Identification of potent pyrazole based APELIN receptor (APJ) agonists

The apelinergic system comprises the apelin receptor and its cognate apelin and elabela peptide ligands of various lengths. This system has become an increasingly attractive target for pulmonary and cardiometabolic diseases. Small molecule regulators of this receptor with good drug-like properties are needed. Recently, we discovered a novel pyrazole based small molecule agonist 8 of the apelin receptor (EC₅₀ = 21.5 µM, K_i = 5.2 µM) through focused screening which was further optimized to initial lead 9 (EC₅₀ = 0.800 µM, K_i = 1.3 µM). In our efforts to synthesize more potent agonists and to explore the structural features important for apelin receptor agonism, we carried out structural modifications at N1 of the pyrazole core as well as the amino acid side-chain of 9. Systematic modifications at these two positions provided potent small molecule agonists exhibiting EC₅₀ values of <100 nM. Recruitment of β-arrestin as a measure of desensitization potential of select compounds was also investigated. Functional selectivity was a feature of several compounds with a bias towards calcium mobilization over β-arrestin recruitment. These compounds may be suitable as tools for in vivo studies of apelin receptor function.     

Patterns of treatment failure for PD-(L)1 refractory extensive-stage small cell lung cancer in continued PD-(L)1 treatment

BackgroundAlthough immunotherapy greatly extends overall survival (OS) of patients with extensive-stage small cell lung cancer (ES-SCLC), a number of patients develop immunotherapy resistance (IR). Patterns of failure in ES-SCLC are not clarified. Our study aims to explore the clinical pattern of IR and prognostic factors for these patients.MethodsThe study was conducted from 117 ES-SCLC patients with immunotherapy between 2018 and 2022. Chi-square tests and Fishers' exact tests was used to explore failure patterns in different populations. Survival analyses of different progression patterns and subsequent treatment regimens were conducted by Kaplan–Meier curves and log-rank test.Results86 (73.5%) patients experienced IR. The patients with smoking (never smoker vs. current or ex-smoker, 59.5 % vs. 81.3%, P = 0.010), liver metastasis (extrahepatic metastasis vs. intrahepatic metastasis, 73.6 % vs. 90.9%, P = 0.050), and distant metastasis status (no distant metastasis vs. distant metastasis, 39.1 % vs. 81.9%, P<0.001) were associated with IR rates. Liver progression had a lower incidence in 1st line immunotherapy (1st line vs. ≥2nd lines, 14.0 % vs. 41.7%, P = 0.004) and a higher incidence in multiple progression (multiple progression vs. Oligo-progression, 39.4 % vs. 17.0%, P = 0.021). Cranial (41.7 % vs. 16.1%, P = 0.012) and distant lymph node (16.7 % vs. 3.2%, P = 0.049) progression were the main failure model for acquired IR in comparison to primary IR. Patients with new lesion progression only (17.73 vs. 9.17 months, P = 0.013) and non-hepatic progression (14.23 vs. 11.67 months, P = 0.042) had a longer OS. Patients in cross-line immunotherapy after IR had a favourable prognosis (17.07 vs. 11.93 months, P = 0.007).ConclusionThe most common failure pattern of immunotherapy for ES-SCLC was lung and regional lymph node progression. Brain and liver progression were the most common extra thoracic failure sites for 1st line and 2nd and more lines immunotherapy, respectively. There was a higher probability of primary IR in 2 lines and above immunotherapy. Patients with new only progression site and cross-line rechallenge immunotherapy had a better prognosis.     

Efficacy of bi-valent whole cell inactivated bacterial vaccine against Motile Aeromonas Septicemia (MAS) in cultured catfishes (Heteropneustes fossilis,Clarias batrachus and pangasius pangasius) in Bangladesh

The Motile Aeromonas Septicemia (MAS) is an important disease of cultured catfishes (Heteropneustes fossilis, Clarias batrachus and Pangasius pangasius), caused by different species of Aeromonas bacteria which have been documented to be higher death rates (≤70%) in Bangladesh since 2016. Present study was conducted to develop bi-valent vaccine using A. hydrophila and A. veronii, and to validate their efficacy via intra-muscular (IM) and oral-routes of immunization in selected species of fishes. Brood fishes of the three species were immunized with three doses of inactivated vaccine (10⁷ CFU /2.3 mg/ml). Hematological parameters of brood fishes and antibody levels (IgM) of broods, their larvae and eggs were determined by ELISA. Additionally, Relative Percent Survivability (RPS) and the IgM levels of the larvae after challenge with virulent A. hydrophila and A. veronii were also evaluated. Findings of this study showed that the lymphocytes, monocytes, granulocytes counts and antibody (IgM) titre of brood fishes, larvae and eggs from the vaccinated fishes were found significantly higher (p< 0.05) compared to the un-vaccinated control groups. Alternatively, antibody levels (IgM) in the larvae of vaccinated group of brood fishes fed with antigen coated feed was exhibited to be remarkably higher (p< 0.05) than the antigen non-fed group. The RPS of larvae of Shing (91.24 ± 2.00%), Magur (88.09 ± 2.88%) and Pangas (93.17 ± 1.52%) was found to be higher in the larvae at 20-day age of vaccinated group compared to non-vaccinated brood fishes group. Findings of this study indicated that the active immunization of brood fishes followed by oral immunization of their larvae feeding with antigen coated feed showed synergistic effect in protecting cultured Shing, Magur and Pangas fishes from frequent attack with Aeromonas spp at any age of their lifetime.     

TLR4 in POMC neurons regulates thermogenesis in a sex-dependent manner

The rising prevalence of obesity has become a worldwide health concern. Obesity usually occurs when there is an imbalance between energy intake and energy expenditure. However, energy expenditure consists of several components, including metabolism, physical activity, and thermogenesis. Toll-like receptor 4 (TLR4) is a transmembrane pattern recognition receptor, and it is abundantly expressed in the brain. Here, we showed that pro-opiomelanocortin (POMC)-specific deficiency of TLR4 directly modulates brown adipose tissue thermogenesis and lipid homeostasis in a sex-dependent manner. Deleting TLR4 in POMC neurons is sufficient to increase energy expenditure and thermogenesis resulting in reduced body weight in male mice. POMC neuron is a subpopulation of tyrosine hydroxylase neurons and projects into brown adipose tissue, which regulates the activity of sympathetic nervous system and contributes to thermogenesis in POMC-TLR4-KO male mice. By contrast, deleting TLR4 in POMC neurons decreases energy expenditure and increases body weight in female mice, which affects lipolysis of white adipose tissue (WAT). Mechanistically, TLR4 KO decreases the expression of the adipose triglyceride lipase and lipolytic enzyme hormone-sensitive lipase in WAT in female mice. Furthermore, the function of immune-related signaling pathway in WAT is inhibited because of obesity, which exacerbates the development of obesity reversely. Together, these results demonstrate that TLR4 in POMC neurons regulates thermogenesis and lipid balance in a sex-dependent manner.     

Impact of baseline telomere length on survival and chemotherapy related toxicity in breast cancer patients receiving (neo)adjuvant anthracycline containing chemotherapy

PurposeThe aim of this study is to assess baseline mean leukocyte telomere length (TL) as a potential predictive factor for chemotherapy toxicity and a prognostic marker for long-term outcome in early breast cancer (BC) patients.Methods445 BC patients were selected, diagnosed between 2007 and 2010 with early BC and treated with (neo)adjuvant fluorouracil, epirubicin and cyclophosphamide (FEC) or with FEC and Docetaxel (FEC-D). RT-qPCR was performed on germline DNA samples collected at diagnosis before any treatment, to measure mean leukocyte TL. Uni- and multivariable logistic regression or Cox proportional hazard regression analyses were carried out to assess correlation between baseline TL and toxicity parameters (derived from the medical chart) or longer-term outcome.ResultsBaseline TL correlated with age as expected (p = 0.005), but not with febrile neutropenia (n = 97), left ventricular ejection fraction >10% decrease (n = 17) nor other toxicity endpoints measured (all p > 0.05). TL was neither associated with overall survival, breast cancer specific survival or distant disease-free survival (all p > 0.05).ConclusionsBaseline TL is not associated with chemotherapy-related toxicity nor long-term outcome in BC patients.     

Heteroarylamide smoothened inhibitors: Discovery of N-[2,4-dimethyl-5-(1-methylimidazol-4-yl)phenyl]-4-(2-pyridylmethoxy)benzamide (AZD8542) and N-[5-(1H-imidazol-2-yl)-2,4-dimethyl-phenyl]-4-(2- pyridylmethoxy)benzamide (AZD7254)

Aberrant hedgehog (Hh) pathway signaling is implicated in multiple cancer types and targeting the Smoothened (SMO) receptor, a key protein of the Hh pathway, has proven effective in treating metastasized basal cell carcinoma. Our lead optimization effort focused on a series of heteroarylamides. We observed that a methyl substitution ortho to the heteroaryl groups on an aniline core significantly improved the potency of this series of compounds. These findings predated the availability of SMO crystal structure in 2013. Here we retrospectively applied quantum mechanics calculations to demonstrate the o-Me substitution favors the bioactive conformation by inducing a dihedral twist between the heteroaryl rings and the core aniline. The o-Me also makes favorable hydrophobic interactions with key residue side chains in the binding pocket. From this effort, two compounds (AZD8542 and AZD7254) showed excellent pharmacokinetics across multiple preclinical species and demonstrated in vivo activity in abrogating the Hh paracrine pathway as well as anti- tumor effects.     

Growth performance,haematological assessment and chemical composition of Nile tilapia,Oreochromis niloticus (Linnaeus, 1758) fed different levels of Aloe vera extract as feed additives in a closed aquaculture system

A 105-day experimental trial was conducted to assess different levels of dietary Aleo vera extract supplementation on water quality parameters, proximate composition, growth performance and haematological parameters of fry Oreochromis niloticus. Four different percentages of dietary leaf extract powder of Aleo vera (ALE) with a basal feed, designated as, i.e., T0 (Control group; without ALE), T1 (1% ALE), T2 (2% ALE), and T3 (3% ALE). Fish fry was reared in concrete tanks (7.0 m, 1.6 m, 1.0: L, W, H; water volume 11.2 m3/tank), with an average initial weight 4.04 ± 0.03 g/ fry, and each treatment was triplicated. Fry was randomly distributed at a stocking rate of 450 individuals/ tanks. The water quality parameters revealed that temperature, pH, salinity, dissolved oxygen (DO) and nitrates were found in a promising range as given by FAO/WHO limits. However, the record values obtained for Electric Conductivity (EC), Total dissolved solids (TDS), and alkalinities were not found in all tanks' suitable range according to FAO/WHO limits. The results revealed a significant impact of different percentages of dietary ALE supplementation on fry's body composition and haematological parameters. Moreover, the final body weight, final body length, average daily weight gain (g), net weight gain (g) and specific growth rate (%) were significantly higher (p < 0.05) in T1 and T2 compared with T0 and T3 treatments. The poorest feed conversion ratio was recorded in the T2 group compared with other treatments. Thus, the current study provides information about the nutritional quality of Nile tilapia culturing in Pakistan.     

Elucidation of interleukin-19 as a therapeutic target for breast cancer by computational analysis and experimental validation

Interleukin 19 (IL-19) is a cytokine produced by monocytes and belongs to the family of IL-10. The IL-19 protein stimulates fibronectin (FN) expression and assembly, metastasis, and cell division in breast cancer (BC) cells. IL-19, which is connected to breast pathogenesis and has an autocrine action in BC cells, is a key predictor of prognosis for many tumour forms, including breast cancer. Augmented IL-19 expression has been related to poorer clinical outcomes for patients with BC and directly enhances proliferation and migration while also serving as a microenvironment for tumour formation. The main aim of our study was to examine the expression profile, functional role, and prognostic significance of interleukin-19 in BC pathogenesis and also to find out the molecular mechanism of IL-19 in BC. In this work, we used the various computational approach and tools, to evaluate the expression profile and prognostic implication of IL-19 in BC and discover the role of IL-19 in BC pathogenesis. IL-19 was shown to be highly upregulated in BC as compared to other interleukins. Also, its levels were highly overexpressed in liminal BC patients, mostly in 3rd stage groups under the age group of 21–40 years. IL-19 levels were increased in BC and elevated expression of IL-19 was examined to have worse overall survival (OS). The KEGG analysis and gene ontology of IL-19 depict that IL-19 is significantly augmented in cytokine activity and receptor-ligand activity and also in the JAK-STAT signaling pathway. Moreover, IL-19 showed a high correlation with IL20RA, as later is involved with the JAK-STAT signaling pathway. The in-vivo and in-vitro studies have also reflected that upregulation of IL-19 enhances tumor development and affects clinical outcomes in BC patients through several pathways including the JAK TAT signalling pathway. Overall, our study indicates that IL-19 increases tumour growth and that inhibiting it in addition to standard treatments will greatly improve BC patient’s therapeutic responses.     

Bimetallic assembly of Fe(III) doped ZnO as an effective nanoantibiotic and its ROS independent antibacterial mechanism

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Discovery of isoquinolinone and naphthyridinone-based inhibitors of poly(ADP-ribose) polymerase-1 (PARP1) as anticancer agents: Structure activity relationship and preclinical characterization

The exploitation of GLU988 and LYS903 residues in PARP1 as targets to design isoquinolinone (I & II) and naphthyridinone (III) analogues is described. Compounds of structure I have good biochemical and cellular potency but suffered from inferior PK. Constraining the linear propylene linker of structure I into a cyclopentene ring (II) offered improved PK parameters, while maintaining potency for PARP1. Finally, to avoid potential issues that may arise from the presence of an anilinic moiety, the nitrogen substituent on the isoquinolinone ring was incorporated as part of the bicyclic ring. This afforded a naphthyridinone scaffold, as shown in structure III. Further optimization of naphthyridinone series led to identification of a novel and highly potent PARP1 inhibitor 34, which was further characterized as preclinical candidate molecule. Compound 34 is orally bioavailable and displayed favorable pharmacokinetic (PK) properties. Compound 34 demonstrated remarkable antitumor efficacy both as a single-agent as well as in combination with chemotherapeutic agents in the BRCA1 mutant MDA-MB-436 breast cancer xenograft model. Additionally, compound 34 also potentiated the effect of agents such as temozolomide in breast cancer, pancreatic cancer and Ewing’s sarcoma models.     

Lipoprotein(a) and Atherosclerotic Cardiovascular Disease,the Impact of Available Lipid-Lowering Medications on Lipoprotein(a): An Update on New Therapies

ObjectiveTo review evidence of existing and new pharmacological therapies for lowering lipoprotein(a) (Lp[a]) concentrations and their impact on clinically relevant outcomes.MethodsWe searched for literature pertaining to Lp(a) and pharmacological treatments in PubMed. We reviewed articles published between 1963 and 2020.ResultsWe found that statins significantly increased Lp(a) concentrations. Therapies that demonstrated varying degrees of Lp(a) reduction included ezetimibe, niacin, proprotein convertase subtilisin/kexin type 9 inhibitors, lipoprotein apheresis, fibrates, aspirin, hormone replacement therapy, antisense oligonucleotide therapy, and small interfering RNA therapy. There was limited data from large observational studies and post hoc analyses showing the potential benefits of these therapies in improving cardiovascular outcomes.ConclusionThere are multiple lipid-lowering agents currently being used to treat hyperlipidemia that also have a Lp(a)-lowering effect. Two RNA therapies specifically targeted to lower Lp(a) are being investigated in phase 3 clinical trials and, thus far, have shown promising results. However, evidence is lacking to determine the clinical relevance of reducing Lp(a). At present, there is a need for large-scale, randomized, controlled trials to evaluate cardiovascular outcomes associated with lowering Lp(a).     

Elevated lipoprotein(a) as a predictor for coronary events in older men

Elevated circulating lipoprotein (a) [Lp(a)] is associated with an increased risk of first and recurrent cardiovascular events; however, the effect of baseline Lp(a) levels on long-term outcomes in an elderly population is not well understood. The current single-center prospective study evaluated the association of Lp(a) levels with incident acute coronary syndrome to identify populations at risk of future events. Lp(a) concentration was assessed in 755 individuals (mean age of 71.9 years) within the community and followed for up to 8 years (median time to event, 4.5 years; interquartile range, 2.5–6.5 years). Participants with clinically relevant high levels of Lp(a) (>50 mg/dl) had an increased absolute incidence rate of ASC of 2.00 (95% CI, 1.0041) over 8 years (P = 0.04). Moreover, Kaplan-Meier cumulative event analyses demonstrated the risk of ASC increased when compared with patients with low (<30 mg/dl) and elevated (30–50 mg/dl) levels of Lp(a) over 8 years (Gray’s test; P = 0.16). Within analyses adjusted for age and BMI, the hazard ratio was 2.04 (95% CI, 1.0–4.2; P = 0.05) in the high versus low Lp(a) groups. Overall, this study adds support for recent guidelines recommending a one-time measurement of Lp(a) levels in cardiovascular risk assessment to identify subpopulations at risk and underscores the potential utility of this marker even among older individuals at a time when potent Lp(a)-lowering agents are undergoing evaluation for clinical use.     

EGFR pathway targeting drugs in head and neck cancer in the era of immunotherapy

Receptor tyrosine kinases (RTKs) are cell surface receptors that bind growth factor ligands and initiate cellular signaling. Of the 20 classes of RTKs, 7 classes, I-V, VIII, and X, are linked to head and neck cancers (HNCs). We focus on the first class of RTK, epidermal growth factor receptor (EGFR), as it is the most thoroughly studied class. EGFR overexpression is observed in 20% of tumors, and expression of EGFR variant III is seen in 15% of aggressive chemoradiotherapy resistant HNCs. Currently, the EGFR monoclonal antibody (mAb) cetuximab is the only FDA approved RTK-targeting drug for the treatment of HNCs. Clinical trials have also included EGFR mAbs, with tyrosine kinase inhibitors, and small molecule inhibitors targeting the EGFR, MAPK, and mTOR pathways. Additionally, Immunotherapy has been found to be effective in 15 to 20% of patients with recurrent or metastatic HNC as a monotherapy. Thus, attempts are underway for the combinatorial treatment of immunotherapy and EGFR mAbs to determine if the recruitment of immune cells in the tumor microenvironment can overcome EGFR resistance.     

Targeting protein kinases benefits cancer immunotherapy

Small-molecule kinase inhibitors have been well established and successfully developed in the last decades for cancer target therapies. However, intrinsic or acquired drug resistance is becoming the major barrier for their clinical application. With the development of immunotherapies, in particular the discovery of immune checkpoint inhibitors (ICIs), the combination of ICIs with other therapies have recently been extensively explored, among which combination of ICIs with kinase inhibitors achieves promising clinical outcome in a plethora of cancer types. Here we comprehensively summarize the potent roles of protein kinases in modulating immune checkpoints both in tumor and immune cells, and reshaping tumor immune microenvironments by evoking innate immune response and neoantigen generation or presentation. Moreover, the clinical trial and approval of combined administration of kinase inhibitors with ICIs are collected, highlighting the precise strategies to benefit cancer immune therapies.     

The hidden potential of glycomarkers: Glycosylation studies in the service of cancer diagnosis and treatment

Changes in the glycosylation process appear early in carcinogenesis and evolve with the growth and spread of cancer. The correlation of the characteristic glycosylation signature with the tumor stage and the appropriate therapy choice is an important issue in translational medicine. Oncologists also pay attention to extracellular vesicles as reservoirs of new cancer glycomarkers that can be potent for cancer diagnosis/prognosis. In this review, we recall glycomarkers used in oncology and show their new glycoforms of improved clinical relevance. We summarize current knowledge on the biological functions of glycoepitopes in cancer-derived extracellular vesicles and their potential use in clinical practice. Is glycomics a future of cancer diagnosis? It may be, but in combination with other omics analyses than alone.     

Ablation of pigment epithelium-derived factor receptor (PEDF-R/Pnpla2) causes photoreceptor degeneration

Photoreceptor cells express the patatin-like phospholipase domain-containing 2 (PNPLA2) gene that codes for pigment epithelium-derived factor receptor (PEDF-R) (also known as ATGL). PEDF-R exhibits phospholipase activity that mediates the neurotrophic action of its ligand PEDF. Because phospholipids are the most abundant lipid class in the retina, we investigated the role of PEDF-R in photoreceptors by generating CRISPR Pnpla2 knock-out mouse lines in a retinal degeneration-free background. Pnpla2^−/− mice had undetectable retinal Pnpla2 gene expression and PEDF-R protein levels as assayed by RT-PCR and immunofluorescence, respectively. The photoreceptors of mice deficient in PEDF-R had deformities as examined by histology and transmission electron microscopy. Pnpla2 knockdown diminished the PLA₂ enzymatic activity of PEDF-R in the retina. Lipidomic analyses revealed the accumulation of lysophosphatidyl choline-DHA and lysophosphatidyl ethanolamine-DHA in PEDF-R-deficient retinas, suggesting a possible causal link to photoreceptor dysfunction. Loss of PEDF-R decreased levels of rhodopsin, opsin, PKCα, and synaptophysin relative to controls. Pnpla2^−/− photoreceptors had surface-exposed phosphatidylserine, and their nuclei were TUNEL positive and condensed, revealing an apoptotic onset. Paralleling its structural defects, PEDF-R deficiency compromised photoreceptor function in vivo as indicated by the attenuation of photoreceptor a- and b-waves in Pnpla2^−/− and Pnpla2^+/− mice relative to controls as determined by electroretinography. In conclusion, ablation of PEDF-R in mice caused alteration in phospholipid composition associated with malformation and malperformance of photoreceptors. These findings identify PEDF-R as an important component for photoreceptor structure and function, highlighting its role in phospholipid metabolism for retinal survival and its consequences.     

PLAG alleviates cisplatin-induced cachexia in lung cancer implanted mice

Chemotherapy-induced cachexia has been a significant challenge to the successful treatment of cancer patients. Chemotherapy leads to loss of muscle, loss of appetite, and excessive weight loss, which makes these necessary treatments intolerable for most patients. Therefore, it is necessary to alleviate cachexia to successfully treat cancer patients.In this study, tumor-implanted mouse models administered cisplatin showed rapid weight loss and reduced feeding rate by the second week of treatment, and 1-palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol (PLAG) effectively alleviated cisplatin-induced cachexia. In mice treated with cisplatin on a sacrificial day after 6 weeks, the weight of the two major leg muscles (quadriceps femoris and gastrocnemius) were reduced by up to 70%, but this muscle reduction was successfully prevented in the PLAG co-treatment group. The distribution and size of muscle fibers that appear in small units in cisplatin-treated mice were restored to normal levels by PLAG co-treatment. Furthermore, myostatin expression levels were upregulated by cisplatin, whereas myostatin decreased to normal levels with muscle recovery in the PLAG co-treated group. Tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6), which are commonly expressed in cachexia, were significantly increased in cisplatin-treated mice but were reduced to normal levels in PLAG co-treated mice. Glucose absorption, an indicator of muscle tissue activity, decreased with cisplatin treatment and recovered to normal levels with PLAG co-treatment. Overall, PLAG effectively alleviated cisplatin-induced cachexia symptoms and reduced tumor growth in tumor-implanted mice.These findings suggest PLAG may be a promising drug to alleviate cachexia in cancer patients receiving chemotherapy.     

Structural Studies Reveal Unique Non-canonical Regulators of G Protein Signaling Homology (RH) Domains in Sorting Nexins

As a subgroup of sorting nexins (SNXs) that contain regulator of G protein signaling homology (RH) domain, SNX-RH proteins, including SNX13, SNX14 and SNX25, were proposed to play bifunctional roles in protein sorting and GPCR signaling regulation. However, mechanistic details of SNX-RH proteins functioning via RH domain remain to be illustrated. Here, we delineate crystal structures of the RH domains of SNX13 and SNX25, revealing a homodimer of SNX13 RH domain mediated by unique extended α4 and α5 helices, and a thiol modulated homodimer of SNX25-RH triggered by a unique cysteine on α6 helix. Further studies showed that RH domains of SNX-RH do not possess binding capacity toward Gα subunits, owing to the lack of critical residues for interaction. Thus, this study identifies a group of novel non-canonical RH domains that can act as a dimerization module in sorting nexins, which provides structural basis for mechanism studies on SNX-RH protein functions.