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Scientific Reports Dec 2023Amyloid proteins are often associated with the onset of diseases, including Alzheimer's, Parkinson's and many others. However, there is a wide class of functional...
Amyloid proteins are often associated with the onset of diseases, including Alzheimer's, Parkinson's and many others. However, there is a wide class of functional amyloids that are involved in physiological functions, e.g., formation of microbial biofilms or storage of hormones. Recent studies showed that an amyloid fibril could affect the aggregation of another protein, even from a different species. This may result in amplification or attenuation of the aggregation process. Insight into amyloid cross-interactions may be crucial for better understanding of amyloid diseases and the potential influence of microbial amyloids on human proteins. However, due to the demanding nature of the needed experiments, knowledge of such interactions is still limited. Here, we present PACT (Prediction of Amyloid Cross-interaction by Threading) - the computational method for the prediction of amyloid cross-interactions. The method is based on modeling of a heterogeneous fibril formed by two amyloidogenic peptides. The resulting structure is assessed by the structural statistical potential that approximates its plausibility and energetic stability. PACT was developed and first evaluated mostly on data collected in the AmyloGraph database of interacting amyloids and achieved high values of Area Under ROC (AUC=0.88) and F1 (0.82). Then, we applied our method to study the interactions of CsgA - a bacterial biofilm protein that was not used in our in-reference datasets, which is expressed in several bacterial species that inhabit the human intestines - with two human proteins. The study included alpha-synuclein, a human protein that is involved in Parkinson's disease, and human islet amyloid polypeptide (hIAPP), which is involved in type 2 diabetes. In both cases, PACT predicted the appearance of cross-interactions. Importantly, the method indicated specific regions of the proteins, which were shown to play a central role in both interactions. We experimentally confirmed the novel results of the indicated CsgA fragments interacting with hIAPP based on the kinetic characteristics obtained with the ThT assay. PACT opens the possibility of high-throughput studies of amyloid interactions. Importantly, it can work with fairly long protein fragments, and as a purely physicochemical approach, it relies very little on scarce training data. The tool is available as a web server at https://pact.e-science.pl/pact/ . The local version can be downloaded from https://github.com/KubaWojciechowski/PACT .
Topics: Humans; Amyloid; Diabetes Mellitus, Type 2; Amyloidogenic Proteins; Peptides; Amyloidosis; Islet Amyloid Polypeptide
PubMed: 38097650
DOI: 10.1038/s41598-023-48886-9 -
BioRxiv : the Preprint Server For... Dec 2023We report a highly significant correlation in brain proteome changes between Alzheimers disease (AD) and CRND8 APP695NL/F transgenic mice. However, integrating protein...
We report a highly significant correlation in brain proteome changes between Alzheimers disease (AD) and CRND8 APP695NL/F transgenic mice. However, integrating protein changes observed in the CRND8 mice with co-expression networks derived from human AD, reveals both conserved and divergent module changes. For the most highly conserved module (M42, matrisome) we find many proteins accumulate in plaques, cerebrovascular amyloid (CAA), dystrophic processes, or a combination thereof. Overexpression of two M42 proteins, midkine (Mdk) and pleiotrophin (PTN), in CRND8 mice brains leads to increased accumulation of A β ; in plaques and in CAA; further, recombinant MDK and PTN enhance A β ; aggregation into amyloid. Multiple M42 proteins, annotated as heparan sulfate binding proteins, bind to fibrillar A β 42 and a non-human amyloid fibril in vitro. Supporting this binding data, MDK and PTN co-accumulate with transthyretin (TTR) amyloid in the heart and islet amyloid polypeptide (IAPP) amyloid in the pancreas. Our findings establish several critical insights. Proteomic changes in modules observed in human AD brains define an A β ; amyloid responsome that is well conserved from mouse model to human. Further, distinct amyloid structures may serve as scaffolds, facilitating the co-accumulation of proteins with signaling functions. We hypothesize that this co-accumulation may contribute to downstream pathological sequalae. Overall, this contextualized understanding of proteomic changes and their interplay with amyloid deposition provides valuable insights into the complexity of AD pathogenesis and potential biomarkers and therapeutic targets.
PubMed: 38076912
DOI: 10.1101/2023.11.29.568318 -
Frontiers in Neurology 2023Dihydroergotamine mesylate (DHE) is an established effective acute therapy for migraine and is often characterized by its broad receptor pharmacology. Knowledge of DHE...
INTRODUCTION
Dihydroergotamine mesylate (DHE) is an established effective acute therapy for migraine and is often characterized by its broad receptor pharmacology. Knowledge of DHE pharmacology largely comes from studies employing older methodologies.
OBJECTIVE
To assess DHE receptor activity using high-throughput methods to screen for functional ß-arrestin activity at G protein-coupled receptors (GPCRs).
METHODS
Functional receptor activities of DHE and sumatriptan succinate (both 10 μM) were screened against 168 GPCRs using the gpcrMAX assay. Agonist and antagonist effects were considered significant if receptor activity was >30% or inhibited by >50%, respectively. Radiolabeled ligand binding assays were performed for DHE (0.01-300 nM for 5-HT and ; 0.3-10,000 nM for 5-HT, α-adrenergic [i.e., α-adrenoceptor], D, and D) to assess specific binding to select receptors.
RESULTS
DHE (10 μM) exhibited agonist activity at α-adrenergic, CXC chemokine receptor 7 (CXCR7), dopamine (D), and 5-hydroxytryptamine (5-HT) receptors and antagonist activity at α-adrenergic (i.e., α-adrenoceptors), calcitonin receptor-receptor activity modifying protein 2 (CTR-RAMP2) or amylin 2 (AMY), D, and 5-HT receptors. Sumatriptan succinate (10 μM) exhibited agonist activity at the 5-HT receptors. DHE demonstrated a half-maximal inhibitory concentration (IC) of 149 nM at the 5-HT receptor and a half-maximal effective concentration (EC) of 6 μM at the CXCR7 receptor. DHE did not bind to the 5-HT receptor at concentrations up to 300 nM and bound poorly to 5-HT and D receptors (IC of 230 and 370 nM, respectively). DHE bound strongly to the D, 5-HT, and α-adrenergic receptors (IC of 0.47, 0.58, and 2.8 nM, respectively).
CONCLUSION
By using a high-throughput β-arrestin recruitment assay, this study confirmed the broad receptor profile of DHE and provided an update on DHE receptor pharmacology as it relates to migraine.
PubMed: 38073648
DOI: 10.3389/fneur.2023.1282846 -
Communications Biology Dec 2023Calcitonin receptor (Calcr) and its brain ligand amylin in the medial preoptic area (MPOA) are found to be critically involved in infant care and social contact...
Calcitonin receptor (Calcr) and its brain ligand amylin in the medial preoptic area (MPOA) are found to be critically involved in infant care and social contact behaviors in mice. In primates, however, the evidence is limited to an excitotoxic lesion study of the Calcr-expressing MPOA subregion (cMPOA) in a family-living primate species, the common marmoset. The present study utilized pharmacological manipulations of the cMPOA and shows that reversible inactivation of the cMPOA abolishes infant-care behaviors in sibling marmosets without affecting other social or non-social behaviors. Amylin-expressing neurons in the marmoset MPOA are distributed in the vicinity of oxytocin neurons in the anterior paraventricular nucleus of the hypothalamus. While amylin infusion facilitates infant carrying selectively, an oxytocin's inverse agonist, atosiban, reduces physical contact with non-infant family members without grossly affecting infant care. These data suggest that the amylin and oxytocin signaling mediate intrafamilial social interactions in a complementary manner in marmosets.
Topics: Humans; Mice; Animals; Preoptic Area; Oxytocin; Callithrix; Islet Amyloid Polypeptide; Drug Inverse Agonism; Social Behavior
PubMed: 38052969
DOI: 10.1038/s42003-023-05593-5 -
RSC Chemical Biology Nov 2023Metal ions have been implicated in several proteinopathies associated to degenerative and neurodegenerative diseases. While the molecular mechanisms for protein...
Metal ions have been implicated in several proteinopathies associated to degenerative and neurodegenerative diseases. While the molecular mechanisms for protein aggregation are still under investigation, recent findings from Cryo-EM point out to polymorphisms in aggregates obtained from patients, as compared to those formed , suggesting that several factors may impact aggregation . One of these factors could be the direct binding of metal ions to the proteins engaged in aggregate formation. In this opinion article, three case studies are discussed to address the question of how metal ion binding to a peptide or protein may impact its conformation, folding, and aggregation, and how this may be relevant in understanding the polymorphic nature of the aggregates related to disease. Specifically, the impact of Cu ions in the amyloid aggregation of amyloid-β and amylin (or IAPP- islet amyloid polypeptide) are discussed and then contrasted to the case of Cu-induced non-amyloid aggregation of human lens γ-crystallin proteins. For the intrinsically disordered peptides amyloid-β and IAPP, the impact of Cu ion binding is highly dependent on the relative location of the metal binding site and the hydrophobic regions involved in β-sheet folding and amyloid formation. Further structural studies of how Cu binding impacts amyloid aggregation pathways and the molecular structure of the final amyloid fibril, both, and , will certainly shed light into the molecular origins of the polymorphisms observed in diseased tissue. Finally, contrasting these cases to that of Cu-induced non-amyloid aggregation of γ-crystallins, it is evident that, although the impact in aggregation - and the nature of the aggregate - may differ in each system, at the molecular level there is a competition between metal ion coordination and the stability of β-sheet structures. Considering the importance of the β-sheet fold in biology, it is fundamental to understand the energetics and molecular details behind such competition. This opinion article aims to highlight future research directions in the field that can help tackle the important question of how metal ion binding may impact protein folding and aggregation and how this relates to disease.
PubMed: 38033729
DOI: 10.1039/d3cb00145h -
American Journal of Physiology.... Feb 2024Seladelpar, a selective peroxisome proliferator-activated receptor δ (PPARδ) agonist, improves markers of hepatic injury in human liver diseases, but histological...
Seladelpar, a selective peroxisome proliferator-activated receptor δ (PPARδ) agonist, improves markers of hepatic injury in human liver diseases, but histological improvement of nonalcoholic steatohepatitis (NASH) and liver fibrosis has been challenging with any single agent. To discover how complementary agents could work with seladelpar to achieve optimal outcomes, this study evaluated a variety of therapeutics (alone and in combination) in a mouse model of NASH. Mice on a high-fat amylin liver NASH (AMLN) diet were treated for 12 wk with seladelpar, GLP-1-R (glucagon-like peptide-1 receptor) agonist liraglutide, apoptosis signal-regulating kinase 1 (ASK1) inhibitor selonsertib, farnesoid X receptor (FXR) agonist obeticholic acid, and with seladelpar in combination with liraglutide or selonsertib. Seladelpar treatment markedly improved plasma markers of liver function. Seladelpar alone or in combination resulted in stark reductions in liver fibrosis (hydroxyproline, new collagen synthesis rate, mRNA indices of fibrosis, and fibrosis staining) compared with vehicle and the other single agents. Robust reductions in liver steatosis were also observed. Seladelpar produced a reorganization of metabolic gene expression, particularly for those genes promoting peroxisomal and mitochondrial lipid oxidation. In summary, substantial improvements in NASH and NASH-induced fibrosis were observed with seladelpar alone and in combination with liraglutide in this model. Broad gene expression analysis suggests seladelpar should be effective in concert with diverse mechanisms of action. NASH is a chronic, progressive, and increasingly problematic liver disease that has been resistant to treatment with individual therapeutics. In this study using a diet-induced mouse model of NASH, we found that the PPARδ agonist seladelpar reduced fibrosis and NASH pathology alone and in combinations with a GLP-1-R agonist (liraglutide) or an ASK1 inhibitor (selonsertib). Liver transcriptome analysis comparing each agent and coadministration suggests seladelpar should be effective in combination with a variety of therapeutics.
Topics: Humans; Mice; Animals; Non-alcoholic Fatty Liver Disease; Liraglutide; PPAR delta; Liver; Liver Cirrhosis; Inflammation; Complementary Therapies; Mice, Inbred C57BL; Acetates; Benzamides; Imidazoles; Pyridines
PubMed: 38014444
DOI: 10.1152/ajpgi.00158.2023 -
Journal of Personalized Medicine Nov 2023The research was aimed to study the associations of adipocytokines with the risk of cardiovascular events and to determine the threshold values of adipocytes for the...
UNLABELLED
The research was aimed to study the associations of adipocytokines with the risk of cardiovascular events and to determine the threshold values of adipocytes for the prognosis of cardiovascular events in a young population.
MATERIALS AND METHODS
The study is an epidemiological cohort study. The analysis included 1240 people aged 25-44 years. The endpoint was combined and included: death from cardiovascular disease, myocardial infarction, probable myocardial infarction, acute cerebrovascular accident, hospitalization for cardiovascular disease, and revascularization. Adipocytokines were determined with a MILLIPLEX panel.
RESULTS
In the examined population, 1.7% of cases of cardiovascular events were detected during cohort observation, of which 28.6% were fatal events. In men, cardiovascular endpoints were recorded 4.3 times more often than in women (17 (81%) vs. 4 (19%), = 0.003). In individuals with cardiovascular events, arterial hypertension (2.6 times), diabetes mellitus (8.6 times), and overweight/obesity (1.5 times) were more often recorded compared to individuals without cardiovascular events. For tumor necrosis factor-alpha (TNFa), the threshold value was 2.5 pg/mL, with sensitivity assessment (Se) at 85.7% and specificity (Sp) at 83.3%. For amylin, the threshold value was 10.5 pg/mL, with Se at 73.7% and Sp at 67.0%. For pancreatic polypeptide (PP), the threshold value was 43.7 pg/mL, with Se at 85.7% and Sp at 56.7%.
CONCLUSION
A method for assessing the risk of cardiovascular events in young people includes determining the levels of amylin, PP, and TNFa in blood serum. The cut-off points for predicting cardiovascular events were levels of amylin above 10.5 pg/mL, PP above 43.7 pg/mL, or a decrease in TNFa below 3.8 pg/mL.
PubMed: 38003897
DOI: 10.3390/jpm13111582 -
Membranes Nov 2023The calcium ion (Ca) has been linked to type 2 diabetes mellitus (T2DM), although the role of Ca in this disorder is the subject of intense investigation. Serum Ca...
The calcium ion (Ca) has been linked to type 2 diabetes mellitus (T2DM), although the role of Ca in this disorder is the subject of intense investigation. Serum Ca dyshomeostasis is associated with the development of insulin resistance, reduced insulin sensitivity, and impaired glucose tolerance. However, the molecular mechanisms involving Ca ions in pancreatic β-cell loss and subsequently in T2DM remain poorly understood. Implicated in the decline in β-cell functions are aggregates of human islet amyloid polypeptide (hIAPP), a small peptide secreted by β-cells that shows a strong tendency to self-aggregate into β-sheet-rich aggregates that evolve toward the formation of amyloid deposits and mature fibrils. The soluble oligomers of hIAPP can permeabilize the cell membrane by interacting with bilayer lipids. Our study aimed to evaluate the effect of Ca on the ability of the peptide to incorporate and form ion channels in zwitterionic planar lipid membranes (PLMs) composed of palmitoyl-oleoyl-phosphatidylcholine (POPC) and on the aggregation process of hIAPP molecules in solution. Our results may help to clarify the link between Ca ions, hIAPP peptide, and consequently the pathophysiology of T2DM.
PubMed: 37999364
DOI: 10.3390/membranes13110878 -
Hepatology Communications Dec 2023NASH causes a tremendous health care burden in the United States. A glucagon-like peptide-1 agonist, semaglutide (Sema), treatment resulted in hepatic steatosis...
BACKGROUND
NASH causes a tremendous health care burden in the United States. A glucagon-like peptide-1 agonist, semaglutide (Sema), treatment resulted in hepatic steatosis reduction in clinical trials of NASH. Lysophosphatidic acid receptor 1 antagonists are known to have antifibrotic effects in several organs. We tested Sema and a novel lysophosphatidic acid receptor 1 antagonist, EPGN2154, individually and in combination to evaluate their efficacy for NASH remission in preclinical models.
METHODS
In the present study, we used (1) C57Bl6/J wild-type mice fed on a high-fat, high-carbohydrate (HFHC) diet for 16 weeks and (2) leptin-deficient mice (ob/ob) fed on an Amylin liver NASH diet for 16 weeks. After 16 weeks, the mice were randomly distributed in equal numbers in (1) no-drug, (2) EPGN2154, (3) Sema, and (4) EPGN2154+Sema treatment groups for 8 additional weeks at a dosage of 10 mg/kg body weight for EPGN2154 (oral gavage, 5 days a week) and 6.17 μg/kg body weight of Sema (subcutaneous injection every alternate day, 3 days a week).
RESULTS
In the wild-type-high-fat, high-carbohydrate model, we observed the most body weight loss in the EPGN2154+Sema combination group compared to the other treatment groups. All groups led to a significant reduction in alanine transaminase levels when compared to high-fat, high-carbohydrate-fed wild type. However, no significant difference in alanine transaminase levels was observed among the treatment groups. In the ob/ob mice study, Sema did not cause body weight loss. Moreover, the EPGN2154 and the combination groups had a lower NAFLD Activity Score and incidence of advanced-stage hepatic fibrosis than the Sema group.
CONCLUSIONS
EPGN2154 demonstrated a hepato-protective effect independent of body weight loss in preclinical NASH models.
Topics: Animals; Mice; Non-alcoholic Fatty Liver Disease; Receptors, Lysophosphatidic Acid; Alanine Transaminase; Body Weight; Diet, High-Fat; Carbohydrates; Weight Loss
PubMed: 37994050
DOI: 10.1097/HC9.0000000000000323 -
Obesity Pillars Dec 2022Chronic non-communicable diseases (CNCD) represent a major cause of morbidity and mortality. Type 2 diabetes mellitus (T2DM) is one of the most prevalent CNCD that is... (Review)
Review
BACKGROUND
Chronic non-communicable diseases (CNCD) represent a major cause of morbidity and mortality. Type 2 diabetes mellitus (T2DM) is one of the most prevalent CNCD that is associated with a significant medical and economic burden. One of the main modifiable risk factors of T2DM is obesity. Many medications used for T2DM can lead to weight gain, worsening one of the root causes of this disease.
METHODS
In this clinical review, we study the effect of medications for T2DM on body weight. We used MEDLINE, Google scholar, PubMed, Scopus, and Embase databases to search for relevant studies between 1 January 1950 to 20 September 2022 in English language. Here, we review the most prescribed medications for T2DM and summarize their effect on patients' body weight. We will also present an expert opinion on a recommended weight-centric approach to treat T2DM.
RESULTS
Multiple T2DM medications have been associated with weight gain. Insulin, sulfonylureas, thiazolidinediones and meglitinides may increase body weight. However, biguanides (e.g., metformin), glucagon-like peptide-1 agonists (e.g., semaglutide, liraglutide, tirzepatide), sodium-glucose cotransporter 2 inhibitors, and amylin analogs (e.g., pramlintide) are associated with significant weight loss. Dipeptidyl peptidase-4 inhibitors are considered weight neutral medications. Experts in the fields of endocrinology and obesity recommend utilizing a weight-centric approach when treating T2DM.
CONCLUSION
Considering the high prevalence and debilitating complication of T2DM, it is of utmost importance to shift from a weight gain approach (i.e., insulin, sulfonylureas) into a weight loss/neutral one (i.e., GLP-1 agonists, SGLT-2 inhibitors, metformin).
PubMed: 37990663
DOI: 10.1016/j.obpill.2022.100045