Discovery of novel, high potent, ABC type PTP1B inhibitors with TCPTP selectivity and cellular activity

A comprehensive review on the research progress of PTP1B inhibitors as antidiabetics

Diabetes mellitus (DM) is a serious global health concern affecting over 500 million people. To put it simply, it is one of the most dangerous metabolic illnesses. Insulin resistance is the root cause of 90% of all instances of diabetes, all of which are classified as Type 2 DM. Untreated, it poses a hazard to civilization since it can lead to terrifying consequences and even death. Oral hypoglycemic medicines presently available act in a variety of ways, targeting various organs and pathways. The use of protein tyrosine phosphatase 1B (PTP1B) inhibitors, on the contrary, is a novel and effective method of controlling type 2 diabetes. PTP1B is a negative insulin signaling pathway regulator; hence, inhibiting PTP1B increases insulin sensitivity, glucose absorption, and energy expenditure. PTP1B inhibitors also restore leptin signaling and are considered a potential obesity target. In this review, we have compiled a summary of the most recent advances in synthetic PTP1B inhibitors from 2015 to 2022 which have scope to be developed as clinical antidiabetic drugs.

Targeting protein tyrosine phosphatases for CDK6-induced immunotherapy resistance

Elucidating the mechanisms of resistance to immunotherapy and developing strategies to improve its efficacy are challenging goals. Bioinformatics analysis demonstrates that high CDK6 expression in melanoma is associated with poor progression-free survival of patients receiving single-agent immunotherapy. Depletion of CDK6 or cyclin D3 (but not of CDK4, cyclin D1, or D2) in cells of the tumor microenvironment inhibits tumor growth. CDK6 depletion reshapes the tumor immune microenvironment, and the host anti-tumor effect depends on cyclin D3/CDK6-expressing CD8+ and CD4+ T cells. This occurs by CDK6 phosphorylating and increasing the activities of PTP1B and T cell protein tyrosine phosphatase (TCPTP), which, in turn, decreases tyrosine phosphorylation of CD3ζ, reducing the signal transduction for T cell activation. Administration of a PTP1B and TCPTP inhibitor prove more efficacious than using a CDK6 degrader in enhancing T cell-mediated immunotherapy. Targeting protein tyrosine phosphatases (PTPs) might be an effective strategy for cancer patients who resist immunotherapy treatment.

Dual PTP1B/TC-PTP Inhibitors: Biological Evaluation of 3-(Hydroxymethyl)cinnoline-4(1H)-Ones

Dual inhibitors of protein phosphotyrosine phosphatase 1B (PTP1B)/T-cell protein phosphotyrosine phosphatase (TC-PTP) based on the 3-(hydroxymethyl)-4-oxo-1,4-dihydrocinnoline scaffold have been identified. Their dual affinity to both enzymes has been thoroughly corroborated by in silico modeling experiments. The compounds have been profiled in vivo for their effects on body weight and food intake in obese rats. Likewise, the effects of the compounds on glucose tolerance, insulin resistance, as well as insulin and leptin levels, have been evaluated. In addition, the effects on PTP1B, TC-PTP, and Src homology region 2 domain-containing phosphatase-1 (SHP1), as well as the insulin and leptin receptors gene expressions, have been assessed. In obese male Wistar rats, a five-day administration of all studied compounds led to a decrease in body weight and food intake, improved glucose tolerance, attenuated hyperinsulinemia, hyperleptinemia and insulin resistance, and also compensatory increased expression of the PTP1B and TC-PTP genes in the liver. The highest activity was demonstrated by 6-Chloro-3-(hydroxymethyl)cinnolin-4(1H)-one (compound 3) and 6-Bromo-3-(hydroxymethyl)cinnolin-4(1H)-one (compound 4) with mixed PTP1B/TC-PTP inhibitory activity. Taken together, these data shed light on the pharmacological implications of PTP1B/TC-PTP dual inhibition, and on the promise of using mixed PTP1B/TC-PTP inhibitors to correct metabolic disorders.

Virtual Screening Based Discovery of PTP1B Inhibitors and Their Biological Evaluations

Background :

The discovery of novel antidiabetics for the treatment of type 2 diabetes mellitus (T2DM) is an important task nowadays because the current treatment approaches have certain limitations. The reported studies showed that the protein tyrosine phosphatase 1B (PTP1B) is a valuable target, can be used to develop significant antidiabetic molecules.

Objective:

In the present investigation, computational methods and biological evaluation studies have been applied to develop novel PTP1B inhibitors with good enzyme binding affinity and activity.

Methods:

Virtual screening (docking) analysis of SPECS database compounds on PTP1B enzyme was performed using Schrodinger software. In vitro and in vivo biological evaluations had been conducted with the identified hits.

Results:

The results revealed that the molecules identified through these studies have shown significant interactions with the active site residues of the PTP1B enzyme. The compounds S1 and S2 provided significant binding interactions with the residues (Arg221 and Gln262) and have shown considerable in vitro PTP1B inhibitory activity and in vivo antidiabetic activity. The compounds S1 and S2 possessed 35.44±0.12% and 33.68±0.08% inhibitory activities, respectively.

Conclusion:

These identified hits will be used as a template for design and development of novel PTP1B inhibitors with a compatible pharmacokinetic profile.

Aldose reductase and protein tyrosine phosphatase 1B inhibitors as a promising therapeutic approach for diabetes mellitus

Diabetes mellitus is a metabolic disease characterized by high blood glucose levels and usually associated with several chronic pathologies. Aldose reductase and protein tyrosine phosphatase 1B enzymes have identified as two novel molecular targets associated with the onset and progression of type II diabetes and related comorbidities. Although many inhibitors against these enzymes have already found in the field of diabetic mellitus, the research for discovering more effective and selective agents with optimal pharmacokinetic properties continues. In addition, dual inhibition of these target proteins has proved as a promising therapeutic approach. A variety of diverse scaffolds are presented in this review for the future design of potent and selective inhibitors of aldose reductase and protein tyrosine phosphatase 1B based on the most important structural features of both enzymes. The discovery of novel dual aldose reductase and protein tyrosine phosphatase 1B inhibitors could be effective therapeutic molecules for the treatment of insulin-resistant type II diabetes mellitus. The methods used comprise a literature survey and X-ray crystal structures derived from Protein Databank (PDB). Despite the available therapeutic options for type II diabetes mellitus, the inhibitors of aldose reductase and protein tyrosine phosphatase 1B could be two promising approaches for the effective treatment of hyperglycemia and diabetes-associated pathologies. Due to the poor pharmacokinetic profile and low in vivo efficacy of existing inhibitors of both targets, the research turned to more selective and cell-permeable agents as well as multi-target molecules.

Anti-diabetic drugs recent approaches and advancements

Diabetes is one of the major diseases worldwide and is the third leading cause of death in the United States. Anti-diabetic drugs are used in the treatment of diabetes mellitus to control glucose levels in the blood. Most of the drugs are administered orally, except for a few of them, such as insulin, exenatide, and pramlintide. In this review, we are going to discuss seven major types of anti-diabetic drugs: Peroxisome proliferator-activated receptor (PPAR) agonist, protein tyrosine phosphatase 1B (PTP1B) inhibitors, aldose reductase inhibitors, α-glucosidase inhibitors, dipeptidyl peptidase IV (DPP-4) inhibitors, G protein-coupled receptor (GPCR) agonists and sodium-glucose co-transporter (SGLT) inhibitors. Here, we are also discussing some of the recently reported anti-diabetic agents with its multi-target pharmacological actions. This review summarises recent approaches and advancement in anti-diabetes treatment concerning characteristics, structure-activity relationships, functional mechanisms, expression regulation, and applications in medicine.

Modified diterpenoids from the tuber of Icacina oliviformis as protein tyrosine phosphatase 1B inhibitors

Two modified diterpenoids featuring a novel 4,12-dioxatetracyclo[8.6.0.0^2,7.0^10,14]hexadecane core, together with a 3,4-seco-pimarane, a 3,4-seco-cleistanthane, and eight pimarane derivatives were isolated from the tuber of Icacina oliviformis.

PTP1b Inhibition, A Promising Approach for the Treatment of Diabetes Type II

BACKGROUND

Diabetes Mellitus (DM), is a metabolic disorder characterized by high blood glucose levels. The main types of diabetes mellitus are Diabetes mellitus type I, Diabetes mellitus type II, gestational diabetes and Diabetes of other etiology. Diabetes type II, the Non Insulin Dependent Type (NIDDM) is the most common type, characterized by the impairment in activation of the intracellular mechanism leading to the insertion and usage of glucose after interaction of insulin with its receptor, known as insulin resistance. Although, a number of drugs have been developed for the treatment of diabetes type II, their ability to reduce blood glucose levels is limited, while several side effects are also observed. Furthermore, none of the market drugs targets the enhancement of the action of the intracellular part of insulin receptor or recuperation of the glucose transport mechanism in GLUT4 dependent cells. The Protein Tyrosine Phosphatase (PTP1b) is the main enzyme involved in insulin receptor desensitization and has become a drug target for the treatment of Diabetes type II. Several PTP1b inhibitors have already been found, interacting with the binding site of the enzyme, surrounding the catalytic amino acid Cys215 and the neighboring area or with the allosteric site of the enzyme, placed at a distance of 20 Å from the active site, around Phe280. However, the research continues for finding more potent inhibitors with increased cell permeability and specificity.

OBJECTIVE

The aim of this review is to show the attempts made in developing of Protein Tyrosine Phosphatase (PTP1b) inhibitors with high potency, selectivity and bioavailability and to sum up the indications for favorable structural characteristics of effective PTP1b inhibitors.

METHODS

The methods used include a literature survey and the use of Protein Structure Databanks such as PuBMed Structure and RCSB and the tools they provide.

CONCLUSION

The research for finding PTP1b inhibitors started with the design of molecules mimicking the Tyrosine substrate of the enzyme. The study revealed that an aromatic ring connected to a polar group, which preferably enables hydrogen bond formation, is the minimum requirement for small inhibitors binding to the active site surrounding Cys215. Molecules bearing two hydrogen bond donor/acceptor (Hb d/a) groups at a distance of 8.5-11.5 Å may form more stable complexes, interacting simultaneously with a secondary area A2. Longer molecules with two Hb d/a groups at a distance of 17 Å or 19 Å may enable additional interactions with secondary sites (B and C) that confer stability as well as specificity. An aromatic ring linked to polar or Hb d/a moieties is also required for allosteric inhibitors. A lower distance between Hb d/a moieties, around 7.5 Å may favor allosteric interaction. Permanent inhibition of the enzyme by oxidation of the catalytic Cys215 has also been referred. Moreover, covalent modification of Cys121, placed near but not inside the catalytic pocket has been associated with permanent inhibition of the enzyme.

Docking Assisted Prediction and Biological Evaluation of Sideritis L. Components with PTP1b Inhibitory Action and Probable Anti-Diabetic Properties

Background:

The main characteristic of Diabetes type II is the impaired activation of intracellular mechanisms triggered by the action of insulin. PTP1b is a Protein Tyrosine Phosphatase that dephosphorylates insulin receptor causing its desensitization. Since inhibition of PTP1b may prolong insulin receptor activity, PTP1b has become a drug target for the treatment of Diabetes II. Although a number of inhibitors have been synthesized during the last decades, the research still continues for the development of more effective and selective compounds. Moreover, several constituents of plants and edible algae with PTP1b inhibitory action have been found, adding this extra activity at the pallet of properties of the specific natural products.

Objective:

Sideritis L. (Lamiaceae) is a herbal plant growing around the Mediterranean sea which is included in the Mediterranean diet for centuries. The present study is the continuation of a previous work where the antioxidant and anti-inflammatory activities of the components of Sideritis L. were evaluated and aimed to investigate the potential of some sideritis’s components to act as PTP1b inhibitors, thus exhibiting the beneficial effect in the treatment of diabetes II.

Methods:

Docking analysis was done to predict PTP1b inhibitory action. Human recombinant PTP1b enzyme was used for the evaluation of the PTP1b inhibitory action, while inhibition of the human LAR and human T-cell PTP was tested for the estimation of the selectivity of the compounds.

Conclusion:

Docking analysis effectively predicted inhibition and mode of inhibitory action. According to the experimental results, four of the components exhibited PTP1b inhibitory action. The most active ones were acetoside, which acted as a competitive inhibitor, with an IC50 of 4 µM and lavandufolioside, which acted as an uncompetitive inhibitor, with an IC50 of 9.3 µM. All four compounds exhibited increased selectivity against PTP1b.

The development of protein tyrosine phosphatase1B inhibitors defined by binding sites in crystalline complexes

Protein tyrosine phosphatase1B (PTP1B), a significant negative regulator in insulin and leptin signaling pathways, has emerged as a promising drug target for Type II diabetes mellitus and obesity. Numerous potent PTP1B inhibitors have been discovered within both academia and pharmaceutical industry. However, nearly all medicinal chemistry efforts have been severely hindered because a vast majority of them demonstrate poor membrane permeability and low-selectivity, especially over T-cell protein tyrosine phosphatase (TCPTP). To search the rules about the selectivity over TCPTP and membrane permeability of PTP1B inhibitors, based on the PTP1B/inhibitor crystal complexes, the development PTP1B inhibitors defined as AB, AC, ABC and ADC types have been concluded in the review.

Current anti-diabetic agents and their molecular targets: A review

Diabetes mellitus is a medical condition characterized by the body's loss of control over blood sugar. The frequency of diagnosed cases and consequential increases in medical costs makes it a rapidly growing chronic disease that threatens human health worldwide. In addition, its unnerving statistical projections are perilous to both the economy of the nation and man's life expectancy. Type-I and type-II diabetes are the two clinical forms of diabetes mellitus. Type-II diabetes mellitus (T2DM) is illustrated by the abnormality of glucose homeostasis in the body, resulting in hyperglycemia. Although significant research attention has been devoted to the development of diabetes regimens, which demonstrates success in lowering blood glucose levels, their efficacies are unsustainable due to undesirable side effects such as weight gain and hypoglycemia. Over the years, heterocyclic scaffolds have been the basis of anti-diabetic chemotherapies; hence, in this review we consolidate the use of bioactive scaffolds, which have been evaluated for their biological response as inhibitors against their respective anti-diabetic molecular targets over the past five years (2012-2017). Our investigation reveals a diverse target set which includes; protein tyrosine phosphatase 1 B (PTP1B), dipeptidly peptidase-4 (DPP-4), free fatty acid receptors 1 (FFAR1), G protein-coupled receptors (GPCR), peroxisome proliferator activated receptor-γ (PPARγ), sodium glucose co-transporter-2 (SGLT2), α-glucosidase, aldose reductase, glycogen phosphorylase (GP), fructose-1,6-bisphosphatase (FBPase), glucagon receptor (GCGr) and phosphoenolpyruvate carboxykinase (PEPCK). This review offers a medium on which future drug design and development toward diabetes management may be modelled (i.e. optimization via structural derivatization), as many of the drug candidates highlighted show promise as an effective anti-diabetic chemotherapy.

The discovery of novel, potent ERR-alpha inverse agonists for the treatment of triple negative breast cancer

The estrogen-related receptor α (ERRα) is an orphan receptor and a novel target for solid tumor therapy, conceivably through effects on the regulation of tumor cell energy metabolism associated with energy stress within solid tumor micro environments. Here we describe the discovery of novel potent inverse agonists of ERRα. In vitro, compound 11 potently inhibits ERRα's transcriptional activity by preventing endogenous PGC-1α and ERRα binding and suppresses the proliferation of different human cancer cell lines and the migration of breast cancer cells (MDA-MB-231). In vivo, compound 11 demonstrates a strong inhibitory effect on the growth of human breast cancer xenografts (MDA-MB-231) and the tumor growth is inhibited by 40.9% after treating with compound 11 (30 mg/kg). The binding mode shows that compound 11 interacts with the binding pocket of ERRα through hydrogen interactions with the residue Gly397 and hydrophobic interactions with the hydrophobic residues. All these results suggest that compound 11 represents a novel potent ERRα inverse agonist and is promising in the discovery of antitumor compounds for the treatment of triple negative breast cancer.

Phloroglucinol Derivatives with Protein Tyrosine Phosphatase 1B Inhibitory Activities from Eugenia jambolana Seeds

Fifteen new phloroglucinol derivatives, jamunones A-O (1-8 and 10-16, respectively), along with one known analogue spiralisone C (9), were isolated from Eugenia jambolana seeds. Their structures were elucidated by detailed nuclear magnetic resonance and mass spectrometry spectroscopic data interpretation. Compounds 1-9, 11, 12, and 14-16 inhibited protein tyrosine phosphatase 1B activity with IC₅₀ values ranging from 0.42 to 3.2 μM.

Possible Integrative Actions of Leptin and Insulin Signaling in the Hypothalamus Targeting Energy Homeostasis

Obesity has emerged as one of the most burdensome conditions in modern society. In this context, understanding the mechanisms controlling food intake is critical. At present, the adipocyte-derived hormone leptin and the pancreatic β-cell-derived hormone insulin are considered the principal anorexigenic hormones. Although leptin and insulin signal transduction pathways are distinct, their regulation of body weight maintenance is concerted. Resistance to the central actions of leptin or insulin is linked to the emergence of obesity and diabetes mellitus. A growing body of evidence suggests a convergence of leptin and insulin intracellular signaling at the insulin-receptor-substrate-phosphatidylinositol-3-kinase level. Moreover, numerous factors mediating the pathophysiology of leptin resistance, a hallmark of obesity, such as endoplasmic reticulum stress, protein tyrosine phosphatase 1B, and suppressor of cytokine signaling 3 also contribute to insulin resistance. Recent studies have also indicated that insulin potentiates leptin-induced signaling. Thus, a greater understanding of the overlapping functions of leptin and insulin in the central nervous system is vital to understand the associated physiological and pathophysiological states. This mini-review focuses on the cross talk and integrative signaling of leptin and insulin in the regulation of energy homeostasis in the brain.