At the Crossroads: Mechanisms of Apoptosis and Autophagy in Cell Life and Death

Melatonin regulates autophagy in granulosa cells from patients with premature ovarian insufficiency via activating Foxo3a

Premature ovarian insufficiency (POI) is a diverse form of female infertility characterized by a decline in ovarian function before the age of 40. Melatonin (MT) is a potential clinical treatment for restoring or safeguarding ovarian function in POI. However, the specific therapeutic mechanism underlying this effect remains unclear. To address this, we conducted experiments using human granulosa cells (GCs) from both POI and normal patients. We examined the expression levels of autophagy-related genes and proteins in GCs through qRT-PCR and western blot analysis. Autophagy flux was monitored in GCs infected with GFP-LC3-adenovirus, and the regulatory function of MT in autophagy was investigated. Additionally, we employed pharmacological intervention of autophagy using 3-Methyladenine (3-MA) and RNA interference of Forkhead box O-3A (FOXO3A) to elucidate the mechanism of MT in the autophagy process. Compared to GCs from normal patients, GCs from POI patients exhibited irregular morphology, decreased proliferation, increased apoptosis, and elevated ROS levels. The expression of autophagy-related genes was downregulated in POI GCs, resulting in reduced autophagic activity. Furthermore, MT levels were decreased in POI GCs, but exogenous MT effectively activated autophagy. Mechanistically, melatonin treatment downregulated FOXO3A expression and induced phosphorylation in POI GCs. Importantly, silencing FOXO3A abolished the protective effect of melatonin on GCs. These findings indicate that autophagy is downregulated in POI GCs, accompanied by a deficiency in MT. Moreover, we demonstrated that supplementing MT can rescue autophagy levels and enhance GC viability through the activation of FOXO3A signaling. Thus, MT-FOXO3A may serve as a potential therapeutic target for POI treatment.

Effect of Inducers and Inhibitors of the Keap1/Nrf2/ARE System on the Viability and Functional Activity of Model Neuronal-Like and Glial Cells

On mouse neuroblastoma (Neuro-2a) and human glioblastoma (U-87 MG) cell lines, we studied the effect of inducers and inhibitors of redox-sensitive signaling system of the antioxidant-responsive element Keap1/Nrf2/ARE on the main processes that determine nerve cell viability and vital activity (proliferative activity, apoptosis, autophagy, and activation of the Keap1/Nrf2/ARE system). Inhibitors of the Keap1/Nrf2/ARE system stimulate apoptosis more pronouncedly than inducers, have a weaker effect on autophagy, and do not change the nuclear to cytoplasmic Nrf2 ratio. In general, the revealed effects testify in favor of the potential effectiveness of stimulating the Keap1/Nrf2/ARE system for the prevention and adjuvant therapy of neurodegenerative diseases.

Telomerase and hallmarks of cancer: An intricate interplay governing cancer cell evolution

Transformed cells must acquire specific characteristics to be malignant. Weinberg and Hanahan characterize these characteristics as cancer hallmarks. Though these features are independently driven, substantial signaling crosstalk in transformed cells efficiently promotes these feature acquisitions. Telomerase is an enzyme complex that maintains telomere length. However, its main component, Telomere reverse transcriptase (TERT), has been found to interact with various signaling molecules like cMYC, NF-kB, BRG1 and cooperate in transcription and metabolic reprogramming, acting as a strong proponent of malignant features such as cell death resistance, sustained proliferation, angiogenesis activation, and metastasis, among others. It allows cells to avoid replicative senescence and achieve endless replicative potential. This review summarizes both the canonical and noncanonical functions of TERT and discusses how they promote cancer hallmarks. Understanding the role of Telomerase in promoting cancer hallmarks provides vital insight into the underlying mechanism of cancer genesis and progression and telomerase intervention as a possible therapeutic target for cancer treatment. More investigation into the precise molecular mechanisms of telomerase-mediated impacts on cancer hallmarks will contribute to developing more focused and customized cancer treatment methods.

Types of Cell Death from a Molecular Perspective

The former conventional belief was that cell death resulted from either apoptosis or necrosis; however, in recent years, different pathways through which a cell can undergo cell death have been discovered. Various types of cell death are distinguished by specific morphological alterations in the cell's structure, coupled with numerous biological activation processes. Various diseases, such as cancers, can occur due to the accumulation of damaged cells in the body caused by the dysregulation and failure of cell death. Thus, comprehending these cell death pathways is crucial for formulating effective therapeutic strategies. We focused on providing a comprehensive overview of the existing literature pertaining to various forms of cell death, encompassing apoptosis, anoikis, pyroptosis, NETosis, ferroptosis, autophagy, entosis, methuosis, paraptosis, mitoptosis, parthanatos, necroptosis, and necrosis.

Proteomic Markers in the Muscles and Brain of Pigs Recovered from Hemorrhagic Stroke

(1) Background: Stroke is the leading cause of serious long-term disability. Walking dysfunction and paresis of the upper extremities occurs in more than 80% of people who have had a stroke. (2) Methods: We studied post-genomic markers in biosamples of muscle and brain tissue from animals that underwent intracerebral hematoma and recovered after 42 days. Our purpose was to understand the biological mechanisms associated with recovery from hemorrhagic stroke. We analyzed the peptides formed after trypsinolysis of samples by HPLC-MS, and the results were processed by bioinformatics methods, including the establishment of biochemical relationships (gene to gene) using topological omics databases such as Reactome and KEGG. (3) Results: In the pig brain, unique compounds were identified which are expressed during the recovery period after traumatic injury. These are molecular factors of activated microglia, and they contribute to the functional recovery of neurons and reduce instances of hematoma, edema, and oxidative stress. Complexes of the main binding factors of the neurotrophins involved in the differentiation and survival of nerve cells were found in muscles. (4) Conclusions: A network of gene interactions has been constructed for proteins involved in the regulation of synaptic transmission, in particular presynaptic vesicular and endocytic processes. The presence of transmitters and transporters associated with stimulation of NMDA receptors at neuromuscular junctions shows the relationship between upper motor neurons and neuromuscular junctions.

Mechanisms of Survival of Cytomegalovirus-Infected Tumor Cells

Human cytomegalovirus (HCMV) DNA and proteins are often detected in malignant tumors, warranting studies of the role that HCMV plays in carcinogenesis and tumor progression. HCMV proteins were shown to regulate the key processes involved in tumorigenesis. While HCMV as an oncogenic factor just came into focus, its ability to promote tumor progression is generally recognized. The review discusses the viral factors and cell molecular pathways that affect the resistance of cancer cells to therapy. CMV inhibits apoptosis of tumor cells, that not only promotes tumor progression, but also reduces the sensitivity of cells to antitumor therapy. Autophagy was found to facilitate either cell survival or cell death in different tumor cells. In leukemia cells, HCMV induces a "protective" autophagy that suppresses apoptosis. Viral factors that mediate drug resistance and their interactions with key cell death pathways are necessary to further investigate in order to develop agents that can restore the tumor sensitivity to anticancer drugs.

Pathogen-Host Interaction Repertoire at Proteome and Posttranslational Modification Levels During Fungal Infections

Prevalence of fungal diseases has increased globally in recent years, which often associated with increased immunocompromised patients, aging populations, and the novel Coronavirus pandemic. Furthermore, due to the limitation of available antifungal agents mortality and morbidity rates of invasion fungal disease remain stubbornly high, and the emergence of multidrug-resistant fungi exacerbates the problem. Fungal pathogenicity and interactions between fungi and host have been the focus of many studies, as a result, lots of pathogenic mechanisms and fungal virulence factors have been identified. Mass spectrometry (MS)-based proteomics is a novel approach to better understand fungal pathogenicities and host–pathogen interactions at protein and protein posttranslational modification (PTM) levels. The approach has successfully elucidated interactions between pathogens and hosts by examining, for example, samples of fungal cells under different conditions, body fluids from infected patients, and exosomes. Many studies conclude that protein and PTM levels in both pathogens and hosts play important roles in progression of fungal diseases. This review summarizes mass spectrometry studies of protein and PTM levels from perspectives of both pathogens and hosts and provides an integrative conceptual outlook on fungal pathogenesis, antifungal agents development, and host–pathogen interactions.

Protective mechanism of FoxO1 against early brain injury after subarachnoid hemorrhage by regulating autophagy

INTRODUCTION

Early brain injury (EBI) plays a key role in the devastating outcomes after subarachnoid hemorrhage (SAH). Autophagy and apoptosis may share a common molecular inducer that regulates the process of cell death. FoxO1, as a key regulator of neuronal autophagy which is involved in apoptosis, has not been reported in SAH rats. This work was to investigate the protective and anti-inflammatory effects of FoxO1 on EBI after SAH by regulating autophagy.

METHODS

In this study, we constructed the SAH model. In experiment I, low dose (50 μl of 1 × 10⁸  IU/ml) or high dose (50 μl of 1 × 10¹⁰  IU/ml) of FoxO1 gene overexpressed adenovirus vector was injected into the lateral ventricle of rats before SAH. In experiment II, we reported the effect of FoxO1 overexpress on nerve function recovery, oedema, BBB leakage, neuronal death in rats after SAH through autophagy regulation. Post-SAH evaluation included neurological function score, brain water content, evans blue exosmosis, pathological changes, inflammatory response and apoptosis.

RESULTS

The experiment I showed that either low or high dose of ad-FoxO1 could significantly improve nerve function, reduce cerebral water content and reduce blood-brain barrier (BBB) destruction in rats, indicating that ad-FoxO1 had a protective effect on brain injury in rats EBI after SAH. In addition, ad-FoxO1 promoted autophagy in rat hippocampal tissue, as evidenced by accumulation of LC3II/I and Beclin-1 and degradation of p62. Furthermore, ad-FoxO1 inhibited the inflammatory response and apoptosis of rat hippocampal neurons after SAH. The experiment II showed that both ad-FoxO1 and rapamycin attenuated the injury of nerve function in rats after SAH, and this synergistic effect further reduced cerebral edema and evansblue extravasation, decreased hippocampus neuronal cell apoptosis, and declined inflammatory response. However, this was contrary to the results of chloroquine. These findings suggested that FoxO1 regulated the neural function of EBI after SAH through the autophagy pathway.

CONCLUSIONS

The findings in this study was beneficial for identifying the novel therapeutic target for the treatment of SAH.