The beclin 1 interactome: Modification and roles in the pathology of autophagy-related disorders

Impact of IRGM gene promoter polymorphisms on susceptibility to chronic HBV infection

The autophagy gene immunity-related GTPase M (IRGM) can affect the immune response against intracellular pathogens. The study was performed to determine any possible association between three IRGM single-nucleotide polymorphisms (SNPs) (rs4958842, rs4958843 and rs4958846) and chronic hepatitis B virus (HBV) infection. A total of 171 chronic HBV-infected individuals and 171 healthy controls were collected. Peripheral blood cells and Sanger sequencing were used to extract genomic DNA and determine the SNP genotypes, respectively. The C allele of rs4958843 is a risk factor for chronic HBV infection in various genetic models, including allelic, codominant and dominant models, with the following respective statistical data: allelic (T vs. C: OR = 1.371, 95% CI = 1.009-1.863, p = .043), codominant (TT vs. CC: OR = 2.137, 95% CI = 1.104-4.138, p = .024) and dominant (TT + TC vs. CC: OR = 1.976, 95% CI = 1.106-3.533, p = .021) models. The genotype and allele distributions of rs4958842 and rs4958846 showed no significant differences between chronic HBV infection patients and healthy controls. IRGM rs4958843 CC genotype carriers had significantly elevated values of alanine transaminase, aspartate transaminase alpha-fetoprotein and total bilirubin (OR = 3.467, 95%CI = 1.167-10.298), which was positively associated with the disease progression of HBV infection. Mutant allele C of IRGM rs4958843 polymorphism is associated with the risk of chronic HBV infection in the Han people in central China and contributes to the disease progression.

An artificial-restriction fragment length polymorphism (A-RFLP) method for genotyping intronic SNP rs7587633 C/T of ATG16L1

SNPs could either cause a disorder or directly alter the efficacy of a particular treatment and act as biological markers. The SNP rs7587633 C/T present in the intronic region of the ATG16L1 gene has been studied for its role in psoriasis vulgaris and Palmoplantar pustulosis. To genotype rs7587633 C/T using PCR-RFLP no restriction site is present for any of the restriction enzymes at the SNP position. To develop an artificial-RFLP method for genotyping rs7587633 C/T, the forward primer was designed in such a way that it resulted in the creation of an EcoRI restriction site in the amplified product which could further be digested with EcoRI to find the genotype of the individual. The newly developed A-RFLP method was applied to genotype the SNP rs7587633 C/T in DNA samples of 100 healthy control individuals. The allelic and genotypic frequencies of the SNPs were 0.80(C), 0.20(T) and 65%(CC), 31%(CT) and 4%(TT), respectively. In conclusion, we developed an A-RFLP method to genotype the SNP rs7587633 C/T which is not present in any of the natural restriction sites and this method could be applied to genotype this SNP in various populations/diseases to find its role.

Autosis: a new form of cell death in myocardial ischemia-reperfusion injury

Cardiomyocytes undergo a variety of cell death events during myocardial ischemia‒reperfusion injury (MIRI). Understanding the causes of cardiomyocyte mortality is critical for the prevention and treatment of MIRI. Among the various types of cell death, autosis is a recently identified type of autophagic cell death with distinct morphological and chemical characteristics. Autosis can be attenuated by autophagy inhibitors but not reversed by apoptosis or necrosis inhibitors. In recent years, it has been shown that during the late phase of reperfusion, autosis is activated, which exacerbates myocardial injury. This article describes the characteristics of autosis, autophagic cell death, and the relationship between autophagic cell death and autosis; reviews the mechanism of autosis in MIRI; and discusses its clinical significance.

Mutagenic primer-based novel multiplex PCR-RFLP technique to genotype BECN1 SNPs rs10512488 and rs11552192

BACKGROUND

Single Nucleotide Polymorphisms (SNPs) in candidate autophagy gene BECN1 could influence its functions thereby autophagy process. BECN1 noncoding SNPs were found to be significantly associated with neurodegenerative disease and type 2 diabetes mellitus. This study aimed to develop a simultaneous genotyping technique for two BECN1 SNPs (rs10512488 and rs11552192).

METHODS

A mutagenic primer-based approach was used to introduce a NdeI restriction site to genotype rs10512488 by Artificial-Restriction Fragment Length Polymorphism (A-RFLP) along with rs11552192 by Polymerase Chain Reaction (PCR)-RFLP. Multiplexing PCR and restriction digestion reactions were set up for simultaneous genotyping of both SNPs in 100 healthy individuals. Genotypic and allele frequencies were manually calculated, and the Hardy-Weinberg Equilibrium was assessed using the chi-square test.

RESULTS

We successfully developed PCR and RFLP conditions for the amplification and restriction digestion of both SNPs within the same tube for genotyping. The results of genotyping by newly developed multiplexing PCR-RFLP technique were concordant with the genotypes obtained by Sanger sequencing of samples. Allelic frequencies of rs10512488 obtained were 0.15 (A) and 0.85 (G), whereas allelic frequencies of rs11552192 were 0.16 (T) and 0.84 (A).

CONCLUSION

The newly developed technique is rapid, cost-effective and time-saving for large-scale applications compared to sequencing methods and would play an important role in low-income settings. For the first time, allelic frequencies of rs10512488 and rs11552192 were reported among the North Indian population.

Jingfang Granule mitigates Coxsackievirus B3-induced myocardial damage by modulating mucolipin 1 expression

ETHNOPHARMACOLOGICAL RELEVANCE

Jingfang Granules (JFG) originate from the traditional herbal formula Jingfang Baidu powder. It has the effects of inducing sweating and dispelling wind. It is a classic medication used for treating external pathogenic factors and viral diseases. However, the therapeutic mechanism of JFG for viral myocarditis needs further clarification.

AIM OF THE STUDY

This study aimed to explore the therapeutic efficacy of JFG on coxsackievirus B3-induced viral myocarditis (VMC), along with the elucidation of its underlying mechanisms.

MATERIALS AND METHODS

C57 BL/6JNifdc mice were divided randomly into several groups: control, model, Jingfang Granule groups (0.23, 0.46, and 0.69 g/20g, respectively), and a positive group (oseltamivir, 19.33 mg/kg). Following the establishment of the VMC model, the mice underwent an 8 -week treatment regimen. Pathological alterations in cardiac tissues and inflammatory protein expression were monitored. Differential gene analysis was conducted utilizing transcriptomic techniques. The differential gene mucolipin 1 (Mcoln1) was knocked down by transfection with siRNA in H9C2 cell, and investigative techniques such as immunoblotting, qRT-PCR, immunofluorescence, JC-1 staining, reactive oxygen species (ROS) detection, and mitochondrial stress testing were employed to examine its mechanism of action.

RESULTS

JFG significantly mitigates the pathological damage observed in the cardiac tissues of CVB3-induced VMC mice and attenuates the expression of inflammatory genes. Subsequently, differentially expressed genes are identified through transcriptomic analysis and validated via PCR. Among these, the upregulation of Mcoln1 promotes autophagy, facilitating the clearance of damaged mitochondria and excessive ROS. This has been substantiated through in vitro experiments. Excessive ROS precipitates a reduction in mitochondrial membrane potential, instigating cell apoptosis. In accordance with TUNEL staining results, JFG acts to inhibit cell apoptosis. To ascertain whether Mcoln1 is a crucial target for JFG in treating VMC, Mcoln1 was suppressed in H9C2 cells. The suppression of Mcoln1 hinders the elevation in autophagy levels post-JFG treatment, obstructs the enhancement of mitochondrial function, and impedes the clearance of ROS. Furthermore, the inhibitory effect of JFG on cell apoptosis is attenuated.

CONCLUSION

The research findings indicate that JFG has a protective effect on CVB3-induced H9C2 cell injury. JFG may exert its effects in VMC treatment by enhancing autophagy to suppress cell apoptosis through the mitochondrial pathway, thereby counteracting cell damage.

Natural compounds target programmed cell death (PCD) signaling mechanism to treat ulcerative colitis: a review

Ulcerative colitis (UC) is a nonspecific inflammatory bowel disease characterized by abdominal pain, bloody diarrhea, weight loss, and colon shortening. However, UC is difficult to cure due to its high drug resistance rate and easy recurrence. Moreover, long-term inflammation and increased disease severity can lead to the development of colon cancer in some patients. Programmed cell death (PCD) is a gene-regulated cell death process that includes apoptosis, autophagy, necroptosis, ferroptosis, and pyroptosis. PCD plays a crucial role in maintaining body homeostasis and the development of organs and tissues. Abnormal PCD signaling is observed in the pathological process of UC, such as activating the apoptosis signaling pathway to promote the progression of UC. Targeting PCD may be a therapeutic strategy, and natural compounds have shown great potential in modulating key targets of PCD to treat UC. For instance, baicalin can regulate cell apoptosis to alleviate inflammatory infiltration and pathological damage. This review focuses on the specific expression of PCD and its interaction with multiple signaling pathways, such as NF-κB, Nrf2, MAPK, JAK/STAT, PI3K/AKT, NLRP3, GPX4, Bcl-2, etc., to elucidate the role of natural compounds in targeting PCD for the treatment of UC. This review used (ulcerative colitis) (programmed cell death) and (natural products) as keywords to search the related studies in PubMed and the Web of Science, and CNKI database of the past 10 years. This work retrieved 72 studies (65 from the past 5 years and 7 from the past 10 years), which aims to provide new treatment strategies for UC patients and serves as a foundation for the development of new drugs.

Zearalenone Promotes Uterine Hypertrophy through AMPK/mTOR Mediated Autophagy

Zearalenone (ZEN), a non-steroidal Fusarium graminearum with an estrogen effect, can cause damage to the gastrointestinal tract, immune organs, liver, and reproductive system. Further analysis of the mechanism of ZEN has become an important scientific issue. We have established in vivo and in vitro models of ZEN intervention, used AMPK/mTOR as a targeted pathway for ZEN reproductive toxicity, and explored the molecular mechanism by which ZEN may induce uterine hypertrophy in weaned piglets. Our study strongly suggested that ZEN can activate the phosphorylation of AMPK in uterine endometrial epithelium cells, affect the phosphorylation level of mTOR through TSC2 and Rheb, induce autophagy, upregulate the expression of proliferative genes PCNA and BCL2, downregulate the expression of apoptotic gene BAX, promote uterine endometrial epithelium cells proliferation, and ultimately lead to thickening of the endometrial and myometrium, increased density of uterine glands, and induce uterine hypertrophy.

Low-molar-mass oat beta-glucan impacts autophagy and apoptosis in early stages of induced colorectal carcinogenesis in rats

Oat beta-glucan is one of the soluble dietary fibre fractions with a wide spectrum of biological activities such as anti-inflammatory and anti-tumour properties. In the present study, the effect of low-molar-mass oat beta-glucan isolate (OβGl) on the level of autophagy and apoptosis in the colorectum of rats with induced early stages of colorectal cancer was investigated. Forty-five male Sprague-Dawley rats were divided into two main groups: control and azoxymethane-induced early-stage colorectal carcinogenesis (CRC). Both groups were divided into three dietary subgroups fed standard feed without OβGl (OβGl-), with 1 % of OβGl (OβGl+1 %) or with 3 % of OβGl (OβGl+3 %). The expression of autophagy (LC3B, beclin-1) and apoptosis (caspase-3, cleaved caspase-3, BAX, BCL-2 and PARP-1) markers was determined by immunohistochemistry, Western blot and PCR analysis. The obtained results showed that the expression of LC3B, caspase-3 and cleaved caspase-3 in the CRC mucosa, and LC3B-II expression in the CRC wall were higher in the OβGl+3 % compared to the OβGl- rats. A higher BAX/BCL-2 ratio was also observed in the CRC OβGl+1 % rats compared to the other CRC animals. In summary, OβGl+3 % has a modulatory effect, stimulating autophagy and the extrinsic apoptosis pathway, while OβGl+1 % has a stimulatory effect on the intrinsic apoptosis pathway.

AutophagyNet: high-resolution data source for the analysis of autophagy and its regulation

Macroautophagy/autophagy is a highly-conserved catabolic procss eliminating dysfunctional cellular components and invading pathogens. Autophagy malfunction contributes to disorders such as cancer, neurodegenerative and inflammatory diseases. Understanding autophagy regulation in health and disease has been the focus of the last decades. We previously provided an integrated database for autophagy research, the Autophagy Regulatory Network (ARN). For the last eight years, this resource has been used by thousands of users. Here, we present a new and upgraded resource, AutophagyNet. It builds on the previous database but contains major improvements to address user feedback and novel needs due to the advancement in omics data availability. AutophagyNet contains updated interaction curation and integration of over 280,000 experimentally verified interactions between core autophagy proteins and their protein, transcriptional and post-transcriptional regulators as well as their potential upstream pathway connections. AutophagyNet provides annotations for each core protein about their role: 1) in different types of autophagy (mitophagy, xenophagy, etc.); 2) in distinct stages of autophagy (initiation, expansion, termination, etc.); 3) with subcellular and tissue-specific localization. These annotations can be used to filter the dataset, providing customizable download options tailored to the user's needs. The resource is available in various file formats (e.g. CSV, BioPAX and PSI-MI), and data can be analyzed and visualized directly in Cytoscape. The multi-layered regulation of autophagy can be analyzed by combining AutophagyNet with tissue- or cell type-specific (multi-)omics datasets (e.g. transcriptomic or proteomic data). The resource is publicly accessible at http://autophagynet.org.Abbreviations: ARN: Autophagy Regulatory Network; ATG: autophagy related; BCR: B cell receptor pathway; BECN1: beclin 1; GABARAP: GABA type A receptor-associated protein; IIP: innate immune pathway; LIR: LC3-interacting region; lncRNA: long non-coding RNA; MAP1LC3B: microtubule associated protein 1 light chain 3 beta; miRNA: microRNA; NHR: nuclear hormone receptor; PTM: post-translational modification; RTK: receptor tyrosine kinase; TCR: T cell receptor; TLR: toll like receptor.

β-asarone improves cognitive impairment and alleviates autophagy in mice with vascular dementia via the cAMP/PKA/CREB pathway

BACKGROUND

Vascular dementia (VD) is the second most common type of dementia after Alzheimer's disease. β-asarone, a major component of Acorus tatarinowii Schott, is important in neurodegenerative and neurovascular diseases. Studies have confirmed that β-asarone can mitigate autophagy and reduce damage in hypoxic cells. We also reported that β-asarone improves learning and memory. This study further clarifies whether β-asarone attenuates cerebral ischaemic injury by acting through the cAMP/PKA/CREB pathway in VD model mice.

METHODS

Here, genes and potential pathways that may be targeted by β-asarone for the treatment of transient cerebral ischaemia (TCI) and cognitive impairment (CI) were obtained using network pharmacology. The two-vessel occlusion method was used to establish the VD model. The Morris water maze test was used to evaluate the effects on memory. Then, the protein levels of mitofusin-2 (Mfn2), brain-derived neurotrophic factor (BDNF), optic atrophy 1 (OPA1), cyclic adenosine monophosphate (cAMP), myelin basic protein (MBP), matrix metalloproteinase-9 (MMP9) and neuron specific enolase (NSE) were determined by ELISA. The levels of superoxide dismutase (SOD) and malonaldehyde (MDA) were measured using commercial kits. Then, qRT-PCR was employed to investigate the expression of the candidate genes screened from the protein-protein interaction (PPI) network. Furthermore, the expression of the autophagy-related proteins Beclin-1, (microtubule-associated protein light chain 3) LC3, p62, postsynaptic density protein 95 (PSD95), protein kinase A (PKA), pPKA, cyclic-AMP response binding protein (CREB), and pCREB was determined by western blotting. The expression of autophagy-related proteins, PSD95 and translocase of outer mitochondrial membrane 20 (TOM20) was determined by immunofluorescence analyses.

RESULTS

The network pharmacological analysis showed 234 targets related to β-asarone, 1,118 genes related to TCI and 2,039 genes associated with CI. Our results confirm that β-asarone treatment not only alleviated brain damage in the VD model by improving mitochondrial and synaptic function, reducing neuronal injury and upregulating the expression of antioxidants but also effectively improved the cognitive behaviour of VD model mice. Moreover, β-asarone downregulated VD-induced RELA and CCND1 mRNA expression. In addition, we validated that β-asarone increased the phosphorylation of PKA and CREB and upregulated cAMP protein expression. The results showed that the cAMP/PKA/CREB signalling pathway was upregulated. Moreover, β-asarone administration decreased the protein expression levels of Beclin-1 and LC3 and increased the expression levels of p62 in VD model mice.

CONCLUSIONS

β-asarone inhibits Beclin-1-dependent autophagy and upregulates the cAMP/PKA/CREB signalling pathway to attenuate mitochondrial and synaptic damage from cerebral ischaemia and improve learning and cognitive abilities in VD model mice.

Autophagy Gene BECN1 Intronic Variant rs9890617 Predisposes Individuals to Hepatitis B Virus Infection

Beclin 1 protein encoded by the BECN1 gene plays a critical role in the autophagy pathway which is utilized by the Hepatitis B virus (HBV) for its replication. HBV is known for the subversion of the host's autophagy process for its multiplication. The aim of this study was to determine the role of BECN1 intronic variants in HBV susceptibility. Intronic region variant rs9890617 was analyzed using Human splicing finder v3.1 and was found to alter splicing signals. A total of 712 individuals (494 HBV infected and 218 healthy controls) were recruited in the study and genotyped by applying Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP). Statistical analysis revealed that the mutant allele T of rs9890617 was significantly associated with the overall disease risk in the allelic model (OR 1.41; 95%CI 1.00-1.99, p = 0.04). On stratifying the data based on the different stages of HBV infection, the mutant genotype showed a significant association with the chronic group in allelic (OR 1.62; 95%CI 1.11-2.39, p = 0.01), dominant (OR 1.64; 95%CI 1.07-2.52, p = 0.02), and co-dominant (OR 1.55; 95%CI 1.00-2.40, p = 0.04) models. Overall, this is the first study regarding beclin 1 variant rs9890617 and we found a significant association of the mutant T allele with the genetic predisposition to HBV infection.

Fluorofenidone Attenuates Renal Interstitial Fibrosis by Enhancing Autophagy and Retaining Mitochondrial Function

BACKGROUND

Fluorofenidone (AKF-PD) is a novel pyridone agent and has potent anti-NLRP3 inflammasome and anti-fibrotic activities. However, the mechanisms underlying its pharmacological actions are not fully understood.

METHODS

A renal fibrosis rat model was established by the unilateral ureteral obstruction (UUO) procedure and the rats were randomized and treated with, or without, AKF-PD for 3 and 7 days. The levels of renal fibrosis, NLRP3 inflammasome activation, mitochondrial function, and autophagy were tested in rat kidney tissues. Macrophages following lipopolysaccharides (LPS) and adenosine 5'-triphosphate (ATP) stimulation were examined by Western blot, spectrophotometry, and TEM.

RESULTS

Compared with the untreated UUO rats, AKF-PD treatment significantly mitigated the UUO procedure-induced renal fibrosis in rats. AKF-PD treatment decreased mitochondrial dysfunction and IL-Iβ and caspase-1 expression in rat kidney tissues and reduced mitochondrial reactive oxygen species production in activated macrophages. Mechanistically, AKF-PD treatment significantly attenuated the PI3K/AKT/mTOR signaling, increased Beclin-1 and LC3 II expression and autophagosome formation, and ameliorated the mitochondrial damage in renal tissues and activated macrophages.

CONCLUSION

The results indicated that AKF-PD treatment inhibited renal interstitial fibrosis by regulating the autophagy-mitochondria-NLRP3 inflammasome pathway.

Targeting autophagy and beyond: Deconvoluting the complexity of Beclin-1 from biological function to cancer therapy

Beclin-1 is the firstly-identified mammalian protein of the autophagy machinery, which functions as a molecular scaffold for the assembly of PI3KC3 (class III phosphatidylinositol 3 kinase) complex, thus controlling autophagy induction and other cellular trafficking events. Notably, there is mounting evidence establishing the implications of Beclin-1 in diverse tumorigenesis processes, including tumor suppression and progression as well as resistance to cancer therapeutics and CSC (cancer stem-like cell) maintenance. More importantly, Beclin-1 has been confirmed as a potential target for the treatment of multiple cancers. In this review, we provide a comprehensive survey of the structure, functions, and regulations of Beclin-1, and we discuss recent advances in understanding the controversial roles of Beclin-1 in oncology. Moreover, we focus on summarizing the targeted Beclin-1-regulating strategies in cancer therapy, providing novel insights into a promising strategy for regulating Beclin-1 to improve cancer therapeutics in the future.

The Prognosis of Cancer Depends on the Interplay of Autophagy, Apoptosis, and Anoikis within the Tumor Microenvironment

Within the tumor microenvironment, the fight between the immune system and cancer influences tumor transformation. Metastasis formation is an important stage in the progression of cancer. This process is aided by cellular detachment and resistance to anoikis, which are achieved by altering intercellular signaling. Autophagy, specifically pro-survival autophagy, aids cancer cells in developing treatment resistance. Numerous studies have shown that autophagy promotes tumor growth and resistance to anoikis. To regulate protective autophagy, cancer-related genes phosphorylate both pro- and anti-apoptotic proteins. Apoptosis, a type of controlled cell death, eliminates damaged or unwanted cells. Anoikis is a type of programmed cell death in which cells lose contact with the extracellular matrix. The dysregulation of these cellular pathways promotes tumor growth and spread. Apoptosis, anoikis, and autophagy interact meticulously and differently depending on the cellular circumstances. For instance, autophagy can protect cancer cells from apoptosis by removing cellular components that are damaged and might otherwise trigger apoptotic pathways. Similarly, anoikis dysregulation can trigger autophagy by causing cellular harm and metabolic stress. In order to prevent or treat metastatic disease, specifically, targeting these cellular mechanisms may present a promising prospect for cancer therapy. This review discourses the state of our understanding of the molecular and cellular mechanisms underlying tumor transformation and the establishment of metastatic tumors. To enhance the prognosis for cancer, we highlight and discuss potential therapeutic approaches that target these processes and genes involved in them.

The Role of Bcl-2 and Beclin-1 Complex in "Switching" between Apoptosis and Autophagy in Human Glioma Cells upon LY294002 and Sorafenib Treatment

BACKGROUND

Gliomas are the most malignant tumors of the central nervous system. One of the factors in their high drug resistance is avoiding programmed death (PCD) induction. This is related to the overexpression of intracellular survival pathways: PI3K-Akt/PKB-mTOR and Ras-Raf-MEK-ERK. Apoptosis and autophagy are co-existing processes due to the interactions between Bcl-2 and beclin-1 proteins. Their complex may be a molecular "toggle-switch" between PCD types. The aim of this research was to investigate the role of Bcl-2:beclin-1 complex in glioma cell elimination through the combined action of LY294002 and sorafenib.

METHODS

Drug cytotoxicity was estimated with an MTT test. The type of cell death was evaluated using variant microscopy techniques (fluorochrome staining, immunocytochemistry, and transmission electron microscopy), as well as the Bcl-2:beclin-1 complex formation and protein localization. Molecular analysis of PCD indicators was conducted through immunoblotting, immunoprecipitation, and ELISA testing. SiRNA was used to block Bcl-2 and beclin-1 expression.

RESULTS

The results showed the inhibitors used in simultaneous application resulted in Bcl-2:beclin-1 complex formation and apoptosis becoming dominant. This was accompanied by changes in the location of the tested proteins.

CONCLUSIONS

"Switching" between apoptosis and autophagy using PI3K and Raf inhibitors with Bcl-2:beclin-1 complex formation opens new therapeutic perspectives against gliomas.

ELABELA protects against diabetic kidney disease by activating high glucose-inhibited renal tubular autophagy

ELABELA (ELA), an endogenous ligand of the apelin receptor (also known as apelin peptide jejunum [APJ]), has been shown to decrease in the plasma of patients with diabetic kidney disease (DKD). In the current study, we explored the potential function as well as the underlying mechanisms of ELA in DKD. We first found that the ELA levels were decreased in the kidneys of DKD mice. Then, we found that ELA administration mitigated renal damage and downregulated the expression of fibronectin, collagen Ⅳ, and transforming growth factor-β1 in the db/db mice and the high glucose cultured HK-2 cells. Furthermore, the autophagy markers, Beclin-1 and LC3-Ⅱ/LC3-Ⅰ ratio, were significantly impaired in DKD, but the ELA treatment reversed these alterations. Mechanistically, the inhibitory effects of ELA on the secretion of fibrosis-associated proteins in high glucose conditions were blocked by pretreatment with 3-methyladenine (an autophagy inhibitor). In summary, these in vivo and in vitro results demonstrate that ELA effectively protects against DKD by activating high glucose-inhibited renal tubular autophagy, potentially serving as a novel therapeutic candidate for DKD.

Piperine Induces Apoptosis and Autophagy in HSC-3 Human Oral Cancer Cells by Regulating PI3K Signaling Pathway

Currently, therapies for treating oral cancer have various side effects; therefore, research on treatment methods employing natural substances is being conducted. This study aimed to investigate piperine-induced apoptosis and autophagy in HSC-3 human oral cancer cells and their effects on tumor growth in vivo. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay demonstrated that piperine reduced the viability of HSC-3 cells and 4',6-diamidino-2-phenylindole staining, annexin-V/propidium iodide staining, and analysis of apoptosis-related protein expression confirmed that piperine induces apoptosis in HSC-3 cells. Additionally, piperine-induced autophagy was confirmed by the observation of increased acidic vesicular organelles and autophagy marker proteins, demonstrating that autophagy in HSC-3 cells induces apoptosis. Mechanistically, piperine induced apoptosis and autophagy by inhibiting the phosphatidylinositol-3-kinase (PI3K)/protein kinase B/mammalian target of rapamycin pathway in HSC-3 cells. We also confirmed that piperine inhibits oral cancer tumor growth in vivo via antitumor effects related to apoptosis and PI3K signaling pathway inhibition. Therefore, we suggest that piperine can be considered a natural anticancer agent for human oral cancer.

Identification of molecular signatures and molecular dynamics simulation of highly deleterious missense variants of key autophagy regulator beclin 1: a computational based approach

Beclin 1 is a key autophagy regulator that also plays significant roles in other intracellular processes such as vacuolar protein sorting. Beclin 1 protein functions as a scaffold in the formation of a multiprotein assemblage during autophagy. Beclin 1 is involved in various diseases such as cancers, neurodegenerative and autophagy-related disorders. In this study, we have used various in silico tools to scan beclin 1 at the molecular level to find its molecular signatures. We have predicted and analysed deleterious non-synonymous single nucleotide polymorphisms (nsSNPs) of beclin 1 causing alterations in its structure and also affecting its interactions with other proteins. In total, twelve coding region deleterious variants were predicted using sequence-based tools and nine were predicted using various structure-based tools. The molecular dynamics (MD) simulations revealed an altered stability of the native structure due to the introduction of mutations. Destabilization of beclin 1 ECD domain was observed due to nsSNPs W300R and E302K. Beclin 1 deleterious nsSNPs were predicted to show significant effects on beclin 1 interactions with ATG14L1, UVRAG and VPS34 proteins and were also predicted to alter the protein-protein interface of beclin 1 complexes. Additionally, beclin 1 was predicted to have thirty-one potential phosphorylation and three ubiquitination sites. In conclusion, the molecular details of beclin 1 could help in the better understanding of its functioning. The study of nsSNPs and their effect on beclin 1 and its interactions might aid in understanding the basis of anomalies caused due to beclin 1 dysfunction.Communicated by Ramaswamy H. Sarma.

miR-100-5p activation of the autophagy response through inhibiting the mTOR pathway and suppression of cerebral infarction progression in mice

In recent years, the association between microRNAs (miRNAs) and autophagy in cerebral infarction (CI) has attracted increasingly more attention. The mammalian target of the rapamycin (mTOR) pathway is a key protein regulating the autophagy response. miR-100-5p can bind to the mTOR protein, but its role in CI remains unclear yet. This experiment aims to clarify the role of miR-100-5p in CI. Bioinformatics analysis was performed to screen differentiated expressed functional genes between CI tissue and normal tissue specimens. In vivo experiments: the mouse model of CI was established by middle cerebral artery occlusion (MCAO) methods, After being treated with miR-100-5p-overexpressing lentivirus, the amount of terminal deoxynucleotidyl transferase (TdT) dUTP nick-end labeling (TUNEL)-positive fluorescence and the fluorescent expression level of mTOR protein were significantly inhibited in the CI region. Western blotting analysis showed that miR-100-5p inhibited the protein expression level of phosphorylated mTOR and total mTOR and enhanced the expression of autophagy-related proteins Beclin, microtubule-associated protein light chain 3II (LC-3II), and autophagy-related gene 7 (ATG-7). For in vitro experiment, after the BV-2 cells were successfully infected with the control lentivirus and miR-100-5p-overexpression lentivirus, they were stimulated with 1% hypoxia and low-glucose medium in a tri-gas incubator for 24 h. It was found that miR-100-5p could significantly lower the protein expression level of phosphorylated mTOR and total mTOR, and increase the expression of the Beclin, LC-3II, ATG-7 autophagy related proteins. miR-100-5p promotes the autophagy response through binding to mTOR protein, thereby inhibiting apoptosis and delaying the progression of CI.

Enhanced Autophagy in Damaged Laminar Tissue of Acute Laminitis Induced by Oligofructose Overloading in Dairy Cows

This study was aimed at determining the autophagy activity in the laminar tissue of dairy cows with oligofructose-induced laminitis. Twelve healthy non-pregnant Holstein cows were randomly divided into two groups of six cows each, entitled the control group and the oligofructose overload group (OF group), respectively. At 0 h, cows in the OF group were gavaged with oligofructose (17 g/kg BW) dissolved in warm deionized water (20 mL/kg BW) through an oral rumen tube, and the dairy cows in the control group were gavaged with the same volume of deionized water by the same method. At -72 h before, as well as 0 h, 6 h, 12 h, 18 h, 24 h, 36 h, 48 h, 60 h, and 72 h after perfusion, clinical evaluations of both groups were monitored. After 72 h, the laminar tissues of the dairy cows in both groups were collected to examine the genes and proteins. The gene expression of ATG5, ATG12, and Beclin1 significantly increased (p < 0.05), whereas that of P62 and mTOR significantly decreased (p < 0.01) in the OF group relative to the control group. The protein expression of Beclin-1 significantly increased (p < 0.05), while that of LC3II significantly decreased (p < 0.05) in the OF group relative to the control group. However, the protein expression of P62 non-significantly reduced (p > 0.05) in the OF group comparative to the control group. Furthermore, the distribution of the Beclin1 protein in the laminar tissue significantly increased (p < 0.01), while that of the P62 protein significantly decreased (p < 0.05) in the OF group than the control group. These findings indicate that the imbalanced gene and protein-level status of autophagy-related markers may be the basic cause for the failure of the epidermal attachment. However, a more detailed gene and protein-level study is needed to further clarify the role of autophagy in the pathogenesis of bovine laminitis.

Bilirubin, an endogenous antioxidant that affects p53 protein and its downstream apoptosis/autophagy-related genes in LS180 and SW480 cell culture models of colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is one of the commonest neoplasms worldwide, which its pathogenesis is strongly correlated with p53 mutations. Antioxidants are believed to decelerate the CRC progression, possibly through interfering with p53 and its downstream target genes and mechanisms. Regarding the potential antioxidant effects of bilirubin, as an incredible endogenous antioxidant, we sought to investigate how bilirubin affected the expression levels of p53 protein and its downstream target genes, including Mdm2, Bcl-2, BECN1 and LC3, in LS180 and SW480 cell culture models of CRC.

METHODS AND RESULTS

Using the MTT (3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl-2H-tetrazolium bromide) assay, 50 and 100 μM concentrations of bilirubin were determined to be non-toxic for both LS180 and SW480 cell lines. Western blot analysis was employed to evaluate the protein expression levels of p53. The results revealed that p53 protein levels were higher in LS180 cells treated with bilirubin compared to the control group. Notwithstanding, in SW480 cells, no considerable changes were observed in p53 protein levels of treated cells compared to the control ones. The quantitative reverse transcriptase-polymerase chain reaction (q RT-PCR) method was used to measure the mRNA expression levels of the apoptosis/autophagy-related genes, Mdm2, Bcl-2, BECN1, and LC3 , as the p53's downstream target genes. Consequently, the expression of Bcl-2 and Mdm2 genes were affected by p53, while BECN1 and LC3 expression levels were decreased in both cell lines.

CONCLUSION

Bilirubin is an endogenous antioxidant with significant anti-tumor effects in the studied CRC cell lines, probably through the regulation of p53 protein expression levels and subsequent control of apoptosis and autophagy, as two key processes involved in cell survival and progression of tumor cells.

Fullerene C60 reduces acute lung injury by suppressing oxidative stress-mediated DMBA-induced apoptosis and autophagy by regulation of cytochrome-C/caspase-3/beclin-1/IL-1α/HO-1/p53 signaling pathways in rats

The objective of this study was to evaluate the effect of fullerene C60 nanoparticles against 7,12-dimethylbenz[a]anthracene (DMBA)-induced lung tissue damage in rats. 60 Wistar albino (8 weeks old) female rats were assigned into four groups: Control Group (C), Fullerene C60, DMBA, and Fullerene C60+DMBA. The rats in the DMBA and Fullerene C60+DMBA groups were administered DMBA (45 mg/kg bw, oral gavage). The rats in Fullerene C60, and Fullerene C60+DMBA groups were administered with Fullerene C60 (1.7 mg/kg bw, oral gavage). Expression levels of cytochrome-C, caspase-3, beclin-1, IL-1α, HO-1 and p53 proteins in lung tissue were determined by western blotting, lipid peroxidation malondialdehyde (MDA) analyzes, glutathione (GSH), glutathione peroxidase (GSH-Px), catalase activity (CAT) and total protein levels were determined by spectrophotometer. In addition, lung tissues were evaluated by histopathologically. Fullerene C60 reduced the increasing of MDA and IL-1α protein expression levels and attenuated histopathological changes in lung. Moreover, fullerene C60 enhanced the protein expression of cytochrome-C, caspase-3, beclin-1, HO-1, and p53, which were decreased in the DMBA group. Fullerene C60 has strong biological activity that it might be an effective approach for lung damage.

The autophagy in ischemic stroke: A regulatory role of non-coding-RNAs

Ischemic stroke (IS) is a central nervous system neurological disorder ascribed to an acute focal trauma, with high mortality and disability, leading to a heavy burden on family and society. Autophagy is a self-digesting process by which damaged organelles and useless proteins are recycled to maintain cellular homeostasis, and plays a pivotal role in the process of IS. Non-coding RNAs (ncRNAs), mainly contains microRNA, long non-coding RNA and circular RNA, have been extensively investigated on regulation of autophagy in human diseases. Recent studies have implied that ncRNAs-regulating autophagy participates in pathophysiological process of IS, including cell apoptosis, inflammation, oxidative stress, blood-brain barrier damage and glial activation, which indicates that regulating autophagy by ncRNAs may be beneficial for IS treatment. This review summarizes the role of autophagy in IS, as well as focuses on the role of ncRNAs-mediated autophagy in IS, for the development of potential therapeutic strategies in this disease.

Impaired Autophagy in Krabbe Disease: The Role of BCL2 and Beclin-1 Phosphorylation

Autophagic impairment was identified in many lysosomal storage diseases and adult neurodegenerative diseases. It seems that this defect could be directly related to the appearance of a neurodegenerative phenotype and could contribute to worsen metabolite accumulation and lysosomal distress. Thus, autophagy is becoming a promising target for supportive therapies. Autophagy alterations were recently identified also in Krabbe disease. Krabbe disease is characterized by extensive demyelination and dysmyelination and it is due to the genetic loss of function of the lysosomal enzyme galactocerebrosidase (GALC). This enzyme leads to the accumulation of galactosylceramide, psychosine, and secondary substrates such as lactosylceramide. In this paper, we induced autophagy through starvation and examined the cellular response occurring in fibroblasts isolated from patients. We demonstrated that the inhibitory AKT-mediated phosphorylation of beclin-1 and the BCL2-beclin-1 complex concur to reduce autophagosomes formation in response to starvation. These events were not dependent on the accumulation of psychosine, which was previously identified as a possible player in autophagic impairment in Krabbe disease. We believe that these data could better elucidate the capability of response to autophagic stimuli in Krabbe disease, in order to identify possible molecules able to stimulate the process.

Piceatannol enhances Beclin-1 activity to suppress tumor progression and its combination therapy strategy with everolimus in gastric cancer

The effects and regulation of Beclin-1-an autophagy-related protein-have not been fully defined, however, a negative correlation has been reported between Beclin-1 expression and carcinogenesis. Meanwhile, no compound has been shown to directly inhibit its activity. Here, we evaluate piceatannol, a naturally occurring polyphenolic compound, as a potential targeting agonist of Beclin-1, to assess its efficacy as an antitumor agent against gastric cancer. More specifically, we determine the effects of piceatannol treatment on cell viability using a monitoring system and colony forming assay. Piceatannol was found to efficiently inhibit the proliferation of several human gastric cancer cell lines. Autophagic flux is increased by piceatannol treatment, and correlates with inhibition of cell proliferation and colony formation. Additionally, microscale thermophoresis and surface plasmon resonance results show a direct interaction between piceatannol and Beclin-1, which reduces the phosphorylation activity of Beclin-1 at the Ser-295 site. Notably, piceatannol impairs the binding of Beclin-1 to Bcl-2 and enhances the recruitment of binding of UV radiation resistance-associated gene protein, which further triggers Beclin-1-dependent autophagy signaling. An increase in autophagic activity via treatment with the mTOR inhibitor, everolimus, effectively sensitizes piceatannol-induced antitumor effects. Xenograft models confirmed that piceatannol inhibits tumor development and elicits a potent synergistic effect with everolimus in vivo. Taken together, the findings of this study strongly support the application of combinatorial piceatannol and everolimus therapy in future clinical trials for gastric cancer patients.

Long-term copper exposure caused hepatocytes autophagy in broiler via miR-455-3p-OXSR1 axis

Copper (Cu) is a common environmental pollutant which has been identified to cause toxic effects on animal bodies. MicroRNAs (miRNAs) are a type of non-coding RNAs involved in the regulation of various cellular activities including autophagy, but the potential regulatory mechanisms after excess Cu intake are still uncertain. Our previous study has prompted that Cu exposure reduced liver miR-455-3p levels. Herein, miR-455-3p was found to be an important molecule in the regulation of Cu-induced autophagy in vivo and in vitro. Histopathology observation of liver tissue indicated that Cu-induced severe hepatic damage including cellular swelling and vacuolization. Meanwhile, excessive Cu exposure not only heighten the mRNA and protein expression levels of Beclin1, Atg5, LC3Ⅰ and LC3Ⅱ, but also decreased miR-455-3p levels. In vitro experiment, Cu-induced autophagy can be attenuated by miR-455-3p overexpression. Additionally, oxidative stress-responsive 1 (OXSR1) was identified as a direct downstream target of miR-455-3p by dual luciferase reporter assays. Moreover, knockdown of OXSR1 can attenuate the autophagy induced by Cu treatment and the miR-455-3p inhibitor. Overall, the miR-455-3p-OXSR1 axis works as a regulator of autophagy under Cu stress, which provides a basis for further revealing the mechanism of chronic Cu poisoning.

Atractylenolide III Ameliorated Autophagy Dysfunction via Epidermal Growth Factor Receptor-Mammalian Target of Rapamycin Signals and Alleviated Silicosis Fibrosis in Mice

Atractylenolide III (ATL-III) is a major active constituent of the natural plant Atractylodes rhizome. Our previous study has shown that ATL-III may alleviate alveolar macrophage apoptosis via the inhibition of the mammalian target of rapamycin (mTOR)-mediated autophagy of human silicosis. Therefore, we aimed to further explore the function of ATL-III in autophagy, apoptosis, and pulmonary fibrosis by establishing the ATL-III-intervened silicosis mouse model in this study. Meanwhile, we sought and then verified potential autophagy-related signaling pathways by matching differentially expressed genes (attained by RNA sequencing) and the autophagy database. In this study, RNA-sequencing results implied that the epidermal growth factor receptor, the crucial upstream activator of mTOR, was seen as a potential autophagy-regulatory molecule in the ATL-III-intervened silicosis mouse model. The finding of this study was that ATL-III might improve the disorder of autophagic degradation via the activation of epidermal growth factor receptor-mTOR signals in the pulmonary tissue of the silicosis mouse model. ATL-III also alleviated cell apoptosis and silicotic fibrosis. Overall, we supposed that ATL-III might be a potential protective medicine, which had a regulatory effect on autophagy, for the intervention of silicotic fibrosis. In the future, the therapeutic drugs for silicosis should be further focused on the development and application of such natural autophagy agents.

Light Chain Amyloidosis–Induced Autophagy Is Mediated by the Foxo3a/Beclin-1 Pathway in Cardiomyocytes

Cardiac amyloidosis is a disease in which the extracellular space of the heart is deposited with and infiltrated by amyloid fibrillar material, and light chain (LC) amyloidosis (AL) is the most serious form of the disease. AL is caused by the overproduction and aggregation of monoclonal immunoglobulin LCs produced by bone marrow plasma cells. Studies have shown that the initial response at a subcellular level to the toxicity of AL is lysosomal dysfunction with impaired autophagy, elevated reactive oxygen species, cellular dysfunction, and cellular death. Therefore, we speculate that the multiple myeloma complicated by cardiac amyloidosis is due to the deposition of λ LC fibrils in cardiomyocytes, leading to dysregulation of autophagy and cell death. We constructed BACN1 siRNA or FOXO3A siRNA and transfected them into H9c2 cells. We detected changes in oxidative stress- and autophagy-related markers. Our results show that monoclonal immunoglobulin λ LCs can form amyloid aggregates, which are cytotoxic to cardiomyocytes. λ LC fibrils deposit on the cell surface, causing oxidative stress and excessive autophagy by increasing Beclin-1 expression and the LC3 II/LC3 I ratio and decreasing p62 expression, ultimately inducing cell death. Beclin-1 knockdown reversed the increase in the LC3 II/LC3 I ratio and the decrease in p62 induced by LC fibrils, while suppressing overactivated autophagy and oxidative stress. Furthermore, LCs reduce the expression of p-Foxo3a (Ser253) (inactive) and promote Foxo3a translocation into the nucleus to perform transcriptional activity, which induces autophagy-related gene overexpression. Silencing Foxo3a can suppress excessive autophagy induced by LC fibrils and protect cells from death. In summary, the results showed that the cytotoxicity of amyloid fibrils formed by λ LCs on cardiomyocytes is triggered by excessive autophagy and is mediated through the Foxo3a/Beclin-1 pathway.

CD8+ T-cell immune escape by SARS-CoV-2 variants of concern

Despite the efficacy of antiviral drug repositioning, convalescent plasma (CP), and the currently available vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the worldwide coronavirus disease 2019 (COVID-19) pandemic is still challenging because of the ongoing emergence of certain new SARS-CoV-2 strains known as variants of concern (VOCs). Mutations occurring within the viral genome, characterized by these new emerging VOCs, confer on them the ability to efficiently resist and escape natural and vaccine-induced humoral and cellular immune responses. Consequently, these VOCs have enhanced infectivity, increasing their stable spread in a given population with an important fatality rate. While the humoral immune escape process is well documented, the evasion mechanisms of VOCs from cellular immunity are not well elaborated. In this review, we discussed how SARS-CoV-2 VOCs adapt inside host cells and escape anti-COVID-19 cellular immunity, focusing on the effect of specific SARS-CoV-2 mutations in hampering the activation of CD8⁺ T-cell immunity.

ATG5: A central autophagy regulator implicated in various human diseases

Autophagy, an intracellular conserved degradative process, plays a central role in the renewal/recycling of a cell to maintain the homeostasis of nutrients and energy within the cell. ATG5, a key component of autophagy, regulates the formation of the autophagosome, a hallmark of autophagy. ATG5 binds with ATG12 and ATG16L1 resulting in E3 like ligase complex, which is necessary for autophagosome expansion. Available data suggest that ATG5 is indispensable for autophagy and has an imperative role in several essential biological processes. Moreover, ATG5 has also been demonstrated to possess autophagy-independent functions that magnify its significance and therapeutic potential. ATG5 interacts with various molecules for the execution of different processes implicated during physiological and pathological conditions. Furthermore, ATG5 genetic variants are associated with various ailments. This review discusses various autophagy-dependent and autophagy-independent roles of ATG5, highlights its various deleterious genetic variants reported until now, and various studies supporting it as a potential drug target.

Dietary isoleucine affects muscle fatty acid and amino acid profiles through regulating lipid metabolism and autophagy in hybrid catfish Pelteobagrus vachelli ♀ × Leiocassis longirostris ♂

The present study explored the impacts of Ile on muscle fatty acid and amino acid profiles, lipid metabolism, and autophagy in hybrid catfish. Seven isonitrogenous (387.8 g/kg protein) semi-purified diets were formulated to contain 5.0 (control), 7.5, 10.0, 12.5, 15.0, 17.5, and 20.0 g Ile/kg diet respectively. The fish (initial weight of 33.11 ± 0.09 g) were randomly assigned to 7 groups for a 56-day trial. Each group has 3 replicates with 30 fish per replicate, fed at 08:00 and 18:00 each day. Results showed that muscle protein and lipid, C14:0, C18:0, C22:0, C14:1, C18:1n-9, polyunsaturated fatty acid (PUFA), Arg, Ile, Ala, Cys, Gly, Tyr, essential amino acid (EAA), and total amino acid (TAA) contents and flavor amino acid (FAA)/TAA in muscle had positive linear and/or quadratic responses to dietary Ile levels (P < 0.05). Fatty acid synthase (FAS), stearoyl-CoA desaturase (SCD), acetyl-CoA carboxylase (ACC), and lipoprotein lipase (LPL) activities had positive linear and/or quadratic responses, but carnitine palmitoyl transferase 1 (CPT1) activity had a negative response with increasing dietary Ile levels (P < 0.05). The mRNA expressions of FAS, SCD, ACC, LPL, fatty acid binding protein 4 (FABP4), FATP1, sterol response element-binding protein 1c (SREBP-1c), sequestosome 1 (SQSTM1), and adenosine 5′-monophosphate-activated protein kinase (AMPK) had positive linear and/or quadratic responses to dietary Ile levels (P < 0.05). The mRNA expressions of hormone-sensitive lipase (HSL), CPT1, peroxisome proliferator-activated receptor α (PPARα), PPARγ, uncoordinated 51-like kinase 1 (ULK1), beclin1 (Becn1), autophagy-related protein 9α (Atg9α), Atg4b, Atg7, autophagy marker light chain 3 B (LC3B), and SQSTM1 in muscle had negative linear and/or quadratic responses to dietary Ile levels (P < 0.05). The p-AMPK and ULK1 protein levels, and p-AMPK/AMPK were decreased by 12.5 g Ile/kg in the diet (P < 0.05). Finally, SQSTM1 protein level had the opposite effect (P < 0.05). The above results indicate that dietary Ile improves fish muscle fatty acid and amino acid profiles potentially via respectively regulating lipid metabolism and autophagy. The Ile requirement of hybrid catfish (33 to 72 g) were estimated to be 12.63, 13.77, 13.75, 11.45, 10.50, 12.53 and 12.21 g/kg diet based on the regression analysis of protein, lipid, SFA, PUFA, FAA, EAA, and TAA muscle contents, respectively.

Cornel Iridoid Glycoside and Its Effective Component Regulate ATPase Vps4A/JNK to Alleviate Autophagy Deficit with Autophagosome Accumulation

Improving autophagy-lysosome fusion has been considered a key method in the treatment of Alzheimer's disease (AD). Cornel iridoid glycoside (CIG) is extracted from Cornus officinalis and has been shown to promote the clearance of tau oligomers via the autophagy pathway. However, the mechanisms of CIG on autophagy deficits are not understood. Here, we found autophagy deficit and tau aggregation in the brains of P301S tau transgenic mice and MAPT cells edited using CRISPR-Cas9 technology. CIG decreased tau aggregation and alleviated autophagic markers involving the JNK/Beclin-1 signaling pathway which demonstrated CIG that might enhance lysosome formation by upregulating ATPase Vps4A expression. Knocking down VPS4A increased autophagosome accumulation and attenuated the effect of CIG on p62. In addition, CIG had no effect on tau oligomers but still inhibited the level of tau monomer in VPS4A knockout cells. The effective component (Sweroside, SWE) of CIG attenuated tau oligomers accumulation and increased Vps4A level but not CHMP2B. SWE could not change the level of tau oligomers in VPS4A knockout cells. In conclusion, CIG suppressed autophagosome accumulation by regulating the ATPase Vps4A/JNK. SWE is a core of active factors of CIG in Vps4A regulation. These findings suggest CIG may be a potential drug in AD treatment.

Trehalose Treatment in Zebrafish Model of Lafora Disease

Mutations in the EPM2A gene encoding laforin cause Lafora disease (LD), a progressive myoclonic epilepsy characterized by drug-resistant seizures and progressive neurological impairment. To date, rodents are the only available models for studying LD; however, their use for drug screening is limited by regulatory restrictions and high breeding costs. To investigate the role of laforin loss of function in early neurodevelopment, and to screen for possible new compounds for treating the disorder, we developed a zebrafish model of LD. Our results showed the epm2a^−/− zebrafish to be a faithful model of LD, exhibiting the main disease features, namely motor impairment and neuronal hyperexcitability with spontaneous seizures. The model also showed increased inflammatory response and apoptotic death, as well as an altered autophagy pathway that occurs early in development and likely contributes to the disease progression. Early administration of trehalose was found to be effective for rescuing motor impairment and neuronal hyperexcitability associated with seizures. Our study adds a new tool for investigating LD and might help to identify new treatment opportunities.

Association of IRGM gene promoter polymorphisms with Hepatitis B Virus infection

BACKGROUND

In response to intracellular pathogens the autophagy gene IRGM plays an essential role in the innate immune response. Various identified IRGM gene risk loci are associated with several diseases, but so far no study is available which shows the association of IRGM with HBV infection.

METHODS

We genotyped promoter variants (rs4958842, rs4958843, and rs4958846) of IRGM in HBV infected patients (551) and healthy controls (247) for their role in HBV infection. The genotyping was done applying methods developed in our laboratory and various biochemical parameters were assessed applying commercially available kits.

RESULTS

Data analysis has shown that the mutant allele A of rs4958842 plays a role in the protection from HBV infection in various genetic models that includes allelic, co-dominant and dominant models with the respective statistical data (OR=0.61; 95%CI=0.48-0.78; p=0.0003), (OR=0.52; 95%CI=0.38-0.71; p=0.0008) and (OR=0.51; 95%CI=0.38-0.70, p=0.0004). In CHB, protective association was observed in allelic (OR=0.48; 95%CI=0.35-0.65, p=0.0004), co-dominant (OR=0.38; 95%CI=0.26-0.54, p=0.0004) and dominant models (OR=0.38; 95%CI=0.26-0.54, p=0.0002). Mutant allele C of rs49598843 was associated with the risk of CHB in co-dominant (OR=1.52; 95%CI=1.07-2.16, p=0.04) and dominant models (OR=1.41; 95%CI=1.00-2.00, p=0.04). The mutant allele C of rs4958846 decreased the risk of HBV infection in allelic (OR=0.74; 95%CI=0.59-0.92, p=0.01), dominant (OR=0.72; 95%CI=0.53-0.98, p=0.05), homozygous (OR=0.42; 95%CI=0.24-0.74, p=0.01) and recessive (OR=0.42; 95%CI=0.24-0.74, p=0.0004) models. However, in asymptomatic group it was associated with the increased chance of HBV infection. Haplotypes, ATT (OR=0.47; 95%CI=0.33-0.68, p=0.001), GTC (OR=0.68; 95%CI=0.51-0.92, p=0.01) protect while GTT (OR=2.01; 95%CI=(1.55-2.60), p<0.0001) predisposes the individuals to HBV infection. All of these p-values mentioned here were obtained after performing Bonferroni correction.

CONCLUSION

In conclusion, our findings revealed that mutant allele A of rs4958842, mutant allele C of rs4958843 and rs4958846 were associated with hepatitis B virus infection in the North Indian population.

Capsaicin inhibits the stemness of anaplastic thyroid carcinoma cells by triggering autophagy-lysosome mediated OCT4A degradation

Capsaicin (CAP) is a well-known anti-cancer agent. Recently, we reported capsaicin-induced apoptosis in anaplastic thyroid cancer (ATC) cells. It is well accepted that the generation of cancer stem cells (CSCs) is responsible for the dedifferentiation of ATC, the most lethal subtype of thyroid cancer with highly dedifferentiation status. Whether CAP inhibited the ATC growth through targeting CSCs needed further investigation. In the present study, CAP was found to induce autophagy in ATC cells through TRPV1 activation and subsequent calcium influx. Meanwhile, CAP dose-dependently decreased the sphere formation capacity of ATC cells. The stemness-inhibitory effect of CAP was further by extreme limiting dilution analysis (ELDA). CAP significantly decreased the protein level of OCT4A in both 8505C and FRO cells. Furthermore, CAP-induced OCT4A degradation was reversed by autophagy inhibitors 3-MA and chloroquine, BAPTA-AM and capsazepine, but not proteasome inhibitor MG132. Collectively, our study firstly showed CAP suppressed the stemness of ATC cells partially via calcium-dependent autophagic degradation of OCT4A. Our study lent credence to the feasible application of capsaicin in limiting ATC stemness.

Aconitine induces autophagy via activating oxidative DNA damage-mediated AMPK/ULK1 signaling pathway in H9c2 cells

ETHNOPHARMACOLOGICAL RELEVANCE

Aconitum species, with a medicinal history of 2000 years, was traditionally used in the treatment of rheumatism, arthritis, bruises, and pains. However, many studies have reported that Aconitum species can cause arrhythmia in experimental animals, resulting in myocardial fibrosis and cardiomyocyte damage. Cardiotoxicity is the main toxic effect of aconitine, but the detailed mechanism remains unclear.

AIM OF THE STUDY

This study aimed to explore the effects and underlying mechanism of autophagy in H9c2 cardiomyocytes induced by aconitine.

MATERIALS AND METHODS

H9c2 cells were incubated with different concentrations of aconitine for 24 h, and the intervention sections were pretreated with various inhibitors for 1 h. The effects of aconitine on the oxidative DNA damage, autophagy and viability of H9c2 cells were evaluated by flow cytometry, confocal microscopy, enzyme-linked immunosorbent assay and Western blot.

RESULTS

In H9c2 cells, the cell viability declined, LDH release rate, the number of autophagosomes, protein expression levels of LC3 and Beclin-1 increased significantly after 24 h of aconitine incubation. The pretreatment of autophagy inhibitor 3-MA decreased markedly autophagosomes and protein expression levels of LC3 and Beclin-1, which suggested that aconitine could induce cell autophagy. The significant increase of ROS and 8-OHdG showed that aconitine could cause oxidative DNA damage through ROS accumulation. Meanwhile, treatment of aconitine dramatically increased AMPK^Thr172 and ULK1^Ser317 phosphorylation, and Compound C inhibited AMPK^Thr172 and ULK1^Ser317 phosphorylation, which proved that aconitine induced autophagy via AMPK activation mediated ULK1 phosphorylation. Antioxidant NAC significantly reduced LDH, ROS and 8-OHdG, inhibited the phosphorylation of AMPK^Thr172 and ULK1^Ser317, and down-regulated autophagosomes and proteins expression levels of LC3 and Beclin-1. Consequently, the inhibition of oxidative DNA damage and AMPK/ULK1 signaling pathway alleviated the aconitine-induced autophagic death of H9c2 cells.

CONCLUSIONS

These results showed that aconitine induces autophagy of H9c2 cardiomyocytes by activating AMPK/ULK1 signaling pathway mediated by oxidative DNA damage. The autophagy induced by aconitine in cardiomyocytes is dependent on the activation of the AMPK pathway, which may provide novel insights into the prevention of aconitine-related toxicity.

Notoginseng Triterpenes Inhibited Autophagy in Random Flaps via the Beclin-1/VPS34/LC3 Signaling Pathway to Improve Tissue Survival

Random flaps are widely used in tissue reconstruction, attributed to the lack of vascular axial limitation. Nevertheless, the distal end of the flap is prone to necrosis due to the lack of blood supply. Notoginseng triterpenes (NTs) are the active components extracted from Panax notoginseng, reducing oxygen consumption and improving the body’s tolerance to hypoxia. However, their role in random flap survival has not been elucidated. In this study, we used a mouse random skin flap model to verify that NT can promote cell proliferation and migration and that increasing blood perfusion can effectively improve the survival area of a skin flap. Our study also showed that the autophagy of random flaps after NT treatment was activated through the Beclin-1/VPS34/LC3 signaling pathway, and the therapeutic effect of NT significantly decreased after VPS34 IN inhibited autophagy. In conclusion, we have demonstrated that NT can significantly improve the survival rate of random flaps through the Beclin-1/VPS34/LC3 signaling pathway, suggesting that it might be a promising clinical treatment option.

Selenoprotein S attenuates high glucose and/or ox-LDL-induced endothelium injury by regulating Akt/mTOR signaling and autophagy

Glucolipid metabolism disorder in diabetes mellitus (DM) causes human endothelial injury and autophagy dysfunction is an important cause of endothelial dysfunction (ED). Selenoprotein S (SelS) could protect endothelium from oxidative stress, inflammatory responses, and apoptosis. This study assessed the effect of SelS on autophagy in glucolipid metabolic disorders and protection of the resulted vascular endothelial injury. The results showed that high glucose (HG), high oxidized low-density lipoprotein (HL), and HG combined with HL (HGL) could reduce viability of human aortic endothelial cells (HAECs), induce HAECs injury and increase SelS expression in a time-dependent manner. HG, HL, and HGL also initially induced autophagy but later reduced it in HAECs, while activity of the Akt/mTOR signaling was inhibited, especially in HGL culture of HAECs. SelS overexpression reduced the endothelial injury and autophagy and activated the Akt/mTOR signaling in HG, HL and HGL-cultured HAECs, compared to the control. Conversely, knockdown of SelS expression had the opposite effects on HAECs. In conclusion, SelS demonstrated a protective effect on endothelial injury induced by high glucose and/or ox-LDL and the underlying molecular events might be related to its regulation of HAECs autophagy by activating the Akt/mTOR signaling. SelS could be a potential intervention target in prevention and treatment of diabetic vascular complications.

Immunohistochemical Analysis of the Beclin-1 Expression Predicts the Progression of Oral Squamous Cell Carcinoma

Background: Autophagy is a cellular process responsible for maintaining homeostasis; a dysregulation of this process is involved in the development and progression of neoplasms. Beclin-1 is one of the major proteins linked to autophagy. However, the data regarding the association between the role of Beclin-1 and the progression of Oral Squamous Cell Carcinoma (OSCC) are rather low. For this reason, the objective of this study is to evaluate, through immunohistochemical techniques, the prognostic role of the expression of Beclin-1 autophagy marker in patients with OSCC. Methods: This is a single-centre retrospective study that includes patients with OSCC admitted to the Maxillofacial Unit of “Magna Graecia” University between January 2019 and September 2020. All the samples obtained from surgery were treated with anti Beclin-1 antibodies and subjected to immunohistochemical methods. Results: A total of 26 samples were analysed and the following variables were evaluated for each: percentage of positive Beclin-1 expression by tumour cells, signal strength of tumour cells, and total score. The variables considered were first normalised according to the D’Agostino and Pearson test, then analysed using the Pearson linear correlation coefficient: a statistically significant correlation was found between the parameters infiltration-intensity (p = 0.0088), infiltration-percent (p = 0.0123), intensity-total score (p = 0.0060). Conclusions: The immunohistochemical evaluation of Beclin-1 revealed a statistically significant correlation between the intensity of the molecule’s expression and a greater degree of infiltration of the neoplasm. Beclin-1 can, therefore, be considered a valid prognostic index of disease.

Synthesis, characterization and antitumor mechanism investigation of ruthenium(II) polypyridyl complexes with artesunate moiety

Six artesunate (ART) conjugated ruthenium(II) complexes (Ru(II)-ART conjugates) with the formula [Ru(N^N)₂bpy(4-CH₃-4'-CH₂OART)](PF₆)₂ (Ru-ART-1-3) and [Ru(N^N)₂bpy(4-CH₂OART-4'-CH₂OART)](PF₆)₂ (Ru-ART-4-6) (N^N = 2,2'-bipyridine (bpy, in Ru-ART-1 and Ru-ART-4), 1,10-phenanthroline (phen, in Ru-ART-2 and Ru-ART-5) and 4,7-diphenyl-1,10-phenanthroline (DIP, in Ru-ART-3 and Ru-ART-6)), were synthesized and characterized. Among them, Ru-ART-1-3 and Ru-ART-4-6 carry one and two ART moieties, respectively. Ru-ART-3 and Ru-ART-6 exhibit better cytotoxicity among six Ru(II)-ART conjugates. These two complexes can be effectively taken up by human cervical carcinoma (HeLa) cells. In addition, they selectively kill cancer cell lines while mildly affect normal cells. Mechanism studies have shown that HeLa cells treated with Ru-ART-3 and Ru-ART-6 show typical apoptotic characteristics (morphology changes, mitochondrial dysfunction, caspase cascade, etc.). On the other hand, the up regulation of Beclin-1 and conversion of LC3-I to LC3-II note the appearance of autophagy. As a result, Ru-ART-3 and Ru-ART-6 induce autophagy-dependent cell apoptosis via mitochondrial dysfunction and reactive oxygen species (ROS) accumulation. In this work, six artesunate (ART) conjugated ruthenium(II) complexes (Ru(II)-ART conjugates) have been synthesized and characterized. Among them, Ru-ART-3 and Ru-ART-6 exhibit better cytotoxicity. Mechanism studies have shown that HeLa cells treated with Ru-ART-3 and Ru-ART-6 show typical apoptotic characteristics (morphology changes, mitochondrial dysfunction, caspase cascade, etc.). On the other hand, the up regulation of Beclin-1 and conversion of LC3-I to LC3-II note the appearance of autophagy.

Luteolin alleviates inorganic mercury-induced kidney injury via activation of the AMPK/mTOR autophagy pathway

Inorganic mercury is a ubiquitous toxic pollutant in the environment. Exposure to inorganic mercury can cause various poisonous effects, including kidney injury. However, no safe and effective treatment for kidney injury caused by inorganic mercury has been found and used. Luteolin (Lut) possesses various beneficial bioactivities. Here, our research aims to investigate the protective effect of Lut on renal injury induced by mercury chloride (HgCl₂) and identify the underlying autophagy regulation mechanism. Twenty-eight 6-8 weeks old Wistar rats were randomly assigned to four groups: control, HgCl₂, HgCl₂ + Lut, and Lut. We performed the determination of oxidative stress and renal function indicators, histopathological analysis, the terminal deoxynucleotidyl transferase-mediated deoxyuracil nucleoside triphosphate nick-end labeling assay to detect apoptosis, western blot detection of autophagy-related protein levels, and atomic absorption method to detect mercury content. Our results showed that Lut ameliorated oxidative stress, apoptosis and restored the autophagy and renal function caused by HgCl₂ in rats. Concretely, the level of nuclear factor E2-related factor, renal adenosine monophosphate-activated protein kinase (AMPK) expression, and autophagy regulation-related proteins levels were down-regulated, and the mammalian target of rapamycin (mTOR) expression was up-regulated by HgCl₂ treatment. However, Lut treatment reversed the above changes. Notably, Lut reduced the accumulation of HgCl₂ in the kidneys and promoted the excretion of HgCl₂ through urine. Collectively, our results demonstrate that Lut can attenuate inorganic mercury-induced renal injury via activating the AMPK/mTOR autophagy pathway. Therefore, Lut may be a potential biological medicine to protect against renal damage induced by HgCl₂.

BMSC-Derived Exosomes Ameliorate LPS-Induced Acute Lung Injury by miR-384-5p-Controlled Alveolar Macrophage Autophagy

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are common critical diseases. Bone marrow mesenchymal stem cell (BMSC) transplantation is previously shown to effectively rescue injured lung tissues. The therapeutic mechanism of BMSC-derived exosomes is not fully understood. Here, we investigated the BMSC-derived exosomal microRNAs (miRNAs) on effecting lipopolysaccharide- (LPS-) induced ALI and its mechanism. In vitro, rat alveolar macrophages were treated with or without exosomes in the presence of 10 μg/ml LPS for 24 h. Cell viability was determined with Cell Counting Kit-8 assay. Apoptotic ratio was determined with TUNEL and Annexin V-FITC/PI double staining. The levels of miR-384-5p and autophagy-associated genes were measured by RT-qPCR and western blot. Autophagy was observed by TEM and assessed by means of the mRFP-GFP-LC3 adenovirus transfection assay. In vivo, we constructed LPS-induced ALI rat models. Exosomes were injected into rats via the caudal vein or trachea 4 h later after LPS treatment. The lung histological pathology was determined by H&E staining. Pulmonary vascular permeability was assessed by wet-to-dry weight ratio and Evans blue dye leakage assay, and inflammatory cytokines in serum and BALF were measured by ELISA. Furthermore, the therapeutic mechanism involved in miR-384-5p and Beclin-1 was determined. The results showed that BMSC-derived exosomes were taken up by the alveolar macrophages and attenuated LPS-induced alveolar macrophage viability loss and apoptosis. Exosomes effectively improved the survival rate of ALI rats within 7 days, which was associated with alleviating lung pathological changes and pulmonary vascular permeability and attenuating inflammatory response. Furthermore, this study for the first time found that miR-384-5p was enriched in BMSC-derived exosomes, and exosomal miR-384-5p resulted in relieving LPS-injured autophagy disorder in alveolar macrophages by targeting Beclin-1. Therefore, exosomal miR-384-5p could be demonstrated as a promising therapeutic strategy for ALI/ARDS.

The ORF8 protein of SARS-CoV-2 mediates immune evasion through down-regulating MHC-Ι

COVID-19, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has become a global pandemic and has claimed over 2 million lives worldwide. Although the genetic sequences of SARS-CoV and SARS-CoV-2 have high homology, the clinical and pathological characteristics of COVID-19 differ significantly from those of SARS. How and whether SARS-CoV-2 evades (cellular) immune surveillance requires further elucidation. In this study, we show that SARS-CoV-2 infection leads to major histocompability complex class Ι (MHC-Ι) down-regulation both in vitro and in vivo. The viral protein encoded by open reading frame 8 (ORF8) of SARS-CoV-2, which shares the least homology with SARS-CoV among all viral proteins, directly interacts with MHC-Ι molecules and mediates their down-regulation. In ORF8-expressing cells, MHC-Ι molecules are selectively targeted for lysosomal degradation via autophagy. Thus, SARS-CoV-2-infected cells are much less sensitive to lysis by cytotoxic T lymphocytes. Because ORF8 protein impairs the antigen presentation system, inhibition of ORF8 could be a strategy to improve immune surveillance.

Protective impact of Spirulina platensis against γ-irradiation and thioacetamide-induced nephrotoxicity in rats mediated by regulation of micro-RNA 1 and micro-RNA 146a

Chronic kidney disease develops popular and medical health problems, especially in developing countries. The objective of this study is to investigate the protective mechanism of Spirulina platensis against γ-irradiation (R) and/or thioacetamide (TAA)-induced nephrotoxicity in rats. Rats intoxicated with R or TAA showed alterations in kidney function markers (urea, creatinine, albumin, and total protein contents), oxidative stress markers (malondialdehyde, reduced glutathione), antioxidant enzymes (superoxide dismutase, catalase), and several inflammatory markers (including, the high-sensitivity C-reactive protein, hypoxia-inducible factor-1 alpha, tumor necrosis factor-alpha, interferon-gamma, some interleukins, and nuclear factor-kappa B). Rats also acquired apoptosis, evinced by high caspase-3 efficacy. This nephrotoxicity mediated by upregulation of the messenger RNA (mRNA) gene expression of the autophagy markers: Beclin-1, microtubule-associated protein LC3, p62 binding protein, immunoglobulin G receptor Fcγ receptor (FcγR), micro-RNA-1 (miR-1), protein expression of phospho-adenosine monophosphate-activated protein kinase, and phospho-mammalian target of rapamycin, along with downregulation of miR-146a mRNA gene expression and alteration of calcium and iron levels. The combined treatment R/TAA enhanced the observed oxidative stress, inflammation, apoptosis, and autophagy that mediated by higher upregulation of miR-1 and downregulation of miR-146a mRNA gene expression. Spirulina platensis administration exhibited a nephroprotective impact on R, TAA, and R/TAA toxicities via regulating miR-1 and miR-146a mRNA gene expression that monitored adenosine monophosphate-activated protein kinase/mammalian target of rapamycin signaling.

A Ganoderma atrum polysaccharide alleviated DSS-induced ulcerative colitis by protecting the apoptosis/autophagy-regulated physical barrier and the DC-related immune barrier

Polysaccharides are one of the main active substances in Ganoderma atrum (G. atrum). The purpose of this study was to explore the protective effect of a G. atrum polysaccharide (PSG-1) on DSS-induced colitis and the underlying mechanism. The results showed that PSG-1 could maintain the integrity of the intestinal structure by promoting the expression of goblet cells and levels of tight junction proteins in the colon of DSS-induced colitis mice. Furthermore, PSG-1 relieved the inhibition of Bcl-2 and the overexpression of caspase-3 and caspase-9 caused by DSS. Simultaneously, PSG-1 restored the expression of Atg5, Atg7 and beclin-1 and inhibited the p-akt and p-mTOR levels, suggesting that PSG-1 promoted autophagy via the Akt/mTOR pathway. Moreover, PSG-1 inhibited the content of DCs in the colon and modulated the expression of IL-10 in DCs. In conclusion, PSG-1 alleviated DSS-induced ulcerative colitis by protecting the apoptosis/autophagy-regulated physical barrier and the DC-related immune barrier.