Publications by authors named "Anish Konkar"

Chronic kidney disease is a debilitating condition associated with significant morbidity and mortality. In recent years, the kidney effects of incretin-based therapies, particularly glucagon-like peptide-1 receptor agonists (GLP-1RAs), have garnered substantial interest in the management of type 2 diabetes and obesity. This review delves into the intricate interactions between the kidney, GLP-1RAs, and glucagon, shedding light on their mechanisms of action and potential kidney benefits.

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Unimolecular triple incretins, combining the activity of glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), and glucagon (GCG), have demonstrated reduction in body weight and improved glucose control in rodent models. We developed SAR441255, a synthetic peptide agonist of the GLP-1, GCG, and GIP receptors, structurally based on the exendin-4 sequence. SAR441255 displays high potency with balanced activation of all three target receptors.

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To improve the power of mediation in high-throughput studies, here we introduce High-throughput mediation analysis (Hitman), which accounts for direction of mediation and applies empirical Bayesian linear modeling. We apply Hitman in a retrospective, exploratory analysis of the SLIMM-T2D clinical trial in which participants with type 2 diabetes were randomized to Roux-en-Y gastric bypass (RYGB) or nonsurgical diabetes/weight management, and fasting plasma proteome and metabolome were assayed up to 3 years. RYGB caused greater improvement in HbA1c, which was mediated by growth hormone receptor (GHR).

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Peptide therapeutics are increasingly used in the treatment of disease, but their administration by injection reduces patient compliance and convenience, especially for chronic diseases. Thus, oral administration of a peptide therapeutic represents a significant advance in medicine, but is challenged by gastrointestinal instability and ineffective uptake into the circulation. Here, we have used glucagon-like peptide-1 (GLP-1) as a model peptide therapeutic for treating obesity-linked type 2 diabetes, a common chronic disease.

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As a gut-restricted, nonabsorbed therapy, polymeric bile acid sequestrants (BAS) play an important role in managing hyperlipidemia and hyperglycemia. Similarly, nonabsorbable sequestrants of dietary phosphate have been used for the management of hyperphosphatemia in end-stage renal disease. To evaluate the potential utility of such polymer sequestrants to treat type 2 diabetes (T2D) and its associated renal and cardiovascular complications, we synthesized a novel polymeric sequestrant, SAR442357, possessing optimized bile acid (BA) and phosphate sequestration characteristics.

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Type 2 diabetes (T2D) is a complex and progressive disease requiring polypharmacy to manage hyperglycaemia and cardiovascular risk factors. However, most patients do not achieve combined treatment goals. To address this therapeutic gap, we have developed MEDI4166, a novel glucagon-like peptide-1 (GLP-1) receptor agonist peptide fused to a proprotein convertase subtilisin/kexin type 9 (PCSK9) neutralising antibody that allows for glycaemic control and low-density lipoprotein cholesterol (LDL-C) lowering in a single molecule.

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Fatty acid esters of hydroxylated fatty acids (FAHFAs) were discovered as a novel class of endogenous mammalian lipids whose profound effects on metabolism have been shown. In the current study, in vitro and in vivo the metabolic effects of two of these FAHFAs, namely palmitic acid-5- (or -9) -hydroxy-stearic acid (5- or 9-PAHSA, respectively) were profiled. In DIO mice fed with differentially composed low- or high-fat diets, acute and subchronic treatment with 5-PAHSA and 9-PAHSA alone, or in combination, did not significantly improve the deranged metabolic status.

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Article Synopsis
  • Researchers have developed new dual agonists that target both GLP-1 and glucagon receptors, showing better results for treating obesity and diabetes compared to standard GLP-1 agonists.
  • The design process utilized advanced techniques like molecular modeling and structural biology to create a specific peptide with a favorable activity ratio between the two receptors.
  • Tested on obese diabetic monkeys, the candidate showed promising results in lowering blood glucose levels and reducing body weight, suggesting potential effectiveness for human treatments.
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Ghrelin, an appetite-stimulatory hormone secreted by the stomach, was discovered as a ligand for the growth hormone secretagogue receptor (GHSR). Through GHSR, ghrelin stimulates growth hormone (GH) secretion, a function that evolved to protect against starvation-induced hypoglycemia. Though the biology mediated by ghrelin has been described in great detail, regulation of ghrelin action is poorly understood.

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Apelin-36 was discovered as the endogenous ligand for the previously orphan receptor APJ. Apelin-36 has been linked to two major types of biological activities: cardiovascular (stimulation of cardiac contractility and suppression of blood pressure) and metabolic (improving glucose homeostasis and lowering body weight). It has been assumed that both of these activities are modulated through APJ.

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Unlabelled: Because nonalcoholic steatohepatitis (NASH) is associated with impaired liver regeneration, we investigated the effects of G49, a dual glucagon-like peptide-1/glucagon receptor agonist, on NASH and hepatic regeneration. C57Bl/6 mice fed chow or a methionine and choline-deficient (MCD) diet for 1 week were divided into 4 groups: control (chow diet), MCD diet, chow diet plus G49, and M+G49 (MCD diet plus G49). Mice fed a high-fat diet (HFD) for 10 weeks were divided into groups: HFD and H+G49 (HFD plus G49).

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We report the discovery of a new monomeric peptide that reduces body weight and diabetic complications in rodent models of obesity by acting as an agonist at three key metabolically-related peptide hormone receptors: glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP) and glucagon receptors. This triple agonist demonstrates supraphysiological potency and equally aligned constituent activities at each receptor, all without cross-reactivity at other related receptors. Such balanced unimolecular triple agonism proved superior to any existing dual coagonists and best-in-class monoagonists to reduce body weight, enhance glycemic control and reverse hepatic steatosis in relevant rodent models.

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This work investigated how cold stress induces the appearance of brown adipocytes (BAs) in brown and white adipose tissues (WATs) of adult mice. In interscapular brown adipose tissue (iBAT), cold exposure increased proliferation of endothelial cells and interstitial cells expressing platelet-derived growth factor receptor, α polypeptide (PDGFRα) by 3- to 4-fold. Surprisingly, brown adipogenesis and angiogenesis were largely restricted to the dorsal edge of iBAT.

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Recombinant human serum albumin (HSA) conjugates of a 15-amino-acid truncated peptide YY (PYY) analogue were prepared using three heterobifunctional linkers [succinimidyl 4-[N-maleimidomethyl]cyclohexane-1-carboxylate (SMCC), 6-maleimidohexanoic acid N-hydroxysuccinimide ester (MHS), and N-[γ-maleimidobutyryloxy]sulfosuccinimide ester (GMBS)] in 2 synthetic steps involving (1) reaction of succinimidyl ester on linker with ε-amine of Lys2 on the peptide and (2) reaction of maleimide on peptide linker with free thiol of Cysteine 34 (Cys34) on albumin. In-process controls using ESI LC-MS were used to follow reactions and identify reaction products. Proteolytic digests of the conjugate revealed that peptide conjugation occurs at Cys34 on HSA.

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We report the discovery and translational therapeutic efficacy of a peptide with potent, balanced co-agonism at both of the receptors for the incretin hormones glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP). This unimolecular dual incretin is derived from an intermixed sequence of GLP-1 and GIP, and demonstrated enhanced antihyperglycemic and insulinotropic efficacy relative to selective GLP-1 agonists. Notably, this superior efficacy translated across rodent models of obesity and diabetes, including db/db mice and ZDF rats, to primates (cynomolgus monkeys and humans).

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We applied noncovalent complexes of digoxigenin (Dig) binding antibodies with digoxigeninylated peptide derivatives to modulate their pharmacokinetic properties. A peptide derivative which activates the Y2R receptor was selectively mono-digoxigeninylated by reacting a NHS-Dig derivative with an ε-amino group of lysine 2. This position tolerates modifications without destroying receptor binding and functionality of the peptide.

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Glucagon, an essential regulator of glucose homeostasis, also modulates lipid metabolism and promotes weight loss, as reflected by the wasting observed in glucagonoma patients. Recently, coagonist peptides that include glucagon agonism have emerged as promising therapeutic candidates for the treatment of obesity and diabetes. We developed a novel stable and soluble glucagon receptor (GcgR) agonist, which allowed for in vivo dissection of glucagon action.

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Several imidazole-based cyclohexyl amides were identified as potent CB-1 antagonists, but they exhibited poor oral exposure in rodents. Incorporation of a hydroxyl moiety on the cyclohexyl ring provided a dramatic improvement in oral exposure, together with a ca. 10-fold decrease in potency.

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A series of pyrrolopyridinones was designed and synthesized as constrained analogs of the pyrazole CB-1 antagonist rimonabant. Certain examples exhibited very potent hCB-1 receptor binding affinity and functional antagonism with Ki and Kb values below 10 nM, and with high selectivity for CB-1 over CB-2 (>100-fold). A representative analog was established to cause significant appetite suppression and reduction in body weight gain in industry-standard rat models used to develop new therapeutics for obesity.

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