Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie最新文献

The coronavirus pandemic has resulted in over 775 million cases and 7 million deaths worldwide, driving efforts to develop therapeutic strategies to control the viral infection. Therapeutic oligonucleotides have shown promise in treating many pathological conditions, including those of viral origin. The present study assessed the in vivo efficacy and safety of ASC1R, a novel therapeutic oligonucleotide of unconventional design targeting the conserved viral RdRp sequence essential for replication. In functional studies, ASC1R was administered to transfected C57BL/6 mice at doses of 1 and 10 mg/kg. Safety assessments included acute toxicity evaluations at doses ranging from 30 to 100 mg/kg, and subacute toxicity evaluations of repeated doses of 1 and 10 mg/kg. Evaluations included general clinical observations, findings at necropsy, measurements of organ weight, and histopathological examinations of the liver, lungs, spleen, and kidneys. ASC1R effectively reduced RdRp levels >94 % within 24 hours following a single 1 mg/kg dose, with no observed organ toxicity. Acute and subacute toxicity assessments found that mice receiving high (≥30 mg/kg) or repeated (10 mg/kg for 7 days) doses of ASC1R showed an increase in relative spleen weight, without histopathological changes. The marked ability of a single low dose of ASC1R (1 mg/kg) to reduce viral RNA suggests its potential for clinical applications, balancing therapeutic efficacy with minimal side effects. Our findings indicate that ASC1R has promise as a viable treatment option for patients with COVID-19.

ADAM17 sheds EGFR/erbB ligands and triggers oncogenic pathways that lead to the progression of solid tumors. We targeted the ADAM17 disintegrin and cysteine rich domain region (D+C) to generate a panel of single-chain antibody fragments (scFvs) that selectively bind to the D or C domains of ADAM17, but not of ADAM10 or ADAM19. From the panel, we selected one scFv, referred to as C12, based on its high binding affinity towards the target, and re-formatted it to a full IgG for further studies. High-resolution cryo-electron microscopy studies documented that the mAb binds to the ADAM17 C-domain that in ADAM proteases, notably ADAM10 and ADAM17, is known to impart substrate-specificity. The C12 mAb significantly inhibited EGFR phosphorylation in cancer cell lines by hindering the cleavage of EGFR ligands tethered to the cell surface. This inhibition provides a mechanism for potential anti-tumor effects, and indeed C12 diminished the viability of a variety of EGFR-expressing cancer cell lines. Cell-based ELISA studies revealed that C12 preferentially bound to activated ADAM17 present on tumor cells, as compared to the autoinhibited ADAM17 that is the predominant form on HEK293 and other non-tumor cells. C12 also exhibited tumor growth inhibition in an ovarian cancer xenograft mouse model. Consistent with its selective tumor cell binding in vitro, radioimmuno PET (positron emission tomography) imaging with ⁸⁹Zr-DFO-C12 in mouse xenograft models confirmed tumoral accumulation of the C12 mAb.

Multi-drug resistance (MDR) poses a significant challenge to cancer treatment. Targeting ATP-binding cassette subfamily B member 1 (ABCB1) is a viable strategy for overcoming MDR. This study examined the preclinical in vitro and animal studies that used gilteritinib, a FLT3 inhibitor that reverses ABCB1-mediated MDR. At nontoxic levels, gilteritinib significantly increased the susceptibility of cancer cells overexpressing ABCB1 to chemotherapeutic drugs. Furthermore, it impaired the development of drug-resistant cell colonies and 3D spheroids. Studies on the reversal mechanism have shown that gilteritinib can directly bind to the drug-binding site of ABCB1, inhibiting drug efflux activity. Consequently, the substrate's drug cytotoxicity increases in MDR cells. Furthermore, gilteritinib increased ATPase activity while leaving ABCB1 expression and subcellular distribution unchanged and inhibited AKT or ERK activation. Docking analysis indicated that Gilteritinib could interact with the drug-binding site of the ABCB1 transporter. In vivo studies have shown that gilteritinib improves the antitumor efficacy of paclitaxel in nude mice without obvious toxic effects. In conclusion, our preclinical investigations show that gilteritinib has the potential to successfully overcome ABCB1-mediated MDR in a clinical environment when combined with substrate medicines.

Background: A phase II clinical trial of metformin (MET) for the treatment of doxorubicin (DOX)-induced cardiotoxicity (NCT02472353) failed.

Objectives: The aims of this study were to confirm MET-mediated protection against DOX-induced cardiotoxicity and its mechanism using H9C2 cells, and to establish a Wistar rat model of DOX-induced cardiotoxicity. Subsequently, Wistar rats were utilized to identify clinically relevant indicators for evaluating MET-mediated protection against DOX-induced cardiotoxicity, thereby facilitating early transition towards successful clinical trials.

Methods: MET-mediated protection was assessed using cell viability and cytotoxicity experiments. Additionally, intramitochondrial reactive oxygen species (ROS) levels were measured using an ROS fluorescent probe (dihydroethidium) to confirm the oxidative stress mechanism. Eighteen Wistar rats were randomly allocated to the control, DOX, and DOX+MET groups; and the body weight, adverse drug reactions (ADRs), myocardial injury, cardiac function, oxidative stress, and histopathology of heart tissues were compared between groups.

Results: H9C2 cells treated with MET/Dexrazoxane demonstrated dose-dependent protection against DOX-induced cardiotoxicity. The fluorescence intensity of H9C2 cells suggested DOX-induced cardiomyocyte toxicity and MET-mediated protection against DOX-induced cardiotoxicity. In vivo experiments confirmed that a rat model of DOX-induced cardiotoxicity was successfully established, but MET-mediated protection against DOX-induced cardiotoxicity was not demonstrated. This was attributed to insufficient energy intake because of ADRs, such as vomiting.

Conclusions: We confirmed the MET-mediated protection against DOX-induced cardiomyocyte toxicity and its mechanism involving the inhibition of oxidative stress in vitro experiments. It is imperative to investigate the optimal conditions for MET-mediated protection against DOX-induced cardiotoxicity in vivo or clinical trials.

Leukemia remains a fatal disease for most affected patients, and a simple and effective therapeutic strategy is urgently needed. Targeted delivery chemo-drugs to leukemia cells shows promise, but the diverse subtypes of leukemia make single-ligand nanomedicine often ineffective. Herein, a dual-aptamer decorated, reduction-responsive dimeric prodrug-based nanoparticle (NP), termed SXP-NPs, was developed using the two leukemia-specific aptamers Sgc8c and XQ-2d, a reduction-responsive podophyllotoxin (POD) dimeric prodrug, and DSPE-PEG2000. Because the receptors of XQ-2d (CD71) and Sgc8c (PTK7) are overexpressed in different subtypes of leukemia cells, SXP-NPs can broadly and selectively recognize these leukemia cells after intravenous administration, subsequently releasing POD in response to the intracellular high-reduction environment to kill the leukemia cells. In vitro experiments showed that these simple SXP-NPs can specifically bind to various leukemia cancer cells and kill them. In vivo experiments revealed that SXP-NPs can remarkably reduce spleen weight, decrease white blood cell counts, and extend overall survival in a preclinical leukemia animal model. The in vitro and in vivo validation demonstrated that SXP-NPs offer several advantages, including high drug-loading potential, broad-spectrum recognition of leukemia cells, reduced systemic toxicity, and enhanced therapeutic effects of the drug. Taken together, this study provides a simple and effective strategy for broad-spectrum leukemia therapy and highlights the clinical potential of SXP-NPs.

Olive leaf is a byproduct of the olive tree that is rich in phenolic compounds with potential anticarcinogenic effects against various cancers, including breast cancer. Nevertheless, the ingestion or topical application of such plant extracts faces certain limitations. These limitations can be addressed by encapsulating the extracts in nanovesicles to enhance their release and bioavailability. This study aims to develop nanovesicles using Olea europaea leaf extract to exploit its potential anti-cancer properties. Soy lecithin was used to form liposomes for encapsulation of the olive leaf extract. In addition, ethanol and glycerol were added to form ethosomes and glycerosomes, respectively. The antiproliferative effect of both the free extract and the three formed nanovesicles was tested in MCF7 and MCF10A cell lines. To comprehend the mechanisms leading to reduced cell viability after exposure to olive leaf extract and its nanovesicles, levels of reactive oxygen species (ROS), mitochondrial membrane potential, and apoptotic stage were evaluated. The results suggest that both, the nanovesicles and the free extract, are antiproliferative agents against MCF7 tumour cells. However, when examining the impact of olive leaf extract and the formulated nanovesicles on MCF10A cells, no reduction in cell viability was observed. Our findings indicate that the anti-tumour effect of the extract and its nanovesicles may be due to increased oxidative stress, mediated by mitochondrial damage. The mechanism through which olive leaf extract exerts its antiproliferative effect on the breast cancer tumour line implies that apoptosis may be induced by the extract via the involvement of a mitochondria-dependent ROS-mediated pathway.

Background: Dilated cardiomyopathy (DCM) is characterized by enlarged, weakened heart ventricles due to chronic fibrosis. Dysfunctional senescent myofibroblasts and excessive citrullination have been implicated in fibrotic diseases. Peptidylarginine deiminases (PADs) are involved in the citrullination of ECM proteins. However, their role in regulating the cellular functions of cardiac myofibroblasts in DCM, is not well understood. This study aimed to evaluate the role of PADs in the cellular biology and fibrotic behavior of myofibroblasts in DCM.

Results: Aged cardiac myofibroblasts derived from dilated cardiomyopathy (DCM, N=5) and healthy (HCF, N=3) participants (35-60 years), were cultured in TGFB-conditioned medium and treated with an irreversible pan-PAD inhibitor BB-Cl-amidine. Our findings showed that, compared with HCFs, DCM myofibroblasts showed high expression of PAD-2, PAD-3, citrullinated proteins and ECM proteins (vimentin, fibronectin, actin, and b-Tubulin). BB-Cl-amidine-mediated PAD inhibition directly affected the cell biology of DCM myofibroblasts, as shown by the reduced migration and invasion of DCM myofibroblasts. It also augmented the apoptosis by activating caspase-3 and decreased senescence by regulating p-53. PAD inhibition did not affect the citrullination of vimentin or fibronectin; however, it decreased collagen 1 A expression.

Conclusions: This study revealed that elevated PAD expression facilitates cellular processes mainly senescence, migration, and invasion. PAD inhibition resulted in the downregulation of these cellular functions, thereby reducing the fibrotic behavior of DCM myofibroblasts.