RIP1/RIP3/MLKL-mediated necroptosis contributes to vinblastine-induced myocardial damage

Cardiac toxicity of brentuximab vedotin: a real-word disproportionality analysis of the FDA Adverse Event Reporting System (FAERS) database

Brentuximab vedotin (BV) has obtained approval for the therapeutic management of classical Hodgkin lymphoma as well as systemic anaplastic large cell lymphoma. Given the inherent constraints of conventional clinical trials, the correlation between BV and cardiac adverse events (AEs) remains enigmatic. The objective of this investigation is to comprehensively assess cardiac AEs attributed to BV by employing advanced data mining techniques, utilizing the FDA Adverse Event Reporting System (FAERS). The indices for the assessment of disproportionality encompass the reporting odds ratio (ROR), the proportional reporting ratio, the information component, and the empirical Bayesian geometric mean. Employing these sophisticated metrics, we gauged the extent of disproportionate occurrences. The dataset was sourced from the FAERS from the first quarter of 2012 to first quarter of 2023, facilitating a comprehensive analysis of the potential correlation between BV and cardiac AEs. This scrutiny encompassed a comparative analysis of both cardiac and non-cardiac AEs. A total of 495 cases of BV's cardiac AEs were discerned, with the identification of 31 preferred terms (PTs). Among these, 8 PTs emerged as conspicuous signals of cardiac AEs, notably encompassing ventricular hypokinesia (ROR 7.59), tachyarrhythmia (ROR 7.06), sinus tachycardia (ROR 6.18), cardiopulmonary failure (ROR 4.44), pericardial effusion (ROR 4.32), acute coronary syndrome (ROR 4.02), cardiomyopathy (ROR 3.30), and tachycardia (ROR 2.76). The manifestation of severe outcomes demonstrates a discernible correlation with the cardiac AEs (P < 0.001). Our investigation furnishes invaluable insights for healthcare practitioners to proactively mitigate the incidence of BV-associated cardiac AEs.

Human adipose-derived stem cells genetically programmed to induce necroptosis for cancer immunotherapy

Herein, we present human adipose-derived stem cells (ADSCs) inserted with the receptor-interacting protein kinase-3 (RIP3) gene (RP@ADSCs), which induces cell necroptosis, for tumor immunotherapy. Necroptosis has characteristics of both apoptosis, such as programmed cell death, and necrosis, such as swelling and plasma membrane rupture, during which damage-related molecular patterns are released, triggering an immune response. Therefore, necroptosis has the potential to be used as an effective anticancer immunotherapy. RP@ADSCs were programmed to necroptosis after a particular time after being injected in vivo, and various pro-inflammatory cytokines secreted during the stem cell death process stimulated the immune system, showing local and sustained anticancer effects. It was confirmed that RIP3 protein expression increased in ADSCs after RP transfection. RP@ADSCs continued to induce ADSCs death for 7 days, and various pro-inflammatory cytokines were secreted through ADSCs death. The efficacy of RP@ADSCs-mediated immunotherapy was evaluated in mouse models bearing GL-26 (glioblastoma) and K1735 (melanoma), and it was found that RP resulted in an increase in the population of long-term cytotoxic T cells and a decrease in the population of regulatory T cells. This shows that RP@ADSCs have potential and applicability as an excellent anticancer immunotherapy agent in clinical practice.

Silibinin, Synergistically Enhances Vinblastine-Mediated Apoptosis in Triple Negative Breast Cancer Cell Line: Involvement of Bcl2/Bax and Caspase-3 Pathway

Background: Triple-negative breast cancer (TNBC) with a poor prognosis and survival is the most invasive subtype of breast cancer. Usually, TNBC requires a chemotherapy regimen at all stages, but chemotherapy drugs have shown many side effects. We assumed that combination therapy of vinblastine and silibinin might reduce the vinblastine toxicity and dose of vinblastine. Materials and Methods: The MDA-MB-231 were cells subjected to MTT assay for IC50 determination and combination effects, which were measured based on Chou-Talalay's method. The type of cell death was determined by using a Flow-cytometric assay. Cell death pathway markers, including Bcl-2, Bax, and caspase-3 were analyzed by western blot and Real-Time PCR. Results: The treatment of MDA-MB-231 cells exhibited IC50 and synergism at the combination of 30 µM of silibinin and 4 µm of vinblastine in cell viability assay (CI=0.69). YO-PRO-1/PI double staining results showed a significant induction of apoptosis when MDA-MB-231 cells were treated with a silibinin and vinblastine combination (p<0.01). Protein levels of Bax and cleaved caspase-3 were significantly upregulated, and Bcl-2 downregulated significantly. Significant upregulation of Bax (2.96-fold) and caspase-3 (3.46-fold) while Bcl-2 was downregulated by 2-fold. Conclusion: Findings established a preclinical rationale for the combination of silibinin and vinblastine. This combination produces synergistic effects in MDA-MB-231 cells by altering pro- and anti-apoptotic genes, which may reduce the toxicity and side effects of vinblastine.

Cell death in atherosclerosis

A complex and evolutionary process that involves the buildup of lipids in the arterial wall and the invasion of inflammatory cells results in atherosclerosis. Cell death is a fundamental biological process that is essential to the growth and dynamic equilibrium of all living things. Serious cell damage can cause a number of metabolic processes to stop, cell structure to be destroyed, or other irreversible changes that result in cell death. It is important to note that studies have shown that the two types of programmed cell death, apoptosis and autophagy, influence the onset and progression of atherosclerosis by controlling these cells. This could serve as a foundation for the creation of fresh atherosclerosis prevention and treatment strategies. Therefore, in this review, we summarized the molecular mechanisms of cell death, including apoptosis, pyroptosis, autophagy, necroptosis, ferroptosis and necrosis, and discussed their effects on endothelial cells, vascular smooth muscle cells and macrophages in the process of atherosclerosis, so as to provide reference for the next step to reveal the mechanism of atherosclerosis.

Advanced application of nanotechnology in active constituents of Traditional Chinese Medicines

Traditional Chinese Medicines (TCMs) have been used for centuries for the treatment and management of various diseases. However, their effective delivery to targeted sites may be a major challenge due to their poor water solubility, low bioavailability, and potential toxicity. Nanocarriers, such as liposomes, polymeric nanoparticles, inorganic nanoparticles and organic/inorganic nanohybrids based on active constituents from TCMs have been extensively studied as a promising strategy to improve the delivery of active constituents from TCMs to achieve a higher therapeutic effect with fewer side effects compared to conventional formulations. This review summarizes the recent advances in nanocarrier-based delivery systems for various types of active constituents of TCMs, including terpenoids, polyphenols, alkaloids, flavonoids, and quinones, from different natural sources. This review covers the design and preparation of nanocarriers, their characterization, and in vitro/vivo evaluations. Additionally, this review highlights the challenges and opportunities in the field and suggests future directions for research. Nanocarrier-based delivery systems have shown great potential in improving the therapeutic efficacy of TCMs, and this review may serve as a comprehensive resource to researchers in this field.

Apoptosis, necroptosis, and pyroptosis as alternative cell death pathways induced by chemotherapeutic agents?

For decades, common chemotherapeutic drugs have been established to trigger apoptosis, the preferred immunologically "silent" form of cell death. The primary objective of this review was to show that various FDA-approved chemotherapeutic drugs, including cisplatin, cyclosporine, doxorubicin, etoposide, 5-fluorouracil, gemcitabine, paclitaxel, or vinblastine can trigger necroptosis and pyroptosis. We aimed to provide the advantages and disadvantages of the induction of the given type of cell death by chemotherapeutical agents. Moreover, we give a short overview of the molecular mechanism of each type of cell death and indicate the existing crosstalks between cell death types. Finally, we provide a comparison of cell death types to facilitate the exploration of cell death types induced by other chemotherapeutical agents. Understanding the cell death pathway induced by a drug can lessen side effects and assist the discovery of new combinations with synergistic effects and low systemic toxicity.

Anti-breast cancer-induced cardiomyopathy: Mechanisms and future directions

With the progression of tumor treatment, the 5-year survival rate of breast cancer is close to 90%. Cardiovascular toxicity caused by chemotherapy has become a vital factor affecting the survival of patients with breast cancer. Anthracyclines, such as doxorubicin, are still some of the most effective chemotherapeutic agents, but their resulting cardiotoxicity is generally considered to be progressive and irreversible. In addition to anthracyclines, platinum- and alkyl-based antitumor drugs also demonstrate certain cardiotoxic effects. Targeted drugs have always been considered a relatively safe option. However, in recent years, some random clinical trials have observed the occurrence of subclinical cardiotoxicity in targeted antitumor drug users, which may be related to the effects of targeted drugs on the angiotensin converting enzyme, angiotensin receptor and β receptor. The use of angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers and beta-blockers may prevent clinical cardiotoxicity. This article reviews the toxicity and mechanisms of current clinical anti-breast cancer drugs and proposes strategies for preventing cardiovascular toxicity to provide recommendations for the clinical prevention and treatment of chemotherapy-related cardiomyopathy.

Role of RIPK3‑CaMKII‑mPTP signaling pathway‑mediated necroptosis in cardiovascular diseases (Review)

Necroptosis, which is distinct from apoptosis and necrosis, serves a crucial role in ontogeny and the maintenance of homeostasis. In the last decade, it has been demonstrated that the pathogenesis of cardiovascular diseases is also linked to necroptosis. Receptor interaction protein kinase (RIPK) 1, RIPK3 and mixed lineage kinase domain‑like protein serve vital roles in necroptosis. In addition to the aforementioned necroptosis‑related components, calcium/calmodulin‑dependent protein kinase II (CaMKII) has been identified as a novel substrate for RIPK3 that promotes the opening of the mitochondrial permeability transition pore (mPTP), and thus, mediates necroptosis of myocardial cells through the RIPK3‑CaMKII‑mPTP signaling pathway. The present review provides an overview of the current knowledge of the RIPK3‑CaMKII‑mPTP‑mediated necroptosis signaling pathway in cardiovascular diseases, focusing on the role of the RIPK3‑CaMKII‑mPTP signaling pathway in acute myocardial infarction, ischemia‑reperfusion injury, heart failure, abdominal aortic aneurysm, atherosclerosis, diabetic cardiomyopathy, hypertrophic cardiomyopathy, atrial fibrillation, and the cardiotoxicity associated with antitumor drugs and other chemicals. Finally, the present review discusses the research status of drugs targeting the RIPK3‑CaMKII‑mPTP signaling pathway.

Identification and validation of a necroptosis-related gene prognostic signature for colon adenocarcinoma

Background

Necroptosis is a novel programmed cell death pathway proposed in 2005, which is mainly activated by the tumor necrosis factor (TNF) family and mediates cellular disassembly via receptor interacting serine/threonine kinase 1 (RIPK1), receptor interacting serine/threonine kinase 3 (RIPK3) and mixed lineage kinase domain like pseudokinase (MLKL). We tried to analyze the relationship of necroptosis-related genes (NRGs) expression with colon adenocarcinoma (COAD) and propose potential therapeutic targets through immunological analysis.

Methods

First, we evaluated the expression of NRGs in COAD patients and constructed a prognostic signature. The prognostic signature was validated using The Cancer Genome Atlas (TCGA)-COAD and GSE39582 datasets, respectively. And the Kaplan-Meier analysis, receiver operating characteristic (ROC) curves, and principal component analysis were used to evaluate the signature. Then we analyzed the enrichment of NRGs in the signature using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. Finally, we analyzed the immunological characteristics of the COAD patients by single sample gene set enrichment analysis (ssGSEA) and predicted the possible immune checkpoints.

Results

We constructed a prognostic signature with 8 NRGs (RIPK3, MLKL, TRAF2, CXCL1, RBCK1, CDKN2A, JMJD7-PLA2G4B and CAMK2B). The Kaplan-Meier analysis, ROC curves, and principal component analysis demonstrated good predictivity of the signature. In addition, we constructed a nomogram with good individualized predictive ability (C-index =0.772). The immunological analysis revealed that the prognosis of COAD was associated with autoimmune function, and we proposed 10 potential therapeutic targets.

Conclusions

Overall, we constructed an NRGs prognostic signature and suggested potential therapeutic targets for the COAD treatment.

Skp2-mediated MLKL degradation confers cisplatin-resistant in non-small cell lung cancer cells

Non-small cell lung cancer (NSCLC) is the most prevalent type of cancer and the leading cause of cancer-related death. Chemotherapeutic resistance is a major obstacle in treating NSCLC patients. Here, we discovered that the E3 ligase Skp2 is overexpressed, accompanied by the downregulation of necroptosis-related regulator MLKL in human NSCLC tissues and cell lines. Knockdown of Skp2 inhibited viability, anchorage-independent growth, and in vivo tumor development of NSCLC cells. We also found that the Skp2 protein is negatively correlated with MLKL in NSCLC tissues. Moreover, Skp2 is increased and accompanied by an upregulation of MLKL ubiquitination and degradation in cisplatin-resistant NSCLC cells. Accordingly, inhibition of Skp2 partially restores MLKL and sensitizes NSCLC cells to cisplatin in vitro and in vivo. Mechanistically, Skp2 interacts and promotes ubiquitination-mediated degradation of MLKL in cisplatin-resistant NSCLC cells. Our results provide evidence of an Skp2-dependent mechanism regulating MLKL degradation and cisplatin resistance, suggesting that targeting Skp2-ubiquitinated MLKL degradation may overcome NSCLC chemoresistance.

Cyclophosphamide enfeebles myocardial isometric contraction force via RIP1/RIP3/MLKL/TRPM7-mediated necroptosis

This study explores the negative impact of cyclophosphamide (CP) on cardiac contractility by specifically examining its effect on the active and passive tension of the cardiac muscle in-vitro and revealing the mechanism through which CP induces myocardial insult in-vivo. In young male Sprague-Dawley rats, cardiac toxicity was induced by a single intraperitoneal injection of CP (150 mg/kg body weight). Axial heart tissue slices were electrically stimulated, and the total isometric contraction force was measured at varying pretension levels. Blood and tissue biochemical assays, and histological/ immuno-histological assessments were conducted to evaluate the underlying molecular mechanisms. Statistical analysis shows that there is a significant difference between the drugged and the control groups in terms of the active tension values. Moreover, the pre-tension stress significantly affects both the active and passive tension values. CP altered heart, body, and heart-to-body weight, desolated cardiac muscle architecture, surged cardiac enzymes (CK-MB, LDH, and cTn l), augmented myocardial oxidative stressors (MDA), and weakened myocardial antioxidant status (SOD and GSH). Mechanistically, cyclophosphamide prompted the necroptotic trajectory evidenced by the activation of RIPK1, RIPK3, MLKL and TRPM7, the inhibition of caspase 8 and BCL2 and the upregulation of the protein/mRNA expression of TNF-α and TNFR1. This study identifies necroptosis as a key factor in cyclophosphamide-evoked myocardial contractility impairment, highlighting its potential as a target for alleviating antitumor-related myocardial damage. This innovative approach to investigating the underlying mechanisms of CP-induced cardiac toxicity offers valuable insights into the potential of developing new therapies to mitigate cyclophosphamide's negative impact.

Study of necrotic apoptosis by pulsed electric field ablation in rabbit left ventricular myocardium

Objective

We investigate the characteristics of histological damage to myocardial cells in the ablation region and surrounding areas of the left ventricular epicardium in rabbits using our self-developed cardiac pulsed electric field (PEF) ablation instrument and ablation catheter.

Methods

Forty eight New Zealand rabbits underwent ablation on the left ventricular myocardium after open-heart exposure with a cardiac arrhythmia PEF ablation device and ablation catheter developed by the Medical Translation Laboratory of Pulsed Electric Field Technology in Zhejiang Province. The ablation parameters were set as biphasic electrical pulses; voltage, ±800 V; pulse width, 10 μs; interphase delay, 500 us. Six rabbits were included in the sham group and 42 other rabbits were randomly divided into immediately, 6-h, 1-, 3-day, 1-, 2-, and 4-week post-ablation groups, with six rabbits in each group. Creatine kinase- (CK)-MB isoenzyme (CK-MB), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH) levels were measured before and at different time points after PEF ablation to analyze their dynamic evolution. Masson staining of tissue block sections of left ventricular myocardial ablation and adjacent tissue heart specimens was performed, and the occurrence of TUNEL apoptosis in myocardium tissue was analyzed.

Results

All rabbits completed the PEF ablation procedure and the follow-up process. After PEF ablation, the levels of cardiac enzymes, including CK-MB, CK, and AST, increased significantly, peaking 1–3 days after the procedure. In particular, those of CK and CK-MB increased by 15–20 times but returned to the preoperative level after 2 weeks. Based on general observation, it was found that the myocardium in the ablation area was swollen immediately after PEF ablation. Masson staining analysis revealed that cardiomyocytes were broken and infiltrated by erythrocytes after 6 h. After 1 day, the cells started to experience atrophy and necrosis; after 3 days, fibrotic replacement of the necrotic area became obvious. Then, by 4 weeks, the myocardial cells were completely replaced by hyperplasia. Apoptosis occurred significantly at 6 h and peaked at 24 h post-ablation, demonstrating a 37.7-fold increase; apoptotic cell counts decreased significantly at 3 days post-ablation, and no significant apoptotic cardiomyocytes were seen after 1 week.

Conclusion

After PEF ablation, cardiomyocytes showed apoptotic process and dyed, at least partially, through a secondary necrosis, the ablation boundary was clear, the ablation area was replaced by structurally intact fibroblasts, no island myocardium tissue were seen, and the ablation area vessels and nerves were not affected.

MiRNAs in renal cell carcinoma

MicroRNAs (miRNAs) are small RNA sequences that act as post-transcriptional regulatory genes to control many cellular processes through pairing bases with a complementary messenger RNA (mRNA). A single miRNA molecule can regulate more than 200 different transcripts and the same mRNA can be regulated by multiple miRNAs. In this review, we highlight the importance of miRNAs and collect the existing evidence on their relationship with kidney cancer.

RIP3 Translocation into Mitochondria Promotes Mitofilin Degradation to Increase Inflammation and Kidney Injury after Renal Ischemia-Reperfusion

The receptor-interacting protein kinase 3 (RIP3) has been reported to regulate programmed necrosis-necroptosis forms of cell death with important functions in inflammation. We investigated whether RIP3 translocates into mitochondria in response to renal ischemia-reperfusion (I/R) to interact with inner mitochondrial protein (Mitofilin) and promote mtDNA release into the cytosol. We found that release of mtDNA activates the cGAS-STING pathway, leading to increased nuclear transcription of pro-inflammatory markers that exacerbate renal I/R injury. Monolateral C57/6N and RIP3^-/- mice kidneys were subjected to 60 min of ischemia followed by either 12, 24, or 48 h of reperfusion. In WT mice, we found that renal I/R injury increased RIP3 levels, as well as its translocation into mitochondria. We observed that RIP3 interacts with Mitofilin, likely promoting its degradation, resulting in increased mitochondria damage and mtDNA release, activation of the cGAS-STING-p65 pathway, and increased transcription of pro-inflammatory markers. All of these effects observed in WT mice were decreased in RIP3^-/- mice. In HK-2, RIP3 overexpression or Mitofilin knockdown increased cell death by activating the cGAS-STING-p65 pathway. Together, this study point to an important role of the RIP3-Mitofilin axis in the initiation and development of renal I/R injury.

RIP3 Contributes to Cardiac Hypertrophy by Influencing MLKL-Mediated Calcium Influx

Receptor-interacting protein 3(RIP3), a RIP family member, has been reported as a critical regulator of necroptosis and involves in the pathogenesis of various heart diseases. However, its role in the development of myocardial hypertrophy after pressure overload is unclear. We aimed to investigate the roles of RIP3 in pathological cardiac hypertrophy. A rat model of myocardial hypertrophy induced by the aortic banding method was used in this study. Neonatal rat cardiomyocytes (NRCMs) were stimulated with angiotensin II (Ang-II) or phenylephrine (PE) to induce neurohumoral stress. Our results showed that RIP3 level was significantly elevated in the hypertrophic myocardium tissues from patients, rats subjected to AB surgery, and NRCMs treated with Ang-II or PE. After downregulation of RIP3 expression in NRCMs, the phenotypes of myocardial hypertrophy were obviously alleviated. In mechanism, we demonstrated that RIP3 interacts with mixed lineage kinase domain-like protein (MLKL) and promotes its cell membrane localization to increase the influx of calcium within cells, thereby mediating the development of myocardial hypertrophy. More interestingly, we found the blockage of calcium influx by 2-aminoethoxydiphenyl borate, and lanthanum chloride efficiently reverses RIP3-induced cardiac remodeling in NRCMs. Taken together, our findings indicate a key role of the RIP3-MLKL signaling pathway in myocardial hypertrophy, which may be a novel promising treatment strategy for myocardial hypertrophy.

Endoplasmic Reticulum-Mitochondria Contacts: A Potential Therapy Target for Cardiovascular Remodeling-Associated Diseases

Cardiovascular remodeling occurs in cardiomyocytes, collagen meshes, and vascular beds in the progress of cardiac insufficiency caused by a variety of cardiac diseases such as chronic ischemic heart disease, chronic overload heart disease, myocarditis, and myocardial infarction. The morphological changes that occur as a result of remodeling are the critical pathological basis for the occurrence and development of serious diseases and also determine morbidity and mortality. Therefore, the inhibition of remodeling is an important approach to prevent and treat heart failure and other related diseases. The endoplasmic reticulum (ER) and mitochondria are tightly linked by ER-mitochondria contacts (ERMCs). ERMCs play a vital role in different signaling pathways and provide a satisfactory structural platform for the ER and mitochondria to interact and maintain the normal function of cells, mainly by involving various cellular life processes such as lipid metabolism, calcium homeostasis, mitochondrial function, ER stress, and autophagy. Studies have shown that abnormal ERMCs may promote the occurrence and development of remodeling and participate in the formation of a variety of cardiovascular remodeling-associated diseases. This review focuses on the structure and function of the ERMCs, and the potential mechanism of ERMCs involved in cardiovascular remodeling, indicating that ERMCs may be a potential target for new therapeutic strategies against cardiovascular remodeling-induced diseases.

[RIP1/RIP3-MLKL signaling pathway correlates with occurrence, progression and prognosis of chronic heart failure]

OBJECTIVE

To detect plasma levels of receptor-interacting protein kinase 1 (RIP1), RIP3 and mixed lineage kinase domain-like protein (MLKL) in patients with chronic heart failure and explore the expression pattern of programmed necrosis signaling pathway RIP1/RIP3-MLKL in the progression of heart failure.

METHODS

The patients with chronic heart failure (NYHA class Ⅱ-Ⅳ) admitted in our hospital between February, 2020 and March, 2021 were prospectively enrolled in this study, with 21 healthy volunteers as the control group. The enrolled patients included 20 with grade Ⅱ, 33 with grade Ⅲ, and 43 with grade Ⅳ cardiac function. Fasting venous blood was collected from all the participants for detecting plasma levels of RIP1, RIP3, and MLKL and protein expressions of RIP1/RIP3-MLKL pathway using enzyme-linked immunosorbent assay (ELISA) and Western blotting. The patients with grade Ⅳ cardiac function were followed up for 5 months to evaluate the clinical prognostic indicators.

RESULTS

Compared with the healthy volunteers, the patients with grade Ⅱ, Ⅲ and Ⅳ cardiac function had significantly increased plasma levels of RIP1, RIP3, and MLKL (P < 0.01), and their levels were significantly higher in grade Ⅲ/Ⅳ patients than in those with grade Ⅱ cardiac function (P < 0.01); the plasma levels of RIP1 and MLKL were significantly higher in grade Ⅳ patients than in grade Ⅲ patients (P < 0.05). The results of Western blotting also showed increased expressions of the proteins in the RIP1/RIP3-MLKL pathway in patients with heart failure. Pearson correlation analysis suggested that in patients with heart failure, the expression levels of RIP1, RIP3, and MLKL were positively correlated with SCR, AST, LVEDD and NT-proBNP (P < 0.05). Follow-up study of the patients with grade Ⅳ cardiac function showed that higher expression levels of RIP1/RIP3-MLKL were associated with a poorer prognosis of the patients.

CONCLUSION

The expressions of RIP1, RIP3 and MLKL are significantly upregulated in patients with heart failure in positive correlation with the severity of the disease condition, and the activation of the RIP1/RIP3-MLKL signaling pathway may contribute to the occurrence, development and prognosis of chronic heart failure.

MLKL and CaMKII Are Involved in RIPK3-Mediated Smooth Muscle Cell Necroptosis

Receptor interacting protein kinase 3 (RIPK3)-mediated smooth muscle cell (SMC) necroptosis has been shown to contribute to the pathogenesis of abdominal aortic aneurysms (AAAs). However, the signaling steps downstream from RIPK3 during SMC necroptosis remain unknown. In this study, the roles of mixed lineage kinase domain-like pseudokinase (MLKL) and calcium/calmodulin-dependent protein kinase II (CaMKII) in SMC necroptosis were investigated. We found that both MLKL and CaMKII were phosphorylated in SMCs in a murine CaCl₂-driven model of AAA and that Ripk3 deficiency reduced the phosphorylation of MLKL and CaMKII. In vitro, mouse aortic SMCs were treated with tumor necrosis factor α (TNFα) plus Z-VAD-FMK (zVAD) to induce necroptosis. Our data showed that both MLKL and CaMKII were phosphorylated after TNFα plus zVAD treatment in a time-dependent manner. SiRNA silencing of Mlkl-diminished cell death and administration of the CaMKII inhibitor myristoylated autocamtide-2-related inhibitory peptide (Myr-AIP) or siRNAs against Camk2d partially inhibited necroptosis. Moreover, knocking down Mlkl decreased CaMKII phosphorylation, but silencing Camk2d did not affect phosphorylation, oligomerization, or trafficking of MLKL. Together, our results indicate that both MLKL and CaMKII are involved in RIPK3-mediated SMC necroptosis, and that MLKL is likely upstream of CaMKII in this process.

miR-217-5p Inhibits Invasion and Metastasis of Prostate Cancer by Targeting Clusterin

Prostate cancer is not easy to metastasize because it is difficult to diagnose at an early stage, and there is no effective treatment currently. miRNA-217-5p has been reported to be a regulator in the process of prostate cancer. This study aimed to investigate how miRNA-217-5p affects the invasion and migration of prostate cancer. Luciferase assay was used to clarify whether the target gene Clusterin (CLU) was interacted directly with miR-217-5p. miR-217-5p and CLU were knocked down by transfecting respective siRNA into DU145 cells. The expression level of epithelial-mesenchymal transition (EMT)-related proteins was detected by Western blotting. Invasion and migration of DU145 cell were examined by wound healing assay. The results showed that miR-217-5p directly interacted with its target gene CLU, and the transfection of si-CLU and si-miR-217-5p had similar ability to regulate the expression level of EMT-related proteins, which in turn affected the migration and invasion of prostate cancer cell line DU145. In addition, miR-217-5p inhibited the expression of EMT-related proteins by regulating the expression of the target gene CLU, and further inhibited the invasion and migration of prostate cancer cells. Our findings provide a theoretical target basis for the treatment of prostate cancer.