4 clinical studies, including long-term follow-up for ≤161 weeks, teduglutide had a safety profile consistent with the individual core pediatric studies and as expected for pediatric patients with SBS-IF who never received teduglutide. The most frequent AEs reflected treatment with teduglutide, complications of the underlying disease, and typical childhood illnesses.

Repeat serial transverse enteroplasty leads to reduction in parenteral nutrition in children with short bowel syndrome.

BACKGROUND/PURPOSE: Following a serial transverse enteroplasty (STEP) procedure some children develop redilation of the small intestine leading to impaired enteral tolerance and inability to wean parenteral nutrition (PN). The benefit of a second STEP procedure (2STEP) has been controversial. METHODS: We performed a retrospective review of our experience (2008-2018) performing 2STEP, with comparative analysis of nutritional outcomes pre- and postsurgery. RESULTS: During this period 2STEP was performed in 23 patients (13 F:10 M) at a median (25%-75%) age of 2.2 (1.2-3.6) years. Median intestinal length was 68 (40-105) cm before and 85 (40-128) cm after 2STEP. Leading up to 2STEP, PN provided almost 75% of estimated calorie needs. By 24 weeks following 2STEP drops in mean PN percent approached statistical significance (p = 0.07) and at most recent follow up the mean PN percentage was statistically better than at the time of operation or 4 weeks prior to 2STEP, and was nearly significant compared with 12 weeks (p = 0.07) and 24 weeks (p = 0.06) prior. Thirteen children were completely off parenteral support. CONCLUSION: When small intestine redilation occurs following a STEP procedure and where PN cannot otherwise be weaned we believe these data support performing a 2STEP. We cannot predict preoperatively which children will ultimately benefit. LEVEL OF EVIDENCE: 3 (retrospective comparative study).

Viral enteritis in intestinal transplant recipients.

Intestinal transplant recipients (ITR) are at high risk for infections due to the high level of immunosuppression required to prevent rejection. There are limited data regarding viral enteritis post-intestinal transplantation. We retrospectively reviewed ITR transplanted between January 2008 and December 2016. Descriptive statistics, including mean (standard deviation) and median (range), were performed. Sixty-one (43.9%) of the 139 transplanted patients had viral enteritis: 26% norovirus, 25% adenovirus, and 9% each rotavirus and sapovirus. The median age of pediatric patients was 1.6 years (0.4-16.9) and for adults 36.3 years (27.1-48.2). Fifty-seven (58%) of 99 pediatric ITR had viral enteritis compared to 4 (10%) of 40 adult ITR. Median time-to-clinical resolution of enteritis for all patients was 5 days (1-92). Standard of care therapies administered: anti-motility agents (10%), anti-emetics agents (14%), and intravenous fluids (42%). There was a higher incidence of viral enteritis in pediatric compared to adults ITR. The majority of viral enteritis episodes resolved within 1 week and were treated with supportive therapy.

Safety and Efficacy of Teduglutide in Pediatric Patients With Intestinal Failure due to Short Bowel Syndrome: A 24-Week, Phase III Study.

BACKGROUND: This study evaluated the safety and efficacy of teduglutide in pediatric patients with short bowel syndrome-associated intestinal failure (SBS-IF). METHODS: A 24-week, phase III trial with 2 randomized, double-blind teduglutide dose groups and a nonblinded standard of care (SOC) arm was used; patients received 0.025 mg/kg or 0.05 mg/kg teduglutide once daily. Safety end points included treatment-emergent adverse events (TEAEs) and growth parameters. The primary efficacy/pharmacodynamic end point was the number of patients who achieved a ≥20% reduction in parenteral support (PS) from baseline at week 24. RESULTS: All 59 enrolled patients completed the study (0.025 mg/kg, n = 24; 0.05 mg/kg, n = 26; SOC, n = 9). Baseline demographics and disease characteristics were comparable among groups. TEAEs were reported by 98% and 100% of patients in the teduglutide and SOC groups, respectively. The most common TEAEs in the teduglutide-treated groups were pyrexia and vomiting. The primary end point was achieved by 13 (54.2%), 18 (69.2%), and 1 (11.1%) patients who received 0.025 mg/kg teduglutide, 0.05 mg/kg teduglutide, and SOC, respectively (P < 0.05 vs SOC). Both 0.025-mg/kg and 0.05-mg/kg teduglutide groups showed clinically significant reductions in PS volume (P < 0.05 vs SOC), PS calories, days per week and hours per day of PS infusions, and increases in enteral nutrition and plasma citrulline at week 24 compared with baseline. Two (8.3%, 0.025 mg/kg teduglutide) and 3 patients (11.5%, 0.05 mg/kg teduglutide) achieved enteral autonomy. CONCLUSION: The safety profile of teduglutide was similar to that reported previously in children and adults. Treatment with teduglutide was associated with significant reductions in PS for pediatric patients with SBS-IF over 24 weeks.

Including colon in intestinal transplantation: a focus on post-transplant renal function - a retrospective study.

Intestinal transplant recipients experience a high rate of renal complications secondary to dehydration due to increased ostomy output. It is hypothesized that inclusion of donor colon in the intestinal allograft may improve renal function in patients without functional native colon by improving fluid absorption. A single-center retrospective study of intestinal transplant recipients compared outcomes of patients receiving en bloc colon as part an intestinal allograft (ICTx), and those not receiving colon (CCNTx), as well as a control group of intestinal transplant recipients with functional native colon (ITx). Forty-seven patients (ICTx n = 17, CCNTx n = 15, ITx n = 15) were studied. One-year post-transplant renal function, as measured by change in glomerular filtration rate (GFR) and blood urea nitrogen (BUN) from baseline, was superior in ICTx (mean delta-GFR of -1.31 and delta-BUN of -1.46) compared to CCNTx (-6.54 and 17.54, P = 0.05 and P = 0.17, respectively) and similar to the ITx controls (0.55 and 2.09). Recipients of donor colon experienced a higher rate of ileostomy reversal when compared to CCNTx (62.5% vs. 20%, P = 0.0008), which was similar to the ITx controls (60%). These findings support the inclusion of en bloc donor colon in the intestinal allograft for recipients without functional native colon.

Failure of abdominal wall closure after intestinal transplantation: Identifying high-risk recipients.

Open abdomen and fascial dehiscence after intestinal transplantation increase morbidity. This study aims to identify recipient and donor factors associated with failure to achieve sustained primary closure (failed-SPC) of the abdomen after intestinal transplant. We conducted a single-center retrospective study of 96 intestinal transplants between 2013 and 2018. Thirty-eight (40%) were adult patients, and 58 were pediatric patients. Median age at transplantation was 36.0 and 5.8 years, respectively. Failed-SPC occurred in 31 (32%) patients. Identified risk factors of failed-SPC included preexisting enterocutaneous fistula (OR: 6.8, CI: 2.4-19.6, P = .0003), isolated intestinal graft (OR: 3.4, CI: 1.24-9.47, P = .02), male sex in adults (OR: 3.93, CI: 1.43-10.8, P = .009), and age over four years (OR: 6.22, CI: 1.7-22.7, P = .004). There was no association with primary diagnosis and prior transplant with failed-SPC. Donor-to-recipient size ratios did not predict failed-SPC. There was an association between failed-SPC and extended median hospital stay (100 vs 57 days, P = .007) and increased time to enteral autonomy in pediatric patients. There is a relationship between failed-SPC and a higher rate of laparotomy (OR: 21.4, CI: 2.78-178.2, P = .0003) and fistula formation posttransplant (OR: 11.4, CI: 2.83-45.84, P = .0005) in pediatric patients. Given inferior outcomes with failed-SPC, high-risk recipients require careful evaluation.

Prophylactic cholecystectomy in short bowel syndrome: Is it being utilized?

INTRODUCTION: Cholelithiasis is common in patients with short bowel syndrome (SBS). Prophylactic cholecystectomy (PC) of the non-diseased gallbladder has been recommended in SBS patients when laparotomy is being undertaken for other reasons. Our aim was to determine if PC is being utilized. METHODS: 500 adults with SBS were seen over a 25 year period. 215 undergoing cholecystectomy prior to SBS were excluded, leaving 285 patients for evaluation. RESULTS: 151 (53%) SBS patients underwent a subsequent laparotomy. 77 underwent cholecystectomy for cholelithiasis at the 1st opportunity. 27 patients underwent a PC at the 1st opportunity. 47 patients did not undergo PC at the 1st opportunity. 17 (36%) of these 47 patients subsequently developed cholelithiasis with 7 undergoing cholecystectomy. Age, gender, diagnosis and initial BMI and need for longterm parenteral nutrition were similar in patients who had PC or did not. PC patients were more likely to have intestinal remnant length <60 cm (59% vs 21%, p < .05). CONCLUSIONS: Overall 10% of SBS patients underwent PC. However, only 36% of eligible patients undergoing laparotomy had a PC.

Demethylase JMJD6 as a New Regulator of Interferon Signaling: Effects of HCV and Ethanol Metabolism.

BACKGROUND & AIMS: Alcohol-induced progression of hepatitis C virus (HCV) infection is related to dysfunction of innate immunity in hepatocytes. Endogenously produced interferon (IFN)α induces activation of interferon-stimulated genes (ISGs) via triggering of the Janus kinase-signal transducer and activator of transcription 1 (STAT1) pathway. This activation requires protein methyltransferase 1-regulated arginine methylation of STAT1. Here, we aimed to study whether STAT1 methylation also depended on the levels of demethylase jumonji domain-containing 6 protein (JMJD6) and whether ethanol and HCV affect JMJD6 expression in hepatocytes. METHODS: Huh7.5-CYP (RLW) cells and hepatocytes were exposed to acetaldehyde-generating system (AGS) and 50 mmol/L ethanol, respectively. JMJD6 messenger RNA and protein expression were measured by real-time polymerase chain reaction and Western blot. IFNα-activated cells either overexpressing JMJD6 or with knocked-down JMJD6 expression were tested for STAT1 methylation, ISG activation, and HCV RNA. In vivo studies have been performed on C57Bl/6 mice (expressing HCV structural proteins or not) or chimeric mice with humanized livers fed control or ethanol diets. RESULTS: AGS exposure to cells up-regulated JMJD6 expression in RLW cells. These results were corroborated by ethanol treatment of primary hepatocytes. The promethylating agent betaine reversed the effects of AGS/ethanol. Similar results were obtained in vivo, when mice were fed control/ethanol with and without betaine supplementation. Overexpression of JMJD6 suppressed STAT1 methylation, IFNα-induced ISG activation, and increased HCV-RNA levels. In contrast, JMJD6 silencing enhanced STAT1 methylation, ISG stimulation by IFNα, and attenuated HCV-RNA expression in Huh7.5 cells. CONCLUSIONS: We conclude that arginine methylation of STAT1 is suppressed by JMJD6. Both HCV and acetaldehyde increase JMJD6 levels, thereby impairing STAT1 methylation and innate immunity protection in hepatocytes exposed to the virus and/or alcohol.