Spectrum of psychiatric adverse reactions to cyclin-dependent kinases 4/6 inhibitors: A pharmacovigilance analysis of the FDA adverse event reporting system.

BACKGROUND: The emergence of cyclin-dependent kinases 4/6 inhibitors (CDK4/6i) represented a major breakthrough in the treatment of breast cancer over the past decade. In both clinical trials and real-world settings, it was observed that patients using CDK4/6i might experience psychiatric adverse events (PAEs). Herein, we conducted a pharmacovigilance study to comprehensively assess the correlation between CDK4/6i and PAEs. METHOD: We obtained individual case safety reports submitted to the FDA Adverse Events Reporting System (FAERS) during the period from January 2015 to December 2023. In disproportionality analysis, the reporting odds ratio (ROR) and information component (IC) values were calculated for each adverse event-drug combination. Univariate logistic regression analysis was utilized to explore factors associated with PAEs following CDK4/6i treatment. RESULTS: A total of 95,591 reports related to CDK4/6i were identified, with 6.72% reporting PAEs, and this proportion exhibited an annual upward trend. Based on the ROR and IC values, 17 categories of PAEs were defined as CDK4/6i-related PAEs. Among these PAEs, insomnia, stress, eating disorder, depressed mood, and sleep disorder were very common, each accounting for over 10% of CDK4/6i reports. Ribociclib showed the highest risk signal of CDK4/6i-related PAEs (ROR = 1.89[1.75-2.04], IC025 = 0.79), followed by palbociclib (ROR = 1.47[1.41-1.53], IC025 = 0.49), while abemaciclib did not exhibit a significant signal (ROR = 0.52[0.44-0.62], IC025 = -1.13). Female sex, younger age and weight exceeding 80 kg were significant risk factors for the incidence of CDK4/6i-related PAEs. CONCLUSIONS: Using data from a real-world, large-scale spontaneous reporting system for adverse drug reactions, our study delineated the spectrum of PAEs to CDK4/6i. This potentially offered valuable insights for healthcare professionals to manage the risk of PAEs in patients receiving CDK4/6i treatment, particularly those with psychiatric disorders.

Cimicifugin, a broad-spectrum inhibitor of Theileria annulata and Plasmodium falciparum CDK7.

Cyclin-dependent kinase 7 is an attractive therapeutic target for the treatment of cancers, and a previous report suggested that Plasmodium falciparum CDK7 is a potential drug target for developing new anti-malarial drugs. In this study, we aimed to characterize and evaluate the drug target potential of Theileria annulata CDK7. Theileria annulata is responsible for tropical theileriosis, which induces a phenotype similar to cancerous cells like immortalization, hyperproliferation, and dissemination. Virtual screening of the MyriaScreen II library predicted 14 compounds with high binding energies to the ATP-binding pocket of TaCDK7. Three compounds (cimicifugin, ST092793, and ST026925) of these 14 compounds were non-cytotoxic to the uninfected bovine cells (BoMac cells). Cimicifugin treatment led to the activation of the extrinsic apoptosis pathway and induced autophagy in T. annulata-infected cells. Furthermore, cimicifugin also inhibited the growth of P. falciparum, indicating that it has both anti-theilerial and anti-malarial activities and that TaCDK7 and PfCDK7 are promising drug targets.

From bench to bedside: Advancing towards therapeutic treatment of vestibular schwannomas.

Vestibular schwannomas are rare intracranial tumors originating from Schwann cells of the vestibular nerve. Despite their benign nature, these tumors can exert significant mass effects and debilitating symptoms, including gradual hearing loss, vertigo, facial nerve dysfunction, and headaches. Current clinical management options encompass wait-and-scan, surgery, radiation therapy, and off-label medication. However, each approach exhibits its own challenges and harbors limitations that underscore the urgent need for therapeutic treatments. Over the past 2 decades, extensive elucidation of the molecular underpinnings of vestibular schwannomas has unraveled genetic anomalies, dysregulated signaling pathways, downstream of receptor tyrosine kinases, disrupted extracellular matrix, inflammatory tumor microenvironment, and altered cerebrospinal fluid composition as integral factors in driving the development and progression of the disease. Armed with this knowledge, novel therapeutic interventions tailored to the unique molecular characteristics of those conditions are actively being pursued. This review underscores the urgency of addressing the dearth of Food and Drug Administration-approved drugs for vestibular schwannoma, highlighting the key molecular discoveries and their potential translation into therapeutics. It provides an in-depth exploration of the evolving landscape of therapeutic development, which is currently advancing from bench to bedside. These ongoing efforts hold the promise of significantly transforming the lives of vestibular schwannoma patients in the future.

Insights into the structural and functional activities of forgotten Kinases: PCTAIREs CDKs.

In cells, signal transduction heavily relies on the intricate regulation of protein kinases, which provide the fundamental framework for modulating most signaling pathways. Dysregulation of kinase activity has been implicated in numerous pathological conditions, particularly in cancer. The druggable nature of most kinases positions them into a focal point during the process of drug development. However, a significant challenge persists, as the role and biological function of nearly one third of human kinases remains largely unknown.Within this diverse landscape, cyclin-dependent kinases (CDKs) emerge as an intriguing molecular subgroup. In human, this kinase family encompasses 21 members, involved in several key biological processes. Remarkably, 13 of these CDKs belong to the category of understudied kinases, and only 5 having undergone broad investigation to date. This knowledge gap underscores the pressing need to delve into the study of these kinases, starting with a comprehensive review of the less-explored ones.Here, we will focus on the PCTAIRE subfamily of CDKs, which includes CDK16, CDK17, and CDK18, arguably among the most understudied CDKs members. To contextualize PCTAIREs within the spectrum of human pathophysiology, we conducted an exhaustive review of the existing literature and examined available databases. This approach resulted in an articulate depiction of these PCTAIREs, encompassing their expression patterns, 3D configurations, mechanisms of activation, and potential functions in normal tissues and in cancer.We propose that this effort offers the possibility of identifying promising areas of future research that extend from basic research to potential clinical and therapeutic applications.

Molecular Insights into the Regulatory Landscape of Protein Kinase C-Related Kinase-2 (PRK2/PKN2) Using Targeted Small Compounds.

The protein kinase C-related kinases (PRKs, also termed PKNs) are important in cell migration, cancer, hepatitis C infection, and nutrient sensing. They belong to a group of protein kinases called AGC kinases that share common features like a C-terminal extension to the catalytic domain comprising a hydrophobic motif. PRKs are regulated by N-terminal domains, a pseudosubstrate sequence, Rho-binding domains and a C2 domain involved in inhibition and dimerization, while Rho and lipids are activators. We investigated the allosteric regulation of PRK2 and its interaction with its upstream kinase PDK1 using a chemical biology approach. We confirmed the PIF-mediated docking interaction of PRK2 with PDK1 and showed that this interaction can be modulated allosterically. We showed that the polypeptide PIFtide and a small compound binding to the PIF-pocket of PRK2 were allosteric activators, by displacing the pseudosubstrate PKL region from the active site. In addition, a small compound binding to the PIF-pocket allosterically inhibited the catalytic activity of PRK2. Together, we confirmed the docking interaction and allostery between PRK2 and PDK1 and described an allosteric communication between the PIF-pocket and the active site of PRK2, both modulating the conformation of the ATP-binding site and the pseudosubstrate PKL-binding site. Our study highlights the allosteric modulation of the activity and the conformation of PRK2 in addition to the existence of at least two different complexes between PRK2 and its upstream kinase PDK1. Finally, the study highlights the potential for developing allosteric drugs to modulate PRK2 kinase conformations and catalytic activity.

Progress with polo-like kinase (PLK) inhibitors: a patent review (2018-present).

INTRODUCTION: Polo-like kinases (PLKs) have five isoforms, all of which play crucial roles in cell cycle and cell proliferation, offering opportunities for drug design and treatment of cancers and other related diseases. Notably, PLK1 and PLK4 have been extensively investigated as cancer drug targets. One distinctive feature of PLKs is the presence of a unique polo-box domain (PBD), which regulates kinase activity and subcellular localization. This provides possibilities for specifically targeting PLKs. AREA COVERED: This article provides an overview of the roles of PLKs in various cancers and related diseases, as well as the drug development involving PLKs, with a particular focus on PLK1 and PLK4. It summarizes the PLK1 and PLK4 inhibitors that have been disclosed in patents or literature (from 2018 - present), which were sourced from SciFinder and WIPO database. EXPERT OPINION: After two decades of drug development on PLKs, several drugs progressed into clinical trials for the treatment of many cancers; however, none of them has been approved yet. Further elucidating the mechanisms of PLKs and identifying and developing highly selective ATP-competitive inhibitors, highly potent drug-like PBD inhibitors, degraders, etc. may provide new opportunities for cancer therapy and the treatment for several nononcologic diseases. PLKs inhibition-based combination therapies can be another helpful strategy.

Uncovering potential CDK9 inhibitors from natural compound databases through docking-based virtual screening and MD simulations.

CONTEXT: Cyclin-dependent kinase 9 (CDK9) plays a significant role in gene regulation and RNA polymerase II transcription under basal and stimulated conditions. The upregulation of transcriptional homeostasis by CDK9 leads to various malignant tumors and therefore acts as a valuable drug target in addressing cancer incidences. Ongoing drug development endeavors targeting CDK9 have yielded numerous clinical candidate molecules currently undergoing investigation as potential CDK9 modulators, though none have yet received Food and Drug Administration (FDA) approval. METHODS: In this study, we employ in silico approaches including the molecular docking and molecular dynamics simulations for the virtual screening over the natural compounds library to identify novel promising selective CDK9 inhibitors. The compounds derived from the initial virtual screening were subsequently employed for molecular dynamics simulations and binding free energy calculations to study the compound's stability under virtual physiological conditions. The first-generation CDK inhibitor Flavopiridol was used as a reference to compare with our novel hit compound as a CDK9 antagonist. The 500-ns molecular dynamics simulation and binding free energy calculation showed that two natural compounds showed better binding affinity and interaction mode with CDK9 receptors over the reference Flavopiridol. They also showed reasonable figures in the predicted absorption, distribution, metabolism, excretion, and toxicity (ADMET) calculations as well as in computational cytotoxicity predictions. Therefore, we anticipate that the proposed scaffolds could contribute to developing potential and selective CDK9 inhibitors subjected to further validations.

UBA2 SUMOylates NQO1 and promotes the proliferation of hepatocellular carcinoma by modulating the MAPK pathway.

In our previous study, we found that small ubiquitin-related modifier (SUMO)-activating enzyme ubiquitin-associated-2 domain (UBA2) was upregulated in hepatocellular carcinoma (HCC) patients who were insensitive to chemoembolization. In this study, we aimed to investigate the role of UBA2 in HCC progression. Three cohorts were used to evaluate the efficacy of UBA2 as a prognostic factor for HCC. Our results indicated that UBA2 was associated with aggressive clinical behaviors and was a strong indicator of poor prognosis in HCC. In vitro experiments demonstrated that UBA2 accelerated cell growth, invasion, and migration. These results were further supported by in vivo experiments. RNA-sequencing analysis indicated NQO1 as a target of UBA2, with its levels altering following UBA2 manipulation. The results were verified by western blotting (WB) and quantitative PCR. The SUMOplot Analysis Program predicted lysine residue K240 as a modification target of UBA2, which was confirmed by immunoprecipitation (IP) assays. Subsequent mutation of NQO1 at K240 in HCC cell lines and functional assays revealed the significance of this modification. In addition, the oncogenic effect of UBA2 could be reversed by the SUMO inhibitor ML792 in vivo and in vitro. In conclusion, our study elucidated the regulatory mechanism of UBA2 in HCC and suggested that the SUMO inhibitor ML792 may be an effective combinatory treatment for patients with aberrant UBA2 expression.

Pharmacological inhibition of CDK4/6 impairs diffuse pleural mesothelioma 3D spheroid growth and reduces viability of cisplatin-resistant cells.

Introduction: Diffuse pleural mesothelioma (DPM) of the pleura is a highly aggressive and treatment-resistant cancer linked to asbestos exposure. Despite multimodal treatment, the prognosis for DPM patients remains very poor, with an average survival of 2 years from diagnosis. Cisplatin, a platinum-based chemotherapy drug, is commonly used in the treatment of DPM. However, the development of resistance to cisplatin significantly limits its effectiveness, highlighting the urgent need for alternative therapeutic strategies. New selective inhibitors of cyclin-dependent kinases 4 and 6 (CDK4/6) have shown promise in various malignancies by inhibiting cell cycle progression and suppressing tumor growth. Recent studies have indicated the potential of abemaciclib for DPM therapy, and a phase II clinical trial has shown preliminary encouraging results. Methods: Here, we tested abemaciclib, palbociclib, and ribociclib on a panel of DPM cell lines and non-tumor mesothelial(MET-5A) cells. Results: Specifically, we focused on abemaciclib, which was the mosteffective cytotoxic agent on all the DPM cell lines tested. Abemaciclib reduced DPM cell viability, clonogenic potential, and ability to grow as three-dimensional (3D) spheroids. In addition, abemaciclib induced prolonged effects, thereby impairing second-generation sphere formation and inducing G0/G1 arrest and apoptosis/ necrosis. Interestingly, single silencing of RB family members did not impair cell response to abemaciclib, suggesting that they likely complement each other in triggering abemaciclib's cytostatic effect. Interestingly, abemaciclib reduced the phosphorylation of AKT, which is hyperactive in DPM and synergized with the pharmacological AKT inhibitor (AKTi VIII). Abemaciclib also synergized with cisplatin and reduced the viability of DPM cells with acquired resistance to cisplatin. Discussion: Overall, our results suggest that CDK4/6 inhibitors alone or in combination with standard of care should be further explored for DPM therapy.

Computational discovery of AKT serine/threonine kinase 1 inhibitors through shape screening for rheumatoid arthritis intervention.

Rheumatoid Arthritis (RA) is a chronic, symmetrical inflammatory autoimmune disorder characterized by painful, swollen synovitis and joint erosions, which can cause damage to bone and cartilage and be associated with progressive disability. Despite expanded treatment options, some patients still experience inadequate response or intolerable adverse effects. Consequently, the treatment options for RA remain quite limited. The enzyme AKT1 is crucial in designing drugs for various human diseases, supporting cellular functions like proliferation, survival, metabolism, and angiogenesis in both normal and malignant cells. Therefore, AKT serine/threonine kinase 1 is considered crucial for targeting therapeutic strategies aimed at mitigating RA mechanisms. In this context, directing efforts toward AKT1 represents an innovative approach to developing new anti-arthritis medications. The primary objective of this research is to prioritize AKT1 inhibitors using computational techniques such as molecular modeling and dynamics simulation (MDS) and shape-based virtual screening (SBVS). A combined SBVS approach was employed to predict potent inhibitors against AKT1 by screening a pool of compounds sourced from the ChemDiv and IMPPAT databases. From the SBVS results, only the top three compounds, ChemDiv_7266, ChemDiv_2796, and ChemDiv_9468, were subjected to stability analysis based on their high binding affinity and favorable ADME/Tox properties. The SBVS findings have revealed that critical residues, including Glu17, Gly37, Glu85, and Arg273, significantly contribute to the successful binding of the highest-ranked lead compounds at the active site of AKT1. This insight helps to understand the specific binding mechanism of these leads in inhibiting RA, facilitating the rational design of more effective therapeutic agents.

Cancer therapy by cyclin-dependent kinase inhibitors (CDKIs): bench to bedside.

A major characteristic of cancer is dysregulated cell division, which results in aberrant growth of cells. Consequently, medicinal targets that prevent cell division would be useful in the fight against cancer. The primary regulator of proliferation is a complex consisting of cyclin and cyclin-dependent kinases (CDKs). The FDA has granted approval for CDK inhibitors (CDKIs) to treat metastatic hormone receptor-positive breast cancer. Specifically, CDK4/6 CDKIs block the enzyme activity of CDK4 and CDK6. Unfortunately, the majority of first-generation CDK inhibitors, also known as pan-CDK inhibitors because they target multiple CDKs, have not been authorized for clinical use owing to their serious side effects and lack of selection. In contrast to this, significant advancements have been created to permit the use of pan-CDK inhibitors in therapeutic settings. Notably, the toxicity and negative consequences of pan-CDK inhibitors have been lessened in recent years thanks to the emergence of combination therapy tactics. Therefore, pan-CDK inhibitors have renewed promise for clinical use when used in a combination regimen. The members of the CDK family have been reviewed and their primary roles in cell cycle regulation were covered in this review. Next, we provided an overview of the state of studies on CDK inhibitors.

SOCS1 and SOCS3 as key checkpoint molecules in the immune responses associated to skin inflammation and malignant transformation.

SOCS are a family of negative inhibitors of the molecular cascades induced by cytokines, growth factors and hormones. At molecular level, SOCS proteins inhibit the kinase activity of specific sets of receptor-associated Janus Activated Kinases (JAKs), thereby suppressing the propagation of intracellular signals. Of the eight known members, SOCS1 and SOCS3 inhibit activity of JAKs mainly induced by cytokines and can play key roles in regulation of inflammatory and immune responses. SOCS1 and SOCS3 are the most well-characterized SOCS members in skin inflammatory diseases, where their inhibitory activity on cytokine activated JAKs and consequent anti-inflammatory action has been widely investigated in epidermal keratinocytes. Structurally, SOCS1 and SOCS3 share the presence of a N-terminal domain containing a kinase inhibitory region (KIR) motif able to act as a pseudo-substrate for JAK and to inhibit its activity. During the last decades, the design and employment of SOCS1 and SOCS3-derived peptides mimicking KIR domains in experimental models of dermatoses definitively established a strong anti-inflammatory and ameliorative impact of JAK inhibition on skin inflammatory responses. Herein, we discuss the importance of the findings collected in the past on SOCS1 and SOCS3 function in the inflammatory responses associated to skin immune-mediated diseases and malignancies, for the development of the JAK inhibitor drugs. Among them, different JAK inhibitors have been introduced in the clinical practice for treatment of atopic dermatitis and psoriasis, and others are being investigated for skin diseases like alopecia areata and vitiligo.

MR-Based Radiomics Predicts CDK6 Expression and Prognostic Value in High-grade Glioma.

RATIONALE AND OBJECTIVES: This study aims to assess the prognostic value of Cyclin-dependent kinases 6 (CDK6) expression levels and establish a machine learning-based radiomics model for predicting the expression levels of CDK6 in high-grade gliomas (HGG). MATERIALS AND METHODS: Clinical parameters and genomic data were extracted from 310 HGG patients in the Cancer Genome Atlas (TCGA) database and 27 patients in the Repository of Molecular Brain Neoplasia Data (REMBRANDT) database. Univariate and multivariate Cox regression, as well as Kaplan-Meier analysis, were performed for prognosis analysis. The correlation between immune cell Infiltration with CDK6 was assessed using spearman correlation analysis. Radiomic features were extracted from contrast-enhanced magnetic resonance imaging (CE-MRI) in the Cancer Imaging Archive (TCIA) database (n = 82) and REMBRANDT database (n = 27). Logistic regression (LR) and support vector machine (SVM) were employed to establish the radiomics model for predicting CDK6 expression. Receiver operating characteristic curve (ROC), calibration curve, and decision curve analysis (DCA) were utilized to assess the predictive performance of the radiomics model. Generate radiomic scores (RS) based on the LR model. An RS-based nomogram was constructed to predict the prognosis of HGG. RESULTS: CDK6 was significantly overexpressed in HGG tissues and was related to lower overall survival. A significant elevation in infiltrating M0 macrophages was observed in the CDK6 high group (P < 0.001). The LR radiomics model for the prediction of CDK6 expression levels (AUC=0.810 in the training cohort, AUC = 0.784 after cross-validation, AUC=0.750 in the testing cohort) was established utilizing three radiomic features. The predictive efficiencies of the RS-based nomogram, as measured by AUC, were 0.769 for 1-year, 0.815 for 3-year, and 0.780 for 5-year, respectively. CONCLUSION: The expression level of CDK6 can impact the prognosis of patients with HGG. The expression level of HGG can be noninvasively prognosticated utilizing a radiomics model.

Endothelial Autophagy Promotes Atheroprotective Communication Between Endothelial and Smooth Muscle Cells via Exosome-Mediated Delivery of miR-204-5p.

BACKGROUND: Cellular communication among different types of vascular cells is indispensable for maintaining vascular homeostasis and preventing atherosclerosis. However, the biological mechanism involved in cellular communication among these cells and whether this biological mechanism can be used to treat atherosclerosis remain unknown. We hypothesized that endothelial autophagy mediates the cellular communication in vascular tissue through exosome-mediated delivery of atherosclerosis-related genes. METHODS: Rapamycin and adeno-associated virus carrying Atg7 short hairpin RNA under the Tie (TEK receptor tyrosine kinase) promoter were used to activate and inhibit vascular endothelial autophagy in high-fat diet-fed ApoE-/- mice, respectively. miRNA microarray, in vivo and in vitro experiments, and human vascular tissue were used to explore the effects of endothelial autophagy on endothelial function and atherosclerosis and its molecular mechanisms. Quantitative polymerase chain reaction and miRNA sequencing were performed to determine changes in miRNA expression in exosomes. Immunofluorescence and exosome coculture experiments were conducted to examine the role of endothelial autophagy in regulating the communication between endothelial cells and smooth muscle cells (SMCs) via exosomal miRNA. RESULTS: Endothelial autophagy was inhibited in thoracic aortas of high-fat diet-fed ApoE-/- mice. Furthermore, rapamycin alleviated high-fat diet-induced atherosclerotic burden and endothelial dysfunction, while endothelial-specific Atg7 depletion aggravated the atherosclerotic burden. miRNA microarray, in vivo and in vitro experiments, and human vascular tissue analysis revealed that miR-204-5p was significantly increased in endothelial cells after high-fat diet exposure, which directly targeted Bcl2 to regulate endothelial cell apoptosis. Importantly, endothelial autophagy activation decreased excess miR-204-5p by loading miR-204-5p into multivesicular bodies and secreting it through exosomes. Moreover, exosomal miR-204-5p can effectively transport to SMCs, alleviating SMC calcification by regulating target proteins such as RUNX2. CONCLUSIONS: Our study revealed the exosomal pathway by which endothelial autophagy protects atherosclerosis: endothelial autophagy activation transfers miR-204-5p from endothelial cells to SMCs via exosomes, both preventing endothelial apoptosis and alleviating SMC calcification. REGISTRATION: URL: https://www.chictr.org.cn/; Unique identifier: ChiCTR2200064155.

Safety and efficacy of selumetinib in pediatric and adult patients with neurofibromatosis type 1 and plexiform neurofibroma.

BACKGROUND: The MEK inhibitor, selumetinib, reduces plexiform neurofibroma (PN) in pediatric patients with neurofibromatosis type 1 (NF1). Its safety and efficacy in adults with PN and effectiveness in other NF1manifestations (e.g., neurocognitive function, growth reduction, and café-au-lait spots) are unknown. METHODS: This open-label, phase 2 trial enrolled 90 pediatric or adult NF1 patients with inoperable, symptomatic, or potentially morbid, measurable PN (≥ 3 cm). Selumetinib was administered at doses of 20 or 25 mg/m2 or 50 mg q 12 hrs for 2 years. Pharmacokinetics, PN volume, growth parameters, neurocognitive function, café-au-lait spots, and quality of life (QoL) were evaluated. RESULTS: Fifty-nine children and 30 adults (median age, 16 years; range, 3-47) received an average of 22±5 (4-26) cycles of selumetinib. Eighty-eight (98.9%) out of 89 per-protocol patients showed volume reduction in the target PN (median, 40.8%; 4.2%-92.2%), and 81 (91%) patients showed partial response (≥ 20% volume reduction). The response lasted until cycle 26. Scores of neurocognitive functions (verbal comprehension, perceptual reasoning, processing speed, and full-scale IQ) significantly improved in both pediatric and adult patients (P <0.05). Prepubertal patients showed increases in height score and growth velocity (P <0.05). Café-au-lait spot intensity decreased significantly (P <0.05). Improvements in QoL and pain scores were observed in both children and adults. All adverse events were CTCAE grade 1 or 2 and were successfully managed without drug discontinuation. CONCLUSION: Selumetinib decrease PN volume in the majority of pediatric and adult NF1 patients while also showing efficacy in non-malignant diverse NF1 manifestations.

(Homo-)harringtonine prevents endothelial inflammation through IRF-1 dependent downregulation of VCAM1 mRNA expression and inhibition of cell adhesion molecule protein biosynthesis.

The plant alkaloid homoharringtonine (HHT) is a Food and Drug Administration (FDA)-approved drug for the treatment of hematologic malignancies. In addition to its well-established antitumor activity, accumulating evidence attributes anti-inflammatory effects to HHT, which have mainly been studied in leukocytes to date. However, a potential influence of HHT on inflammatory activation processes in endothelial cells, which are a key feature of inflammation and a prerequisite for the leukocyte-endothelial cell interaction and leukocyte extravasation, remains poorly understood. In this study, the anti-inflammatory potential of HHT and its derivative harringtonine (HT) on the TNF-induced leukocyte-endothelial cell interaction was assessed, and the underlying mechanistic basis of these effects was elucidated. HHT affected inflammation in vivo in a murine peritonitis model by reducing leukocyte infiltration and proinflammatory cytokine expression as well as ameliorating abdominal pain behavior. In vitro, HT and HHT impaired the leukocyte-endothelial cell interaction by decreasing the expression of the endothelial cell adhesion molecules intracellular adhesion molecule -1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1). This effect was mediated by a bipartite mechanism. While HHT did not affect the prominent TNF-induced pro-inflammatory NF-ĸB signaling cascade, the compound downregulated the VCAM1 mRNA expression in an IRF-1-dependent manner and diminished active ICAM1 mRNA translation as determined by polysome profiling. This study highlights HHT as an anti-inflammatory compound that efficiently hampers the leukocyte-endothelial cell interaction by targeting endothelial activation processes.

Spontaneous Tumor Regression and Reversion: Insights and Associations with Reduced Dietary Phosphate.

Tumors that spontaneously shrink from unknown causes in tumor regression, and that return to normal cells in tumor reversion, are phenomena with the potential to contribute new knowledge and novel therapies for cancer patient survival. Tumorigenesis is associated with dysregulated phosphate metabolism and an increased transport of phosphate into tumor cells, potentially mediated by phosphate overload from excessive dietary phosphate intake, a significant problem in Western societies. This paper proposes that reduced dietary phosphate overload and reregulated phosphate metabolism may reverse an imbalance of kinases and phosphatases in cell signaling and cellular proliferation, thereby activating autophagy in tumor regression and reversion. Dietary phosphate can also be reduced by sickness-associated anorexia, fasting-mimicking diets, and other diets low in phosphate, all of which have been associated with tumor regression. Tumor reversion has also been demonstrated by transplanting cancer cells into a healthy microenvironment, plausibly associated with normal cellular phosphate concentrations. Evidence also suggests that the sequestration and containment of excessive phosphate within encapsulated tumors is protective in cancer patients, preventing the release of potentially lethal amounts of phosphate into the general circulation. Reducing dietary phosphate overload has the potential to provide a novel, safe, and effective reversion therapy for cancer patients, and further research is warranted.

Effect of electroacupuncture intervention on angiogenesis in psoriasis mice. / ç”µé’ˆå¯¹é“¶å±‘ç— å°é¼ è¡€ç®¡ç”Ÿæˆçš„å½±å“åŠæœºåˆ¶ç ”ç©¶.

OBJECTIVES: To observe the effect of electroacupuncture (EA) stimulation of "Zusanli"(ST36) and"Xuehai"(SP10) on the angiogenesis of the local injured skin tissue in mice with psoriasis, so as to explore its mechanisms underlying improvement of psoriasis-induced skin lesions. METHODS: A total of 24 female BALB/c mice aged 6-8 weeks were randomly divided into control, model and EA groups, with 8 mice in each group. The psoriasis-like skin lesion model was established by application of 5% imiquimod (IMQ) cream to the mice's back skin, 62.5 mg/d, for 7 days after local depilation, and the mice of the control group received local application of an equal amount of petroleum jelly once a day for 7 days. EA stimulation (2 Hz/100 Hz) was applied to ST36 and SP10 for 30 min, once daily for 7 consecutive days. Photos of the topical injured skin at the back were taken every day, and the severity of psoriasis lesions (psoriasis area and severity index ï¼»PASIï¼½) was scaled. Following H.E. staining, the morphological changes in the injured skin tissue were observed with epidermal thickness analyzed, and the Masson staining was used to observe the proportion of collagen fibers in the injured skin tissues. Immunohistochemical method was used to detect the expression of microvascular markers CD31 and vascular endothelial growth factor (VEGF) and the microvascular density (MVD) was calculated. Western blot was used to detect the expression levels of CD31, VEGF proteins and mitogen activated protein kinases (MAPK) signaling pathway related proteins p38, phosphorylated p38 (p-p38), extracellular regulated protein kinases (ERK), p-ERK, c-Jun N-terminal kinase (JNK) and p-JNK in the injured skin tissue. RESULTS: Compared with the control group, the mice in the model group showed an evident increase in the erythema score, scales score, skin thickening score and PASI score, epidermal thickness, proportion of the collagen fibers, MVD value of CD31 and VEGF, and expression levels of CD31 and VEGF proteins, and p-p38/p38, p-ERK/ERK and p-JNK/JNK ratios in the injured skin tissue (P<0.001, P<0.01). In contrast to the model group, the EA group had a significant decrease in the levels of all the indexes mentioned above (P<0.05, P<0.01, P<0.001). CONCLUSIONS: EA intervention can improve the psoriasis-like skin lesions induced by IMQ in mice, which may be related with its functions in down-regulating the expression of angiogenic related factors CD31 and VEGF proteins and MAPK signaling pathway related proteins in the topical injured skin tissue.

Inhibition of cysteine-serine-rich nuclear protein 1 ameliorates ischemia-reperfusion injury during liver transplantation in an MAPK-dependent manner.

Hepatic ischemia-reperfusion injury (HIRI) is a critical pathophysiological process during liver transplantation (LT). Multiple genes and signal pathways are dysregulated during HIRI. This study aims to identify genes as potential therapeutic targets for ameliorating HIRI. Datasets containing samples from the human donor liver (GSE151648) and mouse HIRI model (GSE117066) were analyzed to determine differentially expressed genes (DEGs). The selected DEGs were confirmed by real-time PCR and western blot in the hepatocyte hypoxia-reoxygenation (HR) model, mouse HIRI model, and human liver samples after transplantation. Genetic inhibition was used to further clarify the underlying mechanism of the gene in vitro and in vivo. Among the DEGs, CSRNP1 was significantly upregulated (|log FC|= 2.08, P < 0.001), and was positively correlated with the MAPK signal pathway (R = 0.67, P < 0.001). CSRNP1 inhibition by siRNA significantly suppressed apoptosis in the AML-12 cell line after HR (mean Annexin+ ratio = 60.62% vs 42.47%, P = 0.0019), but the protective effect was eliminated with an additional MAPK activator. Knocking down CSRNP1 gene expression by intravenous injection of AAV-shRNA markedly reduced liver injury in mouse HIRI model (ALT: AAV-NC vs AAV-shCsrnp1 = 26,673.5 ± 2761.2 vs 3839.7 ± 1432.8, P < 0.001; AST: AAV-NC vs AAV-shCsrnp1 = 8640.5 ± 1450.3 vs 1786.8 ± 518.3, P < 0.001). Liver-targeted delivery of siRNA by nanoparticles effectively inhibited intra-hepatic genetic expression of Csrnp1 and alleviated IRI by reducing tissue inflammation and hepatocyte apoptosis. Furthermore, CSRNP1 inhibition was associated with reduced activation of the MAPK pathway both in vitro and in vivo. In conclusion, our results demonstrated that CSRNP1 could be a potential therapeutic target to ameliorate HIRI in an MAPK-dependent manner.

The αC-ß4 loop controls the allosteric cooperativity between nucleotide and substrate in the catalytic subunit of protein kinase A.

Allosteric cooperativity between ATP and substrates is a prominent characteristic of the cAMP-dependent catalytic subunit of protein kinase A (PKA-C). This long-range synergistic action is involved in substrate recognition and fidelity, and it may also regulate PKA's association with regulatory subunits and other binding partners. To date, a complete understanding of this intramolecular mechanism is still lacking. Here, we integrated NMR(Nuclear Magnetic Resonance)-restrained molecular dynamics simulations and a Markov State Model to characterize the free energy landscape and conformational transitions of PKA-C. We found that the apoenzyme populates a broad free energy basin featuring a conformational ensemble of the active state of PKA-C (ground state) and other basins with lower populations (excited states). The first excited state corresponds to a previously characterized inactive state of PKA-C with the αC helix swinging outward. The second excited state displays a disrupted hydrophobic packing around the regulatory (R) spine, with a flipped configuration of the F100 and F102 residues at the αC-ß4 loop. We validated the second excited state by analyzing the F100A mutant of PKA-C, assessing its structural response to ATP and substrate binding. While PKA-CF100A preserves its catalytic efficiency with Kemptide, this mutation rearranges the αC-ß4 loop conformation, interrupting the coupling of the two lobes and abolishing the allosteric binding cooperativity. The highly conserved αC-ß4 loop emerges as a pivotal element to control the synergistic binding of nucleotide and substrate, explaining how mutations or insertions near or within this motif affect the function and drug sensitivity in homologous kinases.