Peptide Antagonist Research Articles

Migraine Management in Japan: Current Approaches and Science Narrative Including an Evidence-based Review.

Migraine is a prevalent and highly disabling neurological disorder. Recent progress in neuroscientific research has contributed to the development of new therapies for migraine, including triptans, ditans, calcitonin gene-related peptide (CGRP) antagonists, and CGRP-related monoclonal antibodies. Noninvasive neuromodulation devices have also been developed. We herein review the recent advances in research and the current standard of management for migraine patients.

Recombinant RAGE antagonist peptide promotes alveolar epithelial cell regeneration via the RAGE/MAPKs/MMP2 pathway in emphysema

The progression of chronic obstructive pulmonary disease (COPD) results in irreversible pulmonary damage and sustained inflammatory responses. While alternative approaches have been explored, the specific role of alveolar epithelial cells in the pathogenesis of COPD remains unclear. Additionally, the association between emphysema and DAMP-RAGE signaling in COPD patients are not understood. Therefore, this study demonstrates to determine the therapeutic effect of a RAGE antagonist peptide (RAP), which we previously identified on the pathogenesis of COPD. We assessed the expression of RAGE ligands and RAGE binding signaling in COPD patients using GEO data. PPE-induced emphysema mouse model and AGER-/- mouse were employed, along treated with RAP. The association between RAGE and the development of emphysema was examined in H&E staining and western blot analysis in mouse lung tissue and BALF. We next analyzed the damage caused by oxidative stress and inflammation through CSE and RAP in human alveolar epithelial cell line A549. Our results show that inhibiting of RAGE alleviates emphysema by suppressing inflammation and MMP activity. Inhibition of RAGE in alveolar epithelial cells significantly induced the mitigation of lung injury, independent of macrophage infiltration. Furthermore, it was confirmed that RAP ameliorated CSE-induced oxidative stress, inflammation, and cell cycle arrest in human alveolar epithelial cells. These findings demonstrate that inhibiting RAGE in alveolar epithelial cells suppress lung injury and emphysema by inhibiting oxidative stress-induced inflammation and MMPs, while promoting alveolar epithelial cell proliferation. Furthermore, blocking of the DAMP-RAGE interaction through RAP offers a promising therapeutic approach for mitigating emphysema.

Engineering Modular Peptide Nanoparticles for Ferroptosis-Enhanced Tumor Immunotherapy.

Indoleamine 2,3-dioxygenase 1 (IDO1) inhibitors are promising for treating tumors but have limited efficacy due to the immunosuppressive tumor microenvironment. In this study, we develop an orchestrated nanoparticle system using modular peptide assemblies, where the co-assembled sequences are designed for the specific binding to the hydrophobic and hydrophilic domains, guiding the assembly process and enabling the customization of nanoparticle properties. We exploit the modularity of this platform to integrate a hydrophobic ferroptosis precursor, an IDO1 inhibitor, and a hydrophilic peptidic PD-L1 antagonist for optimizing therapeutic outcomes through ferroptosis-enhanced tumor immunotherapy. The resulting nanoparticles induce immunogenic ferroptosis, enhance the intratumoral function of T lymphocytes, suppress regulatory T cells, and effectively modulate the immunosuppressive tumor microenvironment, thereby facilitating regression of tumor growth. This work provides a modular peptide-based nanoparticle engineering strategy and holds significant potential for advancing cancer treatment.

Healthcare Utilization, Costs, and Treatment Discontinuation in Adults with Episodic Migraine Initiating Galcanezumab Versus Rimegepant: A US Retrospective Claims Analysis.

To date, no study has compared the healthcare resource utilization (HCRU), costs, and discontinuation of the two calcitonin gene-related peptide antagonists, galcanezumab (monoclonal antibody subcutaneously injected monthly) and rimegepant (oral gepant taken every other day), for migraine prevention. This study aimed to assess all-cause and migraine-related HCRU, costs, and treatment discontinuation at 12 months following treatment initiation in commercial/Medicare beneficiaries with episodic migraine who received galcanezumab versus rimegepant as preventive migraine treatment. This retrospective study used the Merative™ MarketScan® Research Databases (June 2020-June 2023). Adults with episodic migraine were grouped into the galcanezumab (≥1 claim) or rimegepant cohort (≥1 claim with quantity≥15 during the index period). Changes from baseline in all-cause and migraine-related HCRU and cost between the propensity score-matched cohorts were determined using Wilcoxon signed rank test and chi-square test. Treatment discontinuation was assessed using Kaplan-Meier analysis and Cox proportional hazards model. All-cause and migraine-related HCRU and costs increased over the 12-month follow-up in both cohorts. The galcanezumab cohort had a significantly lower increase in mean all-cause totalmedical+pharmacycosts (21% lower) and migraine-related totalmedical+pharmacycosts (76% lower) than the rimegepant cohort at the 12-month follow-up (p<0.0001 for both assessments). Mean (standard deviation) number of days from initiation to discontinuation (>60-day gap) was 244.6 (135.3) for galcanezumab cohort and 178.1 (141.1) for rimegepant cohort (p<0.0001). Treatment discontinuation rate was 1.8 times less likely in the galcanezumab cohort than the rimegepant cohort (hazard ratio=1.81, 95% confidence interval=1.56-2.10). Similar trends were observed using a 30-day gap. Among matched patients, both cohorts of patients with episodic migraine showed all-cause and migraine-related total cost increases over 12 months. However, the magnitude of the increases was significantly lower for the galcanezumab cohort than for the rimegepant cohort.Treatment discontinuation rate was significantly lower in the galcanezumab versus the rimegepant cohort.

Novel Peptidomimetic Cyclo-{E(I)-E(W)}Na (CP-88) with Hematopoietic Activity Sustained in Invasive and Oral Administration: Experimental and Preclinical Evaluation.

Over the last decades, significant progress has been made in studying agonistic and antagonistic hematopoietic peptides. The main disadvantage of this class of peptides is their low stability with noninvasive administration methods, which limits the widespread use of hematopoiesis-regulated peptide drugs in medical practice. The aim of this work is to study novel peptidomimetics with hematopoietic activity sustained in invasive and oral administration. The activity of the leading compound cyclopeptide Cyclo-[Glu(Ile)-Glu(Trp)] (CP-88) was compared to that of the pharmaceutical preparation Stemokin in stimulating the population of committed colony-forming cells in intact and irradiated mice. CP-88 peptide increases the relative number of CD34+ cells in the blood and bone marrow, leading to expanded hematopoietic stem cells. CP-88 peptide, applied 48 h before bone marrow extraction, stimulates the population of committed colony-forming cells in the normal bone marrow by 33-37% above the normal level. In recipient mice injected with irradiated bone marrow, this peptide was restored practically to normal levels of colony-forming cells in a wide range of doses at intraperitoneal and oral administration. The toxicological results conclude that in humans, considering interspecies extrapolation, the CP-88 peptide can be practically safe with a single and course administration in doses of up to 100 μg/kg. The results of this investigation underscore the significant potential of CP-88 peptide as a hematopoiesis-regulated drug and instill optimism for its future application in medical practice.

P90 JNJ-77242113 induces a strong and durable pharmacodynamic response in serum and skin of patients with moderate-to-severe psoriasis: 1-year results from FRONTIERs 1 and 2

Abstract JNJ-77242113 (JNJ-2113), a targeted oral peptide that binds the interleukin (IL)-23-receptor to inhibit IL-23 signalling, showed superior clinical efficacy vs. placebo at Week(W) 16 of FRONTIER-1 in patients with moderate-to-severe plaque psoriasis, which correlated with strong serum and skin pharmacodynamic (PD) responses (Bissonnette R, Pinter A, Ferris LK et al. An oral interleukin-23-receptor antagonist peptide for plaque psoriasis. N Engl J Med 2024; 390:510–21). Here, we evaluated JNJ-2113 systemic PD responses through W52 and further characterized the JNJ-2113 skin PD effect, including relationships with clinical response, utilizing tape-strip skin sampling. FRONTIER-1 randomized (1:1:1:1:1:1; 41-43pts/arm) participants to 25 mg QD, 25 mg BID, 50 mg QD, 100 mg QD, 100 mg BID, or placebo through W16. Patients continuing to FRONTIER-2 received the same JNJ-2113 regimen or crossed-over from placebo→100 mg QD through a total of 52-weeks of treatment. Both targeted [β-Defensin-2 (BD-2)/IL-22/IL-17A/IL-17F/IL-23] and broad (5400+ protein Olink® Explore HT) proteomics were conducted using serum samples collected through W52. The BD-2 and Olink® Explore-HT assays were performed on protein lysates extracted from tape-strip samples of lesional and non-lesional skin collected through W16, and correlation between BD-2 levels and psoriasis area and severity index (PASI) scores was evaluated. JNJ-2113 drove significant, rapid, dose-related reductions in serum psoriasis disease biomarker (BD-2/IL-22/IL-17A/IL-17F) levels that continued through W52; largest reductions were with JNJ-2113 100 mg BID [W52 fold-change (FC) from baseline: -3.63/-1.19/-1.03/-1.49, respectively]. Notably, through W52, JNJ-2113 had minimal impact on serum IL-23 (W52 FC from baseline: −0.09) or cytokines involved in broad immune response through W52 as assessed via Olink® Explore-HT. Consistent with serum results, JNJ-2113 100 mg BID significantly reduced BD-2 levels in W16 lesional skin to levels seen in non-lesional skin; this reduction correlated with PASI. Broad proteomics of tape-strip samples showed baseline lesional samples were significantly enriched for psoriasis-relevant proteins (BD-2/IL-22/IL-17A/IL-19 and others) and clustered away from non-lesional samples. Importantly, JNJ-2113 100 mg BID reduced psoriasis-related proteins in W16 tape-strip lesional samples, with a protein signature like non-lesional samples but distinct from baseline lesional and W16 placebo samples, suggesting JNJ-2113 normalized skin inflammation. JNJ-2113 selectively blocked IL-23-driven inflammation and induced a dose-related PD response, with rapid and sustained reduction of biomarkers of the IL-23 pathway and psoriasis disease severity through 1-year of treatment. JNJ-2113 also normalized skin biomarkers, which correlated with reductions in PASI, to drive disease improvement. Our novel approach to tape-strip-derived proteomics demonstrates this minimally invasive alternative to skin biopsies can be used to evaluate disease biology and characterize local treatment response in psoriatic patients.

Double-blinded, randomized tolerance study of a biologically enhanced Nanogel with endothelin-1 and bradykinin receptor antagonist peptides via intra-articular injection for osteoarthritis treatment in horses

BackgroundOsteoarthritis is a leading cause of pain and retirement in athletic horses. Hydro-expansive functionalized nanogels, acting as Drug Delivery Systems, constitute one of the current therapeutic prospects. These nanogels have the potential to combine mechanical benefits through polymers with the biological effect of prolonged release of bioactive molecules. The purpose of this double-blinded randomized tolerance study versus negative control was to evaluate the response of healthy joints to a single injection of the expected efficient dose (further referred to as the trial dose) and overdose of nanogels composed of chitosan and hyaluronic acid and featuring a type A endothelin receptor antagonist and a type B1 bradykinin receptor antagonist. The metacarpophalangeal joints of 8 healthy horses were randomly injected with 2.4 mL of functionalized nanogels and 2.4 mL of saline as control on the contralateral limb. Injections were repeated twice at one-week intervals, followed by injection of a triple dose of nanogel on week four. Clinical, ultrasonographic and synovial fluid cellular and biochemical follow-ups were performed up to three months following the first injection.ResultsNo change in general clinical parameters, lameness or sensitivity to passive flexion of the fetlocks was noted. Mild to moderate synovitis was noted on the day following injection in the treated group, with a significant difference (p < 0.05) compared to the control group. It spontaneously resolved on day 3 following the injections and did not increase with repeated injections. Similar effects were noted after injection of the triple dose but lasted for a week. Synovial fluid markers of inflammation also showed a transient significant increase in the treated group one week after each injection, but no differences were detected at the end of the study.ConclusionsInjections of the expected therapeutic dose of functionalized nanogel in healthy joints induced a mild transient inflammatory response in the joint. Three injections of the trial dose at one-week intervals and injection of thrice the trial dose induce a mildly greater inflammation without harmful effects on joints. Functionalized nanogels are well tolerated prospects for the treatment of osteoarthritis in horses. Their beneficial effects on arthritic joints have yet to be evaluated to determine their therapeutic potential.

Competitive binding of small antagonistic peptides to the OsER1 receptor optimizes rice panicle architecture.

Rice panicle architecture is a pivotal trait that strongly contributes to grain yield. Small peptide ligands from the OsEPF/EPFL family synergistically control panicle architecture by recognition of the OsER1 receptor and subsequent activation of the OsMKKK10-OsMKK4-OsMPK6 cascade, indicating that specific ligand-receptor pairs orchestrate rice panicle development. However, how small homologous peptides fine-tune organ morphogenesis by targeting a common receptor remains elusive. Here, we report that the small peptide OsEPFL5 acts as a ligand of the OsER1 receptor that inactivates the OsMKKK10-OsMKK4-OsMPK6 cascade, suggesting that OsEPFL5 plays the opposite role to that of the OsEPFL6/7/8/9 subfamily in regulating spikelet number per panicle and grain size. Notably, OsEPFL5 competitively replaces the OsEPFL6, OsEPFL7, OsEPFL8, or OsEPFL9 binding to the OsER1 receptor, exposing antagonistic competition between small homologous peptides. Specifically enhancing expression of OsEPFL5 significantly improves grain yield by suppressing functions of the ligand-receptor pairs of OsEPFL6-OsER1, OsEPFL7-OsER1, OsEPFL8-OsER1, and OsEPFL9-OsER1, suggesting that competitive binding to the OsER1 receptor by small antagonistic peptides can optimize rice panicle architecture. Our findings elucidate how a receptor agonist and antagonist define inductive and inhibitory cues to shape rice panicle architecture, thus providing a new method of rationally breaking yield trait coupling by manipulating small antagonistic peptides.

Spinal pituitary adenylate cyclase-activating polypeptide and PAC1 receptor signaling system is involved in the oxaliplatin-induced acute cold allodynia in mice

Chemotherapy-induced peripheral neuropathy (CIPN) is a type of peripheral neuropathy that develops in patients treated with certain anticancer drugs. Oxaliplatin (OXA) causes CIPN in approximately 80–90 % of patients; thus, it is necessary to elucidate its underlying mechanism and develop effective treatments and prevention methods. The purpose of this study was to determine whether the pituitary adenylate cyclase-activating polypeptide (PACAP)/PAC1 receptor system in the spinal dorsal horn is involved in OXA-induced acute cold allodynia and examine the effect of a PAC1 receptor antagonist. Administration of OXA induced acute cold allodynia in wild-type mice, but not in PACAP-/- mice. In the dorsal root ganglia, OXA upregulated PACAP expression, particularly in small-sized neurons. OXA-induced cold allodynia was ameliorated by intrathecal (i.t.) injection of PACAP6–38 (peptide antagonist for PACAP receptor) and PA-8 (small-molecule antagonist specific for PAC1 receptor). I.t. PACAP, but not vasoactive intestinal polypeptide, resulted in cold allodynia, which was blocked by PA-8. OXA induced the activation of spinal astrocytes in a PAC1 receptor-dependent manner. The results suggest that spinal PACAP/PAC1 receptor systems are involved in OXA-induced acute cold allodynia through astrocyte activation. Furthermore, we demonstrated that the systemic administration of PA-8 resulted in therapeutic and preventative effects on OXA-induced acute cold allodynia. Because PA-8 did not affect the anticancer effects of OXA, we propose PAC1 receptor inhibition as a new strategy for the treatment and prevention of CIPN. PerspectiveCold allodynia is a hallmark of OXA-induced peripheral neuropathy. This study demonstrated the involvement of spinal PACAP/PAC1 receptors in OXA-induced acute cold allodynia. We propose PAC1 receptor inhibition as a new strategy for the treatment and prevention of OXA-induced acute cold allodynia.

The antidepressant-like effects of kisspeptin-10 are reversed by kisspeptin antagonist peptide 234 in male rats.

Kisspeptins are reported to be the most potent activators of the hypothalamus-pituitary-gonadal (HPG) axis known to date. Kisspeptin potently elicits gonadotropin-releasing hormone (GnRH) release and luteinizing hormone (LH) secretion, even in the pre-pubertal period. Beyond the hypothalamus, kisspeptin is also expressed in limbic and paralimbic brain regions, which are areas of the neurobiological network primarily implicated in emotional behaviors alongside sexual functions. Therefore, an increasing body of studies has implicated kisspeptin as having many influences on emotional behaviors. The study was set out to explore if the kisspeptin/GPR54 signaling system is required for the anti-depressant-like effect of kisspeptin-10 (KP-10), besides the regulation of the HPG axis. To test this concept, peptide 234 (P234), a kisspeptin antagonist, was given to the male rats, and its modulatory effect on the anti-depressant-like effects of kisspeptin was investigated by using a forced swimming test (FST). The study has also sought to know whether kisspeptin can exert its effects through adrenergic and serotonergic receptors. To investigate this, the agents yohimbine (Yoh), an alpha-2 adrenergic receptor antagonist, and cyproheptadine (Cry), a non-selective 5-HT2 serotonergic receptor antagonist, were administered in the experiments. Our results indicate that, in rats, the anti-depressant-like effects of KP-10 in a modified rat FST are mediated by GPR54 receptors, since the kisspeptin antagonist peptide 234 reversed kisspeptin-induced anti-depressant-like effects. Our data also demonstrate that the anti-depressant-like effects of kisspeptin, at least in part, are mediated by an interaction of the alpha-2 adrenergic and 5-HT2 serotonergic receptors.

Designed Cell-Penetrating Peptide Constructs for Inhibition of Pathogenic Protein Self-Assembly.

Peptides possess a number of pharmacologically desirable properties, including greater chemical diversity than other biomolecule classes and the ability to selectively bind to specific targets with high potency, as well as biocompatibility, biodegradability, and ease and low cost of production. Consequently, there has been considerable interest in developing peptide-based therapeutics, including amyloid inhibitors. However, a major hindrance to the successful therapeutic application of peptides is their poor delivery to target tissues, cells or subcellular organelles. To overcome these issues, recent efforts have focused on engineering cell-penetrating peptide (CPP) antagonists of amyloidogenesis, which combine the attractive intrinsic properties of peptides with potent therapeutic effects (i.e., inhibition of amyloid formation and the associated cytotoxicity) and highly efficient delivery (to target tissue, cells, and organelles). This review highlights some promising CPP constructs designed to target amyloid aggregation associated with a diverse range of disorders, including Alzheimer's disease, transmissible spongiform encephalopathies (or prion diseases), Parkinson's disease, and cancer.

Identification and characterization of vasoactive intestinal peptide receptor antagonists with high-affinity and potent anti-leukemia activity.

Vasoactive intestinal peptide (VIP) is a neuropeptide involved in tumor growth and immune modulating functions. Previous research indicated that a VIP antagonist (VIPhyb) enhances T-cell activation and induces T-cell-dependent anti-leukemic activity in mice. We created a combinatorial library of VIPhyb C-terminal sequence variations to develop a more potent VIP-receptor (VIP-R) antagonist, hypothesizing that specific amino acid substitutions would improve receptor binding and plasma stability. In silico screening analyses identified sequences with improved docking scores predicting increased binding affinity to human VIP receptors VPAC1 and VPAC2. Fifteen peptides were synthesized and tested for their ability to potentiate activation of purified mouse and human T cells and enhance T cell-dependent anti-leukemia responses in murine models of acute myeloid leukemia. Treating C57Bl/6 mice engrafted with a C1498 myeloid leukemia cell line with daily subcutaneous injections of VIP-R antagonist peptides induced T cell activation resulting in specific anti-leukemia responses. Strikingly, the predicted binding affinity of the VIP-R antagonists to VIP receptors correlated positively with their ability to augment mouse T-cell proliferation and anti-leukemia activity. ANT308 and ANT195 emerged as top candidates due to their high predicted VIP-R binding, low EC 50 for in vitro T cell activation, and potent anti-leukemia activities. ANT308 decreased CREB phosphorylation, a downstream signaling pathway of the VIP receptor, and stimulated granzyme B and perforin expression in CD8+ T cells from AML patients. Combining in silico modeling, in vitro T cell activation properties, and in vivo anti-leukemia activity has identified promising VIP-R antagonist candidates for further development as novel immunotherapies for AML, especially for patients with relapsed disease.

EXTH-18. ADAPTER CHIMERIC ANTIGEN RECEPTOR T CELL THERAPY TARGETING SSTR2 IN MENINGIOMA

Abstract Effective treatment options for meningioma patients beyond surgical resection and radiotherapy are limited. This study presents preclinical and translational evidence supporting the efficacy of an adaptor CAR-T cell system targeting Somatostatin Receptor (SSTR) 2 in otherwise untreatable meningiomas. Tissue microarray analysis revealed that SSTR2 expression was generally heterogeneous but high or intermediate in most World Health Organization (WHO) grade 2 (87.8%) and grade 3 (87.5%) meningiomas. The fluorescein-linked, SSTR2 antagonist peptide octofluo was used in conjunction with adaptor FITC (AdFITC) CAR-T cells to treat experimental meningiomas. In vitro, 10 nM octofluo induced tumor cell killing within 72 hours at effector-target cell ratios (E:T) as low as 1:100. This was observed in two human meningioma cell lines, Ben-Men-1 (CAR-T cells vs. untransduced T-cells [UTT]: 47.9% vs. 4.7%, P &amp;lt; 0.001) and IOMM-Lee (CAR-T cells vs. UTT: 40.2% vs. 4.9%, P &amp;lt; 0.001). In vivo, the AdFITC CAR-T cell system inhibited meningioma growth (P = 0.002) and prolonged survival (P = 0.003) in the IOMM-Lee orthotopic model compared to PBS. In a genetically engineered murine meningioma model, the AdFITC CAR-T cell system not only restricted tumor growth (P = 0.0018) and improved survival (P &amp;lt; 0.0001), but cured a substantial proportion of meningioma bearing mice. This treatment also induced the expansion of both CD8+ CAR-T cells (P = 0.0041) and a host T-cell response. Preliminary ex vivo killing assays, involving co-culture of the AdFITC CAR-T cell system with patient-derived meningioma tissue, showed specific lysis rates of 15-20% (ET 1:1) within 12 hours. Targeting SSTR2 with the AdFITC CAR-T cell system emerges as a promising therapeutic approach for meningioma, an early phase clinical trial is warranted.

Safety and Efficacy of Atogepant for the Preventive Treatment of Migraines in Adults: A Systematic Review and Meta-Analysis.

Background: Migraine is a common neurological condition marked by unilateral recurrent pulsating headaches, often associated with systemic signs and symptoms. Recently, calcitonin gene-related peptide (CGRP) antagonists, including atogepant, an oral CGRP receptor antagonist, have emerged as effective and safe treatments. The current study sought to assess the efficacy and safety of atogepant for preventing episodic migraines in adults. Methods: A comprehensive search, following PRISMA guidelines, was conducted using PubMed, Web of Science, and Cochrane Library to identify randomized, double-blind, placebo-controlled trials published up to June 2024. Results: The studies included adult participants with episodic migraine treated with atogepant. The primary outcomes assessed were changes in mean monthly migraine days (MMDs) and monthly headache days (MHDs) over 12 weeks. Secondary outcomes included reduction in acute medication use, 50% responder rates, and adverse events. A meta-analysis using a random-effects model was performed to evaluate efficacy and safety. Six trials with 4569 participants were included. Atogepant significantly reduced mean monthly migraine days (MMDs) and monthly headache days (MHDs) compared to placebo at all doses (10 mg, 30 mg, 60 mg), with the 60 mg dose showing the greatest reduction (mean difference: -1.48 days, p < 0.001). Significant reductions in acute medication use and improved 50% responder rates were also observed for all doses. The safety profile of atogepant was favorable, with common adverse events being mild to moderate, such as constipation and nausea. There were no significant differences in serious adverse events between the atogepant and placebo groups. Conclusions: Atogepant is an effective and well-tolerated option for preventing episodic migraines, showing significant reductions in migraine frequency and acute medication use. However, further studies are necessary to assess its long-term safety and efficacy, especially at higher doses, and to investigate its potential role in personalized treatment strategies for migraine prevention.

Antagonistic CLE peptide pathways shape root meristem tissue patterning.

Secreted CLAVATA3/EMBRYO SURROUNDING REGION (CLE) peptide ligands dimension the stem cell niche of Arabidopsis shoot meristems by signalling through redundant and cross-compensating CLAVATA1 (CLV1)-type receptor kinases. In the root meristem, the CLV1 homologues BARELY ANY MERISTEM 1 (BAM1) and BAM2 drive CLE13/16-mediated formative divisions that produce the ground tissue layers. Here we report that BAM1/2 are also required to initiate the vascular phloem lineage and that cross-compensation between CLV1-type receptors as observed in the shoot does not operate similarly in the root. Rather, we find that BAM3-mediated CLE45 signalling antagonizes BAM1/2-mediated CLE11/12/13 signalling in the phloem initials but not in the ground tissue. We further observe spatiotemporally contrasting CLE signalling requirements for phloem initiation and differentiation, which are shaped by the SHORT ROOT (SHR) pathway. Our findings thus suggest an intricate quantitative interplay between distinct and antagonistic CLE signalling pathways that organizes tissue layer formation in the Arabidopsis root meristem.

Human adipose-derived stem cells promote migration of papillary thyroid cancer cell via leptin pathway

Introduction Obesity is associated with the incidence and poor prognosis of thyroid cancer, but the mechanism is not fully understood. The aim of this study was to investigate the effects of human adipose-derived stem cells (ADSCs) on the invasion and migration of thyroid cancer cells. Methods ADSCs-conditioned medium (ADSC-CM) was collected to culture thyroid cancer cell lines TPC-1 cells and BCPAP cells. The effects of ADSCs on thyroid cancer cell proliferation were determined by CCK8 and EdU assays, and the effects on migration were determined by Transwell and wound closure assays. Leptin neutralizing antibodies (NAB) were added to ADSC-CM to block leptin. In animal experiments, TPC-1 cells and BCPAP cells were injected into the tail vein of nude mice, and the leptin receptor antagonist peptide allo-aca was injected subcutaneously to block the leptin pathway. The number and size of metastatic lung tumours were observed after 8 weeks. Results ADSC-CM significantly promoted the invasion and migration of thyroid cancer cells and upregulated their matrix metalloproteinase 2 (MMP-2) levels, while NAB with the addition of leptin reduced the invasion and migration of thyroid cancer cells and downregulated MMP-2 levels. Allo-aca treatment reduced the number of metastatic lung nodules formed by thyroid cancer cells in nude mice and reduced the diameter of metastatic lesions. Conclusion ADSCs upregulate MMP-2 levels of thyroid cancer cells through exocrine leptin, thereby promoting cancer cell migration, which may be one of the key mechanisms by which obesity increases the invasiveness of thyroid cancer.

Hippocampal Nogo66-NgR1 signaling activation restricts postsynaptic assembly in aged mice with postoperative neurocognitive disorders.

Postoperative neurocognitive disorders (pNCD) are a common neurological complication, especially in elderly following anesthesia and surgery. Yet, the underlying mechanisms of pNCD remain elusive. This study aimed to investigate the molecular mechanisms that compromise synaptic metaplasticity in pNCD development with a focus on the involvement of Nogo-66 receptor 1 (NgR1) in the pathogenesis of pNCD in aged mice. Aged mice subjected to anesthesia and laparotomy surgery exhibited anxiety-like behavior and contextual fear memory impairment. Moreover, the procedure significantly increased NogoA and NgR1 expressions, particularly in the hippocampal CA1 and CA3 regions. This increase led to the depolymerization of F-actin, attributed to the activation of the RhoA-GTPase, resulting in a reduction of dendritic spines and changes in their morphology. Additionally, these changes hindered the efficient postsynaptic delivery of the subunit GluA1 and GluA2 of AMPA receptors (AMPARs), consequently diminishing excitatory neurotransmission in the hippocampus. Importantly, administering the competitive NgR1 antagonist peptide NEP1-40 (Nogo-A extracellular peptide residues 1-40 amino acids of Nogo-66) and Fasudil (a Rho-kinase inhibitor) effectively mitigated synaptic impairments and reversed neurocognitive deficits in aged mice following anesthesia and surgery. Our work indicates that high hippocampal Nogo66-NgR1 signaling disrupts postsynaptic AMPA receptor surface delivery due to F-actin depolymerization in the pathophysiology of pNCD.

Unbiased high-throughput screening of drug-repurposing libraries identifies small-molecule inhibitors of clot retraction

AbstractPlatelet clot retraction, the ultimate phase of platelet thrombus formation, is critical for clot stabilization. It requires functional αIIbβ3 receptors, fibrin, and the integrated actions of the actin-myosin contractile and cytoskeletal systems. Disturbances in clot retraction have been associated with both bleeding and thrombosis. We recently demonstrated that platelets treated with the αIIbβ3 antagonist peptide RGDW, which eliminates fibrinogen-mediated platelet aggregation, are still able to retract clots. We have exploited this observation to develop an unbiased, functional high-throughput assay to identify small-molecule inhibitors of fibrin-mediated clot retraction adapted for a 384-well plate format. We tested 9710 compounds from drug-repurposing libraries (DRLs). These libraries contain compounds that are either US Food and Drug Administration approved or have undergone preclinical/clinical development. We identified 27 compounds from the Library of Pharmacologically Active Compounds library as inhibitors of clot retraction, of which 14 are known inhibitors of platelet function. From the DRLs, we identified 135 compounds (1.6% hit rate). After extensive curation, these compounds were categorized based on the activity of their reported target. Multiple kinase and phosphodiesterase inhibitors with known antiplatelet effects were identified, along with multiple deubiquitination and receptor inhibitors, as well as compounds that have not previously been reported to have antiplatelet activity. Studies of 1 of the deubiquitination inhibitors (degrasyn) suggest that its effects are downstream of thrombin-induced platelet-fibrinogen interactions and thus may permit the separation of platelet thrombin-induced aggregation-mediated events from clot retraction. Additional studies of the identified compounds may lead to novel mechanisms of inhibiting thrombosis.

GAP JUNCTION FUNCTION IS ESSENTIAL FOR SURVIVAL OF ACUTE LYMPHOBLASTIC LEUKEMIA CELLS.

Acute lymphoblastic leukemia has an intimate physical relationship with nonmalignant bone marrow stromal cells. We have recently demonstrated that stromal cells contribute to the survival of leukemia cells and that there is a bidirectional transfer of intracellular material between them. Understanding the mechanisms of stromal support of leukemia may provide insights into new therapies. To test the hypothesis that gap junctions are formed between acute lymphoblastic leukemia cells and nonmalignant stromal cells, and that gap junction function is essential for the survival of leukemia cells. We employed a well-characterized in vitro model of human bone marrow stromal cells and primary human B lymphoblastic leukemia cells and measured leukemia cell survival in coculture using flow cytometry. We measured the effects of gap junction antagonist peptides, carbenoxolone (a drug known to interfere with the gap junction function), and several leukemia chemotherapy drugs including methotrexate upon leukemia cell survival. We demonstrated that stromal cells need to be alive and metabolically active to keep leukemia cells alive. Physical contact between stromal and leukemia cells leads to an increase in gap junction proteins in leukemia cells. Gap junction inhibitory peptides impaired leukemia cell survival as did carbenoxolone, a nonpeptide inhibitor of the gap junction function. Stromal cell survival was not affected. We observed a very modest enhancement of methotrexate antileukemia activity by low-dose carbenoxolone but no significant interactions with dexamethasone, vincristine, mercaptopurine, or doxorubicin. These studies demonstrate that acute lymphoblastic cell survival is impaired by interference with the gap junction function. The development of drugs targeting gap junctions may provide a novel approach to the therapy of acute lymphoblastic leukemia.

Evaluation of rimegepant utilization patterns and patient characteristics among new users: a United States administrative claims-based study

Objective To assess tablet utilization patterns and describe pre-treatment characteristics among new users of rimegepant. Background Rimegepant is the only oral calcitonin gene-related peptide antagonist approved in the United States for both the acute and preventive treatment of migraine. Methods We conducted a retrospective cohort study of people with migraine who initiated treatment with rimegepant using two US commercial claims databases (MarketScan and Optum). Patients (≥18 years old) with migraine who newly initiated rimegepant were included. Patients were stratified into two groups representing acute (quantity = 8) and prevention (quantity = 15 or 16) use cohorts. Baseline characteristics and medication use history were assessed on index and during the 365-day pre-index period. Rimegepant utilization periods were calculated based on days supplied and varying approaches to define use periods. Tablet quantity per 30 days was reported separately for both acute and prevention cohorts. Results In MarketScan, a total of 14,037 rimegepant users were identified; 11,195 (79.8%) in the acute group and 1,880 (13.4%) in the prevention group. Rimegepant utilization for acute use was 4.9 ± 2.1 tablets per 30 days and for preventive use was 13.1 ± 7.7 tablets per 30 days. There was high baseline prevalence of triptan contraindications, warnings, and high cardiovascular risk, with a combined 46.2% meeting one or more of these criteria. Acute medication overuse was also common (25.1%) prior to rimegepant initiation. Results were consistent in the Optum database. Conclusion Our analysis provides the first real-world data available on tablet utilization and characteristics of new users of rimegepant.