On the horizon: trophic peptide growth factors as therapy for neonatal short bowel syndrome

Drug absorption from oral formulations in patients with short bowel syndrome: a comprehensive update of the literature

INTRODUCTION

Drug absorption is often altered and typically diminished in patients with short bowel syndrome (SBS). It is important to understand the patient's gastrointestinal anatomy, the absorptive capacity of the remaining bowel, and the physicochemical and pharmacokinetic properties of the drug to optimize oral pharmacotherapy.

AREAS COVERED

The primary focus was to provide an updated understanding of the absorption of various drugs in patients with short bowel syndrome. Forty-seven studies covering 13 different drug classes were included in the review and study details, patient characteristics, drug characteristics and pharmacokinetic findings were summarized for each drug class.

EXPERT OPINION

Improving and simplifying drug treatment in patients with SBS have high priority, but the patients are multi diseased so knowledge regarding absorption of drugs as e.g. antithrombotic agents, immunosuppressants is urgently needed. Therefore, it is crucial to advance our understanding of the fundamental factors involved in drug absorption, spanning from drug design to pathophysiology. With the growing knowledge in drug design and gastrointestinal pathophysiology, we anticipate the development of computer models that can accurately predict optimal absorption in the future.

Inositol hexaphosphate promotes intestinal adaptation in short bowel syndrome via an HDAC3-mediated epigenetic pathway

Background

Short bowel syndrome (SBS) has high morbidity and mortality rates, and promoting intestinal adaptation of the residual intestine is a critical treatment. Dietary inositol hexaphosphate (IP6) plays an important role in maintaining intestinal homeostasis, but its effect on SBS remains unclear. This study aimed at investigating the effect of IP6 on SBS and clarified its underlying mechanism.

Methods

Forty male Sprague-Dawley rats (3-week-old) were randomly assigned into four groups (Sham, Sham + IP6, SBS, and SBS + IP6 groups). Rats were fed standard pelleted rat chow and underwent resection of 75% of the small intestine after 1 week of acclimation. They received 1 mL IP6 treatment (2 mg/g) or sterile water daily for 13 days by gavage. Intestinal length, levels of inositol 1,4,5-trisphosphate (IP3), histone deacetylase 3 (HDAC3) activity, and proliferation of intestinal epithelial cell-6 (IEC-6) were detected.

Results

IP6 treatment increased the length of the residual intestine in rats with SBS. Furthermore, IP6 treatment caused an increase in body weight, intestinal mucosal weight, and IEC proliferation, and a decrease in intestinal permeability. IP6 treatment led to higher levels of IP3 in feces and serum, and higher HDAC3 activity of the intestine. Interestingly, HDAC3 activity was positively correlated with the levels of IP3 in feces (r = 0.49, P = 0.01) and serum (r = 0.44, P = 0.03). Consistently, IP3 treatment promoted the proliferation of IEC-6 cells by increasing HDAC3 activity in vitro. IP3 regulated the Forkhead box O3 (FOXO3)/Cyclin D1 (CCND1) signaling pathway.

Conclusion

IP6 treatment promotes intestinal adaptation in rats with SBS. IP6 is metabolized to IP3 to increase HDAC3 activity to regulate the FOXO3/CCND1 signaling pathway and may represent a potential therapeutic approach for patients with SBS.

Teduglutide in pediatric intestinal failure: A position statement of the Italian society of pediatric gastroenterology, hepatology and nutrition (SIGENP)

In recent years, the spectrum of possible treatments for Intestinal Failure (IF)-Short Bowel Syndrome (SBS) has been enriched by the implementation of GLP-2 analogues. In Italy, teduglutide (Ted), an analogue of GLP-2, was approved in January 2021 by the Italian Regulatory Agency for Drugs (AIFA) for IF-SBS patients ≥1 year old. According to the Agency indications, Ted can now be prescribed by regional reference centers, with costs fully charged to the National Health Service. Following pediatric-use approval in our country and in light of scarce evidence in childhood, the pediatric network for IF of the Italian Society for Pediatric Gastroenterology, Hepatology and Nutrition (SIGENP) planned to share management methods of Ted in pediatric IF. The main purpose was to identify the best candidates from a cost-effective perspective. Thus, focusing on available literature and on expert opinions, the present position statement provides consensus-based recommendations on the use of Ted for pediatric gastroenterologists and nutritionists treating children with SBS.

Proteomic biomarkers in short bowel syndrome : are we ready to use them in clinical activity?

Introduction: Short bowel syndrome (SBS) is a clinical condition that can affect childhood and adult patients. Biomarker research is expected to be a new frontier in the clinical application, helpful for patients and health-care systems.Areas covered: SBS is usually a consequence of a massive intestinal resection that leads to an intestinal failure because of the reduction of absorptive surface, bacterial overgrowth, and faster intestinal transit. This new condition requires a multidisciplinary expertise to achieve again digestive autonomy. Parental nutrition (PN) supports nutritional status in SBS patients while the new guidelines on intestinal transplantation confirm its strict indication only for patients at actual risk of death on PN. A PubMed literature review from the 1980s up to date was performed, highlighting proteomic biomarkers and growth factor therapies that have shown so far promising results in SBS patients.Expert opinion: Apart from a few specific biomarkers and growth factors, the discovery of specific molecular events is currently under investigation of the proteomic analysis and could potentially represent fundamental, future changes in prevention, diagnosis, therapeutic management, and experimental practices in SBS.

Short bowel syndrome in children and adults: from rehabilitation to transplantation

Short bowel syndrome (SBS) is a dramatic clinical condition in both children and adults; the residual bowel length is not sufficient to avoid intestinal failure, with subsequent malnutrition and growth retardation, and intravenous support is required to provide the nutrients normally coming from the intestine. Apart from the primary disease, the medical status can be worsened by complications of intestinal failure: if there are irreversible, the prognosis is poor unless a successful intestinal rehabilitation is achieved. Areas covered: The rescue of the remnant small bowel requires a multidisciplinary expertise to achieve digestive autonomy. The use of intestinal trophic factors has shown encouraging results in improving the intestinal adaptation process. Whenever the residual bowel length is inadequate, in a well-selected population weaning parenteral nutrition (PN) off could be attempted by surgery through lengthening procedures. A further subset of patients, with total and irreversible intestinal failure and severe complications on PN, may have an indication to intestinal transplantation. This procedure is still affected by poor long-term results. Expert commentary: Novel approaches developed through a multidisciplinary team work, such as manipulation of microbiota or tissue bioengineering, should be added to current therapies to treat successfully SBS.

Interdependency of EGF and GLP-2 Signaling in Attenuating Mucosal Atrophy in a Mouse Model of Parenteral Nutrition

BACKGROUND & AIMS

Total parenteral nutrition (TPN), a crucial treatment for patients who cannot receive enteral nutrition, is associated with mucosal atrophy, barrier dysfunction, and infectious complications. Glucagon-like peptide-2 (GLP-2) and epidermal growth factor (EGF) improve intestinal epithelial cell (IEC) responses and attenuate mucosal atrophy in several TPN models. However, it remains unclear whether these 2 factors use distinct or overlapping signaling pathways to improve IEC responses. We investigated the interaction of GLP-2 and EGF signaling in a mouse TPN model and in patients deprived of enteral nutrition.

METHODS

Adult C57BL/6J, IEC-Egfr^{knock out (KO)} and IEC-pik3r1^KO mice receiving TPN or enteral nutrition were treated with EGF or GLP-2 alone or in combination with reciprocal receptor inhibitors, GLP-2(3-33) or gefitinib. Jejunum was collected and mucosal atrophy and IEC responses were assessed by histologic, gene, and protein expression analyses. In patients undergoing planned looped ileostomies, fed and unfed ileum was analyzed.

RESULTS

Enteral nutrient deprivation reduced endogenous EGF and GLP-2 signaling in mice and human beings. In the mouse TPN model, exogenous EGF or GLP-2 attenuated mucosal atrophy and restored IEC proliferation. The beneficial effects of EGF and GLP-2 were decreased upon Gefitinib treatment and in TPN-treated IEC-Egfr^KO mice, showing epidermal growth factor-receptor dependency for these IEC responses. By contrast, in TPN-treated IEC-pi3kr1^KO mice, the beneficial actions of EGF were lost, although GLP-2 still attenuated mucosal atrophy.

CONCLUSIONS

Upon enteral nutrient deprivation, exogenous GLP-2 and EGF show strong interdependency for improving IEC responses. Understanding the differential requirements for phosphatidylinositol 3-kinase/phosphoAKT (Ser473) signaling may help improve future therapies to prevent mucosal atrophy.

Current and potential therapeutic targets of glucagon-like peptide-2

Glucagon-like peptide-2 (GLP-2) is a gut hormone that promotes highly specific growth and function of the intestinal epithelium. Recent studies have begun to elucidate the complex mechanism of action of GLP-2, which is mediated indirectly through other intestinal factors. Although a long-acting GLP-2 analog has recently been approved for treatment of adult patients with short bowel syndrome, there remain numerous conditions characterized by intestinal insufficiency for which pre-clinical studies, as well as some limited clinical data, support further consideration of GLP-2 for expanded therapeutic use.