Autophagy in Human Health and Disease: Novel Therapeutic Opportunities

DDX3X dynamics, glioblastoma's genetic landscape, therapeutic advances, and autophagic interplay

Glioblastoma is one of the most aggressive and deadly forms of cancer, posing significant challenges for the medical community. This review focuses on key aspects of Glioblastoma, including its genetic differences between primary and secondary types. Temozolomide is a major first-line treatment for Glioblastoma, and this article explores its development, how it works, and the issue of resistance that limits its effectiveness, prompting the need for new treatment strategies. Gene expression profiling has greatly advanced cancer research by revealing the molecular mechanisms of tumors, which is essential for creating targeted therapies for Glioblastoma. One important protein in this context is DDX3X, which plays various roles in cancer, sometimes promoting it or otherwise suppressing it. Additionally, autophagy, a process that maintains cellular balance, has complex implications in cancer treatment. Understanding autophagy helps to identify resistance mechanisms and potential treatments, with Chloroquine showing promise in treating Glioblastoma. This review covers the interplay between Glioblastoma, DDX3X, and autophagy, highlighting the challenges and potential strategies in treating this severe disease.

Quality evaluation of selected expired fluoroquinolones medicines obtained from the public hospitals in Jimma zone, Oromia regional state, Ethiopia

Background

The problem of medicine expiration presents a notable obstacle, resulting in considerable financial losses. Nevertheless, there is currently limited data indicating that certain medications do not experience a significant decrease in effectiveness after their expiration date. Therefore, the aim of the study was to assess the physico-chemical quality of expired fluoroquinolone antibiotics.

Methods

The expired samples of fluoroquinolone antibiotics were purposively collected from public hospitals in the Jimma zone of the Oromia regional state, Ethiopia. A World Health Organization quality evaluation sampling strategy was employed. Then, simple random sampling techniques were utilized for the selection of tablets for the laboratory quality control test. The assay, identification, and dissolution were performed in accordance with the United States Pharmacopeia (USP) guidelines, as well as failure mode and effect analysis (FMEA) techniques.

Results

The finding revealed that about 100% (7/7) expired samples passed pharmacopeia quality specifications for identity and assay tests. However, of the seven expired brands, about 14.3% (1/7) of the sample (Code-002) was unable to release its API content within the USP criteria of 30 min. The risk-based quality evaluation revealed that assay was the most critical quality attributed to ciprofloxacin tablets (RPN = 189), followed by identity (RPN = 100). Assay was also the most critical quality attribute (RPN = 378), followed by identity (RPN = 100) for Norfloxacin tablets. The risk-based desirability function approach showed that 75% (3/4) of ciprofloxacin products were of good quality, and 25% (1) were found to be of acceptable quality, while the desirability function of norfloxacin tablets was found to be excellent 1 (33.3%), good 1 (33.3%), and acceptable 1 (33.3%).

Conclusion

The study revealed that medications can maintain their quality beyond their labeled expiration date. By combining pharmacopeial standards with risk-based approaches like failure mode and effect analysis (FMEA), the study provides a comprehensive evaluation framework. This approach not only confirms the continued effectiveness of expired fluoroquinolone antibiotics but also underscores the potential waste reduction and cost-saving benefits. This could significantly contribute to addressing healthcare challenges in low-resource settings, promoting more efficient pharmaceutical resource utilization.

Beneficial Effect of Olive Oil and Its Derivates: Focus on Hematological Neoplasm

Olive oil (Olea europaea) is one of the major components of the Mediterranean diet and is composed of a greater percentage of monounsaturated fatty acids, such as oleic acid; polyunsaturated fatty acids, such as linoleic acid; and minor compounds, such as phenolic compounds, and particularly hydroxytyrosol. The latter, in fact, are of greater interest since they have found widespread use in popular medicine. In recent years, it has been documented that phenolic acids and in particular hydroxytyrosol have anti-inflammatory, antioxidant, and antiproliferative action and therefore interest in their possible use in clinical practice and in particular in neoplasms, both solid and hematological, has arisen. This work aims to summarize and analyze the studies present in the literature, both in vitro and in vivo, on the possible use of minor components of olive oil in some hematological neoplasms. In recent years, in fact, interest in nutraceutical science has expanded as a possible adjuvant in the treatment of neoplastic pathologies. Although it is worth underlining that, regarding the object of our study, there are still few preclinical and clinical studies, it is, however, possible to document a role of possible interest in clinical practice.

DNA damage-regulated autophagy modulator 1 prevents glioblastoma cells proliferation by regulating lysosomal function and autophagic flux stability

Glioblastoma (GBM) is the most aggressive and life-threatening brain tumor, characterized by its highly malignant and recurrent nature. DNA damage-regulated autophagy modulator 1 (DRAM-1) is a p53 target gene encoding a lysosomal protein that induces macro-autophagy and damage-induced programmed cell death in tumor growth. However, the precise mechanisms underlying how DRAM-1 affects tumor cell proliferation through regulation of lysosomal function and autophagic flux stability remain incompletely understood. We found that DRAM-1 expressions were evidently down-regulated in high-grade glioma and recurrent GBM tissues. The upregulation of DRAM-1 could increase mortality of primary cultured GBM cells. TEM analysis revealed an augmented accumulation of aberrant lysosomes in DRAM-1-overexpressing GBM cells. The assay for lysosomal pH and stability also demonstrated decreasing lysosomal membrane permeabilization (LMP) and impaired lysosomal acidity. Further research revealed the detrimental impact of lysosomal dysfunction, which impaired the autophagic flux stability and ultimately led to GBM cell death. Moreover, downregulation of mTOR phosphorylation was observed in GBM cells following upregulation of DRAM-1. In vivo and in vitro experiments additionally illustrated that the mTOR inhibitor rapamycin increased GBM cell mortality and exhibited an enhanced antitumor effect.

AI-based AlphaFold2 significantly expands the structural space of the autophagy pathway

ABBREVIATIONS

AF2: AlphaFold2; AF2-Mult: AlphaFold2 multimer; ATG: autophagy-related; CTD: C-terminal domain; ECTD: extreme C-terminal domain; FR: flexible region; MD: molecular dynamics; NTD: N-terminal domain; pLDDT: predicted local distance difference test; UBL: ubiquitin-like.

TACkling Cancer by Targeting Selective Protein Degradation

Targeted protein degradation has emerged as an alternative therapy against cancer, offering several advantages over traditional inhibitors. The new degrader drugs provide different therapeutic strategies: they could cross the phospholipid bilayer membrane by the addition of specific moieties to extracellular proteins. On the other hand, they could efficiently improve the degradation process by the generation of a ternary complex structure of an E3 ligase. Herein, we review the current trends in the use of TAC-based technologies (TACnologies), such as PROteolysis TArgeting Chimeras (PROTAC), PHOtochemically TArgeting Chimeras (PHOTAC), CLIck-formed Proteolysis TArgeting Chimeras (CLIPTAC), AUtophagy TArgeting Chimeras (AUTAC), AuTophagosome TEthering Compounds (ATTEC), LYsosome-TArgeting Chimeras (LYTAC), and DeUBiquitinase TArgeting Chimeras (DUBTAC), in experimental development and their progress towards clinical applications.

Application and value of hydrogen sulfide modulated autophagy in sepsis

Sepsis is is anabnormalhost immune responsecausedbyinfection. Antibiotics, anti-viral drugs, and vasoactive drugs have always been used in the traditional treatment of sepsis, but there are no specific and effective drugs in clinical practice. Autophagy is a highly conservative process in biological evolution, and plays an important role in maintaining intracellular homeostasis and cellular self-renewal. Autophagy can remove and degrade misfolding proteins and damaged organelles in cells, providing materials for cell repair and self-renewal. Hydrogen sulfide (H2S) is a colorless gas that smells likerotteneggs. It is the third endogenous gas signal molecule discovered after nitric oxide and carbon monoxide and has become a research hotspot in recent years. H2S has a variety of biological functions and plays an important role in various physiological and pathological processes. Thereisgrowingevidencethat H2S can regulate autophagy. The intervention of autophagy is a promising therapeutic strategy to improve sepsis organ damage. This article reviews the organ protection of autophagy in sepsis and the role of H2S in regulating autophagy in sepsis, revealing that H2S intervention with autophagy may be a a worthy target in sepsis treatment.

Fruits as nutraceuticals: A review of the main fruits included in nutraceutical patents

Fruits have relevant usefulness in the elaboration of nutraceutical compositions and, as it is considered a "natural medicine", its market has been growing exponentially each year. Fruits, in general, contain a large source of phytochemicals, carbohydrates, vitamins, amino acids, peptides and antioxidants that are of interest to be prepared as nutraceuticals. The biological properties of its nutraceuticals can range from antioxidant, antidiabetic, antihypertensive, anti-Alzheimer, antiproliferative, antimicrobial, antibacterial, anti-inflammatory, among others. Furthermore, the need for innovative extraction methods and products reveals the importance of developing new nutraceutical compositions. This review was developed by searching patents of nutraceuticals from January 2015 until January 2022 in Espacenet, the search database of the European Patent Office (EPO). Of 215 patents related to nutraceuticals, 43% (92 patents) were including fruits, mainly berries. A great number of patents were focused on the treatment of metabolic diseases, representing 45% of the total patents. The principal patent applicant was the United States of America (US), with 52%. The patents were applied by researchers, industries, research centers and institutes. It is important to highlight that from 92 fruit nutraceutical patent applications reviewed, 13 already have their products available on the market.

Chemoresistance in pancreatic ductal adenocarcinoma: Overcoming resistance to therapy

Pancreatic ductal adenocarcinoma (PDAC), a prominent cause of cancer deaths worldwide, is a highly aggressive cancer most frequently detected at an advanced stage that limits treatment options to systemic chemotherapy, which has provided only marginal positive clinical outcomes. More than 90% of patients with PDAC die within a year of being diagnosed. PDAC is increasing at a rate of 0.5-1.0% per year, and it is expected to be the second leading cause of cancer-related mortality by 2030. The resistance of tumor cells to chemotherapeutic drugs, which can be innate or acquired, is the primary factor contributing to the ineffectiveness of cancer treatments. Although many PDAC patients initially responds to standard of care (SOC) drugs they soon develop resistance caused partly by the substantial cellular heterogeneity seen in PDAC tissue and the tumor microenvironment (TME), which are considered key factors contributing to resistance to therapy. A deeper understanding of molecular mechanisms involved in PDAC progression and metastasis development, and the interplay of the TME in all these processes is essential to better comprehend the etiology and pathobiology of chemoresistance observed in PDAC. Recent research has recognized new therapeutic targets ushering in the development of innovative combinatorial therapies as well as enhancing our comprehension of several different cell death pathways. These approaches facilitate the lowering of the therapeutic threshold; however, the possibility of subsequent resistance development still remains a key issue and concern. Discoveries, that can target PDAC resistance, either alone or in combination, have the potential to serve as the foundation for future treatments that are effective without posing undue health risks. In this chapter, we discuss potential causes of PDAC chemoresistance and approaches for combating chemoresistance by targeting different pathways and different cellular functions associated with and mediating resistance.

An integrative method for evaluating the biological effects of nanoparticle-protein corona

BACKGROUND

Nanoplastics in the environment can enter the human body through gastrointestinal intake, dermal contact, and pulmonary inhalation, posing a threat to human health. Protein molecules in body fluids will quickly adsorb on the surfaces of the nanoplastics, forming a protein corona, which has implications for the interaction of the nanoplastics with cells and the metabolic pathways of the nanoplastic within cells. For years, practical tools such as dynamic light scattering, transmission electron microscopy, and liquid chromatography have been developed to understand the protein corona of nanoparticles (NPs), either in vitro or in cellular or molecular level. However, an integrated approach to understand the nanoparticles-protein corona is still lacking.

METHODS

Using the most frequently observed environmental nanoplastics, polystyrene nanoplastics (PS), as a standard, we established an integrative structural characterization platform, a biophysical and biochemical evaluation method to investigate the effect of surface charge on protein corona composition. The cellular and molecular mechanisms were also explored through in vitro cellular experiments.

RESULTS

The first integrative method for characterizing biological properties of NPs-protein corona has been established. This method comprehensively covers the critical aspects to understand NPs-protein corona interactions, from structure to function.

CONCLUSIONS

The integrative method for nanoplastics microstructure characterization can be applied to the structural characterization of nanoparticles in nanoscale, which is of universal significance from in vitro characterization to cellular experiments and then to molecular mechanism studies.

GENERAL SIGNIFICANCE

This strategy has high reliability and repeatability and can be applied both in environment and nanomedicine safety assessment.

Autophagy and Apoptosis in Acute Brain Injuries: From Mechanism to Treatment

Significance: Autophagy and apoptosis are two important cellular mechanisms behind brain injuries, which are severe clinical situations with increasing incidences worldwide. To search for more and better treatments for brain injuries, it is essential to deepen the understanding of autophagy, apoptosis, and their interactions in brain injuries. This article first analyzes how autophagy and apoptosis participate in the pathogenetic processes of brain injuries respectively and mutually, then summarizes some promising treatments targeting autophagy and apoptosis to show the potential clinical applications in personalized medicine and precision medicine in the future. Recent Advances: Most current studies suggest that apoptosis is detrimental to brain recovery. Several studies indicate that autophagy can cause unnecessary death of neurons after brain injuries, while others show that autophagy is beneficial for acute brain injuries (ABIs) by facilitating the removal of damaged proteins and organelles. Whether autophagy is beneficial or detrimental in ABIs depends on many factors, and the results from different research groups are diverse or even controversial, making this topic more appealing to be explored further. Critical Issues: Neuronal autophagy and apoptosis are two primary pathological processes in ABIs. How they interact with each other and how their regulations affect the outcome and prognosis of brain injuries remain uncertain, making these answers more critical. Future Directions: Insights into the interplay between autophagy and apoptosis and the accurate regulations of their balance in ABIs may promote personalized and precise treatments in the field of brain injuries. Antioxid. Redox Signal. 38, 234-257.

New Visions on Natural Products and Cancer Therapy: Autophagy and Related Regulatory Pathways

Macroautophagy (autophagy) has been a highly conserved process throughout evolution and allows cells to degrade aggregated/misfolded proteins, dysfunctional or superfluous organelles and damaged macromolecules, in order to recycle them for biosynthetic and/or energetic purposes to preserve cellular homeostasis and health. Changes in autophagy are indeed correlated with several pathological disorders such as neurodegenerative and cardiovascular diseases, infections, cancer and inflammatory diseases. Conversely, autophagy controls both apoptosis and the unfolded protein response (UPR) in the cells. Therefore, any changes in the autophagy pathway will affect both the UPR and apoptosis. Recent evidence has shown that several natural products can modulate (induce or inhibit) the autophagy pathway. Natural products may target different regulatory components of the autophagy pathway, including specific kinases or phosphatases. In this review, we evaluated ~100 natural compounds and plant species and their impact on different types of cancers via the autophagy pathway. We also discuss the impact of these compounds on the UPR and apoptosis via the autophagy pathway. A multitude of preclinical findings have shown the function of botanicals in regulating cell autophagy and its potential impact on cancer therapy; however, the number of related clinical trials to date remains low. In this regard, further pre-clinical and clinical studies are warranted to better clarify the utility of natural compounds and their modulatory effects on autophagy, as fine-tuning of autophagy could be translated into therapeutic applications for several cancers.

Autophagy in adipogenesis: Molecular mechanisms and regulation by bioactive compounds

White adipose tissue expands rapidly due to increased adipocyte number (hyperplasia) and size (hypertrophy), which results in obesity. Adipogenesis is a process of the formation of mature adipocytes from precursor cells. Additionally, obesity-related metabolic complications, such as fatty liver and insulin resistance, are linked to adipogenesis. On the contrary, autophagy is a catabolic process; essential to maintain cellular homeostasis via the degradation or recycling of unnecessary or damaged components. Importantly, autophagy dictates obesity and adipogenesis. Hence, a clear understanding of how autophagy regulates adipogenesis is crucial for drug development and the prevention and treatment of obesity and its associated disorders, such as type 2 diabetes, cardiovascular disease, and cancer. In this review, we highlighted recent findings regarding the crosstalk between adipogenesis and autophagy, as well as the molecules involved. Furthermore, the review discussed how bioactive compounds regulate adipogenesis by manipulating autophagy and underlying molecular mechanisms. Based on in vitro and animal studies, we summarized the effects of bioactive compounds on adipogenesis and autophagy. Hence, human studies are necessary to validate the effectiveness and optimal dosage of these bioactive compounds.

Sesamin Ameliorates Fine Particulate Matter (PM2.5)-Induced Lung Injury via Suppression of Apoptosis and Autophagy in Rats

Lung damage can be caused by fine particulate matter (PM_2.5). Thus, effective prevention strategies for PM_2.5-induced lung injury are urgently required. Sesamin (Ses) is a natural polyphenolic compound that has attracted considerable attention of researchers because of its wide range of pharmacological activities. The present study aims to elucidate whether Ses pretreatment could alleviate PM_2.5-induced lung damage and identify its possible mechanisms. Sprague-Dawley rats were orally dosed with 0.5% carboxymethylcellulose (CMC) and different concentrations of Ses once a day for 21 days. Then, the rats of the PM_2.5 exposure group and Ses-treated group were exposed to PM_2.5 by intratracheal instillation every 2 days for 1 week. Biomarkers associated with lung injury were detected in bronchoalveolar lavage fluid (BALF). Lung tissue was collected for histology, inflammation, oxidative stress, immunohistochemistry, and Western blot. Our results showed that PM_2.5 exposure could cause pathological changes in lung tissue and increase levels of TP, AKP, and ALB in BALF. Meanwhile, exposure to PM_2.5 can cause oxidative stress and inflammation in the lungs. In addition, Ses pretreatment could ameliorate histopathological injury, oxidative stress, and inflammation caused by PM_2.5 exposure. It could also inhibit PM_2.5-induced apoptosis and upregulation of autophagy-associated proteins. Collectively, our study indicated that Ses pretreatment could ameliorate PM_2.5-induced lung damage via inhibiting apoptosis and autophagy in rats.

MT-12 inhibits the proliferation of bladder cells in vitro and in vivo by enhancing autophagy through mitochondrial dysfunction

Bladder cancer (BC) is one of the most common malignancies involving the urinary system. Our previous study demonstrated that cobra venom membrane toxin 12 (MT-12) could effectively inhibit BC cell growth and metastasis and induce apoptosis. However, the specific molecular mechanism remains unknown. In this study, we explored whether MT-12 inhibits BC cell proliferation by inducing autophagy cell death through mitochondrial dysfunction. As a result, MT-12 inhibited proliferation and colony formation in RT4 and T24 cells. In the BC xenograft mouse model, autophagy inhibitor 3-MA alleviated the inhibitory effect of MT-12 on tumor growth. In addition, immunostaining revealed downregulated autophagy in MT-12-treated RT4 and T24 cells. We also found that MT-12 led to dysfunctional mitochondria with decreased mitochondrial membrane potential, mtDNA abundance, and increased ROS production, ultimately inducing autophagic apoptosis via the ROS/JNK/P53 pathway. MT-12 inhibits BC proliferation in vitro and in vivo by enhancing autophagy. MT-12 induces mitochondrial dysfunction and decreases autophagy, leading to increased ROS production, which in turn activates the JNK/p53 pathway, leading to BC apoptosis.

Antiaging Mechanism of Natural Compounds: Effects on Autophagy and Oxidative Stress

Aging is a natural biological process that manifests as the progressive loss of function in cells, tissues, and organs. Because mechanisms that are meant to promote cellular longevity tend to decrease in effectiveness with age, it is no surprise that aging presents as a major risk factor for many diseases such as cardiovascular disease, neurodegenerative disorders, cancer, and diabetes. Oxidative stress, an imbalance between the intracellular antioxidant and overproduction of reactive oxygen species, is known to promote the aging process. Autophagy, a major pathway for protein turnover, is considered as one of the hallmarks of aging. Given the progressive physiologic degeneration and increased risk for disease that accompanies aging, many studies have attempted to discover new compounds that may aid in the reversal of the aging process. Here, we summarize the antiaging mechanism of natural or naturally derived synthetic compounds involving oxidative stress and autophagy. These compounds include: 2-cyano-3,12-dioxoolean-1,9-dien-28-oic acid (CDDO) derivatives (synthetic triterpenoids derived from naturally occurring oleanolic acid), caffeic acid phenethyl ester (CAPE, the active ingredient in honey bee propolis), xanthohumol (a prenylated flavonoid identified in the hops plant), guggulsterone (a plant steroid found in the resin of the guggul plant), resveratrol (a natural phenol abundantly found in grape), and sulforaphane (a sulfur-containing compound found in cruciferous vegetables).

Unravelling potential biomedical applications of the edible flower Tulbaghia violacea

Traditionally, edible flowers have been used as foods and for therapeutic purposes, today they have gained importance due to their bioactive compounds such as flavonols, anthocyanins or other phenolic compounds, which give them potential for biomedical applications. This work evaluated a methanolic extract of Tulbaghia violacea. Eleven individual phenolic compounds were found and quantified by mass spectrometry in the extract. Antioxidant activity tests (TEAC, FRAP and DPPH) and other characterization parameters were assayed (total phenolic content and total flavonoid content). In vitro studies showed antitumoral activity against ovarian tumoral cells mediated by the induction of non-dependent caspase cell death and by the activation of reactive oxygen species. The effect of the extract against features of Alzheimer disease was in vivo assayed in Caenorhabditis elegans. Tulbaghia extract led to a reduction in the 1-42 beta amyloid peptide formation and prevented oxidative stress. These results suggested that Tulbaghia violacea could be a new source of phenolic compounds for nutraceuticals and functional food development.

Integrated Analysis Reveals S100a8/a9 Regulates Autophagy and Apoptosis through the MAPK and PI3K-AKT Signaling Pathway in the Early Stage of Myocardial Infarction

Myocardial infarction (MI), a type of coronary heart disease, has had a significantly increased incidence in recent years. The balance of cardiomyocyte apoptosis and autophagy after MI is one of the main determinants of patient prognosis. Both affect myocardial fibrosis and ventricular remodeling and regulate cell survival. However, there are few studies on the regulation mechanism of cardiomyocyte autophagy and apoptosis in the early stage after MI. In this study, based on analyzing the scRNA-seq and mRNA-seq data of mice in the early stage of MI, we found that the expression of S100a8 and S100a9 increased first and then decreased in the early stage of MI, and their expression level changed with the number of neutrophils. Further, through the functional enrichment analysis of the differentially expressed genes, we found that S100a8 and S100a9 were simultaneously associated with autophagy and apoptosis and could regulate autophagy and apoptosis of cardiomyocytes through MAPK or PI3K-AKT signaling pathways. This study provides valuable insights for clarifying the pathogenesis of early stage MI and improving its early treatment.

Trehalose ameliorates prodromal non-motor deficits and aberrant protein accumulation in a rotenone-induced mouse model of Parkinson's disease

Trehalose has been recently revealed as an attractive candidate to prevent and modify Parkinson's disease (PD) progression by regulating autophagy; however, studies have only focused on the reduction of motor symptoms rather than the modulation of disease course from prodromal stage. This study aimed to evaluate whether trehalose has a disease-modifying effect at the prodromal stage before the onset of a motor deficit in 8-week-old male C57BL/6 mice exposed to rotenone. We found significant decrease in tyrosine hydroxylase immunoreactivity in the substantia nigra and motor dysfunction after 2 weeks rotenone treatment. Mice exposed to rotenone for a week showed an accumulation of protein aggregates in the brain and prodromal non-motor deficits, such as depression and olfactory dysfunction, prior to motor deficits. Trehalose significantly improved olfactory dysfunction and depressive-like behaviors and markedly reduced α-synuclein and p62 deposition in the brain. Trehalose further ameliorated motor impairment and loss of nigral tyrosine hydroxylase-positive cells in rotenone-treated mice. We demonstrated that prodromal non-motor signs in a rotenone-induced PD mouse model are associated with protein aggregate accumulation in the brain and that an autophagy inducer could be valuable to prevent PD progression from prodromal stage by regulating abnormal protein accumulation.

Natural Bioactive Products and Alzheimer’s Disease Pathology: Lessons from Caenorhabditis elegans Transgenic Models

Alzheimer’s disease (AD) is an age-dependent, progressive disorder affecting millions of people. Currently, the therapeutics for AD only treat the symptoms. Although they have been used to discover new products of interest for this disease, mammalian models used to investigate the molecular determinants of this disease are often prohibitively expensive, time-consuming and very complex. On the other hand, cell cultures lack the organism complexity involved in AD. Given the highly conserved neurological pathways between mammals and invertebrates, Caenorhabditis elegans has emerged as a powerful tool for the investigation of the pathophysiology of human AD. Numerous models of both Tau- and Aβ-induced toxicity, the two prime components observed to correlate with AD pathology and the ease of performing RNA interference for any gene in the C. elegans genome, allow for the identification of multiple therapeutic targets. The effects of many natural products in main AD hallmarks using these models suggest promising health-promoting effects. However, the way in which they exert such effects is not entirely clear. One of the reasons is that various possible therapeutic targets have not been evaluated in many studies. The present review aims to explore shared therapeutical targets and the potential of each of them for AD treatment or prevention.

Mechanism of cell death pathways in status epilepticus and related therapeutic agents

The most severe form of epilepsy, status epilepticus (SE), causes brain damage and results in the development of recurring seizures. Currently, the management of SE remains a clinical challenge because patients do not respond adequately to conventional treatments. Evidence suggests that neural cell death worsens the occurrence and progression of SE. The main forms of cell death are apoptosis, necroptosis, pyroptosis, and ferroptosis. Herein, these mechanisms of neuronal death in relation to SE and the alleviation of SE by potential modulators that target neuronal death have been reviewed. An understanding of these pathways and their possible roles in SE may assist in the development of SE therapies and in the discovery of new agents.

Food bioactives lowering risks of chronic diseases induced by fine particulate air pollution: a comprehensive review

Airborne particulate matter (PM) exerts huge negative impacts on human health worldwide, not only targeting the respiratory system but more importantly inducing and aggravating associated chronic diseases like asthma, lung cancer, atherosclerosis, diabetes mellitus and Alzheimer diseases. Food-derived bioactive compounds like vitamins, dietary polyphenols, omega-3 polyunsaturated fatty acids and sulforaphane are feasible alternative therapeutic approaches against PM-mediated potential health damages, drawing great attention in recent years. In this review, the association between PM exposure and risks of developing chronic diseases, and the detailed mechanisms underlying the detrimental effects of PM will be discussed. Subsequently, principal food-derived bioactive compounds, with emphasize on the preventative or protective effects against PM, along with potential mechanisms will be elucidated. This comprehensive review will discuss and present current research findings to reveal the nutritional intervention as a preventative or therapeutic strategy against ambient air pollution, thereby lowering the risk of developing chronic diseases.

Why Senescent Cells Are Resistant to Apoptosis: An Insight for Senolytic Development

Cellular senescence is a process that leads to a state of irreversible cell growth arrest induced by a variety of intrinsic and extrinsic stresses. Senescent cells (SnCs) accumulate with age and have been implicated in various age-related diseases in part via expressing the senescence-associated secretory phenotype. Elimination of SnCs has the potential to delay aging, treat age-related diseases and extend healthspan. However, once cells becoming senescent, they are more resistant to apoptotic stimuli. Senolytics can selectively eliminate SnCs by targeting the SnC anti-apoptotic pathways (SCAPs). They have been developed as a novel pharmacological strategy to treat various age-related diseases. However, the heterogeneity of the SnCs indicates that SnCs depend on different proteins or pathways for their survival. Thus, a better understanding of the underlying mechanisms for apoptotic resistance of SnCs will provide new molecular targets for the development of cell-specific or broad-spectrum therapeutics to clear SnCs. In this review, we discussed the latest research progresses and challenge in senolytic development, described the significance of regulation of senescence and apoptosis in aging, and systematically summarized the SCAPs involved in the apoptotic resistance in SnCs.

The Yin and Yang dualistic features of autophagy in thermal burn wound healing

Burn healing should be regarded as a dynamic process consisting of two main, interrelated phases: (a) the inflammatory phase when neutrophils and monocytes infiltrate the injury site, through localized vasodilation and fluid extravasation, and (b) the proliferative-remodeling phase, which represents a key event in wound healing. In the skin, both canonical autophagy (induced by starvation, oxidative stress, and environmental aggressions) and non-canonical or selective autophagy have evolved to play a discrete, but, essential, “housekeeping” role, for homeostasis, immune tolerance, and survival. Experimental data supporting the pro-survival roles of autophagy, highlighting its Yang, luminous and positive feature of this complex but insufficient explored molecular pathway, have been reported. Autophagic cell death describes an “excessive” degradation of important cellular components that are necessary for normal cell function. This deadly molecular mechanism brings to light the darker, concealed, Yin feature of autophagy. Autophagy seems to perform dual, conflicting roles in the angiogenesis context, revealing once again, its Yin–Yang features. Autophagy with its Yin–Yang features remains the shadow player, able to decide quietly whether the cell survives or dies.

Nutritional interventions based on dietary restriction and nutrient reductions for the prevention of doxorubicin chemotherapy side effects

BACKGROUND: Doxorubicin (DOX) is one of most used chemotherapeutic drugs, but it has important adverse effects. Nutrition has a critical role to prevent or minimize chemotherapy side effects. Caloric and nutrient restriction has been widely studied in different health fields showing extensive beneficial effects. Given the importance of these interventions, it is expected that some of them have benefits in patients under DOX chemotherapy. OBJECTIVE: This review aimed to compile published studies evaluating the effects of different dietary intetrventions based on restriction of calories or certain nutrients against DOX-induced damage and toxicity. RESULTS: Caloric restriction and partial reduction of fat have shown to reduce DOX cardiotoxicity correlating with a reduction of oxidative stress. Reduction of dietary fat was proved to act in the same sense at liver and kidney. Studies in relation to protein reduction is more elevated has focused only on kidneys and bone, and under certain circumstances, these interventions could increase susceptibility to DOX toxicity. CONCLUSIONS: The promising effects of restriction of dietary fat, protein and sodium on differerent organs have been supported by a greater number of studies among all the dietary interventions evaluated. Still, clinical studies are necessary to confirm the potential usefulness of these interventions.

ERK inhibition in glioblastoma is associated with autophagy activation and tumorigenesis suppression

PURPOSE

Autophagy-dependent tumorigenic growth is one of the most commonly reported molecular mechanisms in glioblastoma (GBM) progression. However, the mechanistic correlation between autophagy and GBM is still largely unexplored, especially the roles of autophagy-related genes involved in GBM oncogenesis. In this study, we aimed to explore the genetic alterations that interact with both autophagic activity and GBM tumorigenesis, and to investigate the molecular mechanisms of autophagy involved in GBM cell death and survival.

METHOD

For this purpose, we systematically explored the alterations of autophagic molecules at the genome level in human GBM samples through deep RNA sequencing. The effect of genetic and pharmacologic inhibition of ERK on GBM growth in vitro and in vivo was researched. An image-based tracking analysis of LC3 using mCherry-eGFP-LC3 plasmid, and transmission electron microscopy were utilized to monitor autophagic flux. Immunoblot analysis was used to measure the related proteins.

RESULTS

MAPK ERK expression was identified as one of the most probable autophagy-related transcriptional responses during GBM growth. The genetic and pharmacologic inhibition of ERK in vivo and in vitro led to cell death, demonstrating its critical role for GBM proliferation and survival. To our surprise, autophagic activities were excessively activated and resulted in cytodestructive effects on GBM cells upon ERK inhibitor treatment. Furthermore, based on the observation of downregulation of mTOR signaling, we speculated the ERK inhibitor-induced GBM cells death might depend on mTOR-mediated pathway, leading to autophagy dysregulation. Accordingly, the in vivo and in vitro experiments revealed that the mTOR inhibitor rapamycin further increased cell mortality and exhibited enhanced antitumor effect on GBM cells when co-treated with the ERK inhibitor.

CONCLUSION

Our data creatively demonstrated that the autophagy-related regulator ERK maintains autophagic activity during GBM tumorigenesis via mTOR signaling pathway. The pharmacologic inhibition of both mTOR and ERK signaling exhibited synergistic therapeutic effect on GBM growth in vivo and in vitro, which has certain novelty and may provide a potential therapeutic approach for GBM treatment in the future.

Epigallocatechin-3-gallate pretreatment alleviates doxorubicin-induced ferroptosis and cardiotoxicity by upregulating AMPKα2 and activating adaptive autophagy

Reports indicate that the mechanism of doxorubicin (Dox)-induced cardiotoxicity is very complex, involving multiple regulatory cell death forms. Furthermore, the clinical intervention effect is not ideal. Iron dependence, abnormal lipid metabolism, and excess reactive oxygen species generation, three characteristics of ferroptosis, are potential therapeutic intervention targets. Here, we confirmed in vitro and in vivo that at least autophagy, apoptosis, and ferroptosis are involved in Dox cardiotoxicity-induced damage. When the neonatal rat cardiomyocytes and H9C2 cells or C57BL/6 mice were subjected to Dox-induced cardiotoxicity, epigallocatechin-3-gallate pretreatment could effectively decrease iron accumulation, inhibit oxidative stress and abnormal lipid metabolism, and thereby alleviate Dox cardiotoxicity-induced ferroptosis and protect the myocardium according to multiple functional, enzymatic, and morphological indices. The underlying mechanism was verified to involve the upregulation and activation of AMP-activated protein kinase α2, which promoted adaptive autophagy, increased energy supply, and maintained mitochondrial function. We believe that epigallocatechin-3-gallate is a candidate phytochemical against Dox-induced cardiotoxicity.

Identification and validation of an autophagy-related signature for predicting survival in lower-grade glioma

Abnormal levels of autophagy have been implicated in the pathogenesis of multiple diseases, including cancer. However, little is known about the role of autophagy-related genes (ARGs) in low-grade gliomas (LGG). Accordingly, the aims of this study were to assess the prognostic values of ARGs and to establish a genetic signature for LGG prognosis. Expression profile data from patients with and without primary LGG were obtained from The Cancer Genome Atlas (TCGA) and Genome Tissue Expression databases, respectively, and consensus clustering was used to identify clusters of patients with distinct prognoses. Nineteen differentially expressed ARGs were selected with threshold values of FDR < 0.05 and |log2 fold change (FC)| ≥ 2, and functional analysis revealed that these genes were associated with autophagy processes as expected. An autophagy-related signature was established using a Cox regression model of six ARGs that separated patients from TCGA training cohort into high- and low-risk groups. Univariate and multivariate Cox regression analysis indicated that the signature-based risk score was an independent prognostic factor. The signature was successfully validated using the TCGA testing, TCGA entire, and Chinese Glioma Genome Atlas cohorts. Stratified analyses demonstrated that the signature was associated with clinical features and prognosis, and gene set enrichment analysis revealed that autophagy- and cancer-related pathways were more enriched in high-risk patients than in low-risk patients. The prognostic value and expression of the six signature-related genes were also investigated. Thus, the present study constructed and validated an autophagy-related prognostic signature that could optimize individualized survival prediction in LGG patients.

Diabetes Mellitus and Periodontitis Share Intracellular Disorders as the Main Meeting Point

Diabetes and periodontitis are two of the most prevalent diseases worldwide that negatively impact the quality of life of the individual suffering from them. They are part of the chronic inflammatory disease group or, as recently mentioned, non-communicable diseases, with inflammation being the meeting point among them. Inflammation hitherto includes vascular and tissue changes, but new technologies provide data at the intracellular level that could explain how the cells respond to the aggression more clearly. This review aims to emphasize the molecular pathophysiological mechanisms in patients with type 2 diabetes mellitus and periodontitis, which are marked by different impaired central regulators including mitochondrial dysfunction, impaired immune system and autophagy pathways, oxidative stress, and the crosstalk between adenosine monophosphate-activated protein kinase (AMPK) and the renin-angiotensin system (RAS). All of them are the shared background behind both diseases that could explain its relationship. These should be taken in consideration if we would like to improve the treatment outcomes. Currently, the main treatment strategies in diabetes try to reduce glycemia index as the most important aspect, and in periodontitis try to reduce the presence of oral bacteria. We propose to add to the therapeutic guidelines the handling of all the intracellular disorders to try to obtain better treatment success.

Pharmacological Activation of Autophagy Restores Cellular Homeostasis in Ultraviolet-(B)-Induced Skin Photodamage

Ultraviolet (UV) exposure to the skin causes photo-damage and acts as the primary etiological agent in photo-carcinogenesis. UV-B exposure induces cellular damage and is the major factor challenging skin homeostasis. Autophagy allows the fundamental adaptation of cells to metabolic and oxidative stress. Cellular dysfunction has been observed in aged tissues and in toxic insults to cells undergoing stress. Conversely, promising anti-aging strategies aimed at inhibiting the mTOR pathway have been found to significantly improve the aging-related disorders. Recently, autophagy has been found to positively regulate skin homeostasis by enhancing DNA damage recognition. Here, we investigated the geno-protective roles of autophagy in UV-B-exposed primary human dermal fibroblasts (HDFs). We found that UV-B irradiation to HDFs impairs the autophagy response in a time- and intensity-independent manner. However, improving autophagy levels in HDFs with pharmacological activators regulates the UV-B-induced cellular stress by decreasing the induction of DNA photo-adducts, promoting the DNA repair process, alleviating oxidative and ER stress responses, and regulating the expression levels of key cell cycle regulatory proteins. Autophagy also prevents HDFs from UV-B-induced nuclear damage as is evident in TUNEL assay and Acridine Orange/Ethidium Bromide co-staining. Salubrinal (an eIF2α phosphatase inhibitor) relieves ER stress response in cells and also significantly alleviates DNA damage and promotes the repair process in UV-B-exposed HDFs. P62-silenced HDFs show enhanced DNA damage response and also disturb the tumor suppressor PTEN/pAKT signaling axis in UV-B-exposed HDFs whereas Atg7-silenced HDFs reveal an unexpected consequence by decreasing the UV-B-induced DNA damage. Taken together, these results suggest that interventional autophagy offers significant protection against UV-B radiation-induced photo-damage and holds great promise in devising it as a suitable therapeutic strategy against skin pathological disorders.

The Protein-Independent Role of Phosphate in the Progression of Chronic Kidney Disease

Several factors contribute to renal-function decline in CKD patients, and the role of phosphate content in the diet is still a matter of debate. This study aims to analyze the mechanism by which phosphate, independent of protein, is associated with the progression of CKD. Adult Munich-Wistar rats were submitted to 5/6 nephrectomy (Nx), fed with a low-protein diet, and divided into two groups. Only phosphate content (low phosphate, LoP, 0.2%; high phosphate, HiP, 0.95%) differentiated diets. After sixty days, biochemical parameters and kidney histology were analyzed. The HiP group presented worse renal function, with higher levels of PTH, FGF-23, and fractional excretion of phosphate. In the histological analysis of the kidney tissue, they also showed a higher percentage of interstitial fibrosis, expression of α-actin, PCNA, and renal infiltration by macrophages. The LoP group presented higher expression of beclin-1 in renal tubule cells, a marker of autophagic flux, when compared to the HiP group. Our findings highlight the action of phosphate in the induction of kidney interstitial inflammation and fibrosis, contributing to the progression of renal disease. A possible effect of phosphate on the dysregulation of the renal cell autophagy mechanism needs further investigation with clinical studies.

Platelet-Derived Growth Factor Regulates the Biological Behavior of Oral Mucosal Fibroblasts by Inducing Cell Autophagy and Its Mechanism

Objective

To explore the effect of platelet-derived growth factor (PDGF) on oral mucosal fibroblast autophagy and further elucidate the molecular mechanism by which PDGF-BB regulates the biological behavior of oral mucosal fibroblasts by inducing autophagy.

Methods

Primary oral mucosal fibroblasts were isolated and cultured by the tissue block and trypsin methods and identified by indirect immunofluorescence vimentin detection. We detected the autophagy marker Beclin-1 and fibrosis marker Col-I of the primary oral mucosal fibroblasts at different time points after stimulating the fibroblasts with different PDGF-BB concentrations by Western blotting and determined the best experimental concentration and stimulation time of PDGF-BB. Then, indirect immunofluorescence, Western blotting, and quantitative real-time polymerase chain reaction (PCR) were used to detect the effect of PDGF-BB on the expression of autophagy-related and fibrotic proteins before and after 3-methyladenine (3-MA) intervention. Additionally, the effect of 3-MA on the proliferation and migration of primary oral mucosal fibroblasts stimulated by PDGF-BB was detected by the MTT method and a scratch experiment. The effect of PDGF-BB on Beclin-1 and phosphatidylinositol-3 kinase class 3 (PI3KC3) interaction was detected by co-immunoprecipitation.

Results

The results demonstrated that PDGF-BB could induce autophagy of the oral mucosal fibroblasts, showing a certain time and dose correlation. It induced cell autophagy through Beclin-1 and PI3KC3 interaction to promote the proliferation, migration, conversion, and collagen synthesis of the fibroblasts. However, 3-MA inhibited the combination of Beclin-1 and PI3KC3 and weakened the fibroblasts' proliferation, migration, conversion, and collagen synthesis activities.

Conclusion

Overall, PDGF-BB induces autophagy through the Beclin-1 pathway to regulate the biological behavior of oral mucosal fibroblasts.

Mitophagy and apoptosis mediated by ROS participate in AlCl3-induced MC3T3-E1 cell dysfunction

Aluminum (Al), as a common environmental pollutant, causes osteoblast (OB) dysfunction and then leads to Al-related bone diseases (ARBD). One of the mechanisms of ARBD is oxidative stress, which leads to an increase in the production of reactive oxygen species (ROS). ROS can induce mitochondrial damage, thereby inducing mitophagy and apoptosis. But whether mitophagy and apoptosis mediated by ROS, and the role of ROS in AlCl₃-induced MC3T3-E1 cell dysfunction is still unclear. In this study, MC3T3-E1 cells used 0 mM Al (control group), 2 mM Al (Al group), 5 mM N-acetyl cysteine (NAC) (NAC group), 2 mM Al and 5 mM NAC (Al + NAC group) for 24 h. We found AlCl₃-induced MC3T3-E1 cell dysfunction accompanied by oxidative stress, apoptosis, and mitophagy. While NAC, a ROS scavenger treatment, restored cell function and alleviated the mitophagy and apoptosis. These results suggested that mitophagy and apoptosis mediated by ROS participate in AlCl₃-induced MC3T3-E1 cell dysfunction.

The neuroprotective effects of polyphenols, their role in innate immunity and the interplay with the microbiota

Neurodegenerative disorders, particularly in the elderly population, represent one of the most pressing social and health-care problems in the world. Besides the well-established role of both oxidative stress and inflammation, alterations of the immune response have been found to be closely linked to the development of neurodegenerative diseases. Interestingly, various scientific evidence reported that an altered gut microbiota composition may contribute to the development of neuroinflammatory disorders. This leads to the proposal of the concept of the gut-brain-immune axis. In this scenario, polyphenols play a pivotal role due to their ability to exert neuroprotective, immunomodulatory and microbiota-remodeling activities. In the present review, we summarized the available literature to provide a scientific evidence regarding this neuroprotective and immunomodulatory effects and the interaction with gut microbiota of polyphenols and, the main signaling pathways involved that can explain their potential therapeutic application in neurodegenerative diseases.

Molecular Interactions between Dietary Lipids and Bone Tissue during Aging

Age-related bone disorders such as osteoporosis or osteoarthritis are a major public health problem due to the functional disability for millions of people worldwide. Furthermore, fractures are associated with a higher degree of morbidity and mortality in the long term, which generates greater financial and health costs. As the world population becomes older, the incidence of this type of disease increases and this effect seems notably greater in those countries that present a more westernized lifestyle. Thus, increased efforts are directed toward reducing risks that need to focus not only on the prevention of bone diseases, but also on the treatment of persons already afflicted. Evidence is accumulating that dietary lipids play an important role in bone health which results relevant to develop effective interventions for prevent bone diseases or alterations, especially in the elderly segment of the population. This review focuses on evidence about the effects of dietary lipids on bone health and describes possible mechanisms to explain how lipids act on bone metabolism during aging. Little work, however, has been accomplished in humans, so this is a challenge for future research.

Polyphenol Supplementation Reverses Age-Related Changes in Microglial Signaling Cascades

Microglial activity in the aging neuroimmune system is a central player in aging-related dysfunction. Aging alters microglial function via shifts in protein signaling cascades. These shifts can propagate neurodegenerative pathology. Therapeutics require a multifaceted approach to understand and address the stochastic nature of this process. Polyphenols offer one such means of rectifying age-related decline. Our group used mass spectrometry (MS) analysis to explicate the complex nature of these aging microglial pathways. In our first experiment, we compared primary microglia isolated from young and aged rats and identified 197 significantly differentially expressed proteins between these groups. Then, we performed bioinformatic analysis to explore differences in canonical signaling cascades related to microglial homeostasis and function with age. In a second experiment, we investigated changes to these pathways in aged animals after 30-day dietary supplementation with NT-020, which is a blend of polyphenols. We identified 144 differentially expressed proteins between the NT-020 group and the control diet group via MS analysis. Bioinformatic analysis predicted an NT-020 driven reversal in the upregulation of age-related canonical pathways that control inflammation, cellular metabolism, and proteostasis. Our results highlight salient aspects of microglial aging at the level of protein interactions and demonstrate a potential role of polyphenols as therapeutics for age-associated dysfunction.

Fibrosis: Sirtuins at the checkpoints of myofibroblast differentiation and profibrotic activity

Fibrotic diseases are still a serious concern for public health, due to their high prevalence, complex etiology and lack of successful treatments. Fibrosis consists of excessive accumulation of extracellular matrix components. As a result, the structure and function of tissues are impaired, thus potentially leading to organ failure and death in several chronic diseases. Myofibroblasts represent the principal cellular mediators of fibrosis, due to their extracellular matrix producing activity, and originate from different types of precursor cells, such as mesenchymal cells, epithelial cells and fibroblasts. Profibrotic activation of myofibroblasts can be triggered by a variety of mechanisms, including the transforming growth factor-β signalling pathway, which is a major factor driving fibrosis. Interestingly, preclinical and clinical studies showed that fibrotic degeneration can stop and even reverse by using specific antifibrotic treatments. Increasing scientific evidence is being accumulated about the role of sirtuins in modulating the molecular pathways responsible for the onset and development of fibrotic diseases. Sirtuins are NAD⁺ -dependent protein deacetylases that play a crucial role in several molecular pathways within the cells, many of which at the crossroad between health and disease. In this context, we will report the current knowledge supporting the role of sirtuins in the balance between healthy and diseased myofibroblast activity. In particular, we will address the signalling pathways and the molecular targets that trigger the differentiation and profibrotic activation of myofibroblasts and can be modulated by sirtuins.

High glucose suppresses autophagy through the AMPK pathway while it induces autophagy via oxidative stress in chondrocytes

Diabetes (DB) is a risk factor for osteoarthritis progression. High glucose (HG) is one of the key pathological features of DB and has been demonstrated to induce apoptosis and senescence in chondrocytes. Autophagy is an endogenous mechanism that can protect cells against apoptosis and senescence. The effects of HG on autophagy in cells including chondrocytes have been studied; however, the results have been inconsistent. The current study aimed to elucidate the underlying mechanisms, which could be associated with the contrasting outcomes. The present study revealed that HG can induce apoptosis and senescence in chondrocytes, in addition to regulating autophagy dynamically. The present study demonstrated that HG can cause oxidative stress in chondrocytes and suppress the AMPK pathway in a dose-dependent manner. Elimination of oxidative stress by Acetylcysteine, also called N-acetyl cysteine (NAC), downregulated autophagy and alleviated HG-stimulated apoptosis and senescence, while activation of the AMPK signaling pathway by AICAR not only upregulated autophagy but also alleviated HG-stimulated apoptosis and senescence. A combined treatment of NAC and AICAR was superior to treatment with either NAC or AICAR. The study has demonstrated that HG can suppress autophagy through the AMPK pathway and induce autophagy via oxidative stress in chondrocytes.

Evidence supporting beneficial effects of virgin olive oil compared to sunflower and fish oils from the point of view of aging and longevity

Diet plays a central role in aging and in the prevention of age-related diseases. Specifically, dietary lipids have influence on processes like oxidative stress or inflammation. This review summarizes and compares the effects of lifelong feeding on three different fat sources, namely virgin olive oil, sunflower oil or fish oil (which differ in fatty acid profile and minor components content) in the pancreas, liver, alveolar bone and femur of old rats. Also, effects on longevity and causes of death are summarized. Animals fed on virgin olive oil had a lower number of β cells and insulin content in the pancreas, less liver fibrosis, less loss of alveolar bone, and greater bone mass density in the femur. In general, the markers of oxidative damage at the liver, pancreatic, gingival and systemic levels were also lower in animals fed on virgin olive oil compared to those treated with sunflower or fish oil. Finally, although the animals died from similar causes regardless of the experimental group, virgin olive oil increased lifespan compared to sunflower oil. Therefore, it is evidenced the chance to modulate the effects of the physiological aging process by diet and, more specifically, by dietary fat.

Positively Correlated CD47 Activation and Autophagy in Umbilical Cord Blood-Derived Mesenchymal Stem Cells during Senescence

Autophagy plays a critical role in stem cell maintenance and is related to cell growth and cellular senescence. It is important to find a quality-control marker for predicting senescent cells. This study verified that CD47 could be a candidate to select efficient mesenchymal stem cells (MSCs) to enhance the therapeutic effects of stem cell therapy by analyzing the antibody surface array. CD47 expression was significantly decreased during the expansion of MSCs in vitro (p < 0.01), with decreased CD47 expression correlated with accelerated senescence phenotype, which affected cell growth. UCB-MSCs transfected with CD47 siRNA significantly triggered the downregulation of pRB and upregulation of pp38, which are senescence-related markers. Additionally, autophagy-related markers, ATG5, ATG12, Beclin1, and LC3B, revealed significant downregulation with CD47 siRNA transfection. Furthermore, autophagy flux following treatment with an autophagy inducer, rapamycin, has shown that CD47 is a key player in autophagy and senescence to maintain and regulate the growth of MSCs, suggesting that CD47 may be a critical key marker for the selection of effective stem cells in cell therapy.

p75NTR silencing inhibits proliferation, migration, and extracellular matrix deposition of hypertrophic scar fibroblasts by activating autophagy through inhibiting the PI3K/Akt/mTOR pathway

Hypertrophic scar (HS) results from abnormal wound healing, accompanied by excessive hypercellularity, migration, and extracellular matrix (ECM) deposition. Autophagy dysregulation plays crucial roles during HS formation. The overexpressed p75 neurotrophin receptor (p75NTR) in injured skin tissue after wound healing becomes a factor aggravating scar. This study was designed to investigate the role of p75NTR and p75NTR-mediated autophagy in the process of HS. The results revealed that p75NTR expression was significantly upregulated while that of autophagy proteins was downregulated in cicatrix at 3 and 6 months after a burn, which was recovered at 12 months. p75NTR silencing inhibited proliferation, migration, and ECM deposition of hypertrophic scar fibroblasts (HSF), whereas p75NTR overexpression presented the opposite results. Silencing of p75NTR reduced the expression of PI3K/Akt/mTOR signaling molecules while enhancing that of autophagy proteins. Importantly, PI3K agonist (IGF-1) intervention notably decreased the levels of LC3B II/I and Beclin-1 and restored the inhibitory effects of p75NTR silencing on proliferation, migration, and ECM deposition of HSF. Concurrently, autophagy inhibitor 3-methyladenine (3-MA) treatment exhibited the same variation trends with IGF-1. Taken together, these findings demonstrated that p75NTR silencing inhibits proliferation, migration, and ECM deposition of HSF by activating autophagy by inhibiting the PI3K/Akt/mTOR pathway.

The mechanisms and reversal strategies of tumor radioresistance in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is one of most lethal malignancies with high aggressive potential in the world. Radiotherapy is used as one curative treatment modality for ESCC patients. Due to radioresistance, the 5-year survival rates of patients after radiotherapy is less than 20%. Tumor radioresistance is very complex and heterogeneous. Cancer-associated fibroblasts (CAFs), as one major component of tumor microenvironment (TME), play critical roles in regulating tumor radioresponse through multiple mechanisms and are increasingly considered as important anti-cancer targets. Cancer stemness, which renders cancer cells to be extremely resistant to conventional therapies, is involved in ESCC radioresistance due to the activation of Wnt/β-catenin, Notch, Hedgehog and Hippo (HH) pathways, or the induction of epithelial-mesenchymal transition (EMT), hypoxia and autophagy. Non-protein-coding RNAs (ncRNAs), which account for more than 90% of the genome, are involved in esophageal cancer initiation and progression through regulating the activation or inactivation of downstream signaling pathways and the expressions of target genes. Herein, we mainly reviewed the role of CAFs, cancer stemness, non-coding RNAs as well as others in the development of radioresistance and clarify the involved mechanisms. Furthermore, we summarized the potential strategies which were reported to reverse radioresistance in ESCC. Together, this review gives a systematic coverage of radioresistance mechanisms and reversal strategies and contributes to better understanding of tumor radioresistance for the exploitation of novel intervention strategies in ESCC.

Construction autophagy-related prognostic risk signature to facilitate survival prediction, individual treatment and biomarker excavation of epithelial ovarian cancer patients

Background

Existing clinical methods for prognosis evaluating for Epithelial Ovarian Cancer (EOC) patients had defects of invasive, unsystematic and subjective and little data are available for individualizing treatment, therefore, to identify potential prognostic markers and new therapeutic targets for EOC is urgently required.

Results

Expression of 232 autophagy-related genes (ARGs) in 354 EOC and 56 human ovarian surface epithelial specimens from 7 independent laboratories were analyzed, 31 mRNAs were identified as DEARGs. We did functional and pathway enrichment analysis and constructed protein–protein interaction network for all DEARGs. To screen out candidate DEARGs related to EOC patients’ survival and construct an autophagy-related prognostic risk signature, univariate and multivariate Cox proportional hazards models were established separately. Finally, 5 optimal independent prognostic DEARGs (PEX3, DNAJB9, RB1, HSP90AB1 and CXCR4) were confirmed and the autophagy-related risk model was established by the 5 prognostic DEARGs. The accuracy and robustness of the prognostic risk model for survival prediction were evaluated and verified by analyzing the correlation between EOC patients’ survival status, clinicopathological features and risk scores.

Conclusions

The autophagy-related prognostic risk model can be independently used to predict overall survival in EOC patients, it can also potentially assist in individualizing treatment and biomarker development.