British Journal of Pharmacology最新文献

Background and purpose: Triple-negative breast cancer (TNBC) has poorer outcomes than other breast cancers (BC), including HER2⁺ BC. Cathepsin D (CathD) is a poor prognosis marker overproduced by BC cells, hypersecreted in the tumour microenvironment with tumour-promoting activity. Here, we characterized the immunomodulatory activity of the anti-CathD antibody F1 and its improved Fab-aglycosylated version (F1M1) in immunocompetent mouse models of TNBC (C57BL/6 mice harbouring E0771 cell grafts) and HER2-amplified BC (BALB/c mice harbouring TUBO cell grafts).

Experimental approach: CathD expression was evaluated by western blotting and immunofluorescence, and antibody binding to CathD by ELISA. Antibody anti-tumour efficacy was investigated in mouse models. Immune cell recruitment and activation were assessed by immunohistochemistry, immunophenotyping, and RT-qPCR.

Key results: F1 and F1M1 antibodies remodelled the tumour immune landscape. Both antibodies promoted innate antitumour immunity by preventing the recruitment of immunosuppressive M2-polarized tumour-associated macrophages (TAMs) and by activating natural killer cells in the tumour microenvironment of both models. This translated into a reduction of T-cell exhaustion markers in the tumour microenvironment that could be locally supported by enhanced activation of anti-tumour antigen-presenting cell (M1-polarized TAMs and cDC1 cells) functions. Both antibodies inhibited tumour growth in the highly-immunogenic E0771 model, but only marginally in the immune-excluded TUBO model, indicating that anti-CathD immunotherapy is more relevant for BC with a high immune cell infiltrate, as often observed in TNBC.

Conclusion and implication: Anti-CathD antibody-based therapy triggers the anti-tumour innate and adaptive immunity in preclinical models of BC and is a promising immunotherapy for immunogenic TNBC.

Linked articles: This article is part of a themed issue Immunotherapy in Cancer. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v183.6/issuetoc.

Background and purpose: Letermovir and ganciclovir are used to prevent cytomegalovirus (CMV) infection, but the generation of resistant viruses and the interactions between wild and resistant CMV have not been studied. We evaluated the effect of letermovir/ganciclovir on the release of the wild-type and letermovir/ganciclovir-resistant CMV in their coinfected or superinfected cells.

Experimental approach: We analysed the extracellular CMV infectivity released from CMV-infected cells treated with letermovir and ganciclovir. Subsequently, we characterized growth of letermovir/ganciclovir-resistant viruses in wild-type CMV-infected cells in the presence of letermovir/ganciclovir, respectively.

Key results: The number of infectious cells resuming viral replication after letermovir/ganciclovir removal decreased over time, and the CMV-infected cells treated with letermovir or ganciclovir remained infectious for 1 month. During the treatment course, letermovir-/ganciclovir-resistant viruses arise from CMV infection foci, and we investigated the proliferation of resistant viruses in the presence of letermovir/ganciclovir. Letermovir inhibited superinfected CMV release by inhibiting the superinfected CMV from using the DNA terminase-packaging complex pathway occupied by a prior infected CMV. Co-infection and superinfection of ganciclovir-resistant CMV in wild-type CMV-infected cells inhibited viral release by inhibiting DNA synthesis by ganciclovir phosphorylated by wild-type UL97. These results suggested that letermovir-resistant CMV emerging in wild-type CMV-infected cells would not easily spread to the surrounding wild-type CMV-infected cells in CMV-infected patients under letermovir.

Conclusion and implications: Despite different mechanisms of action, both drugs inhibited the spread of newly emerging resistant viruses around wild-type CMV-infected lesions during letermovir/ganciclovir treatment, suggesting the practical use of both drugs and strategies for treating drug-resistant CMV.

The immunotherapy revolution with the use of immune checkpoint inhibitors (ICIs) started with the clinical use of the first ICI, ipilimumab, in 2011. Since then, the field of ICI therapy has rapidly expanded - with the FDA approval of 10 different ICI drugs so far and their incorporation into the therapeutic regimens of a range of malignancies. While ICIs have shown high anti-cancer efficacy, they also have characteristic side effects, termed immune-related adverse events (irAEs). These side effects hinder the therapeutic potential of ICIs and, therefore, finding ways to prevent and treat them is of paramount importance. The current protocols to manage irAEs follow an empirical route of steroid administration and, in more severe cases, ICI withdrawal. However, this approach is not optimal in many cases, as there are often steroid-refractory irAEs, and there is a potential for corticosteroid use to promote tumour progression. This review surveys the current alternative approaches to the treatments for irAEs, with the goal of summarizing and highlighting the best attempts to treat irAEs, without compromising anti-tumour immunity and allowing for rechallenge with ICIs after resolution of the irAEs. LINKED ARTICLES: This article is part of a themed issue Immunotherapy in Cancer. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v183.6/issuetoc.

Background and purpose: Communication between various cardiac cells by paracrine factors and exosomes has an important role in myocardial ischaemia/reperfusion (I/R) injury. It remains unclear whether exosomes derived from healthy cardiac fibroblasts affect I/R injury and, if so, what are the underlying mechanisms?

Experimental approach: Cardiac fibroblasts were isolated from neonatal rats, adult rats and adult rats subjected to I/R. Their exosomes were designated as follows: neonatal cardiac fibroblasts (N-Exo), adult rat cardiac fibroblasts (A-Exo) and cardiac fibroblasts in a remote non-ischaemic area (R-Exo). Apoptosis of cardiomyocytes and the role of a cluster of microRNAs from exosomes in I/R injury were investigated.

Key results: N-Exo, A-Exo and R-Exo were taken up by ischaemic cardiomyocytes through clathrin heavy chain (Cltc)-mediated endocytosis, enhancing cardiomyocyte apoptosis and increasing myocardial infarct size in rats and mice. Inhibiting Cltc-mediated endocytosis with chlorpromazine reduced the pro-apoptotic effects of N-Exo in neonatal rat cardiomyocytes under anoxia/reoxygenation. A functional cluster of miRNAs (miR-9a-5p, miR-92b-3p, miR-181a-5p, miR-494-3p and miR-708-5p) from exosomes was identified and promoted cardiomyocyte apoptosis via a common gene, Rap1b. R-Exo downregulated cardiac Rap1b and Bcl2 in I/R rats. Mimics of these miRNAs reduced luciferase activity of the Rap1b gene and were blocked by site-directed mutagenesis of the Rap1b gene at miRNAs binding sites. Co-immunoprecipitation demonstrated that Rap1b protein bound to ERK1/2 and Cltc.

Conclusions and implications: Exosomes from non-ischaemic fibroblasts worsen I/R injury by promoting apoptosis of ischaemic cardiomyocytes through a cluster of miRNAs targeting the Rap1b/ERK1/2 pathway, highlighting Rap1b restoration as a potential therapeutic strategy.

Contemporary strategies in cancer immunotherapy, despite remarkable success, remain constrained by inherent limitations such as suboptimal patient responses, the emergence of drug resistance, and the manifestation of pronounced adverse effects. Consequently, the need for alternative strategies for immunotherapy becomes clear. Protein tyrosine phosphatases (PTPs) wield a pivotal regulatory influence over an array of essential cellular processes. Substantial research has underscored the potential in targeting PTPs to modulate the immune responses and/or regulate antigen presentation, thereby presenting a novel paradigm for cancer immunotherapy. In this review, we focus on recent advances in genetic and biological validation of several PTPs as emerging targets for immunotherapy. We also highlight recent development of small molecule inhibitors and degraders targeting these PTPs as novel cancer immunotherapeutic agents. LINKED ARTICLES: This article is part of a themed issue Immunotherapy in Cancer. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v183.6/issuetoc.

Growing understanding of immune cell regulation and the tumour microenvironment is transforming cancer therapy by enabling the development of tailored immunomodulatory agents, novel combination treatments and new immunotherapy targets. As a result, cancer types and stages once considered incurable or requiring radical surgery can now be managed with effective therapeutic combinations that preserve organs, extend survival and improve patients' quality of life. The themed issue of the British Journal of Pharmacology features four review articles that explore recent advancements in cancer immunotherapy and new approaches to overcome challenges in immunotherapy. Furthermore, the issue includes two research articles that present novel antibodies that remodel the tumour immune landscape and novel approaches to reprogram the tumour microenvironment to increase the efficacy of chimeric antigen receptor T-cell therapy (CAR-T) immunotherapy. LINKED ARTICLES: This article is part of a themed issue Immunotherapy in Cancer. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v183.6/issuetoc.

Background and purpose: Euphorbia pekinensis (EP) is known to cause significant intestinal toxicity, primarily manifesting as severe diarrhoea, yet the precise molecular mechanisms and the active components responsible have remained elusive. This study aimed to identify the diarrheal constituents of EP and elucidate the molecular pathway through which they induce gut toxicity.

Experimental approach: The laxative effects of EP components were assessed in vivo using mouse models and diarrhoea-related indicators, with histological analysis of intestinal tissue. Ex vivo rabbit intestinal tract assays were employed to study smooth muscle contraction. The underlying mechanism was investigated using intestinal organoid fluorescence co-localization and analysis of tryptophan metabolites in mice to determine the role of enterochromaffin (EC) cells and serotonin (5-HT).

Key results: We identified specific glycosphingolipids (GSLs), including a novel hexosylceramide (HexCer), as the primary toxic agents in EP. These GSLs act as direct agonists of the TRPA1 ion channel on intestinal EC cells. This activation triggers a TRPA1-mediated influx of Ca²⁺ into EC cells, leading to excessive 5-HT release. The resulting localized overstimulation of 5-HT receptors causes aberrant intestinal smooth muscle contraction and epithelial hypersecretion, culminating in severe diarrhoea.

Conclusion and implications: This research reveals that the gut toxicity of EP is driven by a previously unrecognized GSL-TRPA1-5-HT signalling pathway in the intestinal epithelium. These findings provide a clear mechanistic basis for EP-induced diarrhoea and highlight a potential new target for managing gut toxicity.

Background and purpose: Hydnocarpin D (HD) is a flavonolignan compound isolated from Hydnocarpus wightiana. This study was to investigate the effect of HD on ovarian cancer mediated by the regulation of SERPINE1.

Experimental approach: Cytotoxicity was assessed by the MTT assay. Cell migration and invasion were examined using wound healing and Boyden chamber assays. An orthotopic xenograft model was constructed to determine the inhibitory effect of HD on ovarian cancer in vivo. Differential gene expression was screened by RNA sequencing. A 3'-UTR luciferase assay was performed to confirm the regulatory effect of microRNA-145-5p on SERPINE1. Small interfering RNA and microRNA mimics/inhibitors were introduced to elucidate the mechanism.

Key results: HD inhibited the migration and invasion of SKOV3 and OVCAR4 cells without showing cytotoxic effects. HD inhibited the growth and metastasis of ovarian cancer in vivo. RNA-sequencing analysis suggested that HD suppressed metastasis by inhibiting SERPINE1 expression. Free uPA, which is not bound to PAI-1 (SERPINE1), was up-regulated, whereas vitronectin, integrin αV and phosphorylated FAK, the downstream metastasis-related signalling factors for PAI-1, were down-regulated after treatment with HD. SERPINE1 inhibition attenuated the effect of HD on reducing cell migration and rhPAI-1 enhanced the effect of HD. We identified microRNA-145-5p as the post-transcriptional repressor of SERPINE1. MicroRNA-145-5p was up-regulated by HD, and its overexpression enhanced the inhibition of PAI-1 expression and migration by HD, whereas its inhibition had the opposite effect.

Conclusion and implications: We showed that HD inhibits metastasis in ovarian cancer by up-regulating microRNA-145-5p, which targets SERPINE1, inhibiting vitronectin/integrin/FAK signalling.

Background and purpose: Lysine demethylase 1A (KDM1A; LSD1) plays anti-ferroptosis role and has been confirmed to be lowly expressed in Alzheimer disease (AD). This study explores whether LSD1 affects the progression of AD by regulating ferroptosis and related mechanisms involved.

Experimental approach: AD mice (APP/PS1 double transgenic) were injected with adeno-associated virus expressing LSD1 overexpression vector, or siRNA against leucine carboxyl methyltransferase 1 (LCMT1)/transcription factor EB (TFEB). SH-SY5Y cells were treated with Aβ1-42 to establish an AD cell injury model. The levels of lipid peroxidation and ferroptosis-related markers were tested to evaluate ferroptosis. The protein levels of LSD1, O-GlcNAcase (OGA), forkhead box transcription factor A2 (FOXA2), LCMT1, protein phosphatase 2A catalytic subunit alpha (PP2A) and TFEB were detected by western blot. The mRNA levels of LSD1 and OGA were assessed using quantitative real-time PCR. Interactions between targets were measured by ChIP-qPCR, DNA pull down, co-immunoprecipitation and dual-luciferase reporter assay.

Key results: LSD1 upregulation suppressed neuronal ferroptosis to attenuate AD progression in mice. Further, LSD1 overexpression alleviated Aβ1-42-induced cell injury by reducing OGA transcription and expression. OGA inhibited FOXA2 O-GlcNAcylation modification to promote its expression and transcriptional activity. Also, FOXA2 repressed LCMT1-mediated the activation of PP2A and TFEB. Furthermore, LSD1 alleviated AD process by inhibiting neuronal ferroptosis through the regulation of OGA/FOXA2/LCMT1/PP2A/TFEB axis.

Conclusions and implications: Overall, LSD1 restrained neuronal ferroptosis to alleviate the progression of AD by regulating LCMT1/PP2A/TFEB pathway via OGA-mediated FOXA2 O-GlcNAcylation modification, providing novel mechanistic insights into the deeper understanding of AD pathogenesis and the development of potential drug targets.

Cardiac remodelling and fibrosis after myocardial infarction or during chronic diseases, such as arterial and pulmonary hypertension or diabetes mellitus, continue to be the more important prognostic factors in determining survival, and so the search for effective anti-fibrotic interventions is an important target for research and therapy in cardiology. It has been suggested that compounds with anti-inflammatory and antioxidant properties (such as cannabinoids) may represent interesting therapeutic alternatives, due to their ability to influence pro-fibrotic signalling and inhibit pathological extracellular matrix deposition in the heart. This review describes the more important signalling pathways involved in cardiac fibrosis and some new concepts regarding the utility of cannabinoids and modulation of the endocannabinoid system (ESC) as therapeutic interventions against cardiac fibrosis. The studies presented in this review suggest that specific cannabinoid type 2 receptor activation and peripheral cannabinoid Type 1 receptor blockade appear particularly promising. The potential for the cardioprotective anti-fibrotic effects of cannabinoids and ECS modulators appears to lie in their high antioxidant and anti-inflammatory efficacy, which limits the progression of fibrotic lesions and restores normal regulation of molecular signalling pathways.