MiR196a-5p in extracellular vesicles released from human nasopharyngeal carcinoma enhance the phagocytosis and secretion of microglia by targeting ROCK1

MicroRNA-129-5p-mediated translational repression of microglial ROCK1 leads to enhanced phagocytosis

ROCK1 plays an important role in phagocytosis by inducing cytoskeletal rearrangement. Although the transcriptional regulation of ROCK1 is known but its post-transcriptional regulation is underexplored. We intended to find a mechanism of microglial phagocytosis through possible post-transcriptional regulation of ROCK1. The study identified miR-129-5p as a regulator of microglial phagocytosis following exposure to an environmental stressor, arsenic, combining in silico analysis, mutational analysis, in vitro experiments, and validation in Balb/c mouse model. The in silico analysis and in vitro studies with mouse primary neonatal microglia, BV2 microglia, ex vivo microglia and human microglial cell line CHME3 revealed that arsenic exposure increases microglial phagocytic activity. Arsenic exposure was also observed to increase the level of miR-129-5p and consequently decreases the level of ROCK1 protein. In vitro experiments and mutational analysis confirmed the in silico predicted binding site of miR-129-5p on the 3'UTR of ROCK1 and also confirmed the shuttling of ROCK1 mRNA into the cytoplasmic-processing body (p-body) in mouse microglia. Downstream to ROCK1, Rac1 has also been studied to pinpoint the partners in the signaling axis. The role of miR-129-5p in microglial phagocytosis was studied in vitro and validated in vivo in BALB/c mouse by stereotactically injecting anti-miR-129-5p and assessing the phagocytosis in ex vivo microglia and co-localization of Iba1 and PSD95 in brain cryosection. Finally, experiments with arsenic, anti-miR-129-5p, ROCK1 & Rac1 siRNA in various combinations confirmed the miR-129-5p→ROCK1→Rac1→Phagocytosis signaling axis. Overall, the study revealed miR-129-5p as an important regulator of microglial phagocytosis with potential implication in synaptic plasticity and neurodegenerative complications.

An integrated analysis of multiple datasets reveals novel gene signatures in human granulosa cells

Granulosa cells (GCs) play crucial roles in oocyte maturation. Through gap junctions and extracellular vesicles, they mediate the exchange of molecules such as microRNAs and messenger RNAs. Different ovarian cell types exhibit unique gene expression profiles, reflecting their specialized functions and stages. By combining RNA-seq data from various cell types forming the follicle, we aimed at capturing a wide range of expression patterns, offering insights into the functional diversity and complexity of the transcriptome regulation across GCs. Herein, we performed an integrated bioinformatics analysis of RNA sequencing datasets present in public databases, with a unique and standardized workflow., By combining the data from different studies, we successfully increased the robustness and reliability of our findings and discovered novel genes, miRNAs, and signaling pathways associated with GCs function and oocyte maturation. Moreover, our results provide a valuable resource for further wet-lab research on GCs biology and their impact on oocyte development and competence.

The Role of Microglia in Brain Metastases: Mechanisms and Strategies

Brain metastases and related complications are one of the major fatal factors in cancer. Patients with breast cancer, lung cancer, and melanoma are at a high risk of developing brain metastases. However, the mechanisms underlying the brain metastatic cascade remain poorly understood. Microglia, one of the major resident macrophages in the brain parenchyma, are involved in multiple processes associated with brain metastasis, including inflammation, angiogenesis, and immune modulation. They also closely interact with metastatic cancer cells, astrocytes, and other immune cells. Current therapeutic approaches against metastatic brain cancers, including small-molecule drugs, antibody-coupled drugs (ADCs), and immune-checkpoint inhibitors (ICIs), have compromised efficacy owing to the impermeability of the blood-brain barrier (BBB) and complex brain microenvironment. Targeting microglia is one of the strategies for treating metastatic brain cancer. In this review, we summarize the multifaceted roles of microglia in brain metastases and highlight them as potential targets for future therapeutic interventions.

MiR-155 enhances phagocytosis of alveolar macrophages through the mTORC2/RhoA pathway

Alveolar macrophage phagocytosis is significantly reduced in Chronic obstructive pulmonary disease, and cigarette smoke extract is one of the chief reasons for this decrease. Nevertheless, the specific underlying mechanism remains elusive. In this study, the role and possible mechanism of miR-155-5p/mTORC2/RhoA in the phagocytosis of mouse alveolar macrophages (MH-S) were explored. Our results revealed that cigarette smoke extract intervention reduced MH-S cell phagocytosis and miR-155-5p expression. Meanwhile, the dual-luciferase reporter assay validated that Rictor is a target of miR-155-5p. On the one hand, transfecting miR-155-5p mimic, mimic NC, miR-155-5p inhibitor, or inhibitor NC in MH-S cells overexpressing miR-155-5p increased the Alveolar macrophage phagocytotic rate, up-regulated the expression level of RhoA and p-RhoA, and down-regulated that of mTOR and Rictor mRNA and protein. On the other hand, inhibiting the expression of miR-155-5p lowered the phagocytotic rate, up-regulated the expression of mTOR, Rictor mRNA, and protein, and down-regulated the expression of RhoA and p-RhoA, which taken together, authenticated that miR-155-5p participates in macrophage phagocytosis via the mTORC2/RhoA pathway. Finally, confocal microscopy demonstrated that cells overexpressing miR-155-5p underwent cytoskeletal rearrangement during phagocytosis, and the phagocytic function of cells was enhanced, signaling that miR-155-5p participated in macrophage skeletal rearrangement and enhanced alveolar macrophage phagocytosis by targeting the expression of Rictor in the mTORC2/RhoA pathway.

Application of small extracellular vesicles in the diagnosis and prognosis of nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a malignant tumor originating from the epithelium of the nasopharynx. The disease is insidious, and most patients are diagnosed at the advanced stage, resulting in poor prognosis. Early diagnosis is important to reduce NPC mortality. Small extracellular vesicles (sEVs) are rich in a variety of bioactive molecules, such as proteins, nucleic acids, and lipids, which can participate in the physiological and pathological regulation of the body by affecting the function of target cells. Numerous studies have shown that some RNAs and proteins in sEVs of tumor origin have a key role in the development of NPC and are potential candidates for malignancy detection. Studying the relationship between the cargoes of these sEVs and NPC may help in the diagnosis of the disease. Here in this review, we summarize the application of sEVs as biomarkers in the diagnosis of NPC and their role in NPC metastasis and prognosis. In addition, we discuss possible future applications and limitations of sEVs as biomarkers.

Cytokine Landscape in Central Nervous System Metastases

The central nervous system is the location of metastases in more than 40% of patients with lung cancer, breast cancer and melanoma. These metastases are associated with one of the poorest prognoses in advanced cancer patients, mainly due to the lack of effective treatments. In this review, we explore the involvement of cytokines, including interleukins and chemokines, during the development of brain and leptomeningeal metastases from the epithelial-to-mesenchymal cell transition and blood–brain barrier extravasation to the interaction between cancer cells and cells from the brain microenvironment, including astrocytes and microglia. Furthermore, the role of the gut–brain axis on cytokine release during this process will also be addressed.

Extracellular Vesicles in the Progression and Therapeutic Resistance of Nasopharyngeal Carcinoma

Nasopharyngeal carcinoma (NPC) is an epithelial malignancy largely associated with Epstein-Barr virus (EBV) infection, which is frequently reported in east and southeast Asia. Extracellular vesicles (EVs) originate from the endosome or plasma membrane, which plays a critical role in tumor pathogenesis for their character of cell-cell communication and its cargos, including proteins, RNA, and other molecules that can target recipient cells and affect their progression. To date, numerous studies have indicated that EVs have crucial significance in the progression, metastasis, and therapeutic resistance of NPC. In this review, we not only summarize the interaction of NPC cells and the tumor microenvironment (TME) through EVs, but also explain the role of EVs in radiation and drug resistance of NPC, which poses a severe threat to cancer therapy. Therefore, EVs may show great potential as biomarkers in the early diagnosis of interfered targets of NPC therapy.