Teduglutide: A Review of its Use in the Treatment of Patients with Short Bowel Syndrome

Exogenous Glucagon-like Peptide 2 Counteracts Exogenous Cholecystokinin-induced Gallbladder Contraction in Healthy Men

BACKGROUND AND OBJECTIVE

Studies in humans and mice have demonstrated that the gut hormone glucagon-like peptide 2 (GLP-2) promotes gallbladder relaxation and refilling. Here, we assessed the effect of exogenous GLP-2 on gallbladder motility in the fasted state of healthy men with and without infusion of the potent gallbladder-contracting hormone cholecystokinin (CCK).

METHODS

In a randomized, double-blind, placebo-controlled, crossover study, 15 male participants (mean [SD]: age 24.7 [3.6] years; body mass index 22.9 [1.6] kg/m2) underwent 4 experimental days receiving 2 infusions on each day: either CCK (0.4 pmol × kg-1 × min-1, time 0-180 minutes) + GLP-2 (10 pmol × kg-1 × min-1, time 30-240 minutes), CCK + placebo, placebo + GLP-2, or placebo + placebo, respectively. Gallbladder volume was measured at baseline and throughout the 4-hour study day using ultrasonography.

RESULTS

Compared to placebo + placebo, GLP-2 + placebo did not affect gallbladder volume, but when infused in combination with CCK, GLP-2 completely abolished the strong gallbladder-contracting effect seen during CCK + placebo infusion, restoring baseline levels of gallbladder volume.

CONCLUSION

Exogenous GLP-2 counteracts exogenous CCK-induced gallbladder emptying in healthy men, pointing to a possible therapeutic potential for GLP-2 as a relaxing modulator of gallbladder smooth muscle tone (eg, as a bridge to surgery in biliary colic). The effect may also explain the gallbladder-related adverse events reported for GLP-2 receptor agonists used in the treatment of short bowel syndrome.

CLINICAL TRIAL REGISTRATION NUMBER

NCT04651868.

Incretin hormones and obesity

The incretin hormones glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) play critical roles in co-ordinating postprandial metabolism, including modulation of insulin secretion and food intake. They are secreted from enteroendocrine cells in the intestinal epithelium following food ingestion, and act at multiple target sites including pancreatic islets and the brain. With the recent development of agonists targeting GLP-1 and GIP receptors for the treatment of type 2 diabetes and obesity, and the ongoing development of new incretin-based drugs with improved efficacy, there is great interest in understanding the physiology and pharmacology of these hormones.

Cholecystitis following the initiation of glucagon-like peptide-2 analogue for short bowel syndrome: A case report

Patients with short bowel syndrome (SBS) have a risk for cholelithiasis and cholecystitis, particularly those who have received long-term parenteral nutrition (PN). Teduglutide (Revestive), a glucagon-like peptide-2 (GLP-2) analogue, is the first effective therapy approved for treating patients with SBS via self-subcutaneous injection. It also pharmacologically inhibits gallbladder contraction, which may increase the risks for cholelithiasis and cholecystitis. Here, we report a case of cholecystitis occurring after the introduction of a GLP-2 analogue in a patient with SBS and cholelithiasis. A 16-year-old girl, with a residual intestinal anatomy of 5 cm jejunum and left colon, was referred to our hospital for further treatment of SBS. She underwent jejunocolic anastomosis 2 months later. After that, she received PN for 2.5 years. Teduglutide treatment was initiated to reduce PN dependence. Several asymptomatic gallbladder stones were found during a routine ultrasound examination before drug initiation. On day 31 of teduglutide treatment, right subcostal pain with fever occurred, and the patient was diagnosed with acute cholecystitis. GLP-2 analogue treatment was temporarily discontinued. The patient underwent gallbladder drainage followed by cholecystectomy 3 weeks later. Histopathological findings illustrated mucosal hyperplasia of the gallbladder. Her postoperative course was uneventful, and teduglutide was restarted 2 weeks postoperatively. GLP-2 analogues promote gallbladder refilling and epithelial hyperplasia, which may be a risk factor for cholecystitis in patients with cholelithiasis, as observed in our patient. Based on our experience, patients with SBS and established asymptomatic cholelithiasis may be considered for prophylactic cholecystectomy before the administration of GLP-2 analogues.

Pancreatitis Associated With Teduglutide: A Disproportionality Analysis via the Food and Drug Administration Adverse Event Reporting System (FAERS) Database

Introduction Teduglutide is a glucagon-like peptide-2 analog that is indicated for the treatment of short bowel syndrome (SBS) by reducing patient dependence on parenteral support. Due to the rarity of SBS as well as the recent timeline of the adoption of teduglutide, the safety of teduglutide is relatively poorly understood. Several recent clinical case reports have highlighted elevated pancreatic enzymes and pancreatitis as a concerning complication of teduglutide. This prompts a systematic study of the association between pancreatitis and teduglutide. Methods This study conducts a case-control design disproportionality analysis by using data from the US Food and Drug Administration Adverse Event Reporting System (FAERS). Reports from the first quarter of 2020 through the first quarter of 2024 were retrieved from this database, and a disproportionality analysis was conducted. The analysis consisted of traditional methods of analyzing adverse drug events such as the reporting odds ratio (ROR) and proportional reporting ratio (PRR), as well as Bayesian methods such as the empirical Bayes geometric mean (EBGM) and information component (IC). A confidence interval for ROR and PRR that excludes a ratio of 1 or a confidence interval for IC that excludes a score of 0 was used as the criterion for a statistically significant association between pancreatitis risk and teduglutide use. Results Out of 11,696 reports of teduglutide adverse effects in over four years of adverse effects data drawn from the FAERS database, 79 cases of pancreatitis were identified. The disproportionality analysis revealed an ROR of 3.73 (95% CI (2.99, 4.66)), a PRR of 3.71 (95% CI (2.97, 4.63)), an EBGM of 3.70, and an IC of 1.84 (95% CI (1.51, 2.16)). All of these statistics indicate a statistically significant association between pancreatitis risk and teduglutide use. Conclusion The results reveal a statistically significant association between pancreatitis risk and teduglutide use. Our findings highlight the necessity for the careful monitoring of pancreatitis in patients undergoing teduglutide therapy going forward.

Normothermic Preservation of the Intestinal Allograft

Intestinal allotransplantation was first described in the 1960s and successfully performed in the 1980s. Since that time, less progress has been made in the preservation of the allograft before transplantation and static cold storage remains the current standard. Normothermic machine perfusion represents an opportunity to simultaneously preserve, assess, and recondition the organ for transplantation and improve the procurement radius for allografts. The substantial progress made in the field during the last 60 years, coupled with the success of the preclinical animal model of machine perfusion-preserved intestinal transplantation, suggest we are approaching the point of clinical application.

An insight into the pharmacology of cysteine/methionine containing peptide drugs

Since last century, peptides have emerged as potential drugs with >90 FDA approvals for various targets with several in the pipeline. Sulphur, in peptides is present either as thiol (-SH) from Cys or thioether from Met. In this review, all the peptides approved by FDA since 2000 containing sulphur have been included. Among them ∼50 % contains disulphide bridges. This clearly demonstrates the significance of disulphide bonds in peptide drugs. This can be achieved synthetically by using orthogonal protecting groups (PGs) for -SH. These PGs are compatible with Solid Phase Peptide Synthesis (SPPS), which is still the method of choice for peptide synthesis. The orthogonal PGs used for Cys thiol side chain protecting for disulphide bond formation have been included which are currently in use both by academia and industry from small scale to large scale synthesis. In addition, the details of the FDA approved drugs containing Cys and Met (or both) have also been discussed.

Managing fluid balance and nutritional status in a short bowel syndrome patient awaiting intestinal transplant: a case report

BACKGROUND

Despite being a long-term therapy for patients with short bowel syndrome (SBS), subcutaneous injections of teduglutide promote the regeneration of the gastrointestinal tract. Such cases are particularly concerning for patients with residual small bowel.

METHODS

In this report, we present a case of an SBS patient with only 5 cm of remaining small bowel and a high-output duodenal stoma, who was treated with teduglutide.

RESULTS

The initiation of teduglutide injections in our patient resulted in a reduction of stoma output, improvement in the patient's nutritional status, regulation of fluid balance, and stabilization of their clinical condition.

CONCLUSIONS

This case suggests that subcutaneous injections of teduglutide, when combined with appropriate nutritional care, can effectively treat high-output stomas, even in cases where the small bowel is nearly absent.

Computational peptide discovery with a genetic programming approach

The development of peptides for therapeutic targets or biomarkers for disease diagnosis is a challenging task in protein engineering. Current approaches are tedious, often time-consuming and require complex laboratory data due to the vast search spaces that need to be considered. In silico methods can accelerate research and substantially reduce costs. Evolutionary algorithms are a promising approach for exploring large search spaces and can facilitate the discovery of new peptides. This study presents the development and use of a new variant of the genetic-programming-based POET algorithm, called POETRegex , where individuals are represented by a list of regular expressions. This algorithm was trained on a small curated dataset and employed to generate new peptides improving the sensitivity of peptides in magnetic resonance imaging with chemical exchange saturation transfer (CEST). The resulting model achieves a performance gain of 20% over the initial POET models and is able to predict a candidate peptide with a 58% performance increase compared to the gold-standard peptide. By combining the power of genetic programming with the flexibility of regular expressions, new peptide targets were identified that improve the sensitivity of detection by CEST. This approach provides a promising research direction for the efficient identification of peptides with therapeutic or diagnostic potential.

Expression, Purification and Characterization of Functional Teduglutide Using GST Fusion System in Prokaryotic Cells

Purpose

Teduglutide is the first and only FDA-approved drug for long-term treatment of short bowel syndrome (SBS). The current study aimed to present an approach for production of teduglutide using recombinant DNA technology.

Methods

The coding gene for teduglutide was cloned into pGEX-2T vector, where coding sequence for factor Xa cleavage site was added between GST and teduglutide coding genes. The GST-teduglutide protein was overexpressed in E. coli BL21 (DE3) strain and affinity purified using glutathione sepharose affinity column.

Results

On-column proteolytic activity of factor Xa followed by size exclusion chromatography resulted in the pure teduglutide. Circular dichroism (CD) spectropolarimetry showed that the produced teduglutide folds into mainly α-helical structure (>50%), as expected. In mass spectroscopy analysis, the fragments of teduglutide resulted by cyanogen bromide cleavage as well as those expected theoretically due to mass fragmentation were identified. The functionality of the produced peptide was evaluated by measuring its proliferative effect on Caco2 intestinal epithelial cells, and the results indicated that produced teduglutide induces cell proliferation by 19±0.30 and 33±7.82 % at 1.21 and 3.64 µM concentrations, respectively, compared to untreated cells.

Conclusion

Teduglutide was successfully expressed and purified and its functionality and structural integrity were confirmed by in vitro experiments. We believe that the experimental-scale method presented in the current study can be useful for pilot-scale and also industrial-scale production of teduglutide.

Comprehensive physicochemical characterization of a peptide-based medicine: Teduglutide (Revestive®) structural description and stress testing

Teduglutide (Revestive®) is a glucagon-like peptide-2 analogue used for the treatment of short bowel syndrome, a rare life-threatening condition in which the amount of functional gut is too short to enable proper absorption of nutrients and fluids. During handling prior to administration to the patient in hospital, it is possible that peptide-based medicines may be exposed to environmental stress conditions that could affect their quality. It is therefore essential to carry out stress testing studies to evaluate how such medicines respond to these stresses. For this reason, in this paper we present a strategy for a comprehensive analytical characterization of a peptide and a stress testing study in which it was subjected to various stress conditions: heating at 40 °C and 60 °C, light exposure and shaking. Several complementary analytical techniques were used throughout this study: Far UV circular dichroism, intrinsic protein fluorescence spectroscopy, dynamic light scattering, size-exclusion chromatography and intact and peptide mapping reverse-phase chromatography coupled to mass spectrometry. To the best of our knowledge, this is the first study to offer an in-depth description of the chemical structure of teduglutide peptide and its physicochemical characteristics after stress stimuli were applied to the reconstituted medicine Revestive®.

New insights into the structure and function of class B1 GPCRs

G protein-coupled receptors (GPCRs) are the largest family of cell surface receptors. Class B1 GPCRs constitute a subfamily of 15 receptors that characteristically contain large extracellular domains (ECDs) and respond to long polypeptide hormones. Class B1 GPCRs are critical regulators of homeostasis, and as such, many are important drug targets. While most transmembrane proteins, including GPCRs, are recalcitrant to crystallization, recent advances in electron cryo-microscopy (cryo-EM) have facilitated a rapid expansion of the structural understanding of membrane proteins. As a testament to this success, structures for all the class B1 receptors bound to G proteins have been determined by cryo-EM in the past five years. Further advances in cryo-EM have uncovered dynamics of these receptors, ligands, and signalling partners. Here, we examine the recent structural underpinnings of the class B1 GPCRs with an emphasis on structure-function relationships.

Therapeutic Potential of GLP-2 Analogs in Gastrointestinal Disorders: Current Knowledge, Nutritional Aspects, and Future Perspectives

PURPOSE OF REVIEW

Although Glucagon-like peptide (GLP)-1 receptor agonists have been used for almost two decades in the treatment of diabetes mellitus type 2 and, lately, in obesity, recent years have seen an increasing interest in the pharmacological agonism of other proglucagon-derived peptides, including GLP-2. Herein, we aimed to review the available evidence on the effects of GLP-2 agonism from animal and clinical studies. Furthermore, we summarize the current clinical applications of GLP-2 agonists among patients with intestinal failure associated with short bowel syndrome (SBS-IF) as well as potential future expansion of their indications to other intestinal disorders.

RECENT FINDINGS

Evidence from preclinical studies has highlighted the cellular trophic and functional beneficial actions of GLP-2 on small intestinal and colonic mucosa. Subsequently, pharmacologic agonism of GLP-2 has gathered interest for the treatment of patients with conditions pertaining to the loss of intestinal anatomical and/or functional integrity to a degree requiring parenteral support, collectively referred to as intestinal failure. GLP-2 analogs positively influence nutrient absorption in animal models and humans, although continued therapy is likely needed for sustained effects. The degradation-resistant GLP-2-analog teduglutide has received approval for the treatment of SBS-IF, in which it may decisively reduce patient dependency on parenteral support and improve quality of life. Another two longer-acting analogs, glepaglutide and apraglutide, are currently undergoing phase III clinical trials. The use of GLP-2 analogs is effective in the management of SBS-IF and may show promise in the treatment of other severe gastrointestinal disorders associated with loss of effective intestinal resorptive surface area.

Method for identification and quantification of intact teduglutide peptide using (RP)UHPLC-UV-(HESI/ORBITRAP)MS

Teduglutide (Revestive®, 10 mg mL^-1) is a recombinant human glucagon-like peptide 2 analogue, used in the treatment of short bowel syndrome, a serious and highly disabling condition which results from either too small a length of intestine or loss of critical intestinal function. The determination of therapeutic compounds of protein-nature is always challenging due to their complex structure. In this work, we present a fast, straightforward reversed phase (RP)UHPLC-UV-(HESI/ORBITRAP)MS method for the identification and quantification of the intact teduglutide peptide. The method has been developed and validated in accordance with the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use (ICH) guidelines; therefore, linearity, limits of detection and quantification, accuracy (precision and trueness), robustness, system suitability and specificity using the signal from the UV and MS, have been evaluated. The validation performance parameters obtained from the UV and MS signals were compared throughout the work, to select the most suitable. To study the specificity of the method and the impact of medicine mishandling under hospital conditions, force degradation studies were performed, i.e. thermal (40 °C and 60 °C), shaking (mechanical) and light (accelerated exposition) effects. Identification by the exact mass of teduglutide was achieved and it was confirmed that the peptide does not undergo any post-translational modifications (PTMs). To the best of our knowledge, the present work reports the first method developed for the simultaneous identification, structural characterization, and quantification of the therapeutic teduglutide peptide. Finally, the proposed method is able to indicate stability when quantifying the intact teduglutide since detects and characterises the exact mass of the degradation/modification products.

Tracking the physicochemical stability of teduglutide (Revestive®) clinical solutions over time in different storage containers

Teduglutide, the active ingredient of the medicine Revestive® (5 mg), is a recombinant therapeutic peptide that mimics the effects of the endogenous glucagon-like peptide 2 (GLP-2). It stimulates intestinal growth, adaptation and function in patients with Short Bowel Syndrome who are dependent on parenteral nutrition. The Summary of Product Characteristics recommends immediate use of the reconstituted solutions and the discarding of any subsequent surplus. This study aims to carry out a long-term stability study that reproduces hospital conditions of use which provide sound evidence regarding the use of teduglutide surplus beyond the Summary Product Characteristics recommendations. We conducted a stability study of teduglutide solutions prepared from a 5 mg vial of Revestive®. Some of the solutions were stored in their original vial after reconstitution, while others were repackaged in plastic syringes to evaluate their physicochemical stability over time. For this purpose, we applied a set of previously validated analytical methodologies to evaluate the main critical quality attributes of teduglutide, i.e., primary (including post-tralational modifications), secondary and tertiary structures, aggregates, particulate, concentration and pH. The results indicate that the solutions maintain high physicochemical stability over time, regardless of the storage temperature (4ºC or -20ºC) or the storage container (vials or syringes). This research provides new data on the stability of Revestive® that will be of great value to hospital pharmacists. This comprehensive assessment of the physicochemical long-term stability of TGT has demonstrated that under the storage conditions and over the period studied here, the medicine maintains its quality, efficacy and safety profiles.

Improvement in metabolic indices including thyroid hormones via enhanced absorption of nutrients by Teduglutide in short bowel syndrome

Introduction and importance

Short bowel syndrome is characterized by maldigestion and malabsorption resulting in deficiencies of multiple nutrients including vitamins and minerals. Most subjects required parental elimination for survival. GLP-2 RA Teduglutide was recently approved for treatment of short bowel syndrome especially for those requiring parenteral support. Our intent in reporting this subject is to demonstrate the utility of Teduglutide in improving multiple metabolic indices in presence of short bowel syndrome.

Case presentation and clinical discussion

66-year-old Caucasian female presented with a history of short bowel syndrome and associated vitamin deficiencies, hypothyroidism requiring large dose (300 μg) of levothyroxine, diarrhea and liver cirrhosis. Upon starting teduglutide the subject saw improvement in her symptoms. Moreover, daily dose of Levothyroxine required a gradual decrease to maintain desirable serum concentrations of Free T4, Free T3 and TSH. Serum levels of several vitamins attained greater than therapeutic concentrations requiring dosage reductions. Also notable was the improvement in her liver function tests, remission from ascites and episodes of hepatic encephalopathy and regeneration of liver nodules.

Conclusion

Following administration of GLP2 therapy, an adult subject with short bowel syndrome with concurrent hypothyroidism and multiple vitamin deficiencies, demonstrated a marked improvement in her metabolic parameters resulting in reduction in daily medication doses along with improvement in manifestations of liver cirrhosis.

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Unique case report of remission of Metabolic abnormalities

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hepatic cirrhosis and encephalopathy following administration of GLP2 receptor agonist in a patient

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short bowel syndrome

Changes in Parenteral Nutrition Requirements and BMI in Patients with Parenteral Nutrition-Dependent Short Bowel Syndrome after Stopping Teduglutide-9 Years of Follow-Up

Teduglutide (TED) is widely used in patients with short-bowel-syndrome-associated intestinal failure (SBS-IF) to enhance intestinal adaptation and reduce the need for parenteral support (PS). There are limited data on the effects of discontinuing TED. In this study, we describe the changes in parenteral nutrition (PN) requirements and body mass index (BMI) in a 9-year follow-up of patients receiving home parenteral nutrition after discontinuation of the TED treatment. We performed a retrospective analysis of changes in weekly PN orders and BMI in all patients with PN-dependent SBS from two Polish home parenteral nutrition (HPN) centers who received teduglutide between 2009 and 2013 and still required HPN 9 years after discontinuation of the TED treatment. Data included in the analysis were collected prospectively at mandatory visits to the HPN centers at 12, 24, 60, 84, and 108 months after drug discontinuation and compared with values before and after TED treatment. Weekly PN volume values varied significantly between all of the above time points from baseline to 9 years after TED discontinuation (χ2 = 34.860, p < 0.001). After an initial increase within the first year after treatment discontinuation (not statistically significant), the PN volume requirements remained stable for 4 years and increased 5−9 years after treatment discontinuation. The rate of patients requiring an increase in PN volume was 84.62% at 60 and 84 months and 92.30% at 108 months. At 9 years after cessation of the TED treatment, 53.85% of the study group required a 21.21% increase in PN volume compared with values before treatment. The need for PN volume in patients with PN-dependent SBS who discontinued the TED treatment increased within the first year and 4−5 years after treatment cessation, and in some cases might even exceed pretreatment values after 9 years.

An updated overview of glucagon-like peptide-2 analog trophic therapy for short bowel syndrome in adults

Short bowel syndrome (SBS) is a clinical condition characterized by a failure to achieve optimal intestinal adaptation, which is necessary to maintain oral/enteral autonomy. At present, the treatment options for SBS are primarily intestinal replacement and rehabilitation. Intestinal rehabilitation mainly includes non-transplantation surgery and intestinal rehabilitation measures. In recent years, intestinal rehabilitation in patients with SBS using nutritional intestinal hormones, especially glucagon-like peptide-2 analogs, has made great progress. Many high-quality studies have provided evidence-based medical findings to support the development of clinical guidelines. This article reviews the latest research advancements regarding the use of glucagon-like peptide-2 analogs (teduglutide, glepaglutide, and apraglutide) in the treatment of SBS.

Therapeutic peptides: current applications and future directions

Peptide drug development has made great progress in the last decade thanks to new production, modification, and analytic technologies. Peptides have been produced and modified using both chemical and biological methods, together with novel design and delivery strategies, which have helped to overcome the inherent drawbacks of peptides and have allowed the continued advancement of this field. A wide variety of natural and modified peptides have been obtained and studied, covering multiple therapeutic areas. This review summarizes the efforts and achievements in peptide drug discovery, production, and modification, and their current applications. We also discuss the value and challenges associated with future developments in therapeutic peptides.

The Enteroendocrine System in Obesity

The enteroendocrine system coordinates the physiological response to food intake by regulating rates of digestion, nutrient absorption, insulin secretion, satiation and satiety. Gut hormones with important anorexigenic and/or insulinotropic roles include glucagon-like peptide 1 (GLP-1), peptide YY (PYY_3-36), cholecystokinin (CCK) and glucose-dependent insulinotropic peptide (GIP). High BMI or obesogenic diets do not markedly disrupt this enteroendocrine system, which represents a critical target for inducing weight loss and treating co-morbidities in individuals with obesity.

Population pharmacokinetics and exposure-response analyses of teduglutide in adult and pediatric patients with short bowel syndrome

Teduglutide is a recombinant analog of human glucagon‐like peptide‐2 that regulates the functional and structural integrity of the cells lining the gastrointestinal tract. Teduglutide is approved for the treatment of patients with short bowel syndrome (SBS) who are dependent on parenteral support (PS). Population pharmacokinetic (PK) and exposure‐response analyses were performed to support teduglutide dosing in patients with SBS. The analysis included 219 patients with SBS (aged <1 year, 5 patients; 1–11 years, 86 patients; 12–17 years, 8 patients; 18–79 years, 120 patients), and 259 non‐SBS subjects (including healthy volunteers and subjects with renal or liver impairment). A one‐compartment model with first‐order absorption and linear elimination adequately characterized the PKs of teduglutide. In patients with SBS, the apparent clearance (CL/F), volume of distribution (V/F), and elimination half‐life of teduglutide were 16.0 L/h, 33.9 L, and 1.47 h, respectively. CL/F depended on body weight and renal function, and V/F depended on body weight and age. Maximum concentration (C_max) of teduglutide was similar in adult and pediatric patients, and in Japanese and non‐Japanese patients. A time‐ and exposure‐response model dependent on the C_max of teduglutide adequately characterized the reduction in PS over more than 2 years of treatment. Daily dosing of 0.05 mg/kg teduglutide resulted in a maximum reduction in PS of 5.76 L/week. Higher C_max values were associated with a more important reduction in PS over time. Adult and pediatric patients with SBS presented similar PKs and response to teduglutide.

Expression, purification and molecular dynamics simulation of extracellular domain of glucagon-like peptide-2 receptor linked to teduglutide

Teduglutide is the only drug approved for long-term treatment of short bowel syndrome (SBS). This drug exerts its pharmacological effects via binding to the GLP-2 receptors (ECD-GLP2R) located in intestinal tissue. The three dimensional (3D) structure of ECD-GLP2R hasn't been determined yet and hence its mode of interaction with agonists/antagonists is not clear. Therefore, it would be of great importance to develop a structural scaffold for investigation of ECD-GLP2R interactions with its binders. For this, the current study aimed to produce fusion protein of ECD-GLP2R-teduglutide. The ECD-GLP2R-teduglutide protein was expressed in bacterial expression system and purified using affinity and size exclusion chromatography techniques. Using circular dichroism the secondary structure content of purified protein was determined which was comparable to that of theoretical calculations. The low structural stability of purified protein (ΔG = 3.64 kJ.mol^-1) was elucidated by monitoring its fluorescence emission at the presence of various concentrations of GdnHCl as a denaturant. Finally, a 3D model for ECD-GLP2R-teduglutide protein was generated and validated using molecular dynamics simulation whose information alongside the experimental studies can be useful for providing new insight into the mode of interaction of ECD-GLP2R with its specific ligands in order to design potent and specific GLP2R agonists.

Clustering of Zika Viruses Originating from Different Geographical Regions using Computational Sequence Descriptors

BACKGROUND

In this report, we consider a data set, which consists of 310 Zika virus genome sequences taken from different continents, Africa, Asia and South America. The sequences, which were compiled from GenBank, were derived from the host cells of different mammalian species (Simiiformes, Aedes opok, Aedes africanus, Aedes luteocephalus, Aedes dalzieli, Aedes aegypti, and Homo sapiens).

METHODS

For chemometrical treatment, the sequences have been represented by sequence descriptors derived from their graphs or neighborhood matrices. The set was analyzed with three chemometrical methods: Mahalanobis distances, principal component analysis (PCA) and self organizing maps (SOM). A good separation of samples with respect to the region of origin was observed using these three methods.

RESULTS

Study of 310 Zika virus genome sequences from different continents. To characterize and compare Zika virus sequences from around the world using alignment-free sequence comparison and chemometrical methods.

CONCLUSION

Mahalanobis distance analysis, self organizing maps, principal components were used to carry out the chemometrical analyses of the Zika sequence data. Genome sequences are clustered with respect to the region of origin (continent, country). Africa samples are well separated from Asian and South American ones.

Designing Novel Teduglutide Analogues with Improved Binding Affinity: An In Silico Peptide Engineering Approach

INTRODUCTION

Short bowel syndrome (SBS) is a disabling condition that occurs following the loss of substantial portions of the intestine, leading to inadequate absorption of nutrients and fluids. Teduglutide is the only drug that has been FDA-approved for long-term treatment of SBS. This medicine exerts its biological effects through binding to the GLP-2 receptor.

METHODS

The current study aimed to use computational mutagenesis approaches to design novel potent analogues of teduglutide. To this end, the constructed teduglutide-GLP2R 3D model was subjected to the alanine scanning mutagenesis where ARG²⁰, PHE²², ILE²³, LEU²⁶, ILE²⁷ and LYS³⁰ were identified as the key amino acids involved in ligand-receptor interaction. In order to design potent teduglutide analogues, using MAESTROweb machine learning method, the residues of teduglutide were virtually mutated into all naturally occurring amino acids and the affinity improving mutations were selected for further analysis using PDBePISA methodology which interactively investigates the interactions established at the interfaces of macromolecules.

RESULTS

The calculations resulted in D15I, D15L, D15M and N24M mutations, which can improve the binding ability of the ligand to the receptor. The final evaluation of identified mutations was performed by molecular dynamics simulations, indicating that D15I and D15M are the most reliable mutations to increase teduglutide affinity towards its receptor.

CONCLUSION

The findings in the current study may facilitate designing more potent teduglutide analogues leading to the development of novel treatments in short bowel syndrome.

Experience With Teduglutide in Pediatric Short Bowel Syndrome: First Real-life Data

OBJECTIVES

The aim of the study was to describe the experience with teduglutide of several Spanish hospitals in pediatric patients with SBS (SBS).

METHODS

Seventeen pediatric patients with intestinal failure associated with SBS were treated with teduglutide. Patients received 0.05 mg · kg · day of subcutaneous teduglutide. Patients' demographics and changes in parenteral nutrition (PN) needs, fecal losses, and citrulline level initially and at 3, 6, and 12 months were collected, as well as any adverse events.

RESULTS

Patients were receiving 55 ml · kg · day and 33 kcal · kg · day of parenteral supplementation on average at baseline (2 patients received only hydroelectrolytic solution). A total of 12/17 patients achieved parenteral independence: 3 patients after 3 months of treatment, 4 patients at 6 months, and 5 after 12 months. One patient discontinued treatment 1 year after the beginning as no changes in parenteral support or fecal losses were obtained. All others decreased their intravenous requirements by 50%. One patient suffered an episode of cholecystitis, and another one with a pre-existing cardiac disease, developed a cardiac decompensation.

CONCLUSIONS

Teduglutide seems to be a safe and effective treatment in the pediatric SBS population with better results than in the pivotal study as well as in the adult population.

Glucagon-Like Peptide-2 Analogue ZP1849 Augments Colonic Anastomotic Wound Healing

Background

The enteroendocrine hormone glucagon-like peptide- (GLP-) 2 is a potent trophic factor in the gastrointestinal tract. The GLP-2 receptor (GLP-2R) is expressed in the stroma of the large bowel wall, which is the major therapeutic target area to prevent anastomotic leakage. We investigated the efficacy of the long-acting GLP-2 analogue ZP1849 on colonic anastomotic wound healing.

Methods

Eighty-seven male Wistar rats were stratified into four groups and received daily treatment with vehicle or ZP1849 starting one day before (day -1) end-to-end anastomosis was constructed in the left colon on day 0, and on days 0 (resected colon segment), 3, and 5, gene expressions of GLP-2R, Ki67, insulin-like growth factor- (IGF-) 1, type I (COL1A1) and type III (COL3A1) procollagens, cyclooxygenase- (COX-) 1, COX-2, and matrix metalloproteinase- (MMP-) 7 were quantified by RT-qPCR. Breaking strength, myeloperoxidase (MPO), transforming growth factor- (TGF-) β1, and soluble collagen proteins were measured on days 3 and 5.

Results

ZP1849 treatment increased Ki67 (P < 0.0001) and IGF-1 (P < 0.05) mRNA levels in noninjured colon day 0, and postoperatively in the anastomotic wounds compared to vehicle-treated rats. ZP1849-treated rats had increased (P = 0.042) anastomotic breaking strength at day 5 compared with vehicle. COL1A1 and COL3A1 mRNA levels (P < 0.0001) and soluble collagen proteins (P < 0.05) increased from day 3 to day 5 in ZP1849-treated rats, but not in vehicle-treated rats. COX-2 mRNA and MPO protein levels decreased from day 3 to day 5 (P < 0.001) in both groups. ZP1849 treatment reduced TGF-β1 protein levels on day 5 (P < 0.001) but did not impact MMP-7 transcription.

Conclusions

The GLP-2 analogue ZP1849 increased breaking strength, IGF-1 expression, and cell proliferation, which may be beneficial for colonic anastomotic wound healing.

Pharmacological Characterization of Apraglutide, a Novel Long-Acting Peptidic Glucagon-Like Peptide-2 Agonist, for the Treatment of Short Bowel Syndrome

Glucagon-like peptide-2 (GLP-2) agonists have therapeutic potential in clinical indications in which the integrity or absorptive function of the intestinal mucosa is compromised, such as in short bowel syndrome (SBS). Native hGLP-2, a 33-amino acid peptide secreted from the small intestine, contributes to nutritional absorption but has a very short half-life because of enzymatic cleavage and renal clearance and thus is of limited therapeutic value. The GLP-2 analog teduglutide (Revestive/Gattex; Shire Inc.) has been approved for use in SBS since 2012 but has a once-daily injection regimen. Pharmacokinetic (PK) and pharmacodynamic studies confirm that apraglutide, a novel GLP-2 analog, has very low clearance, long elimination half-life, and high plasma protein binding compared with GLP-2 analogs teduglutide and glepaglutide. Apraglutide and teduglutide retain potency and selectivity at the GLP-2 receptor comparable to native hGLP-2, whereas glepaglutide was less potent and less selective. In rat intravenous PK studies, hGLP-2, teduglutide, glepaglutide, and apraglutide had clearances of 25, 9.9, 2.8, and 0.27 ml/kg per minute, respectively, and elimination half-lives of 6.4, 19, 16, and 159 minutes, respectively. The unique PK profile of apraglutide administered via intravenous and subcutaneous routes was confirmed in monkey and minipig and translated into significantly greater in vivo pharmacodynamic activity, measured as small intestinal growth in rats. Apraglutide showed greater intestinotrophic activity than the other peptides when administered at less-frequent dosing intervals because of its prolonged half-life. We postulate that apraglutide offers several advantages over existing GLP-2 analogs and is an excellent candidate for the treatment of gastrointestinal diseases, such as SBS. SIGNIFICANCE STATEMENT: Apraglutide is a potent and selective GLP-2 agonist with an extremely low clearance and prolonged elimination half-life, which differentiates it from teduglutide (the only approved GLP-2 agonist). The enhanced pharmacokinetics of apraglutide will benefit patients by enabling a reduced dosing frequency and removing the need for daily injections.

Prevention of aspartimide formation during peptide synthesis using cyanosulfurylides as carboxylic acid-protecting groups

Although peptide chemistry has made great progress, the frequent occurrence of aspartimide formation during peptide synthesis remains a formidable challenge. Aspartimide formation leads to low yields in addition to costly purification or even inaccessible peptide sequences. Here, we report an alternative approach to address this longstanding challenge of peptide synthesis by utilizing cyanosulfurylides to mask carboxylic acids by a stable C-C bond. These functional groups-formally zwitterionic species-are exceptionally stable to all common manipulations and impart improved solubility during synthesis. Deprotection is readily and rapidly achieved under aqueous conditions with electrophilic halogenating agents via a highly selective C-C bond cleavage reaction. This protecting group is employed for the synthesis of a range of peptides and proteins including teduglutide, ubiquitin, and the low-density lipoprotein class A. This protecting group strategy has the potential to overcome one of the most difficult aspects of modern peptide chemistry.

Functional, Diagnostic and Therapeutic Aspects of Gastrointestinal Hormones

Gastrointestinal (GI) hormones are essential to many physiologic functions in our body. They have many GI and extra-GI functions. Some of the functions of these hormones, which have GI and extra-GI sources, are still unknown. Specific GI hormones can affect the brain to control food intake, while others can proliferate normal and neoplastic tissue when their receptors are expressed in certain neoplasms. GI hormones also have many diagnostic and therapeutic roles. Physiologic and pathophysiologic aspects as well as the diagnostic and therapeutic values of GI hormones are elaborated in this review.

Intestinal inflammatory and redox responses to the perioperative administration of teduglutide in rats

Purpose:

To investigate the inflammatory and redox responses to teduglutide on an animal model of laparotomy and intestinal anastomosis.

Methods:

Wistar rats (n=62) were allocated into four groups: "Ileal Resection and Anastomosis" vs. "Laparotomy", each one split into "Postoperative Teduglutide Administration" vs. "No Treatment"; and euthanized at the third or the seventh day. Ileal and blood samples were recovered at the baseline and at the euthanasia. Flow cytometry was used to study the inflammatory response (IL-1α, MCP-1, TNF-α, IFN-γ and IL-4 levels), oxidative stress (cytosolic peroxides, mitochondrial reactive species, intracellular glutathione and mitochondrial membrane potential) and cellular viability and death (annexin V/propidium iodide double staining).

Results:

Postoperative teduglutide treatment was associated with higher cellular viability index and lower early apoptosis ratio at the seventh day; higher cytosolic peroxides level at the third day and mitochondrial overgeneration of reactive species at the seventh day; higher tissue concentration of IL-4 and lower local pro-to-anti-inflammatory cytokines ratio at the seventh day.

Conclusion:

Those findings suggest an intestinal pro-oxidative and anti-inflammatory influence of teduglutide on the peri-operative context with a potential interference in the intestinal anastomotic healing.

Teduglutide: A Review in Short Bowel Syndrome

Subcutaneous teduglutide (Revestive^®), a glucagon-like peptide-2 analogue that increases intestinal absorption, is approved in the EU for the treatment of short bowel syndrome (SBS) in patients aged ≥1 year who are stable following a period of postsurgical intestinal adaptation. In a phase III trial in adults with SBS intestinal failure (IF) dependent on parenteral support (PS), a significantly greater proportion of teduglutide 0.05 mg/kg/day than placebo recipients achieved a ≥20% reduction in weekly PS volume from baseline to week 20 and maintained it to week 24. The proportion of patients who had a reduction in one or more days on PS was also significant with teduglutide compared with placebo. Improved intestinal absorption and reduced PS requirements were generally maintained in the longer term. Results from a phase III trial in paediatric patients with SBS-IF dependent on PS were consistent with those in adults. Adverse events were mostly of mild to moderate severity and generally consistent with the underlying condition or known mechanism of the drug (e.g. central line-related issues, gastrointestinal events). Teduglutide is therefore a useful treatment option in children (aged ≥1 year), adolescents and adults with SBS.

Intestinal Epithelial Stem Cells: Distinct Behavior After Surgical Injury and Teduglutide Administration

BACKGROUND

Previous studies suggest that intestinal epithelial stem cells (IESC), critical drivers of homeostasis and regeneration, include two subpopulations: crypt-based columnar and "position +4" stem cells, identified by Lgr5 and Bmi1 biomarkers, respectively. Teduglutide is an enterotrophic counterpart of glucagon-like peptide 2. This study aimed to investigate the response of putative IESC to surgical injury and teduglutide administration on an animal model of intestinal resection and anastomosis.

METHODS

Wistar rats (n = 59) were distributed into four groups: "Ileal Resection" versus "Laparotomy", subsequently subdivided into "Postoperative Teduglutide Administration" versus "No Treatment"; and sacrificed at third or seventh days, with ileal sample harvesting. Flow cytometry was used to analyze epithelial stem cells with monoclonal antibodies against Lgr5, Bmi1 and also CD44, CD24, CD166, and Grp78 surface markers.

RESULTS

Surgical trauma induced an increase of epithelial stem cells population at third day (9.0 ± 0.3 versus 5.7 ± 0.3%, p = 0.0001), which was more intense and involved all subpopulations after ileal resection. At seventh day, teduglutide was significantly associated with higher proportion of Lgr5⁺/Bmi1^- cells (5.8 ± 0.1 versus 2.9 ± 0.3%, p = 0.005) and, on the contrary, lower percentage of Lgr5^-/Bmi1⁺ cells (0.03 ± 0.01 versus 1.9 ± 0.1%, p = 0.049) after ileal resection; and higher proportion of Lgr5⁺/Bmi1⁺ cells (1.7 ± 0.1 versus 1.1 ± 0.2%, p = 0.028) after isolated laparotomy. After surgery, Lgr5⁺/Bmi1^- and Lgr5^-/Bmi1⁺ subpopulations demonstrated an inverse correlation and both correlated negatively with Grp78 labeling index. Lgr5^-/Bmi1⁺ and CD44⁺/CD24^low/CD166⁺/Grp78⁺ cells proportions exhibited a high grade positive correlation.

CONCLUSION

Those observations support the existence of two epithelial stem cells subpopulations with distinct behavior after surgical injury and teduglutide treatment.

New insights and interventions for short bowel syndrome

PURPOSE OF REVIEW

This review summarizes recent innovations in the treatment of patients with short bowel syndrome.

RECENT FINDINGS

The use of surgical procedures, growth factor stimulation, and bioengineering approaches to increase absorptive surface area of the intestine is examined. While the morphology of the intestine is clearly altered by these interventions, it is less clear that the overall function of the intestine is improved.

SUMMARY

Continued innovations will likely bring about new therapeutic options for patients with short bowel syndrome. Careful evaluations of the impact of these interventions await controlled clinical trials.

Alveolar Rhabdomyosarcoma in a 69-Year-Old Woman Receiving Glucagon-Like Peptide-2 Therapy

A 69-year-old woman was diagnosed with alveolar rhabdomyosarcoma (ARMS) of the nasopharynx. She has a history of catastrophic thromboembolic event in the abdomen that caused short-gut syndrome and dependence on total parenteral nutrition (TPN) twelve hours per day. She was treated for short-gut syndrome with teduglutide, a glucagon-like peptide-2 (GLP-2) analog, which led to reduction of TPN requirements. However, a few months later, she developed metastatic alveolar rhabdomyosarcoma. Though a causative relationship is unlikely between the peptide and ARMS due to the brief time course between teduglutide therapy and sarcoma diagnosis, neoplastic growth may have been accelerated by the GLP-2 analog, causing release of IGF-1. The transmembrane receptor for IGF-1 is frequently overexpressed in ARMS and is implicated in cell proliferation and metastatic behavior. This case describes a rare incidence of metastatic alveolar rhabdomyosarcoma in a sexagenarian and possibly the first case reported associated with the use of teduglutide. Teduglutide was discontinued due to a potential theoretical risk of acceleration of sarcoma growth, and the patient's rhabdomyosarcoma is in remission following sarcoma chemotherapy.

Novel delivery systems for improving the clinical use of peptides

Peptides have long been recognized as a promising group of therapeutic substances to treat various diseases. Delivery systems for peptides have been under development since the discovery of insulin for the treatment of diabetes. The challenge of using peptides as drugs arises from their poor bioavailability resulting from the low permeability of biological membranes and their instability. Currently, subcutaneous injection is clinically the most common administration route for peptides. This route is cost-effective and suitable for self-administration, and the development of appropriate dosing equipment has made performing the repeated injections relatively easy; however, only few clinical subcutaneous peptide delivery systems provide sustained peptide release. As a result, frequent injections are needed, which may cause discomfort and additional risks resulting from a poor administration technique. Controlled peptide delivery systems, able to provide required therapeutic plasma concentrations over an extended period, are needed to increase peptide safety and patient compliancy. In this review, we summarize the current peptidergic drugs, future developments, and parenteral peptide delivery systems. Special emphasis is given to porous silicon, a novel material in peptide delivery. Biodegradable and biocompatible porous silicon possesses some unique properties, such as the ability to carry exceptional high peptide payloads and to modify peptide release extensively. We have successfully developed porous silicon as a carrier material for improved parenteral peptide delivery. Nanotechnology, with its different delivery systems, will enable better use of peptides in several therapeutic applications in the near future.

Glucagon--Early breakthroughs and recent discoveries

Glucagon was discovered in 1922 as a hyperglycemic factor in the pancreas. During its early history up to 1970, glucagon was shown to increase circulating glucose through stimulating glycogenolysis in the liver. It was also shown to be a constituent of islet non-β cells and to signal through G protein coupled receptors and cyclic AMP. Furthermore, its chemical characteristics, including amino acid sequence, and its processing from the preproglucagon gene had been established. During the modern research during the last 40 years, glucagon has been established as a key hormone in the regulation of glucose homeostasis, including a key role for the glucose counterregulation to hypoglycemia and for development of type 2 diabetes, and today glucagon is a potential target for treatment of the disease. Glucagon has also been shown to be a key factor beyond glucose control and involved in many processes. For the coming, future research, studies will be focused on α-cell biology beyond glucagon, hyperglucagonemia in other conditions than diabetes, its involvement in the regulation of body weight and energy expenditure and the potential of glucagon as a target for other diseases than type 2 diabetes, such as type 1 diabetes and obesity. This review summarizes the more than 90 years history of this important hormone as well as discusses potential future research regarding glucagon.

Glucose absorption in small intestinal diseases

Recent developments in the field of diabetes and obesity management have established the central role of the gut in glucose homeostasis; not only is the gut the primary absorptive site, but it also triggers neurohumoral feedback responses that regulate the pre- and post-absorptive phases of glucose metabolism. Structural and/or functional disorders of the intestine have the capacity to enhance (e.g.: diabetes) or inhibit (e.g.: short-gut syndrome, critical illness) glucose absorption, with potentially detrimental outcomes. In this review, we first describe the normal physiology of glucose absorption and outline the methods by which it can be quantified. Then we focus on the structural and functional changes in the small intestine associated with obesity, critical illness, short gut syndrome and other malabsorptive states, and particularly Type 2 diabetes, which can impact upon carbohydrate absorption and overall glucose homeostasis.