A novel long-acting oxyntomodulin analogue eliminates diabetes and obesity in mice

Supramolecular approach to the design of nanocarriers for antidiabetic drugs: targeted patient-friendly therapy

Diabetes and its complications derived are among serious global health concerns that critically deteriorate the quality of life of patients and, in some cases, result in lethal outcome. Herein, general information on the pathogenesis, factors aggravating the course of the disease and drugs used for the treatment of two types of diabetes are briefly discussed. The aim of the review is to introduce supramolecular strategies that are currently being developed for the treatment of diabetes mellitus and that present a very effective alternative to chemical synthesis, allowing the fabrication of nanocontainers with switchable characteristics that meet the criteria of green chemistry. Particular attention is paid to organic (amphiphilic and polymeric) formulations, including those of natural origin, due to their biocompatibility, low toxicity, and bioavailability. The advantages and limitations of different nanosystems are discussed, with emphasis on their adaptivity to noninvasive administration routes.<br>The bibliography includes 378 references.

Dual glucagon-like peptide-1 and glucagon receptor agonism reduces energy intake in type 2 diabetes with obesity

AIMS

To establish which components of energy balance mediate the clinically significant weight loss demonstrated with use of cotadutide, a glucagon-like peptide-1 (GLP-1)/glucagon receptor dual agonist, in early-phase studies.

MATERIALS AND METHODS

We conducted a phase 2a, single-centre, randomized, placebo-controlled trial in overweight and obese adults with type 2 diabetes. Following a 16-day single-blind placebo run-in, participants were randomized 2:1 to double-blind 42-day subcutaneous treatment with cotadutide (100-300 μg daily) or placebo. The primary outcome was percentage weight change. Secondary outcomes included change in energy intake (EI) and energy expenditure (EE).

RESULTS

A total of 12 participants (63%) in the cotadutide group and seven (78%) in the placebo group completed the study. The mean (90% confidence interval [CI]) weight change was -4.0% (-4.9%, -3.1%) and -1.4% (-2.7%, -0.1%) for the cotadutide and placebo groups, respectively (p = 0.011). EI was lower with cotadutide versus placebo (-41.3% [-66.7, -15.9]; p = 0.011). Difference in EE (per kJ/kg lean body mass) for cotadutide versus placebo was 1.0% (90% CI -8.4, 10.4; p = 0.784), assessed by doubly labelled water, and -6.5% (90% CI -9.3, -3.7; p < 0.001), assessed by indirect calorimetry.

CONCLUSION

Weight loss with cotadutide is primarily driven by reduced EI, with relatively small compensatory changes in EE.

An imbalanced GLP-1R/GIPR co-agonist peptide with a site-specific N-terminal PEGylation to maximize metabolic benefits

Glycemic and body weight control gained from GLP-1R agonists remains an unmet need for diabetes and obesity treatment, leading to the development of GLP-1R/GIPR co-agonists. An imbalance in GLP-1R/GIPR agonism may extensively maximize the glucose- and weight-lowering effects. Hence, we prepared a potent and imbalanced GLP-1R/GIPR co-agonist, and refined its action time through a site-specific N-terminal PEGylation strategy. The pharmacological efficacy of these resulting long-acting co-agonists was interrogated both in vitro and in vivo. The results showed that peptide 1 possessed potent and imbalanced receptor-stimulating potency favoring GIP activity, but its hypoglycemic action was disrupted probably resulting from its short half-life. After PEGylation to improve the pharmacokinetics, the pharmacological effects were amplified compared to native peptide 1. Among the resulting derivatives, D-5K exhibited significant glycemic, HbA1c, body-weight, and food-intake control, outperforming GLP-1R mono-agonists. Based on its excellent pharmacological profiles, D-5K may hold the great therapeutic potential for diabetes and obesity treatment.

Design and discovery of a highly potent ultralong-acting GLP-1 and glucagon co-agonist for attenuating renal fibrosis

The role of co-agonists of glucagon-like peptide-1 receptor (GLP-1R) and glucagon receptor (GCGR) in chronic kidney disease (CKD) remains unclear. Herein we found that GLP-1R and GCGR expression levels were lower in the kidneys of mice with CKD compared to healthy mice and were correlated with disease severity. Interestingly, GLP-1R or GCGR knockdown aggravated the progression of kidney injury in both diabetic db/db mice and non-diabetic mice undergoing unilateral ureteral obstruction (UUO). Based on the importance of GLP-1R and GCGR in CKD, we reported a novel monomeric peptide, 1907-B, with dual-agonism on both GLP-1R and GCGR. The data confirmed that 1907-B had a longer half-life than long-acting semaglutide in rats or cynomolgus monkeys (∼2-3 fold) and exhibited better therapeutic contribution to CKD than best-in-class monoagonists, semaglutide, or glucagon, in db/db mice and UUO mice. Various lock-of-function models, including selective pharmacological activation and genetic knockdown, confirmed that 1907-B's effects on ameliorating diabetic nephropathy in db/db mice, as well as inhibiting kidney fibrosis in UUO mice, were mediated through GLP-1 and glucagon signaling. These findings highlight that 1907-B, a novel GLP-1R and GCGR co-agonist, exerts multifactorial improvement in kidney injuries and is an effective and promising therapeutic option for CKD treatment.

One Anastomosis Transit Bipartition (OATB): Rational and Mid-term Outcomes

BACKGROUND

The "One-anastomosis transit bipartition" (OATB) is a promising emerging technique in the metabolic syndrome treatment.

OBJECTIVE

To demonstrate the results achieved with OATB in the first 5 years after surgery.

METHOD

Cross-sectional, retrospective study, with individuals undergoing primary OATB. Individuals included in the study were: ≥ 18 years, BMI ≥ 35 kg/m2; and excluded smoking habits, drug dependence, inflammatory bowel diseases. The data analyzed demographic, anthropometric, surgical, clinical, and nutritional.

RESULTS

Sixty eight participants, 75% women, average age 45.5 years and BMI 41 kg/m2. Associated diseases: osteoarthritis (52.9%), hypertension (48.5%) and type 2 diabetes mellitus-T2DM (39.7%). All underwent laparoscopy, without conversions. Average operative time is 122.6 ± 31.7 min, and hospital stay is 2.2 ± 0.8 days. The common channel length 27 and 41 patients with 250 cm and 300 cm respectively. We registered no intraoperative complications, 2 (2.9%) early complications, and 14 (20.6%) late complications. In the first 6 months, 94.7% (250 cm) and 88.9% (300 cm) of the patients no longer used medication for T2DM, with no statistical difference between the two groups. The incidence of nutritional disorders at any time during follow-up: hypovitaminosis D (14.7%), folate hypovitaminosis (14.7%), elevated PTH (7.4%), hypoproteinemia (5.9%) and anemia (5.9%). We found no statistically significant difference between 250 and 300 cm common channel groups.

CONCLUSION

We conclude that OATB is a safe and effective technique, demonstrating good control of T2DM and metabolic syndrome. There is a requirement to treat previous nutritional deficits. We need more long-term evidence and comparison to other surgical techniques.

Discovery of a Novel Glucagon-like Peptide-1 (GLP-1) Analogue from Bullfrog and Investigation of Its Potential for Designing GLP-1-Based Multiagonists

In this study, we aimed to discover novel GLP-1 analogues from natural sources. We investigated GLP-1 analogues from fish and amphibians, and bullfrog GLP-1 (bGLP-1) showed the highest potency. Starting with bGLP-1, we explored the structure-activity relationship and performed optimization and long-acting modifications, resulting in a potent analogue called 2f. Notably, 2f exhibited superior effects on food intake, glycemic control, and body weight compared to semaglutide. Furthermore, we explored the usefulness of bGLP-1 in designing GLP-1-based multiagonists. Using the bGLP-1 sequence, we designed novel dual GLP-1/glucagon receptor agonists and triple GLP-1/GIP/glucagon receptor agonists. The selected dual GLP-1/glucagon receptor agonist 3o and triple GLP-1/GIP/glucagon receptor agonist 4b exhibited significant therapeutic effects on lipid regulation, glycemic control, and body weight. Overall, our study highlights the potential of discovering potent GLP-1 receptor agonists from natural sources. Additionally, utilizing natural GLP-1 analogues for designing multiagonists presents a practical approach for developing antiobesity and antidiabetic agents.

OXM-104, a potential candidate for the treatment of obesity, NASH and type 2 diabetes

OBJECTIVE

Dual glucagon-like peptide-1 (GLP-1) and glucagon receptor agonists are therapeutic agents with an interesting liver-specific mode of action suitable for metabolic complications. In this study, dual GLP-1 and glucagon receptor agonist OXM-104 is compared head-to-head with the once-daily dual GLP-1 and glucagon receptor agonist cotadutide and GLP-1 receptor agonist semaglutide to explore the metabolic efficacy of OXM-104.

METHODS

The in vitro potencies of OXM-104, cotadutide and semaglutide were assessed using reporter assays. In addition, in vivo efficacy was investigated using mouse models of diet-induced obesity (DIO mice), diabetes (db/db mice) and diet-induced NASH mice (MS-NASH).

RESULTS

OXM-104 was found to only activate the GLP-1 and glucagon with no cross-reactivity at the (GIP) receptor. Cotadutide was also found to activate the GLP-1 and glucagon receptors, whereas semaglutide only showed activity at the GLP-1 receptor. OXM-104, cotadutide, and semaglutide elicited marked reductions in body weight and improved glucose control. In contrast, hepatoprotective effects, i.e., reductions in steatosis and fibrosis, as well as liver fibrotic biomarkers, were more prominent with OXM-104 and cotadutide than those seen with semaglutide, demonstrated by an improved NAFLD activity score (NAS) by OXM-104 and cotadutide, underlining the importance of the glucagon receptor.

CONCLUSION

These results show that dual GLP-1 and glucagon receptor agonism is superior to GLP-1 alone. OXM-104 was found to be a promising therapeutic candidate for the treatment of metabolic complications such as obesity, type 2 diabetes and NASH.

Mechanisms of bariatric surgery for weight loss and diabetes remission

Obesity and type 2 diabetes(T2D) lead to defects in intestinal hormones secretion, abnormalities in the composition of bile acids (BAs), increased systemic and adipose tissue inflammation, defects of branched-chain amino acids (BCAAs) catabolism, and dysbiosis of gut microbiota. Bariatric surgery (BS) has been shown to be highly effective in the treatment of obesity and T2D, which allows us to view BS not simply as weight-loss surgery but as a means of alleviating obesity and its comorbidities, especially T2D. In recent years, accumulating studies have focused on the mechanisms of BS to find out which metabolic parameters are affected by BS through which pathways, such as which hormones and inflammatory processes are altered. The literatures are saturated with the role of intestinal hormones and the gut-brain axis formed by their interaction with neural networks in the remission of obesity and T2D following BS. In addition, BAs, gut microbiota and other factors are also involved in these benefits after BS. The interaction of these factors makes the mechanisms of metabolic improvement induced by BS more complicated. To date, we do not fully understand the exact mechanisms of the metabolic alterations induced by BS and its impact on the disease process of T2D itself. This review summarizes the changes of intestinal hormones, BAs, BCAAs, gut microbiota, signaling proteins, growth differentiation factor 15, exosomes, adipose tissue, brain function, and food preferences after BS, so as to fully understand the actual working mechanisms of BS and provide nonsurgical therapeutic strategies for obesity and T2D.

Pharmaceutical Strategies to Improve Druggability of Potential Drug Candidates in Nonalcoholic Fatty Liver Disease Therapy

Nonalcoholic fatty liver disease (NAFLD) has become globally prevalent and is the leading cause of chronic liver disease. Although NAFLD is reversible without medical intervention in the early stage, the condition could be sequentially worsened to nonalcoholic steatohepatitis (NASH) and, eventually, cirrhosis and hepatic cancer. The progression of NAFLD is related to various factors such as genetics, pre-disposed metabolic disorders, and immunologic factors. Thankfully, to date, there have been accumulating research efforts and, as a result, different classes of potent drug candidates have been discovered. In addition, there have also been various attempts to explore pharmaceutical strategies to improve the druggability of drug candidates. In this review, we provided a brief overview of the drug candidates that have undergone clinical trials. In the latter part, strategies for developing better drugs are discussed.

Emerging roles of oxyntomodulin-based glucagon-like peptide-1/glucagon co-agonist analogs in diabetes and obesity

Oxyntomodulin (OXM) is an endogenous peptide hormone secreted from the intestines following nutrient ingestion that activates both glucagon-like peptide-1 (GLP-1) and glucagon receptors. OXM is known to exert various effects, including improvement in glucose tolerance, promotion of energy expenditure, acceleration of liver lipolysis, inhibition of food intake, delay of gastric emptying, neuroprotection, and pain relief. The antidiabetic and antiobesity properties have led to the development of biologically active and enzymatically stable OXM-based analogs with proposed therapeutic promise for metabolic diseases. Structural modification of OXM was ongoing to enhance its potency and prolong half-life, and several GLP-1/glucagon dual receptor agonist-based therapies are being explored in clinical trials for the treatment of type 2 diabetes mellitus and its complications. In the present article, we provide a brief overview of the physiology of OXM, focusing on its structural-activity relationship and ongoing clinical development.

Obesity and cancer: Mouse models used in studies

There is increasing evidence that obesity is associated with the occurrence and development of malignant tumors. When studying the relationship between obesity and malignant tumors, it is very important to choose an appropriate animal model. However, BALB/c nude mice and other animals commonly used to study tumor xenograft (human-derived tumor cell lines) transplantation models are difficult to induce obesity, while C57BL/6 mice and other model animals commonly used for obesity research are not suitable for tumor xenograft transplantation. Therefore, it is difficult to replicate both obesity and malignancy in animal models at the same time. This review summarizes several experimental animal models and protocols that can simultaneously induce obesity and tumor xenografts.

Discovery of novel OXM-based glucagon-like peptide 1 (GLP-1)/glucagon receptor dual agonists

Novel glucagon receptor (GCGR) and glucagon-like peptide 1 receptor (GLP-1R) dual agonists are reported to have improved efficacy over GLP-1R mono-agonists in treating type 2 diabetes (T2DM) and obesity. Here, we describe the discovery of a novel oxyntomodulin (OXM) based GLP-1R/GCGR dual agonist with potent and balanced potency toward GLP-1R and GCGR. The lead peptide OXM-7 was obtained via stepwise rational design and long-acting modification. In ICR and db/db mice, OXM-7 exhibited prominent acute and long-acting hypoglycemic effects. In diet-induced obesity (DIO) mice, twice-daily administration of OXM-7 produced significant weight loss, normalized lipid metabolism, and improved glucose control. In DIO-nonalcoholic steatohepatitis (NASH) mice, OXM-7 treatment significantly reversed hepatic steatosis, and reduced serum and hepatic lipid levels. These preclinical data suggest the therapeutic potential of OXM-7 as a novel anti-diabetic, anti-steatotic and/or anti-obesity agent.

Impact of Oats on Appetite Hormones and Body Weight Management: A Review

PURPOSE OF REVIEW

This study aims to review the hunger hormones in obesity management and the impact of oats in regulating these hormones for hunger suppression and body weight management. In this review, the impact of various edible forms of oats like whole, naked, sprouted, or supplemented has been investigated for their appetite hormones regulation and weight management.

RECENT FINDINGS

The onset of obesity has been greatly associated with the appetite-regulating hormones that control, regulate, and suppress hunger, satiety, or energy expenditure. Many observational and clinical studies prove that oats have a positive effect on anthropometric measures like BMI, waist circumference, waist-to-hip ratio, lipid profile, total cholesterol, weight, appetite, and blood pressure. Many studies support the concept that oats are rich in protein, fiber, healthy fats, Fe, Zn, Mg, Mn, free phenolics, ß-glucan, ferulic acid, avenanthramides, and many more. Beta-glucan is the most important bioactive component that lowers cholesterol levels and supports the defense system of the body to prevent infections. Hence, several clinical studies supported oats utilization against obesity, appetite hormones, and energy regulation but still, some studies have shown no or little significance on appetite. Results of various studies revealed the therapeutic potentials of oats for body weight management, appetite control, strengthening the immune system, lowering serum cholesterol, and gut microbiota promotion by increased production of short-chain fatty acids.

Discovery of a potent and long-acting Xenopus GLP-1-based GLP-1/glucagon/Y2 receptor triple agonist

The combination of incretin-based therapies and PYY analogue has shown great potential for the treatment of type 2 diabetes (T2DM) and obesity. In this study we developed the first example of a unimolecular triple agonist peptide to simultaneously target GLP-1, glucagon and Y₂ receptors, aiming for superior weight loss and better glycemic control. The strategy for constructing such a unimolecular triple agonist peptide is the conjugation of the GLP-1R/GCGR dual-agonistic moiety and PYY moiety via maleimide-thiol specific reaction. A novel triple agonist peptide, 3b, was identified via stepwise structure optimization, long-acting modification and in vitro receptor screens. Peptide 3b exhibited potent and balanced GCGR and GLP-1R activities as well as potent and highly selective Y₂R activity. Peptide 3b potently reduced food intake without triggering nausea associated behavior in kaolin consumption and conditioned taste aversion assays. In diet induced obesity (DIO) mice, a lower dose of 3b achieved significantly better effects on lipid metabolism, body weight, and glycemic control than higher dose of GLP-1R mono-agonist, GLP-1R/GCGR dual agonist and GLP-1R/Y₂R dual agonist counterparts. Collectively, these data support the therapeutic potential of our GLP-1R/GCGR/Y₂R triple agonist 3b as a novel anti-obesity and anti-diabetic agent. Targeting GLP-1R, GCGR and Y₂R with unimolecular triple agonist peptide offers a route to develop new obesity and T2DM treatments.

Targeted therapeutics and novel signaling pathways in non-alcohol-associated fatty liver/steatohepatitis (NAFL/NASH)

Non-alcohol-associated fatty liver/steatohepatitis (NAFL/NASH) has become the leading cause of liver disease worldwide. NASH, an advanced form of NAFL, can be progressive and more susceptible to developing cirrhosis and hepatocellular carcinoma. Currently, lifestyle interventions are the most essential and effective strategies for preventing and controlling NAFL without the development of fibrosis. While there are still limited appropriate drugs specifically to treat NAFL/NASH, growing progress is being seen in elucidating the pathogenesis and identifying therapeutic targets. In this review, we discussed recent developments in etiology and prospective therapeutic targets, as well as pharmacological candidates in pre/clinical trials and patents, with a focus on diabetes, hepatic lipid metabolism, inflammation, and fibrosis. Importantly, growing evidence elucidates that the disruption of the gut-liver axis and microbe-derived metabolites drive the pathogenesis of NAFL/NASH. Extracellular vesicles (EVs) act as a signaling mediator, resulting in lipid accumulation, macrophage and hepatic stellate cell activation, further promoting inflammation and liver fibrosis progression during the development of NAFL/NASH. Targeting gut microbiota or EVs may serve as new strategies for the treatment of NAFL/NASH. Finally, other mechanisms, such as cell therapy and genetic approaches, also have enormous therapeutic potential. Incorporating drugs with different mechanisms and personalized medicine may improve the efficacy to better benefit patients with NAFL/NASH.

Site-specific N-terminal PEGylation-based controlled release of biotherapeutics: An application for GLP-1 delivery to improve pharmacokinetics and prolong hypoglycemic effects

PEGylation is a well-established technology for half-life extension in drug delivery. In this study, we aimed to develop a site-specific N-terminal PEGylation for biotherapeutics to achieve controlled release, using GLP-1 as a model. An additional threonine was introduced at N-terminal GLP-1. Followed by periodate oxidation, hydrazide-based PEGylation was achieved in a site-selective manner under reductive condition. Two homogenous monovalent mPEG_5k-GLP-1 (peptide 4) and mPEG_20k-GLP-1 (peptide 5) were successfully constructed. After PEGylation, the degradation by DPP-IV and rat plasma was obviously reduced. Their pharmacokinetic performances were enhanced at the expense of impaired GLP-1R stimulating potency, and their hypoglycemic effects were improved in different degrees. Compared with conventional strategies, this approach is devoid of the restriction and alteration of native peptide sequences, and can produce utterly homogenous conjugates with excellent selectivity and efficiency. It provides a practical controlled release approach for peptides by site-specific modification to achieve better pharmacological and therapeutic properties.

Biomaterial-Based Therapeutic Strategies for Obesity and Its Comorbidities

Obesity is a global public health issue that results in many health complications or comorbidities, including type 2 diabetes mellitus, cardiovascular disease, and fatty liver. Pharmacotherapy alone or combined with either lifestyle alteration or surgery represents the main modality to combat obesity and its complications. However, most anti-obesity drugs are limited by their bioavailability, target specificity, and potential toxic effects. Only a handful of drugs, including orlistat, liraglutide, and semaglutide, are currently approved for clinical obesity treatment. Thus, there is an urgent need for alternative treatment strategies. Based on the new revelation of the pathogenesis of obesity and the efforts toward the multi-disciplinary integration of materials, chemistry, biotechnology, and pharmacy, some emerging obesity treatment strategies are gradually entering the field of preclinical and clinical research. Herein, by analyzing the current situation and challenges of various new obesity treatment strategies such as small-molecule drugs, natural drugs, and biotechnology drugs, the advanced functions and prospects of biomaterials in obesity-targeted delivery, as well as their biological activities and applications in obesity treatment, are systematically summarized. Finally, based on the systematic analysis of biomaterial-based obesity therapeutic strategies, the future prospects and challenges in this field are proposed.

Discovery of once-weekly, peptide-based selective GLP-1 and cholecystokinin 2 receptors co-agonizts

A group of long-acting, peptide-based, and selective GLP-1R/CCK-2R dual agonizts were identified by rational design. Guided by sequence analysis, structural elements of the CCK-2R agonist moiety were engineered into the GLP-1R agonist Xenopus GLP-1, resulting in hybrid peptides with potent GLP-1R/CCK-2R dual activity. Further modifications with fatty acids resulted in novel metabolically stable peptides, among which 3d and 3 h showed potent GLP-1R and CCK-2R activation potencies and comparable stability to semaglutide. In food intake tests, 3d and 3 h also showed a potent reduction in food intake, superior to that of semaglutide. Moreover, the acute hypoglycemic and insulinotropic activities of 3d and 3 h were better than that of semaglutide and ZP3022. Importantly, the limited pica response following 3d and 3 h administration in SD rats preliminarily indicated that the food intake reduction effects of 3d and 3 h are independent of nausea/vomiting. In a 35-day study in db/db mice, every two days administration of 3d and 3 h increased islet areas and numbers, insulin contents, β-cell area, β-cell proliferation, as well as improved glucose tolerance, and decreased HbA1c, to a greater extent than ZP3022 and semaglutide. In a 21-day study in DIO mice, once-weekly administration of 3d and 3 h significantly induced body weight loss, improved glucose tolerance, and normalized lipid metabolism, to a greater extent than semaglutide. The current study showed the antidiabetic and antiobesity potentials of GLP-1R/CCK-2R dual agonizts that warrant further investigation.

The current significance and prospects for the use of dual receptor agonism GLP-1/Glucagon

The therapeutic arsenal for treating type 2 diabetes mellitus (T2DM) has been enriched recently with the inclusion of type 1 glucagon-like peptide (GLP-1). GLP-1 receptor agonists (RA) secondarily reduce appetite, decrease gastric emptying, and reduce body weight. This effect has been used to treat overweight/obesity, especially with comorbidities associated with T2DM. However, the first formulations and adverse effects gradually gave way to new formulations with fewer unpleasant effects and a more extended period of action (weekly subcutaneous administration and even oral administration), which improved the acceptance and adherence to the treatment. Therefore, titration of GLP-1RA should be done gradually. Furthermore, when side effects are consistent and intolerable after weeks/months of titration, a lower dose or a combination of antidiabetic therapies should be implemented, avoiding treatment interruption. The effort to produce increasingly powerful molecules with fewer side effects is the driving force behind the pharmaceutical industry. The unimolecular dual agonism GLP-1RA plus glucagon receptor agonism (GRA) represents an updated pharmacological indication for controlling blood glucose levels in treating T2DM and its comorbidities, showing better effects with less adverse impact than mono GLP-1RA. There are currently different proposals in this way by different laboratories. Nevertheless, the experimental results are promising and show that soon, we will have the contribution of new drugs for the treatment of T2DM.

Nitric oxide facilitates the targeting Kupffer cells of a nano-antioxidant for the treatment of NASH

Kupffer cells are a key source of reactive oxygen species (ROS) and are implicated in the development of steatohepatitis and fibrosis in nonalcoholic steatohepatitis (NASH). We recently developed a polythiolated and mannosylated human serum albumin (SH-Man-HSA), a nano-antioxidant that targets Kupffer cells, in which the mannosyl units on albumin allows their specific uptake by Kupffer cells via the mannose receptor C type 1 (MRC1), and in which the polythiolation confers antioxidant activity. The aim of this study was to investigate the therapeutic potential of SH-Man-HSA in NASH model mice. In livers from mice and/or patients with NASH, we observed a reduced blood flow in the liver lobes and the down-regulation in MRC1 expression in Kupffer cells, and SH-Man-HSA alone failed to improve the pathological phenotype in NASH. However, the administration of a nitric oxide (NO) donor restored hepatic blood flow and increased the expression of the mannose receptor C type 2 (MRC2) instead of MRC1. Consequently, treatment with a combination of SH-Man-HSA and an NO donor improved oxidative stress-associated pathology. Finally, we developed a hybrid type of nano-antioxidant (SNO-Man-HSA) via the S-nitrosation of SH-Man-HSA. This nanomedicine efficiently delivered both NO and thiol groups to the liver, with a hepatoprotective effect that was comparable to the combination therapy of SH-Man-HSA and an NO donor. These findings suggest that SNO-Man-HSA has the potential for functioning as a novel nano-therapy for the treatment of NASH.

Partial agonism improves the anti-hyperglycaemic efficacy of an oxyntomodulin-derived GLP-1R/GCGR co-agonist

OBJECTIVE

Glucagon-like peptide-1 and glucagon receptor (GLP-1R/GCGR) co-agonism can maximise weight loss and improve glycaemic control in type 2 diabetes and obesity. In this study, we investigated the cellular and metabolic effects of modulating the balance between G protein and β-arrestin-2 recruitment at GLP-1R and GCGR using oxyntomodulin (OXM)-derived co-agonists. This strategy has been previously shown to improve the duration of action of GLP-1R mono-agonists by reducing target desensitisation and downregulation.

METHODS

Dipeptidyl dipeptidase-4 (DPP-4)-resistant OXM analogues were generated and assessed for a variety of cellular readouts. Molecular dynamic simulations were used to gain insights into the molecular interactions involved. In vivo studies were performed in mice to identify the effects on glucose homeostasis and weight loss.

RESULTS

Ligand-specific reductions in β-arrestin-2 recruitment were associated with slower GLP-1R internalisation and prolonged glucose-lowering action in vivo. The putative benefits of GCGR agonism were retained, with equivalent weight loss compared to the GLP-1R mono-agonist liraglutide despite a lesser degree of food intake suppression. The compounds tested showed only a minor degree of biased agonism between G protein and β-arrestin-2 recruitment at both receptors and were best classified as partial agonists for the two pathways measured.

CONCLUSIONS

Diminishing β-arrestin-2 recruitment may be an effective way to increase the therapeutic efficacy of GLP-1R/GCGR co-agonists. These benefits can be achieved by partial rather than biased agonism.

The therapeutic potential of GLP-1 analogues for stress-related eating and role of GLP-1 in stress, emotion and mood: a review

Stress and low mood are powerful triggers for compulsive overeating, a maladaptive form of eating leading to negative physical and mental health consequences. Stress-vulnerable individuals, such as people with obesity, are particularly prone to overconsumption of high energy foods and may use it as a coping mechanism for general life stressors. Recent advances in the treatment of obesity and related co-morbidities have focused on the therapeutic potential of anorexigenic gut hormones, such as glucagon-like peptide 1 (GLP-1), which acts both peripherally and centrally to reduce energy intake. Besides its appetite suppressing effect, GLP-1 acts on areas of the brain involved in stress response and emotion regulation. However, the role of GLP-1 in emotion and stress regulation, and whether it is a viable treatment for stress-induced compulsive overeating, has yet to be established. A thorough review of the pre-clinical literature measuring markers of stress, anxiety and mood after GLP-1 exposure points to potential divergent effects based on temporality. Specifically, acute GLP-1 injection consistently stimulates the physiological stress response in rodents whereas long-term exposure indicates anxiolytic and anti-depressive benefits. However, the limited clinical evidence is not as clear cut. While prolonged GLP-1 analogue treatment in people with type 2 diabetes improved measures of mood and general psychological wellbeing, the mechanisms underlying this may be confounded by associated weight loss and improved blood glucose control. There is a paucity of longitudinal clinical literature on mechanistic pathways by which stress influences eating behavior and how centrally-acting gut hormones such as GLP-1, can modify these. (250).

Post-pancreatitis diabetes mellitus: investigational drugs in preclinical and clinical development and therapeutic implications

Introduction: Post-pancreatitis diabetes mellitus is one of the most common types of secondary diabetes. The pharmaceutical armamentarium in the field of diabetology can be broadened if the design of novel drugs is informed by pathogenetic insights from studies on post-pancreatitis diabetes mellitus.Areas covered: The article provides an overview of preclinical and clinical studies of compounds selectively antagonizing the gastric inhibitory peptide receptor, simultaneously stimulating both the glucagon-like peptide-1 and glucagon receptors, and activating ketogenesis.Expert opinion: The current pharmacotherapy for post-pancreatitis diabetes mellitus is relatively ineffective. This type of diabetes represents a unique platform for rigorous, efficient, and practical search for glucose-lowering therapeutic candidates. Various methods of gastric inhibitory peptide receptor (expressed in the pancreas) antagonism have undergone extensive preclinical testing in diabetes, with promising compounds being trialed in man. Molecular mimicry with oxyntomodulin ─ an extra-pancreatic hormone homologous with pancreatic hormone glucagon and involved in the regulation of exocrine pancreatic function ─ could be harnessed. The emerging findings of a salutary effect of ketosis mimetics in people with prediabetes set the stage for a novel approach to preventing diabetes.

The Function of Gastrointestinal Hormones in Obesity-Implications for the Regulation of Energy Intake

The global burden of obesity and the challenges of prevention prompted researchers to investigate the mechanisms that control food intake. Food ingestion triggers several physiological responses in the digestive system, including the release of gastrointestinal hormones from enteroendocrine cells that are involved in appetite signalling. Disturbed regulation of gut hormone release may affect energy homeostasis and contribute to obesity. In this review, we summarize the changes that occur in the gut hormone balance during the pre- and postprandial state in obesity and the alterations in the diurnal dynamics of their plasma levels. We further discuss how obesity may affect nutrient sensors on enteroendocrine cells that sense the luminal content and provoke alterations in their secretory profile. Gastric bypass surgery elicits one of the most favorable metabolic outcomes in obese patients. We summarize the effect of different strategies to induce weight loss on gut enteroendocrine function. Although the mechanisms underlying obesity are not fully understood, restoring the gut hormone balance in obesity by targeting nutrient sensors or by combination therapy with gut peptide mimetics represents a novel strategy to ameliorate obesity.