Inhibition of SIRT1/2 upregulates HSPA5 acetylation and induces pro-survival autophagy via ATF4-DDIT4-mTORC1 axis in human lung cancer cells

Emerging role of sirtuins in non‑small cell lung cancer (Review)

Non‑small cell lung cancer (NSCLC) is a highly prevalent lung malignancy characterized by insidious onset, rapid progression and advanced stage at the time of diagnosis, making radical surgery impossible. Sirtuin (SIRT) is a histone deacetylase that relies on NAD+ for its function, regulating the aging process through modifications in protein activity and stability. It is intricately linked to various processes, including glycolipid metabolism, inflammation, lifespan regulation, tumor formation and stress response. An increasing number of studies indicate that SIRTs significantly contribute to the progression of NSCLC by regulating pathophysiological processes such as energy metabolism, autophagy and apoptosis in tumor cells through the deacetylation of histones or non‑histone proteins. The present review elaborates on the roles of different SIRTs and their mechanisms in NSCLC, while also summarizing novel therapeutic agents based on SIRTs. It aims to present new ideas and a theoretical basis for NSCLC treatment.

Phenformin activates ER stress to promote autophagic cell death via NIBAN1 and DDIT4 in oral squamous cell carcinoma independent of AMPK

The efficient clinical treatment of oral squamous cell carcinoma (OSCC) is still a challenge that demands the development of effective new drugs. Phenformin has been shown to produce more potent anti-tumor activities than metformin on different tumors, however, not much is known about the influence of phenformin on OSCC cells. We found that phenformin suppresses OSCC cell proliferation, and promotes OSCC cell autophagy and apoptosis to significantly inhibit OSCC cell growth both in vivo and in vitro. RNA-seq analysis revealed that autophagy pathways were the main targets of phenformin and identified two new targets DDIT4 (DNA damage inducible transcript 4) and NIBAN1 (niban apoptosis regulator 1). We found that phenformin significantly induces the expression of both DDIT4 and NIBAN1 to promote OSCC autophagy. Further, the enhanced expression of DDIT4 and NIBAN1 elicited by phenformin was not blocked by the knockdown of AMPK but was suppressed by the knockdown of transcription factor ATF4 (activation transcription factor 4), which was induced by phenformin treatment in OSCC cells. Mechanistically, these results revealed that phenformin triggers endoplasmic reticulum (ER) stress to activate PERK (protein kinase R-like ER kinase), which phosphorylates the transitional initial factor eIF2, and the increased phosphorylation of eIF2 leads to the increased translation of ATF4. In summary, we discovered that phenformin induces its new targets DDIT4 and especially NIBAN1 to promote autophagic and apoptotic cell death to suppress OSCC cell growth. Our study supports the potential clinical utility of phenformin for OSCC treatment in the future.

Research progress on Sirtuins (SIRTs) family modulators

Sirtuins (SIRTs) represent a class of nicotinamide adenine dinucleotide (NAD+)-dependent protein deacetylases that exert a crucial role in cellular signal transduction and various biological processes. The mammalian sirtuins family encompasses SIRT1 to SIRT7, exhibiting therapeutic potential in counteracting cellular aging, modulating metabolism, responding to oxidative stress, inhibiting tumors, and improving cellular microenvironment. These enzymes are intricately linked to the occurrence and treatment of diverse pathological conditions, including cancer, autoimmune diseases, and cardiovascular disorders. Given the significance of histone modification in gene expression and chromatin structure, maintaining the equilibrium of the sirtuins family is imperative for disease prevention and health restoration. Mounting evidence suggests that modulators of SIRTs play a crucial role in treating various diseases and maintaining physiological balance. This review delves into the molecular structure and regulatory functions of the sirtuins family, reviews the classification and historical evolution of SIRTs modulators, offers a systematic overview of existing SIRTs modulation strategies, and elucidates the regulatory mechanisms of SIRTs modulators (agonists and inhibitors) and their clinical applications. The article concludes by summarizing the challenges encountered in SIRTs modulator research and offering insights into future research directions.

Acetyl-CoA metabolism as a therapeutic target for cancer

Acetyl-coenzyme A (acetyl-CoA), an essential metabolite, not only takes part in numerous intracellular metabolic processes, powers the tricarboxylic acid cycle, serves as a key hub for the biosynthesis of fatty acids and isoprenoids, but also serves as a signaling substrate for acetylation reactions in post-translational modification of proteins, which is crucial for the epigenetic inheritance of cells. Acetyl-CoA links lipid metabolism with histone acetylation to create a more intricate regulatory system that affects the growth, aggressiveness, and drug resistance of malignancies such as glioblastoma, breast cancer, and hepatocellular carcinoma. These fascinating advances in the knowledge of acetyl-CoA metabolism during carcinogenesis and normal physiology have raised interest regarding its modulation in malignancies. In this review, we provide an overview of the regulation and cancer relevance of main metabolic pathways in which acetyl-CoA participates. We also summarize the role of acetyl-CoA in the metabolic reprogramming and stress regulation of cancer cells, as well as medical application of inhibitors targeting its dysregulation in therapeutic intervention of cancers.

Discovery of Novel SIRT1/2 Inhibitors with Effective Cytotoxicity against Human Leukemia Cells

The sirtuin enzyme family members, SIRT1 and SIRT2, play both tumor-promoting and tumor-suppressing roles, depending on the context and experimental conditions. Compounds that inhibit either SIRT1 or SIRT2 show promising antitumor effects in several types of cancer models, both in vitro and in vivo. The simultaneous inhibition of SIRT1 and SIRT2 is helpful in treating cancer by completely blocking p53 deacetylation, leading to cell death. However, only a few SIRT1/2 dual inhibitors have been developed. Here, we report the discovery of a novel series of SIRT1/2 dual inhibitors via a rational drug design that involved virtual screening and a substructure search. Eleven of the derived compounds exhibited high inhibitory activities, with IC50 < 5 μM and high specificity for both SIRT1 and SIRT2. Compounds hsa55 and PS9 strongly induced apoptosis and showed antiproliferative effects against human leukemia cell lines, which could be due to their ability to increase of p53 and α-tubulin acetylation, as we observed in MOLM-13 cells. Therefore, the new scaffolds of these compounds and their efficacy in leukemia cell lines provide important clues for the further development of novel anti-leukemia drugs.

Therapeutic hyperthermia regulates complement C3 activation and suppresses tumor development through HSPA5/NFκB/CD55 pathway in nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is endemic in Southern China and Southeast Asia. Hyperthermia is widely used in combination with chemotherapy and radiotherapy to enhance therapeutic efficacy in NPC treatment, but the underlying anti-tumor mechanisms of hyperthermia remain unclear. Complement C3 has been reported to participate in the activation of immune system in the tumor microenvironment, leading to tumor growth inhibition. In this study, we aimed to explore the effect and mechanisms of hyperthermia and investigate the functional role of complement C3 in NPC hyperthermia therapy (HT). The serum levels of complement C3 before and after hyperthermia therapy in patients with NPC were analyzed. NPC cell lines SUNE1 and HONE1 were used for in vitro experiment to evaluate the function of complement C3 and HT on cell proliferation and apoptosis. SUNE1 xenograft mouse model was established and tumor-bearing mice were treated in water bath at a constant temperature of 43°C. Tumor samples were collected at different time points to verify the expression of complement C3 by immunohistochemical staining and western blot. The differential expressed genes after hyperthermia were analyzed by using RNA sequencing. We found that complement could enhance hyperthermia effect on suppressing proliferation and promoting apoptosis of tumor cells in NPC. Hyperthermia decreased the mRNA expression of complement C3 in tumor cells, but promoted the aggregation and activation circulating C3 in NPC tumor tissue. By using in vitro hyperthermia-treated NPC cell lines and SUNE1 xenograft tumor-bearing mice, we found that the expression of heat shock protein 5 (HSPA5) was significantly upregulated. Knockdown of HSPA5 abrogated the anti-tumor effect of hyperthermia. Moreover, we demonstrated that hyperthermia downregulated CD55 expression via HSPA5/NFκB (P65) signaling and activated complement cascade. Our findings suggest that therapeutic hyperthermia regulates complement C3 activation and suppresses tumor development via HSPA5/NFκB/CD55 pathway in NPC.

Unraveling the Post-Translational Modifications and therapeutical approach in NSCLC pathogenesis

Non-Small Cell Lung Cancer (NSCLC) is the most prevalent kind of lung cancer with around 85% of total lung cancer cases. Despite vast therapies being available, the survival rate is low (5 year survival rate is 15%) making it essential to comprehend the mechanism for NSCLC cell survival and progression. The plethora of evidences suggests that the Post Translational Modification (PTM) such as phosphorylation, methylation, acetylation, glycosylation, ubiquitination and SUMOylation are involved in various types of cancer progression and metastasis including NSCLC. Indeed, an in-depth understanding of PTM associated with NSCLC biology will provide novel therapeutic targets and insight into the current sophisticated therapeutic paradigm. Herein, we reviewed the key PTMs, epigenetic modulation, PTMs crosstalk along with proteogenomics to analyze PTMs in NSCLC and also, highlighted how epi‑miRNA, miRNA and PTM inhibitors are key modulators and serve as promising therapeutics.

DDIT4 promotes malignancy of head and neck squamous cell carcinoma

This study investigated the cancer-promoting effect of ferroptosis regulator DNA damage-inducible transcript 4 (DDIT4) and its relevant mechanisms. Vital ferroptosis-related genes were identified using bioinformatic methods on the basis of data collected from TCGA and seven other online databases. Cell Counting Kit-8 (CCK8), colony formation, wound-healing and transwell assays, and western blot analysis were conducted for verifying the biological role of DDIT4 in vitro. The immune score and tumor purity were calculated using R package "estimate." The relationship was identified between DDIT4 expression and immune cell infiltration using ssGSEA and CIBERSORT algorithms. R package "Seurat" was used to perform unsupervised clustering of the single cells, and "SingleR" was utilized for annotation. R package "STUtility" was employed to plot the spatial expression of DDIT4. For trajectory analysis, monocle was used to predict cell differentiation and demonstrate the expression of DDIT4 at each state. Here, DDIT4 overexpression was observed in Head and Neck Squamous Cell Carcinoma (HNSCC) cohort, and DDIT4 upregulation showed a positive correlation with larger tumor size, lymph node metastasis, more advanced TNM stage and higher tumor mutational burden (TMB). Moreover, DDIT4 knockdown could markedly inhibit the proliferation, colony formation, invasion and migration of HNSCC cells, as well as suppress the expression of HIF-1a, VEGF and vimentin. In comparison, DDIT4 overexpression showed a negative correlation with immune score and infiltrations of several immune cells. DDIT4 played crucial roles in the differentiation of CAFs and T cells. Collectively, this study demonstrates that DDIT4 contributes a critical role in HNSCC progression. The positive feedback regulation between DDIT4 and HIF-1a may be a potential target for HNSCC treatment.

SIRT1 as a Potential Therapeutic Target for Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a common, preventable, and treatable disease characterized by irreversible airflow obstruction and lung function decline. It is well established that COPD represents a major cause of morbidity and mortality globally. Due to the substantial economic and social burdens associated with COPD, it is necessary to discover new targets and develop novel beneficial therapies. Although the pathogenesis of COPD is complex and remains to be robustly elucidated, numerous studies have shown that oxidative stress, inflammatory responses, cell apoptosis, autophagy, and aging are involved in the pathogenesis of COPD. Sirtuin 1 (SIRT1) is a nicotinamide adenine dinucleotide (NAD+)-dependent deacetylase belonging to the silent information regulator 2 (Sir2) family. Multiple studies have indicated that SIRT1 plays an important role in oxidative stress, apoptosis, inflammation, autophagy, and cellular senescence, which contributes to the pathogenesis and development of COPD. This review aimed to discuss the functions and mechanisms of SIRT1 in the progression of COPD and concluded that SIRT1 activation might be a potential therapeutic strategy for COPD.

Non-canonical functions of spliceosome components in cancer progression

Dysregulation of pre-mRNA splicing is a common hallmark of cancer cells and it is associated with altered expression, localization, and mutations of the components of the splicing machinery. In the last few years, it has been elucidated that spliceosome components can also influence cellular processes in a splicing-independent manner. Here, we analyze open source data to understand the effect of the knockdown of splicing factors in human cells on the expression and splicing of genes relevant to cell proliferation, migration, cell cycle regulation, DNA repair, and cell death. We supplement this information with a comprehensive literature review of non-canonical functions of splicing factors linked to cancer progression. We also specifically discuss the involvement of splicing factors in intercellular communication and known autoregulatory mechanisms in restoring their levels in cells. Finally, we discuss strategies to target components of the spliceosome machinery that are promising for anticancer therapy. Altogether, this review greatly expands understanding of the role of spliceosome proteins in cancer progression.

Epigenetic and post-translational modifications in autophagy: biological functions and therapeutic targets

Autophagy is a conserved lysosomal degradation pathway where cellular components are dynamically degraded and re-processed to maintain physical homeostasis. However, the physiological effect of autophagy appears to be multifaced. On the one hand, autophagy functions as a cytoprotective mechanism, protecting against multiple diseases, especially tumor, cardiovascular disorders, and neurodegenerative and infectious disease. Conversely, autophagy may also play a detrimental role via pro-survival effects on cancer cells or cell-killing effects on normal body cells. During disorder onset and progression, the expression levels of autophagy-related regulators and proteins encoded by autophagy-related genes (ATGs) are abnormally regulated, giving rise to imbalanced autophagy flux. However, the detailed mechanisms and molecular events of this process are quite complex. Epigenetic, including DNA methylation, histone modifications and miRNAs, and post-translational modifications, including ubiquitination, phosphorylation and acetylation, precisely manipulate gene expression and protein function, and are strongly correlated with the occurrence and development of multiple diseases. There is substantial evidence that autophagy-relevant regulators and machineries are subjected to epigenetic and post-translational modulation, resulting in alterations in autophagy levels, which subsequently induces disease or affects the therapeutic effectiveness to agents. In this review, we focus on the regulatory mechanisms mediated by epigenetic and post-translational modifications in disease-related autophagy to unveil potential therapeutic targets. In addition, the effect of autophagy on the therapeutic effectiveness of epigenetic drugs or drugs targeting post-translational modification have also been discussed, providing insights into the combination with autophagy activators or inhibitors in the treatment of clinical diseases.

Identification of Autophagy-Related Targets of Berberine against Non-Small Cell Lung Cancer and Their Correlation with Immune Cell Infiltration By Combining Network Pharmacology, Molecular Docking, and Experimental Verification

OBJECTIVE

Non-small cell lung cancer (NSCLC) is the most common lung cancer type with high incidence. This study aimed to reveal the anti-NSCLC mechanisms of berberine and identify novel therapeutic targets.

METHODS

Berberine-related targets were acquired from SuperPred, SwissTargetPrediction, and GeneCards. NSCLC-re-lated targets were collected from GeneCards and DisGeNET. Differentially expressed genes (DEGs) were identified GEO database, UCSC Xena, and limma. GO and KEGG analyses were performed using clusterProfiler. Autophagy-related genes and transcriptional factors were collected from HADb and KnockTF, respectively. STRING and Cytoscape were used for PPI network analysis. Immune cell infiltration in NSCLC was assessed using CIBERSORT, and its correlation with autophagy-related targets was evaluated. Molecular docking was conducted using PyMOL and AutoDock. qRT-PCR and CCK-8 assay was used for in vitro verification.

RESULTS

Thirty intersecting targets of berberine-related targets, NSCLC-related targets, and DEGs were obtained. GO and KEGG analyses revealed that the intersecting targets were mainly implicated in oxidative stress, focal adhesion, and cell-substrate junction, as well as AGE-RAGE, relaxin, FoxO, and estrogen signaling pathways. Significantly, CAPN1, IKBKB, and SIRT2 were identified as the foremost autophagy-related targets, and 21 corresponding transcriptional factors were obtained. PPI network analysis showed that CAPN1, IKBKB, and SIRT2 interacted with 50 other genes. Fifty immune cell types, such as B cells naive, T cells CD8, T cells CD4 naive, T cells follicular helper, and monocytes, were implicated in NSCLC pathogenesis, and CAPN1, IKBKB, and SIRT2 were related to immune cells. Molecular docking revealed the favorable binding activity of berberine with CAPN1, IKBKB, and SIRT2. In vitro assays showed lower CAPN1, IKBKB, and SIRT2 expression in NSCLC cells than that in normal cells. Notably, berberine inhibited the viability and elevated CAPN1, IKBKB, and SIRT2 expression in NSCLC cells.

CONCLUSIONS

Berberine might treat NSCLC mainly by targeting CAPN1, IKBKB, and SIRT2.

Emerging roles of activating transcription factor (ATF) family members in tumourigenesis and immunity: Implications in cancer immunotherapy

Activating transcription factors, ATFs, are a group of bZIP transcription factors that act as homodimers or heterodimers with a range of other bZIP factors. In general, ATFs respond to extracellular signals, indicating their important roles in maintaining homeostasis. The ATF family includes ATF1, ATF2, ATF3, ATF4, ATF5, ATF6, and ATF7. Consistent with the diversity of cellular processes reported to be regulated by ATFs, the functions of ATFs are also diverse. ATFs play an important role in cell proliferation, apoptosis, differentiation and inflammation-related pathological processes. The expression and phosphorylation status of ATFs are also related to neurodegenerative diseases and polycystic kidney disease. Various miRNAs target ATFs to regulate cancer proliferation, apoptosis, autophagy, sensitivity and resistance to radiotherapy and chemotherapy. Moreover, ATFs are necessary to maintain cell redox homeostasis. Therefore, deepening our understanding of the regulation and function of ATFs will provide insights into the basic regulatory mechanisms that influence how cells integrate extracellular and intracellular signals into genomic responses through transcription factors. Under pathological conditions, especially in cancer biology and response to treatment, the characterization of ATF dysfunction is important for understanding how to therapeutically utilize ATF2 or other pathways controlled by transcription factors. In this review, we will demonstrate how ATF1, ATF2, ATF3, ATF4, ATF5, ATF6, and ATF7 function in promoting or suppressing cancer development and identify their roles in tumour immunotherapy.

Will Sirtuin 2 Be a Promising Target for Neuroinflammatory Disorders?

Neuroinflammatory disorder is a general term that is associated with the progressive loss of neuronal structure or function. At present, the widely studied diseases with neuroinflammatory components are mainly divided into neurodegenerative and neuropsychiatric diseases, namely, Alzheimer’s disease, Parkinson’s disease, depression, stroke, and so on. An appropriate neuroinflammatory response can promote brain homeostasis, while excessive neuroinflammation can inhibit neuronal regeneration and damage the central nervous system. Apart from the symptomatic treatment with cholinesterase inhibitors, antidepressants/anxiolytics, and neuroprotective drugs, the treatment of neuroinflammation is a promising therapeutic method. Sirtuins are a host of class III histone deacetylases, that require nicotinamide adenine dinucleotide for their lysine residue deacetylase activity. The role of sirtuin 2 (SIRT2), one of the sirtuins, in modulating senescence, myelin formation, autophagy, and inflammation has been widely studied. SIRT2 is associated with many neuroinflammatory disorders considering it has deacetylation properties, that regulate the entire immune homeostasis. The aim of this review was to summarize the latest progress in regulating the effects of SIRT2 on immune homeostasis in neuroinflammatory disorders. The overall structure and catalytic properties of SIRT2, the selective inhibitors of SIRT2, the relationship between immune homeostasis and SIRT2, and the multitasking role of SIRT2 in several diseases with neuroinflammatory components were discussed.

Association of sirtuins (SIRT1-7) with lung and intestinal diseases

"Exterior-interior correlation between the lung and large intestine" is one of the important contents of traditional Chinese medicine. This theory describes the role of the lung and the intestine in association with disease treatment. The "lung-gut" axis is a modern extension of the "exterior-interior correlation between lung and large intestine" theory in TCM. Sirtuin (SIRT) is a nicotinamide adenine dinucleotide (NAD⁺)-dependent enzyme family with deacetylase properties, which is highly conserved from bacteria to humans. The sirtuin defines seven silencing regulatory proteins (SIRT1-7) in human cells. It can regulate aging, metabolism, and certain diseases. Current studies have shown that sirtuins have dual characteristics, acting as both tumor promoters and tumor inhibitors in cancers. This paper provides a comparative summary of the roles of SIRT1-7 in the intestine and lung (both inflammatory diseases and tumors), and the promoter/suppressor effects of targeting SIRT family microRNAs and modulators of inflammation or tumors. Sirtuins have great potential as drug targets for the treatment of intestinal and respiratory diseases. Meanwhile, it may provide new ideas of future drug target research.

Molecular Fingerprint of BMD Patients Lacking a Portion in the Rod Domain of Dystrophin

BMD is characterized by a marked heterogeneity of gene mutations resulting in many abnormal dystrophin proteins with different expression and residual functions. The smaller dystrophin molecules lacking a portion around exon 48 of the rod domain, named the D8 region, are related to milder phenotypes. The study aimed to determine which proteins might contribute to preserving muscle function in these patients. Patients were subdivided, based on the absence or presence of deletions in the D8 region, into two groups, BMD1 and BMD2. Muscle extracts were analyzed by 2-D DIGE, label-free LC-ESI-MS/MS, and Ingenuity pathway analysis (IPA). Increased levels of proteins typical of fast fibers and of proteins involved in the sarcomere reorganization characterize BMD2. IPA of proteomics datasets indicated in BMD2 prevalence of glycolysis and gluconeogenesis and a correct flux through the TCA cycle enabling them to maintain both metabolism and epithelial adherens junction. A 2-D DIGE analysis revealed an increase of acetylated proteoforms of moonlighting proteins aldolase, enolase, and glyceraldehyde-3-phosphate dehydrogenase that can target the nucleus promoting stem cell recruitment and muscle regeneration. In BMD2, immunoblotting indicated higher levels of myogenin and lower levels of PAX7 and SIRT1/2 associated with a set of proteins identified by proteomics as involved in muscle homeostasis maintenance.

Clinical Roles of Risk Model Based on Differentially Expressed Genes in Mesenchymal Stem Cells in Prognosis and Immunity of Non-small Cell Lung Cancer

The tumor microenvironment (TME) plays an important regulatory role in the progression of non-small cell lung cancer (NSCLC). Mesenchymal stem cells (MSCs) in the TME might contribute to the occurrence and development of cancer. This study evaluates the role of differentially expressed genes (DEGs) of MSCs and the development of NSCLC and develops a prognostic risk model to assess the therapeutic responses. The DEGs in MSCs from lung tissues and from normal tissues were analyzed using GEO2R. The functions and mechanisms of the DEGs were analyzed using the Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). Additionally, the Cancer Genome Atlas (TCGA) database was used to determine the expression levels of the DEGs of MSCs in the NSCLC tissues. The prognostic factors of NSCLC related to MSCs were screened by survival analysis, meta-analysis, Cox regression analysis, and a prognostic risk model and nomogram was developed. The signaling mechanisms and immune roles that risk model participate in NSCLC development were determined via Gene Set Enrichment Analysis and CIBERSORT analysis. Compared to the normal tissues, 161 DEGs were identified in the MSCs of the lung tissues. These DEGs were associated with mechanisms, such as DNA replication, nuclear division, and homologous recombination. The overexpression of DDIT4, IL6, ITGA11, MME, MSX2, POSTN, and TRPA1 were associated with dismal prognosis of NSCLC patients. A high-risk score based on the prognostic risk model indicated the dismal prognosis of NSCLC patients. The nomogram showed that the age, clinical stage, and risk score affected the prognosis of NSCLC patients. Further, the high-risk model was associated with signaling mechanisms, such as the ECM-receptor interaction pathways, cytokine-cytokine receptor interaction, and MAPK pathways, involved in the progression of NSCLC and was also related to the components of the immune system, such as macrophages M0, T follicular helper cells, regulatory T cells. Therefore, the risk model and nomogram that was constructed on the basis of MSC-related factors such as POSTN, TRPA1, and DDIT4 could facilitate the discovery of target molecules that participate in the progression of NSCLC, which might also serve as new candidate markers for evaluating the prognosis of NSCLC patients.

TKI resistant-based prognostic immune related gene signature in LUAD, in which FSCN1 contributes to tumor progression

Drug resistance reflects the evolution of tumors, which is the main cause of recurrence and death. Currently, EGFR-TKI treatment is the first-line therapy for lung adenocarcinoma (LUAD) patients. Although EGFR-TKI achieved good effects at the beginning, most of the LUAD patients eventually acquired resistance. Therefore, it's urgently need to develop a strong criterion for identifying these patients who may benefit from additional therapy. In this study, we established a three TKI resistant-related gene signature (DDIT4, OAS3, FSCN1), and determined that's an accuracy, independent and specific prognostic model for LUAD patients. Patients categorized as high-risk by this signature showed more sensitive to chemotherapy, and exhibited higher expression of common immune checkpoints such as PD-L1/B3H7/PD-L2/IDO1. Moreover, these patients were characterized by increased infiltration of M0 macrophage and activated memory CD4⁺ T cells. The expression and prognostic values of DDIT4, FSCN1 and OAS3 were further confirmed in clinical data. In addition, experimental data showed that FSCN1 promoted LUAD development via PI3K/AKT signaling. In conclusion, this signature is highly predictive of prognostic in LUAD patients, and may serve as a powerful prediction tool for LUAD patients to further choose chemo- and immunotherapies.

A Novel Predictive Model Incorporating Ferroptosis-Related Gene Signatures for Overall Survival in Patients with Lung Adenocarcinoma

BACKGROUND Lung adenocarcinoma (LUAD) is the predominant histological type of lung cancer with high morbidity and mortality. Ferroptosis is regarded as a new pattern of programmed cell death concerned with the progression of lung cancer characterized by lipid peroxidation. Nevertheless, the prognostic role of ferroptosis-related genes for LUAD warrant to be explored. MATERIAL AND METHODS RNA sequencing and relevant clinical patient data were obtained from public-access databanks. A prognostic model was constructed through the LASSO Cox regression in the cancer genome atlas cohort. The diagnostic value of the prognostic model was further evaluated in the gene expression omnibus cohort. RESULTS Most of the ferroptosis-related genes (69.9%) were differentially expressed between tumor and adjacent non-cancerous tissues. 43 differentially expressed genes showed a close association with the prognosis of LUAD patients (adjusted p-value <0.05). An 18-gene signature was built and applied to assign patients into high vs low-risk groups. Compared with the high-risk group, patients defined as the low-risk group suffered significantly prolonged OS. Both uni- and multivariate analyses demonstrated that the signature-based score served as a crucial role in influencing the OS of LUAD patients (hazard ratio >1, p<0.001). The immunity-related signaling pathway was enriched in the functional analysis and the infiltration of the immune cells showed a great difference between groups. CONCLUSIONS The predictive model could be applied for prognostic prediction for LUAD. Targeting ferroptosis could be a possible curative strategy against LUAD, and immunomodulation may be one of the potential mechanisms.

Transcriptional and Post-Transcriptional Regulation of Autophagy

Autophagy is a widely conserved process in eukaryotes that is involved in a series of physiological and pathological events, including development, immunity, neurodegenerative disease, and tumorigenesis. It is regulated by nutrient deprivation, energy stress, and other unfavorable conditions through multiple pathways. In general, autophagy is synergistically governed at the RNA and protein levels. The upstream transcription factors trigger or inhibit the expression of autophagy- or lysosome-related genes to facilitate or reduce autophagy. Moreover, a significant number of non-coding RNAs (microRNA, circRNA, and lncRNA) are reported to participate in autophagy regulation. Finally, post-transcriptional modifications, such as RNA methylation, play a key role in controlling autophagy occurrence. In this review, we summarize the progress on autophagy research regarding transcriptional regulation, which will provide the foundations and directions for future studies on this self-eating process.

The role of protein acetylation in carcinogenesis and targeted drug discovery

Protein acetylation is a reversible post-translational modification, and is involved in many biological processes in cells, such as transcriptional regulation, DNA damage repair, and energy metabolism, which is an important molecular event and is associated with a wide range of diseases such as cancers. Protein acetylation is dynamically regulated by histone acetyltransferases (HATs) and histone deacetylases (HDACs) in homeostasis. The abnormal acetylation level might lead to the occurrence and deterioration of a cancer, and is closely related to various pathophysiological characteristics of a cancer, such as malignant phenotypes, and promotes cancer cells to adapt to tumor microenvironment. Therapeutic modalities targeting protein acetylation are a potential therapeutic strategy. This article discussed the roles of protein acetylation in tumor pathology and therapeutic drugs targeting protein acetylation, which offers the contributions of protein acetylation in clarification of carcinogenesis, and discovery of therapeutic drugs for cancers, and lays the foundation for precision medicine in oncology.

Mitophagy in depression: Pathophysiology and treatment targets

Mitochondria, the 'powerhouse' of eukaryotic cells, play a key role in cellular homeostasis. However, defective mitochondria increase mitochondrial ROS (mtROS) production and cell-free mitochondrial DNA (mtDNA) release, leading to increased inflammation. Mitophagy is a vital pathway, which selectively removes defective mitochondria through the process of autophagy. Thus, an impairment in the mitophagy pathway might trigger the gradual accumulation of defective mitochondria. Accumulating evidence suggest that inflammation and mitochondrial dysfunction are linked to the pathogenesis of depression. In this article, we have reviewed the role of impaired mitophagy as a contributing factor in depression pathophysiology. Further, we have discussed the potential therapeutic interventions aimed at modulating mitophagy in depression.

Emerging role of SIRT2 in non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is one of the most devastating cancer types, accounting for >80% of lung cancer cases. The median relative survival time of patients with NSCLC is <1 year. Lysine acetylation is a major post-translational modification that is required for various biological processes, and abnormal protein acetylation is associated with various diseases, including NSCLC. Protein deacetylases are currently considered cancer permissive partly due to malignant cells being sensitive to deacetylase inhibition. Sirtuin 2 (SIRT2), a primarily cytosolic nicotinamide adenine dinucleotide-dependent class III protein deacetylase, has been shown to catalyze the removal of acetyl groups from a wide range of proteins, including tubulin, ribonucleotide reductase regulatory subunit M2 and glucose-6-phosphate dehydrogenase. In addition, SIRT2 is also known to possess lysine fatty deacylation activity. Physiologically, SIRT2 serves as a regulator of the cell cycle and of cellular metabolism. It has been shown to play important roles in proliferation, migration and invasion during carcinogenesis. It is notable that both oncogenic and tumor suppressive functions of SIRT2 have been described in NSCLC and other cancer types, suggesting a context-specific role of SIRT2 in cancer progression. In addition, inhibition of SIRT2 exhibits a broad anticancer effect, indicating its potential as a therapeutic for NSCLC tumors with high expression of SIRT2. However, due to the diverse molecular and genetic characteristics of NSCLC, the context-specific function of SIRT2 remains to be determined. The current review investigated the functions of SIRT2 during NSCLC progression with regard to its regulation of metabolism, stem cell-like features and autophagy.

PPARα and PPARγ Signaling Is Enhanced in the Brain of the Naked Mole-Rat, a Mammal that Shows Intrinsic Neuroprotection from Oxygen Deprivation

Naked mole-rats (NMRs) are a long-lived animal that do not develop age-related diseases including neurodegeneration and cancer. Additionally, NMRs have a profound ability to consume reactive oxygen species (ROS) and survive long periods of oxygen deprivation. Here, we evaluated the unique proteome across selected brain regions of NMRs at different ages. Compared to mice, we observed numerous differentially expressed proteins related to altered mitochondrial function in all brain regions, suggesting that the mitochondria in NMRs may have adapted to compensate for energy demands associated with living in a harsh, underground environment. Keeping in mind that ROS can induce polyunsaturated fatty acid peroxidation under periods of neuronal stress, we investigated docosahexaenoic acid (DHA) and arachidonic acid (AA) peroxidation under oxygen-deprived conditions and observed that NMRs undergo DHA and AA peroxidation to a far less extent compared to mice. Further, our proteomic analysis also suggested enhanced peroxisome proliferator-activated receptor (PPAR)-retinoid X receptor (RXR) activation in NMRs via the PPARα-RXR and PPARγ-RXR complexes. Correspondingly, we present several lines of evidence supporting PPAR activation, including increased eicosapetenoic and omega-3 docosapentaenoic acid, as well as an upregulation of fatty acid-binding protein 3 and 4, known transporters of omega-3 fatty acids and PPAR activators. These results suggest enhanced PPARα and PPARγ signaling as a potential, innate neuroprotective mechanism in NMRs.

Cognitive Impairment and Dementia: Gaining Insight through Circadian Clock Gene Pathways

Neurodegenerative disorders affect fifteen percent of the world's population and pose a significant financial burden to all nations. Cognitive impairment is the seventh leading cause of death throughout the globe. Given the enormous challenges to treat cognitive disorders, such as Alzheimer's disease, and the inability to markedly limit disease progression, circadian clock gene pathways offer an exciting strategy to address cognitive loss. Alterations in circadian clock genes can result in age-related motor deficits, affect treatment regimens with neurodegenerative disorders, and lead to the onset and progression of dementia. Interestingly, circadian pathways hold an intricate relationship with autophagy, the mechanistic target of rapamycin (mTOR), the silent mating type information regulation 2 homolog 1 (Saccharomyces cerevisiae) (SIRT1), mammalian forkhead transcription factors (FoxOs), and the trophic factor erythropoietin. Autophagy induction is necessary to maintain circadian rhythm homeostasis and limit cortical neurodegenerative disease, but requires a fine balance in biological activity to foster proper circadian clock gene regulation that is intimately dependent upon mTOR, SIRT1, FoxOs, and growth factor expression. Circadian rhythm mechanisms offer innovative prospects for the development of new avenues to comprehend the underlying mechanisms of cognitive loss and forge ahead with new therapeutics for dementia that can offer effective clinical treatments.

Development and Validation of a Robust Ferroptosis-Related Prognostic Signature in Lung Adenocarcinoma

Background

Lung adenocarcinoma (LUAD) is the most common subtype of non-small cell lung cancer. Ferroptosis is a newly recognized process of cell death, which is different from other forms of cell death in morphology, biochemistry, and genetics, and has played a vital role in cancer biology. This study aimed to identify a ferroptosis-related gene signature associated with LUAD prognosis.

Methods

Dataset TCGA-LUAD which came from the TCGA portal was taken as the training cohort. GSE72094 and GSE68465 from the GEO database were treated as validation cohorts. Two hundred fifty-nine ferroptosis-related genes were retrieved from the FerrDb database. In the training cohort, Kaplan–Meier and univariate Cox analyses were conducted for preliminary screening of ferroptosis-related genes with potential prognostic capacity. These genes then entered into the LASSO Cox regression model, constructing a gene signature. The latter was then evaluated in the training and validation cohorts via Kaplan–Meier, Cox, and ROC analyses. In addition, the correlations between risk score and autophagy were examined by Pearson correlation coefficient. The analyses of GSEA and immune infiltrating were performed for better studying the function annotation of the gene signature and the character of each kind of immune cells played in the tumor microenvironment.

Results

A 15-gene signature was found from the training cohort and validated by Kaplan–Meier and Cox regression analyses, revealing its independent prognosis value in LUAD. Moreover, the ROC analysis was conducted, confirming a strong predictive ability that this signature owned for LUAD prognosis. One hundred fifty-one of 222 (68.01%) autophagy-related genes were discovered significantly correlated with risk scores. Analyses of GSEA and immune infiltration exhibited in detail the specific pathways that associate with the 15-gene signature and identified the crucial roles of resting mast cells and resting dendritic cells owned in the prognosis of the 15-gene signature.

Conclusion

In this present study, a novel ferroptosis-related 15-gene signature (RELA, ACSL3, YWHAE, EIF2S1, CISD1, DDIT4, RRM2, PANX1, TLR4, ARNTL, LPIN1, HERPUD1, NCOA4, PEBP1, and GLS2) was built. It could accurately predict the prognosis of LUAD and was related to resting mast cells and resting dendritic cells, which provide potential for the personalized outcome prediction and the development of new therapies in LUAD population.

Uncarboxylated osteocalcin promotes osteogenesis and inhibits adipogenesis of mouse bone marrow-derived mesenchymal stem cells via the PKA-AMPK-SIRT1 axis

Osteoporosis is a bone disease characterized by reduced bone density, thin cortical bone and large gaps in the bone's honeycomb structure, which increases the risk of bone fragility. Uncarboxylated osteocalcin (unOC), a vitamin K-dependent bone protein, is known to regulate carbohydrate and energy metabolism. A previous study demonstrated that unOC promotes the differentiation of mouse bone marrow-derived mesenchymal stem cells (BMSCs) into osteoblasts, but inhibits their differentiation into adipocytes. However, the underlying mechanism remains unknown. The present study showed that unOC regulated the differentiation potential of BMSCs via protein kinase A (PKA)/AMP-activated protein kinase (AMPK)/sirtuin 1 (SIRT1) signaling. SIRT1, a member of the sirtuin family with deacetylation functions, was upregulated by unOC in BMSCs. Transfection analyses with SIRT1 small interfering RNA indicated that the unOC-induced differentiation shift in BMSCs required SIRT1. Examination of SIRT1 downstream targets revealed that unOC regulated the acetylation levels of runt-related transcription factor (RUNX) 2 and peroxisome proliferator-activated receptor γ (PPARγ). Therefore, unOC inhibited adipogenic differentiation by PPARγ acetylation and promoted osteogenic differentiation by RUNX2 deacetylation. Moreover, phosphorylated PKA and AMPK protein levels increased after unOC treatment, which led to the upregulation of SIRT1. Western blot analysis with PKA and AMPK inhibitors indicated that the PKA-AMPK signaling pathway functioned upstream of SIRT1 and positively regulated SIRT1 expression. These findings led us to propose a model in which unOC regulated BMSC osteogenic differentiation through the PKA-AMPK-SIRT1 axis, giving evidence towards the therapeutic potential of unOC in osteoporosis treatment.

SIRT5 regulates autophagy and apoptosis in gastric cancer cells

OBJECTIVE

Accumulating evidence illustrates that sirtuins (SIRTs) regulate autophagy and apoptosis in cancer cells; however, the role of SIRT5 in gastric cancer (GC) cells remains unknown. In this study, we examined the role of SIRT5 in GC cells.

METHODS

We detected SIRT5 protein levels in freshly collected samples from patients with GC. Next, we studied the function of SIRT5 in autophagy. Furthermore, the signaling pathway through which SIRT5 enhanced autophagy in GC cells was detected. In addition, we established a GC cell apoptosis model to analyze the role of SIRT5 in apoptosis.

RESULTS

SIRT5 expression was downregulated in GC tissues. We discovered that SIRT5 promoted autophagy in GC cells. We demonstrated that SIRT5 enhanced autophagy in GC cells via the AMP-activated protein kinase-mammalian target of rapamycin signaling pathway. In addition, SIRT5 was degraded during apoptosis in GC cells. Meanwhile, we observed that calpains and caspase-related proteins were associated with SIRT5-related GC cell apoptosis.

CONCLUSIONS

SIRT5 is a crucial regulator of autophagy and apoptosis in GC cell lines that can maintain the balance of autophagy and apoptosis.

DDIT4 Novel Mutations in Pancreatic Cancer

Pancreatic cancer is one of the most common malignancies worldwide. This study is aimed at searching the possible genetic mutations and the value of novel gene mutation in the DNA damage-inducible transcript 4 (DDIT4) and signaling pathway in pancreatic cancer. Polymerase chain reaction (PCR) was performed to amplify the DNA sequences of DDIT4 from patients with pancreatic ductal adenocarcinoma. In addition, we used IHC to detect the expression level of DDIT4 in patients with pancreatic cancer in different types of gene mutation. Double-labeled immunofluorescence was employed to explore the expression levels of DDIT4/LC3 and their potential correlation. Our work indicated the two novel stable gene mutations in DDIT4 mRNA 3'-untranslated region (m.990 U>A and m.1246 C>U). Thirteen samples were found to have mutation in the DDIT4 3'-untranslated regions (UTR). To further verify the influence of gene mutation on protein expression, we performed immunohistochemistry on different gene mutation types, and we found a correlation between DDIT4 expression and gene mutation, which is accompanied by nuclear staining deepening. In order to further discuss the clinical value of DDIT4 gene mutation, immunofluorescence suggested that the expression of DDIT4 colocated with LC3; thus, we speculated that DDIT4 mutation may be involved in autophagy in pancreatic cancer cell. In this study, we found mutation in the 3'-UTR region of DDIT4, which may be associated with DDIT4 expression and tumor autophagy in pancreatic cancer tissues.

Role of SIRT2 in regulating the dexamethasone-activated autophagy pathway in skeletal muscle atrophy

The proteolytic autophagy system is involved in a major regulatory pathway in dexamethasone (Dex)-induced muscle atrophy. Sirtuin 2 (SIRT2) is known to modulate autophagy signaling, exerting effects in skeletal muscle atrophy. We examined the effects of SIRT2 on autophagy in Dex-induced myoatrophy. Tostudy this, mice were randomly distributed among the normal, Dex, and sirtinol groups. C2C12 cells were differentiated into myotubes and transduced with lentivirus carrying Sirt2-green fluorescent protein (GFP) or Sirt2 short hairpin RNA (Sirt2-shRNA)-GFP. To evaluate the mass and function of skeletal muscles, we measured myofiber cross-sectional area, myotube size, gastrocnemius (GA) muscle wet mass:body mass ratio (%), and time to exhaustion. The expression levels of SIRT2, myosin heavy chain, microtubule-associated protein 1 light chain 3 (LC3), and Beclin-1 were measured using Western blotting and quantitative reverse transcription - polymerase chain reaction. Inhibition of SIRT2 markedly attenuated GA muscle mass and endurance capacity. The same phenotype was observed in Sirt2-shRNA-treated myotubes, as evidenced by their decreased size. Conversely, overexpression of SIRT2 alleviated Dex-induced myoatrophy in vitro. Moreover, SIRT2 negatively regulated the expression of LC3b and Beclin-1 in skeletal muscles. These findings suggest that SIRT2 activation protects myotubes against Dex-induced atrophy through inhibition of the autophagy system; this phenomenon may serve as a target for treating glucocorticoid-induced myopathy.

Targeting the core of neurodegeneration: FoxO, mTOR, and SIRT1

The global increase in lifespan noted not only in developed nations, but also in large developing countries parallels an observed increase in a significant number of non-communicable diseases, most notable neurodegenerative disorders. Neurodegenerative disorders present a number of challenges for treatment options that do not resolve disease progression. Furthermore, it is believed by the year 2030, the services required to treat cognitive disorders in the United States alone will exceed $2 trillion annually. Mammalian forkhead transcription factors, silent mating type information regulation 2 homolog 1 (Saccharomyces cerevisiae), the mechanistic target of rapamycin, and the pathways of autophagy and apoptosis offer exciting avenues to address these challenges by focusing upon core cellular mechanisms that may significantly impact nervous system disease. These pathways are intimately linked such as through cell signaling pathways involving protein kinase B and can foster, sometimes in conjunction with trophic factors, enhanced neuronal survival, reduction in toxic intracellular accumulations, and mitochondrial stability. Feedback mechanisms among these pathways also exist that can oversee reparative processes in the nervous system. However, mammalian forkhead transcription factors, silent mating type information regulation 2 homolog 1, mechanistic target of rapamycin, and autophagy can lead to cellular demise under some scenarios that may be dependent upon the precise cellular environment, warranting future studies to effectively translate these core pathways into successful clinical treatment strategies for neurodegenerative disorders.

ATF4 promotes lung cancer cell proliferation and invasion partially through regulating Wnt/β-catenin signaling

Activating transcription factor 4 (ATF4) is a member of the cAMP response element binding (CREB) protein family and has been reported to participate in cancer progression; however, its molecular mechanism is not fully understood. In this study, we investigated the function of ATF4 in non-small cell lung cancer and its molecular regulation. We detected cytoplasmic and nuclear ATF4 expression in lung cancer A549, H1299, and LK2 cells, and the total expression of ATF4 was higher than that in HBE cells (p < 0.05). Higher nuclear ATF4 expression was detected in all these cells compared to cytoplasmic ATF4 expression (p < 0.05). Overexpression of ATF4 in A549 cells significantly promoted cancer cell growth and invasion (p < 0.05). Expression of Wnt signaling molecules, including β-catenin, MMP7, and cyclin D1, and the activity of canonical Wnt signaling were also significantly promoted by ATF4 (p < 0.05). ICG001, a canonical Wnt signaling inhibitor that selectively inhibits β-catenin/ cyclic adenosine monophosphate response element binding protein (CBP) interaction, significantly inhibited cancer cell invasion and Wnt signaling. The function of ATF4 was also significantly inhibited by ICG001 (p < 0.05). However, compared to treatment with ICG001, the invasion ability of cancer cells treated with both ICG001 and ATF4 cDNA significantly increased (p < 0.05), which indicates that the function of ATF4 was not dependent only on Wnt/β-catenin signaling. The function of ATF4 in the regulation of β-catenin expression was not significantly affected by ICG001 (p > 0.05). The function of ATF4 to promote the activity of Wnt/β-catenin signaling in cancer cells was abolished by treatment with ICG001 (p > 0.05). These results indicate that ATF4 may contribute to lung cancer progression at least partly by regulating Wnt/β-catenin signaling.

A review of the mechanism of DDIT4 serve as a mitochondrial related protein in tumor regulation

DDIT4 is a mitochondrial and tumor-related protein involved in anti-tumor therapy resistance, proliferation, and invasion, etc. Its expression level increases under the stress such as chemotherapy, hypoxia, and DNA damage. A number of clinical studies have confirmed that DDIT4 can change the behavior of tumor cells and the prognosis of patients with cancer. However, the role of DDIT4 in promoting or suppressing cancer is still inconclusive. This article summarized the four characteristics of DDIT4 including a mitochondria-related protein, interactions with various protein molecules, immune and metabolic cell related proteins and participator in the oxygen sensing pathway, which may be related to the progress of cancer.

Sirtuins' control of autophagy and mitophagy in cancer

Mammalian cells use a specialized and complex machinery for the removal of altered proteins or dysfunctional organelles. Such machinery is part of a mechanism called autophagy. Moreover, when autophagy is specifically employed for the removal of dysfunctional mitochondria, it is called mitophagy. Autophagy and mitophagy have important physiological implications and roles associated with cellular differentiation, resistance to stresses such as starvation, metabolic control and adaptation to the changing microenvironment. Unfortunately, transformed cancer cells often exploit autophagy and mitophagy for sustaining their metabolic reprogramming and growth to a point that autophagy and mitophagy are recognized as promising targets for ongoing and future antitumoral therapies. Sirtuins are NAD+ dependent deacylases with a fundamental role in sensing and modulating cellular response to external stresses such as nutrients availability and therefore involved in aging, oxidative stress control, inflammation, differentiation and cancer. It is clear, therefore, that autophagy, mitophagy and sirtuins share many common aspects to a point that, recently, sirtuins have been linked to the control of autophagy and mitophagy. In the context of cancer, such a control is obtained by modulating transcription of autophagy and mitophagy genes, by post translational modification of proteins belonging to the autophagy and mitophagy machinery, by controlling ROS production or major metabolic pathways such as Krebs cycle or glutamine metabolism. The present review details current knowledge on the role of sirtuins, autophagy and mitophagy in cancer to then proceed to discuss how sirtuins can control autophagy and mitophagy in cancer cells. Finally, we discuss sirtuins role in the context of tumor progression and metastasis indicating glutamine metabolism as an example of how a concerted activation and/or inhibition of sirtuins in cancer cells can control autophagy and mitophagy by impinging on the metabolism of this fundamental amino acid.

DENR promotes translation reinitiation via ribosome recycling to drive expression of oncogenes including ATF4

Translation efficiency varies considerably between different mRNAs, thereby impacting protein expression. Translation of the stress response master-regulator ATF4 increases upon stress, but the molecular mechanisms are not well understood. We discover here that translation factors DENR, MCTS1 and eIF2D are required to induce ATF4 translation upon stress by promoting translation reinitiation in the ATF4 5'UTR. We find DENR and MCTS1 are only needed for reinitiation after upstream Open Reading Frames (uORFs) containing certain penultimate codons, perhaps because DENR•MCTS1 are needed to evict only certain tRNAs from post-termination 40S ribosomes. This provides a model for how DENR and MCTS1 promote translation reinitiation. Cancer cells, which are exposed to many stresses, require ATF4 for survival and proliferation. We find a strong correlation between DENR•MCTS1 expression and ATF4 activity across cancers. Furthermore, additional oncogenes including a-Raf, c-Raf and Cdk4 have long uORFs and are translated in a DENR•MCTS1 dependent manner.

Dysregulation of metabolic flexibility: The impact of mTOR on autophagy in neurodegenerative disease

Non-communicable diseases (NCDs) that involve neurodegenerative disorders and metabolic disease impact over 400 million individuals globally. Interestingly, metabolic disorders, such as diabetes mellitus, are significant risk factors for the development of neurodegenerative diseases. Given that current therapies for these NCDs address symptomatic care, new avenues of discovery are required to offer treatments that affect disease progression. Innovative strategies that fill this void involve the mechanistic target of rapamycin (mTOR) and its associated pathways of mTOR complex 1 (mTORC1), mTOR complex 2 (mTORC2), AMP activated protein kinase (AMPK), trophic factors that include erythropoietin (EPO), and the programmed cell death pathways of autophagy and apoptosis. These pathways are intriguing in their potential to provide effective care for metabolic and neurodegenerative disorders. Yet, future work is necessary to fully comprehend the entire breadth of the mTOR pathways that can effectively and safely translate treatments to clinical medicine without the development of unexpected clinical disabilities.

New Insights for nicotinamide: Metabolic disease, autophagy, and mTOR

Metabolic disorders, such as diabetes mellitus (DM), are increasingly becoming significant risk factors for the health of the global population and consume substantial portions of the gross domestic product of all nations. Although conventional therapies that include early diagnosis, nutritional modification of diet, and pharmacological treatments may limit disease progression, tight serum glucose control cannot prevent the onset of future disease complications. With these concerns, novel strategies for the treatment of metabolic disorders that involve the vitamin nicotinamide, the mechanistic target of rapamycin (mTOR), mTOR Complex 1 (mTORC1), mTOR Complex 2 (mTORC2), AMP activated protein kinase (AMPK), and the cellular pathways of autophagy and apoptosis offer exceptional promise to provide new avenues of treatment. Oversight of these pathways can promote cellular energy homeostasis, maintain mitochondrial function, improve glucose utilization, and preserve pancreatic beta-cell function. Yet, the interplay among mTOR, AMPK, and autophagy pathways can be complex and affect desired clinical outcomes, necessitating further investigations to provide efficacious treatment strategies for metabolic dysfunction and DM.

Silencing Sirtuin 6 induces cell cycle arrest and apoptosis in non-small cell lung cancer cell lines

Sirtuins (SIRT1-7), are NAD-dependent deacetylases and ADP-ribosyl transferases, plays a major part in carcinogenesis. The previous report suggests that in cancer, sirtuins gained tremendous interest and critical regulators of the unusual processes. In carcinogenesis, sirtuins possess either tumor suppressor or promoter. However, in lung cancer condition the studies of sirtuins are less studied. Hence, this designed study investigates the impact of multifaceted sirtuins in NSCLC cells. We evaluated the mRNA and protein expressions of sirtuins by RTPCR and western blot. We found SIRT6 significantly overexpressed in NCI-H520, A549, and NCI-H460 compared with the normal BEAS-2B cell line. Silencing of SIRT6 by siRNA in NSCLC cells caused activation of p53/p21 mediated inhibition of cell proliferation leading to arrest in cell cycle and apoptosis induction. Our results implied that SIRT6 is a tumor promoter in NSCLC development, progression, and regulation. The silencing of SIRT6 to be a novel therapy for lung cancer.

microRNA-579 upregulation mediates death of human macrophages with mycobacterium tuberculosis infection

Mycobacterium tuberculosis (MTB) infection could induce death of host human macrophages, promoting bacterial spread. In the current study we tested the potential role of microRNA-579 (miR-579) in the death of macrophages infected with MTB. In the primary human macrophages MTB infection induced upregulation of miR-579 but downregulation of its mRNA targets, SIRT1 and PDK1, which were accompanied by significant macrophage death and apoptosis. miR-579 inhibition, by its anti-sense sequence, restored SIRT1-PDK1 expression and significantly attenuated MTB-induced cytotoxicity and apoptosis in human macrophages. Conversely, ectopic overexpression of miR-579 further downregulated SIRT1-PDK1 expression and exacerbated MTB-induced cytotoxicity in human macrophages. Further studies showed that cPWWP2A, the miR-579's endogenous sponge circRNA, was downregulated in MTB-infected macrophages. Conversely, forced overexpression of cPWWP2A, by a recombinant adeno-associated virus construct, reversed MTB-induced miR-579 upregulation and macrophage cytotoxicity. Taken together, our results show that miR-579 upregulation mediates MTB-induced macrophage cytotoxicity. Targeting cPWWP2A-miR-579 axis could be a novel strategy to protect human macrophages from MTB infection.