Oral Semaglutide, the First Ingestible Glucagon-Like Peptide-1 Receptor Agonist: Could It Be a Magic Bullet for Type 2 Diabetes?

Bile acid metabolism and signaling in health and disease: molecular mechanisms and therapeutic targets

Bile acids, once considered mere dietary surfactants, now emerge as critical modulators of macronutrient (lipid, carbohydrate, protein) metabolism and the systemic pro-inflammatory/anti-inflammatory balance. Bile acid metabolism and signaling pathways play a crucial role in protecting against, or if aberrant, inducing cardiometabolic, inflammatory, and neoplastic conditions, strongly influencing health and disease. No curative treatment exists for any bile acid influenced disease, while the most promising and well-developed bile acid therapeutic was recently rejected by the FDA. Here, we provide a bottom-up approach on bile acids, mechanistically explaining their biochemistry, physiology, and pharmacology at canonical and non-canonical receptors. Using this mechanistic model of bile acids, we explain how abnormal bile acid physiology drives disease pathogenesis, emphasizing how ceramide synthesis may serve as a unifying pathogenic feature for cardiometabolic diseases. We provide an in-depth summary on pre-existing bile acid receptor modulators, explain their shortcomings, and propose solutions for how they may be remedied. Lastly, we rationalize novel targets for further translational drug discovery and provide future perspectives. Rather than dismissing bile acid therapeutics due to recent setbacks, we believe that there is immense clinical potential and a high likelihood for the future success of bile acid therapeutics.

Real-World Use of Oral and Subcutaneous Semaglutide in Routine Clinical Practice in the UK: A Single-Centre, Retrospective Observational Study

INTRODUCTION

Semaglutide, the only glucagon-like peptide-1 receptor agonist (GLP-1 RA) available in subcutaneous and oral formulation for treatment of type 2 diabetes (T2D), has demonstrated clinically significant improvements in glycaemic control and weight in clinical trials. This study aimed to gain insights into the use of both formulations and evaluate their clinical effectiveness in a secondary care clinic in Wales.

METHODS

This was a retrospective observational analysis of adults with T2D initiated on oral or subcutaneous semaglutide. Changes from baseline in glycated haemoglobin (HbA1c), weight and other metabolic parameters were evaluated.

RESULTS

At baseline, participants (n = 103) had a mean age of 57.3 years, mean HbA1c of 79.1 mmol/mol (9.38%), mean weight of 111.8 kg and body mass index (BMI) of 39.6 kg/m2 (no statistically significant differences between oral and subcutaneous groups). At 6-month follow-up, statistically significant improvements in HbA1c (- 19.3 mmol/mol [- 1.77%] and - 20.8 mmol/mol [- 1.90%]), body weight (- 9.0 kg and - 7.2 kg), and BMI (- 3.3 kg/m2 and - 2.5 kg/m2) were observed for oral and subcutaneous semaglutide, respectively. No statistically significant differences between the formulations were observed, and safety profiles were comparable.

CONCLUSIONS

Both formulations of semaglutide provided clinically and statistically significant reductions in HbA1c and weight in real-world practice. Oral GLP-1 RA may offer a practical and effective option for the management of T2D.

Neurolysin Knockout Mice in a Diet-Induced Obesity Model

Neurolysin oligopeptidase (E.C.3.4.24.16; Nln), a member of the zinc metallopeptidase M3 family, was first identified in rat brain synaptic membranes hydrolyzing neurotensin at the Pro-Tyr peptide bond. The previous development of C57BL6/N mice with suppression of Nln gene expression (Nln-/-), demonstrated the biological relevance of this oligopeptidase for insulin signaling and glucose uptake. Here, several metabolic parameters were investigated in Nln-/- and wild-type C57BL6/N animals (WT; n = 5-8), male and female, fed either a standard (SD) or a hypercaloric diet (HD), for seven weeks. Higher food intake and body mass gain was observed for Nln-/- animals fed HD, compared to both male and female WT control animals fed HD. Leptin gene expression was higher in Nln-/- male and female animals fed HD, compared to WT controls. Both WT and Nln-/- females fed HD showed similar gene expression increase of dipeptidyl peptidase 4 (DPP4), a peptidase related to glucagon-like peptide-1 (GLP-1) metabolism. The present data suggest that Nln participates in the physiological mechanisms related to diet-induced obesity. Further studies will be necessary to better understand the molecular mechanism responsible for the higher body mass gain observed in Nln-/- animals fed HD.

Usage of Glucagon-Like Peptide-1 for Obesity in Children; Updated Review of Clinicaltrials.gov

Background

Obesity in both adults and children is a primary health concern that can lead to many complications at a young age, including insulin resistance, type 2 diabetes, and other diseases. Glucagon-like peptide-1 receptor agonists (GLP-1) are drugs utilized to treat diabetes, but they are also approved as an adjunct to a low-calorie diet to reduce body weight and to enhance the metabolic profile readings for diabetic and non-diabetic patients. However, their efficacy and safety in children have not been extensively examined.

Aim

To identify glucagon-like peptide-1 medications for obesity in pediatric participants (aged up to 17 years old).

Methods

Analysis of all clinical trials registered on ClinicalTrials.gov for obesity using GLP-1 as a treatment for children.

Results

As of January 26th, 2023, 10,828 clinical trials were found. The search included childhood obesity using GLP-1. The number of trials on the use of GLP-1 to treat childhood obesity is limited. The final number of analyzed trials was 19. GLP-1 has been shown to result in the effective management of body gain among children.

Conclusion

Exenatide, semaglutide, and liraglutide were the only GLP-1 medications used as the pharmacotherapy option. It has been studied in many circumstances eg, to treat children with severe obesity, PCOS, hypothalamic obesity, glucose tolerance, and as a complementary treatment alongside behavior-lifestyle change and surgery for obesity.

Modulation of engineered nanomaterial interactions with organ barriers for enhanced drug transport

The biomedical use of nanoparticles (NPs) has been the focus of intense research for over a decade. As most NPs are explored as carriers to alter the biodistribution, pharmacokinetics and bioavailability of associated drugs, the delivery of these NPs to the tissues of interest remains an important topic. To date, the majority of NP delivery studies have used tumor models as their tool of interest, and the limitations concerning tumor targeting of systemically administered NPs have been well studied. In recent years, the focus has also shifted to other organs, each presenting their own unique delivery challenges to overcome. In this review, we discuss the recent advances in leveraging NPs to overcome four major biological barriers including the lung mucus, the gastrointestinal mucus, the placental barrier, and the blood-brain barrier. We define the specific properties of these biological barriers, discuss the challenges related to NP transport across them, and provide an overview of recent advances in the field. We discuss the strengths and shortcomings of different strategies to facilitate NP transport across the barriers and highlight some key findings that can stimulate further advances in this field.

Challenges and opportunities in delivering oral peptides and proteins

INTRODUCTION

Rapid advances in bioengineering enable the use of complex proteins as therapeutic agents to treat diseases. Compared with conventional small molecule drugs, proteins have multiple advantages, including high bioactivity and specificity with low toxicity. Developing oral dosage forms with active proteins is a route to improve patient compliance and significantly reduce production costs. However, the gastrointestinal environment remains a challenge to this delivery path due to enzymatic degradation, low permeability, and weak absorption, leading to reduced delivery efficiency and poor clinical outcomes.

AREAS COVERED

This review describes the barriers to oral delivery of peptides and complex proteins, current oral delivery strategies utilized and the opportunities and challenges ahead to try and circumvent these barriers. Oral protein drugs on the market and clinical trials provide insights and approaches for advancing delivery strategies.

EXPERT OPINION

Although most current studies on oral protein delivery rely on in vitro and in vivo animal data, the safety and limitations of the approach in humans remain uncertain. The shortage of clinical data limits the development of new or alternative strategies. Therefore, designing appropriate oral delivery strategies remains a significant challenge and requires new ideas, innovative design strategies and novel model systems.

Overcoming the shortcomings of peptide-based therapeutics

Peptides have traditionally been perceived as poor drug candidates due to unfavorable characteristics mainly regarding their pharmacokinetic behavior, including plasma stability, membrane permeability and circulation half-life. Nonetheless, in recent years, general strategies to tackle those shortcomings have been established, and peptides are subsequently gaining increasing interest as drugs due to their unique ability to combine the advantages of antibodies and small molecules. Macrocyclic peptides are a special focus of drug development efforts due to their ability to address so called ‘undruggable’ targets characterized by large and flat protein surfaces lacking binding pockets. Here, the main strategies developed to date for adapting peptides for clinical use are summarized, which may soon help usher in an age highly shaped by peptide-based therapeutics. Nonetheless, limited membrane permeability is still to overcome before peptide therapeutics will be broadly accepted.