Kinase Inhibitor Research Articles

Research trends and hotspots of radioiodine-refractory thyroid cancer treatment in the twenty-first century: a bibliometric analysis.

The treatment of radioiodine-refractory differentiated thyroid cancer (RAIR-DTC) has made significant advancements in the twenty-first century. This study aimed to assess the current state of research and identify potential new directions by conducting a bibliometric analysis of scientific publications on RAIR-DTC treatment. Publications relevant to RAIR-DTC, published from January 1, 2000, to December 31, 2023, were retrieved from the Web of Science Core Collection. Bibliometric analyses of major keywords, authors, countries, institutions, publications, and journals were conducted using CiteSpace and VOSviewer. A total of 859 papers were included in the analysis. The results demonstrated a rising trend in the number of publications over time. The United States was identified as the leading contributor in terms of publication output, citations, and international collaborations. Gustave Roussy emerged as the top organization in publication productivity, while the journal Thyroid had the highest number of related publications. The research on RAIR treatment was categorized into three key hotspots: clinical trials of targeted therapies, novel therapeutic strategies, and debates surrounding the RAIR-DTC management. RAIR-DTC research is expanding from the clinical trial phase of tyrosine kinase inhibitor monotherapy to a more complex combination therapy strategy, in particular, the synergistic effect of immune checkpoint inhibitors and other therapeutic agents, requiring more high-quality prospective studies to validate the clinical benefits. Moreover, the timely identification of RAIR-DTC patients holds the potential to enable early disease intervention, constituting a pivotal novel research direction in the future.

Ni‐MOF Engineered System Targeting Macrophage Aurora A Kinase for Bone Loss Prevention Through PD‐L1 Activation

AbstractPostmenopausal bone loss due to estrogen deficiency necessitates effective therapeutic strategies. Our study explores targeting macrophage Aurora A kinase to mitigate bone loss. Aurora A kinase phosphorylation is observed being increased in bone marrow‐derived macrophages (BMDMs) from ovariectomy (OVX) mice, along with a reduction in programmed death‐ligand 1 (PD‐L1) expression. Detailed analysis reveals that PD‐L1 plays an immunomodulatory role by lowering the ratio of T helper 17 cells and regulatory T cells. The metabolic shift toward glycolysis through transcriptome sequencing, induced by Aurora A kinase inhibition, is essential for PD‐L1 expression in BMDMs. The interaction between Aurora A kinase and cytochrome C oxidase subunit 5B is found to enhance PD‐L1 expression. To apply these findings therapeutically, a multifunctional system is developed using a Nickel‐metal organic framework combined with bisphosphonate and MLN8237 (BP@Ni‐MOF/MLN8237). This system targets bone tissues through bisphosphonate and effectively delivers MLN8237 to macrophages, promoting PD‐L1 expression for a favorable immune environment. Moreover, this system exhibits an obvious angiogenic effect. The present study highlights the crucial roles of macrophage Aurora A kinase and PD‐L1 in maintaining bone homeostasis as well as the angiogenesis effect by Ni‐MOF engineered system, presenting a promising therapeutic approach to prevent postmenopausal bone loss.

Mechanisms Regulating Mitochondrial Transfer in Human Corneal Epithelial Cells.

The intraepithelial corneal nerves (ICNs) innervating the cornea are essential to corneal epithelial cell homeostasis. Rho-associated kinase (ROCK) inhibitors (RIs) have been reported to play roles in neuron survival after injury and in mitochondrial transfer between corneal epithelial cells. In this study, the mechanisms human corneal limbal epithelial (HCLE) cells use to control intercellular mitochondrial transfer are assessed. Mitotracker and AAV1 mitotag eGFPmCherry were used to allow us to study mitochondrial transfer between HCLE cells and neurons in co-cultures and in HCLE cultures. A mitochondrial transfer assay was developed using HCLE cells to quantify the impact of cell stress and inhibition of phagocytosis, gap junctions, and ROCK on mitochondrial transfer, cell adhesion, migration, matrix deposition, and mitochondrial content. Bidirectional mitochondrial transfer occurs between HCLE cells and neurons. Mitochondrial transfer among HCLE cells is inhibited when gap junction function is reduced and enhanced by acid stress and by inhibition of either phagocytosis or ROCK. Media conditioned by RI-treated cells stimulates cell adhesion and mitochondrial transfer. Maximal mitochondrial transfer takes place when gap junctions are functional, when ROCK and phagocytosis are inhibited, and when cells are stressed by low pH media. Treatments that reduce mitochondrial content increase HCLE cell mitochondrial transfer. ROCK inhibition in co-cultures causes the release and adhesion of mitochondria to substrates where they can be engulfed by migrating HCLE cells and growing axons and their growth cones.

Targeted intervention in nerve-cancer crosstalk enhances pancreatic cancer chemotherapy.

Nerve-cancer crosstalk has gained substantial attention owing to its impact on tumour growth, metastasis and therapy resistance. Effective therapeutic strategies targeting tumour-associated nerves within the intricate tumour microenvironment remain a major challenge in pancreatic cancer. Here we develop Escherichia coli Nissle 1917-derived outer membrane vesicles conjugated with nerve-binding peptide NP41, loaded with the tropomyosin receptor kinase (Trk) inhibitor larotrectinib (Lar@NP-OMVs) for tumour-associated nerve targeting. Lar@NP-OMVs achieve efficient nerve intervention to diminish neurite growth by disrupting the neurotrophin/Trk signalling pathway. Moreover, OMV-mediated repolarization of M2-like tumour-associated macrophages to an M1-like phenotype results in nerve injury, further accentuating Lar@NP-OMV-induced nerve intervention to inhibit nerve-triggered proliferation and migration of pancreatic cancer cells and angiogenesis. Leveraging this strategy, Lar@NP-OMVs significantly reduce nerve infiltration and neurite growth promoted by gemcitabine within the tumour microenvironment, leading to augmented chemotherapy efficacy in pancreatic cancer. This study sheds light on a potential avenue for nerve-targeted therapeutic intervention for enhancing pancreatic cancer therapy.

Osteosarcoma cells depend on MCL-1 for survival, and osteosarcoma metastases respond to MCL-1 antagonism plus regorafenib in vivo

Osteosarcoma is the most common form of primary bone cancer, which primarily afflicts children and adolescents. Chemotherapy, consisting of doxorubicin, cisplatin and methotrexate (MAP) increased the 5-year osteosarcoma survival rate from 20% to approximately 60% by the 1980s. However, osteosarcoma survival rates have remained stagnant for several decades. Patients whose disease fails to respond to MAP receive second-line treatments such as etoposide and, in more recent years, the kinase inhibitor regorafenib. BCL-2 and its close relatives enforce cellular survival and have been implicated in the development and progression of various cancer types. BH3-mimetics antagonize pro-survival members of the BCL-2 family to directly stimulate apoptosis. These drugs have been proven to be efficacious in other cancer types, but their use in osteosarcoma has been relatively unexplored to date. We investigated the potential efficacy of BH3-mimetics against osteosarcoma cells in vitro and examined their cooperation with regorafenib in vivo. We demonstrated that osteosarcoma cell lines could be killed through inhibition of MCL-1 combined with BCL-2 or BCL-xL antagonism. Inhibition of MCL-1 also sensitized osteosarcoma cells to killing by second-line osteosarcoma treatments, particularly regorafenib. Importantly, we found that inhibition of MCL-1 with the BH3-mimetic S63845 combined with regorafenib significantly prolonged the survival of mice bearing pulmonary osteosarcoma metastases. Together, our results highlight the importance of MCL-1 in osteosarcoma cell survival and present a potential therapeutic avenue that may improve metastatic osteosarcoma patient outcomes.

Inhibitory effect of 1,4,5,6-tetrahydroxy-7,8-diprenylxanthone against NSCLC with L858R/T790M/C797S mutant EGFR

Epidermal growth factor receptor (EGFR)-activating mutations are critical factors in the development of EGFR-driven non-small-cell lung cancer (NSCLC), and molecular targeted therapies have focused on inhibiting these mutations. EGFR tyrosine kinase inhibitors (TKIs) have remarkable inhibitory effects on NSCLC with EGFR mutations. However, acquired resistance limits the clinical application of EGFR-TKIs, highlighting the need for discovery of novel therapeutic strategies. 1,4,5,6-tetrahydroxy-7,8-diprenylxanthone is a natural product derived from Garcinia xanthochymus, has shown potential anti-tumor activity, but the underlying mechanism needs further elucidation. In this study, we developed Ba/F3 and NIH/3T3 cells harboring EGFR L858R/T790M/C797S mutation, and then found that 1,4,5,6-tetrahydroxy-7,8-diprenylxanthone exerted inhibitory effects against cells with EGFR L858R/T790M/C797S mutation. Additionally, 1,4,5,6-tetrahydroxy-7,8-diprenylxanthone exhibited potent anti-tumor activity against cells harboring the triple-mutant EGFR by promoting apoptosis and inducing changes in cell cycle distribution. Furthermore, 1,4,5,6-tetrahydroxy-7,8-diprenylxanthone was found to significantly reduce tumor growth via suppressing the phosphorylation of EGFR in tumor tissues. These effects are associated with binding of 1,4,5,6-tetrahydroxy-7,8-diprenylxanthone to EGFR resulting in the suppression of extracellular signal-regulated kinase (Erk) phosphorylation. In conclusion, our results suggest that 1,4,5,6-tetrahydroxy-7,8-diprenylxanthone may be a potential novel candidate for further investigation and treatment of NSCLC with the triple-mutant EGFR.

PRDM16 Induces Methylation of FLT3 to Promote FLT3-ITD Signaling and Leukemia Progression.

Internal tandem duplication (ITD) in the FMS-like receptor tyrosine kinase-3 (FLT3) is one of the most frequent mutations in acute myeloid leukemia (AML) and is associated with poor prognosis. FLT3-ITD mutations result in endoplasmic reticulum (ER) retention and constitutive autophosphorylation of FLT3. The PR/SET domain 16 (PRDM16) is highly expressed in FLT3-ITD+ AML patients, suggesting it might play a role in leukemogenesis. Here, we revealed that genetic and pharmacological suppression of PRDM16 greatly slowed the progression of FLT3-ITD-driven leukemia, sensitized leukemic cells to tyrosine kinase inhibitors (TKIs), and extended the survival of leukemic mice. PRDM16 enhanced activation of oncogenic FLT3-ITD and ligand-dependent activation of wild-type FLT3 in leukemic cells. Mechanistically, PRDM16 mediated monomethylation of FLT3-ITD at lysine 614 and promoted its ER localization, resulting in enhanced FLT3 signaling in leukemia cells. Moreover, pharmacological suppression of FLT3-ITD methylation in combination with TKIs increased the elimination of FLT3-ITD+ AML cells. Altogether, these results suggest that PRDM16 boosts oncogenic FLT3 signaling in leukemic cells by prompting FLT3-ITD methylation. Therefore, PRDM16 may serve as a therapeutic target for AML.

Review of BCL2 inhibitors for the treatment of Waldenström’s macroglobulinaemia and non-IgM lymphoplasmacytic lymphoma

Lymphoplasmacytic lymphoma (LPL) is a relatively rare form of indolent B-cell non-Hodgkin’s lymphoma, termed Waldenström’s macroglobulinaemia (WM) in the presence of an IgM paraprotein. Although traditionally treated with combination chemoimmunotherapy, the management is evolving in the era of targeted molecular therapies including Bruton’s tyrosine kinase inhibitors (BTKi). However, intolerance and refractoriness to BTKi mean newer agents are required, and the prognosis of so-called quadruple-refractory patients is poor. BCL2 is an anti-apoptotic, pro-survival protein that promotes lymphoma cell survival. Inhibition of BCL2 using first-in-class agent venetoclax has already altered the treatment paradigm in other conditions, including chronic lymphocytic leukaemia (CLL). In-vivo inhibition of BCL2 has been shown to lead to apoptosis of LPL/WM cells. Five studies have published results on the use of BCL2 inhibitors in WM to date, including oblimersen sodium, venetoclax, and sonrotoclax. Fixed-duration venetoclax resulted in high response rates, but many patients relapsed following the completion of therapy. The combination of venetoclax with ibrutinib resulted in higher and relatively deep response rates, but unexpected deaths due to ventricular events mean this combination cannot be explored. Two pivotal trials are currently evaluating the use of fixed-duration venetoclax, either in combination with rituximab or pirtobrutinib, whereas another multi-arm study is studying the use of continuous sonrotoclax monotherapy for R/R WM or in fixed-duration combination with Zanubrutinib for treatment-naïve patients. The potential role of BCL2 inhibitors in WM/LPL remains under study, with many hopeful that they may provide an additional chemotherapy-free oral alternative for patients requiring treatment. In an indolent condition with existing effective treatment regimens, including CIT and cBTKi, cost-effectiveness and toxicity profile will be key, although an additional treatment modality for quadruple-refractory patients with limited treatment options is urgently required.

Targeting AXL cellular networks in kidney fibrosis

IntroductionThe incidence of chronic kidney disease (CKD) is increasing, in parallel with risk factors including obesity and diabetes mellitus. AXL plays a central role in CKD, providing a rationale to evaluate clinical AXL targeting agents.MethodsTo determine the efficacy and underlying molecular mechanisms of AXL inhibition in CKD, we employed a murine unilateral ureteral obstruction (UUO) model preventively treated with a selective AXL kinase inhibitor (bemcentinib) during disease progression. We isolated kidneys at an early (3 days) or late (15 days) timepoint and profiled the cell populations using mass cytometry.ResultsPreventive treatment with bemcentinib significantly attenuated fibrosis in the UUO model. The anti-fibrotic effect correlated with a decrease in mesangial cells and inhibition of innate immune cell infiltration, while the proportion of epithelial cells increased. We mapped AXL expression to a unique network of cells in the kidney: mesangial cells, pericytes, macrophages and dendritic cells.DiscussionWe propose that AXL targeting affects an important cellular interaction network underlying fibrotic progression. These results support the clinical application of AXL targeting agents to treat CKD.

Time to Rethink Bronchiolitis Obliterans Syndrome Following Lung or Hematopoietic Cell Transplantation in Pediatric Patients

Background: Similar in histological characteristics and clinical manifestations, bronchiolitis obliterans syndrome (BOS) can develop following lung transplantation (LTx) or hematopoietic cell transplantation (HCT). In contrast to lung transplantation, where BOS is restricted to the lung allograft, HCT-related systemic graft-versus-host disease (GVHD) is the root cause of BOS. Because lung function declines following HCT, diagnosis becomes more difficult. Given the lack of proven effective medicines, treatment is based on empirical evidence. Methods: Cross-disciplinary learning is crucial, and novel therapies are under investigation to improve survival and avoid LTx. Recent advances have focused on updating the understanding of the etiology, clinical features, and pathobiology of BOS. It emphasizes the significance of learning from experts in other transplant modalities, promoting cross-disciplinary knowledge. Results: Our treatment algorithms are derived from extensive research and expert clinical input. It is important to ensure that immunosuppression is optimized and that any other conditions or contributing factors are addressed, if possible. Clear treatment algorithms are provided for each condition, drawing from the published literature and consensus clinical opinion. There are several novel therapies currently being investigated, such as aerosolized liposomal cyclosporine, Janus kinase inhibitors, antifibrotic therapies, and B-cell-directed therapies. Conclusions: We urgently need innovative treatments that can greatly increase survival rates and eliminate the need for LTx or re-transplantation.

Efficacy and safety of immune checkpoint inhibitors combined with chemotherapy or tyrosine kinase inhibitors in advanced endometrial cancer: A systematic review and meta-analysis.

The objective of this meta-analysis was to conduct a comprehensive assessment of the therapeutic effectiveness and safety profile of the combination of immune checkpoint inhibitors (ICIs) with either chemotherapy or tyrosine kinase inhibitors (TKIs) in the treatment of advanced-stage endometrial cancer (EC). This meta-analysis conducted a thorough literature search across PubMed, Cochrane Library, Embase, and Web of Science databases from their earliest records up to November 18th, 2023, identifying qualified randomized controlled trials (RCTs), cohort studies, and single-arm trials for inclusion in the analysis. The meta-analysis were performed to quantify and analyzed the evidence from the existing literature, focusing on outcomes including the objective response rate (ORR), disease control rate (DCR), duration of response (DOR), overall survival (OS), progression-free survival (PFS), and adverse events (AE). A total of 13 studies were included. In terms of ICI combined with chemotherapy, the single-arm trials showed that ICI combined with chemotherapy was effective in improving the ORR, but the overall rate of AE was higher. The results based on RCT suggested that ICI combined with chemotherapy resulted in a longer PFS of 12-24 months and OS of 18-month compared to the control group in advanced EC. In terms of ICI combined with TKI, the pooled ORR was 39.0%, the pooled DCR was 79.9%, the pooled OS rate was 50.4%, and the pooled overall AE rate was 95.8%, the pooled grade ≥3 AE rate was 73.8%, the pooled median progression-free survival (mPFS) was 6.126 months, and pooled OS was 15.099 months in advanced EC. The integrative therapeutic approach combining (ICIs) with chemotherapy or (TKIs demonstrates notable clinical efficacy in advanced EC, which can prolong the survival and help to disease control. Nevertheless, it is imperative for clinicians to be vigilant regarding the potential for adverse reactions to emerge. In addition, more RCTs are needed to solidify this study's efficacy and safety further.

Comprehensive Analysis of the Significance of Cyclin Dependent Kinase Inhibitor Genes in the Prognosis of Cervical Cancer

Comprehensive Analysis of the Significance of Cyclin Dependent Kinase Inhibitor Genes in the Prognosis of Cervical Cancer

YAP regulates HER3 signaling-driven adaptive resistance to RET inhibitors in RET-aberrant cancer.

Rearranged during transfection (RET) aberrations represent a targetable oncogene in several tumor types, with RET inhibitors displaying marked efficacy. However, some patients with RET-aberrant cancer are insensitive to RET tyrosine kinase inhibitors (TKIs). Recently, drug-tolerant mechanisms have attracted attention as targets for initial therapies to overcome drug resistance. The underlying mechanisms of drug-tolerant cell emergence treated with RET-TKIs derived from RET-aberrant cancer cells remain unknown. This study investigated the role of YAP-mediated HER3 signaling in the underlying mechanisms of adaptive resistance to RET-TKIs in RET-aberrant cancer cells. Four RET-aberrant cancer cell lines were used to assess sensitivity to the RET-TKIs selpercatinib and pralsetinib and to elucidate molecular mechanisms underlying adaptive resistance using RNA sequencing, phospho-RTK antibody arrays, chromatin immunoprecipitation assay, and luciferase reporter assays. Clinical specimens from patients with RET-fusion-positive lung cancer were analyzed for pre-treatment YAP expression and correlated with treatment outcomes. In high YAP-expressing RET-aberrant cancer cells, YAP-mediated HER3 signaling activation maintained cell survival and induced the emergence of cells tolerant to the RET-TKIs selpercatinib and pralsetinib. The pan-ErBB inhibitor afatinib and YAP/TEAD inhibitors verteporfin and K-975 sensitized YAP-expressing RET-aberrant cancer cells to the RET-TKIs selpercatinib and pralsetinib. Pre-treatment YAP expression in clinical specimens obtained from patients with RET-fusion-positive lung cancer was associated with poor RET-TKI treatment outcomes. The YAP-HER3 axis is crucial for the survival and adaptive resistance of high YAP-expressing RET-aberrant cancer cells treated with RET-TKIs. Combining YAP/HER3 inhibition with RET-TKIs represents a highly potent strategy for initial treatment.

Emerging Trends in Quinoxaline‐based Analogs as Protein Kinase Inhibitors: Structural Developments and SAR Insights

Cancer remains a leading cause of mortality and has been recognized as a significant global health concern. Although numerous effective anticancer agents are available; most of the current drugs lack specificity, leading to common side‐effects associated with chemotherapy. Recent research, however, offers promise for developing more targeted and safer anticancer therapies through protein kinase inhibition. Quinoxaline derivatives represent a notable class of heterocyclic compounds. The extensive spectrum of biological activities demonstrated by quinoxalines has garnered substantial research interest. Quinoxaline and its derivatives have emerged as a novel class of chemotherapeutic agents with significant activity against various tumors through protein kinase inhibition. This review aims to elucidate recent advancements in the quinoxaline derivatives targeting protein kinase along with structural developments and structure‐activity relationships associated with these compounds.

Bone Mineral Density, C-Terminal Telopeptide of Type I Collagen, and Osteocalcin as Monitoring Parameters of Bone Remodeling in CML Patients Undergoing Imatinib Therapy: A Basic Science and Clinical Review

Background: Chronic myeloid leukemia (CML) is one of the most commonly found types of myeloproliferative neoplasms, characterized by increased proliferation of granulocytic cells without losing their differentiation ability. Imatinib, a tyrosine kinase inhibitor (TKI), can be effectively used as therapy for CML. However, Imatinib can affect bone turnover thus having clinical implications on the bones of CML patients undergoing long-term Imatinib therapy. However, parameters that can accurately describe the bone condition in CML patients receiving Imatinib still need further study. A combination of imaging techniques such as bone mineral density (BMD) and bone turnover activity markers such as C-terminal telopeptide of type I collagen (CTX-1) and osteocalcin has the potential to be used as monitoring parameters for bone density abnormalities in CML patients receiving Imatinib. Objectives: This article explains the rationale for using BMD, CTX-1, and osteocalcin as monitoring parameters of bone remodeling in CML patients receiving Imatinib. Results: First, the physiological process of bone turnover will be explained. Then, we describe the role of tyrosine kinase in bone metabolism. Next, the impact of Imatinib on BMD, CTX-1, and osteocalcin will be explained. Conclusion: The assessment of bone health of CML patients on Imatinib should include both BMD tests and bone turnover marker assays such as CTX-1 and osteocalcin.

Temporal variation in p38-mediated regulation of DUX4 in facioscapulohumeral muscular dystrophy

Facioscapulohumeral muscular dystrophy (FSHD) is a degenerative muscle disease caused by loss of epigenetic silencing and ectopic reactivation of the embryonic double homeobox protein 4 gene (DUX4) in skeletal muscle. The p38 MAP kinase inhibitor losmapimod is currently being tested in FSHD clinical trials due to the finding that p38 inhibition suppresses DUX4 expression in preclinical models. However, the role of p38 in regulating DUX4 at different myogenic stages has not been investigated. We used genetic and pharmacologic tools in FSHD patient-derived myoblasts/myocytes to explore the temporal role of p38 in differentiation-induced DUX4 expression. Deletion of MAPK14/11 or inhibition of p38α/β caused a significant reduction in early differentiation-dependent increases in DUX4 and DUX4 target gene expression. However, in MAPK14/11 knockout cells, there remains a differentiation-associated increase in DUX4 and DUX4 target gene expression later in differentiation. Furthermore, pharmacologic inhibition of p38α/β only partially decreased DUX4 and DUX4 target gene expression in late differentiating myotubes. In xenograft studies, p38α/β inhibition by losmapimod failed to suppress DUX4 target gene expression in late FSHD xenografts. Our results show that while p38 is critical for DUX4 expression during early myogenesis, later in myogenesis a significant level of DUX4 expression is independent of p38α/β activity.

LRRK2 Inhibitors as Promising Treatment for Parkinson's Disease.

Parkinson's disease (PD) is one of the most prevalent neurodegenerative disorders, with current treatments offering only temporary symptomatic relief. There is an urgent need for the development of novel therapeutic approaches. Abnormal increases in LRRK2 kinase activity have been identified in both sporadic and familial PD patients, suggesting that inhibiting LRRK2 kinase activity presents a promising avenue for the pursuit of effective PD treatment strategies. In this Viewpoint, we discuss the exciting new insights regarding the development of LRRK2 kinase inhibitors as a treatment for Parkinson's disease.

The MET Oncogene: An Update on Targeting Strategies

The MET receptor, commonly known as HGF (hepatocyte growth factor) receptor, is a focus of extensive scientific research. MET has been linked to embryonic development, tissue regeneration following injury, tumorigenesis, and cancer metastasis. These functions underscore its involvement in numerous cellular processes, including stemness, proliferation, motility, cell dissociation, and survival. However, the enigmatic nature of MET becomes apparent in the context of cancer. When MET remains persistently activated, since its gene undergoes genetic alterations, it initiates a complex signaling cascade setting in motion an aggressive and metastatic program that is characteristic of malignant cells and is known as “invasive growth”. The expanding knowledge of MET signaling has opened up numerous opportunities for therapeutic interventions, particularly in the realm of oncology. Targeting MET presents a promising strategy for developing novel anti-cancer treatments. In this review, we provide an updated overview of drugs designed to modulate MET signaling, highlighting MET kinase inhibitors, degraders, anti-MET/HGF monoclonal antibodies, and MET-targeted antibody–drug conjugates. Through this review, we aim to contribute to the ongoing advancement of therapeutic strategies targeting MET signaling.

Mouse liver blood flow is regulated by hepatic stellate cells in response to the sympathetic neurotransmitter norepinephrine

BackgroundThere is no clear information on the regulation of liver blood flow by the autonomic nervous system. We conducted this study to investigate whether quiescent hepatic stellate cells (qHSCs) regulate liver blood flow in response to the sympathetic neurotransmitter norepinephrine (NE). MethodsqHSCs isolated from mice were cultured in Dulbecco's modified Eagle medium without fetal bovine serum for 1 day on collagen gel. NE-induced qHSC contraction was evaluated using the quantitative single-cell contraction measurement method that we had developed previously. For the measurement of liver perfusion pressure in situ, a buffer solution was perfused from the portal vein in mice. ResultsNE-induced a reversible contraction of qHSCs. This contraction was suppressed by the nonmuscle myosin II inhibitor blebbistatin, the myosin light chain kinase inhibitor ML-9, the Rho kinase inhibitor H-1152, the calmodulin inhibitor W-7, the store-operated calcium channel inhibitor YM-58483, and the IP3 receptor inhibitor xestospongin C. In contrast, the transient receptor potential C channel inhibitor SKF96365 did not affect the NE-induced contraction. ConclusionThese results suggest that qHSCs contract in response to NE. New & noteworthyThe present study provides direct evidence for the first time that norepinephrine (NE) induces a reversible contraction of isolated single quiescent hepatic stellate cells (qHSCs) and further suggests that the NE-mediated qHSC contraction participates in the regulation of liver blood flow in vivo.

Structure-property Relationships Reported for the New Drugs Approved in 2023.

Drug-like properties play pivotal roles in drug adsorption, distribution, metabolism, excretion, and toxicity. Therefore, efficiently optimizing these properties is essential for the successful development of novel therapeutics. Understanding the structure-property relationships of clinically approved drugs can provide valuable insights for drug design and optimization strategies. Among the new drugs approved in 2023, which include 31 small-molecule drugs in the US, the structureproperty relationships of nine drugs were compiled from the medicinal chemistry literature, in which detailed information on pharmacokinetic and/or physicochemical properties was reported not only for the final drug but also for its key analogs generated during drug development. The structure- property relationships of nine newly approved drugs are summarized, including three kinase inhibitors and three G-protein-coupled receptor antagonists. Several optimization strategies, such as bioisosteric replacement and steric handle installation, have successfully produced clinical candidates with enhanced physicochemical and pharmacokinetic properties. The summarized structure- property relationships demonstrate how appropriate structural modifications can effectively improve overall drug-like properties. The ongoing exploration of structure-property relationships of clinically approved drugs is expected to offer valuable guidance for developing future drugs.