Calcium homeostasis and ER stress in control of autophagy in cancer cells

Cancer-associated fibroblasts: heterogeneity, tumorigenicity and therapeutic targets

Cancer, characterized by its immune evasion, active metabolism, and heightened proliferation, comprises both stroma and cells. Although the research has always focused on parenchymal cells, the non-parenchymal components must not be overlooked. Targeting cancer parenchymal cells has proven to be a formidable challenge, yielding limited success on a broad scale. The tumor microenvironment(TME), a critical niche for cancer cell survival, presents a novel way for cancer treatment. Cancer-associated fibroblast (CAF), as a main component of TME, is a dynamically evolving, dual-functioning stromal cell. Furthermore, their biological activities span the entire spectrum of tumor development, metastasis, drug resistance, and prognosis. A thorough understanding of CAFs functions and therapeutic advances holds significant clinical implications. In this review, we underscore the heterogeneity of CAFs by elaborating on their origins, types and function. Most importantly, by elucidating the direct or indirect crosstalk between CAFs and immune cells, the extracellular matrix, and cancer cells, we emphasize the tumorigenicity of CAFs in cancer. Finally, we highlight the challenges encountered in the exploration of CAFs and list targeted therapies for CAF, which have implications for clinical treatment.

The mechanisms underlying the cardiac effects of modified citrus pectin in obese rats with myocardial ischemia: Role of galectin-3

BACKGROUND

Modified citrus pectin (MCP) is used as a nutritional supplement that inhibits galectin-3 activity, a central player in the cardiac damage associated with different pathological situations. In fact, we have previously observed that MCP improved cardiac function in obese infarcted rats that was associated with a reduction in cardiac fibrosis. Therefore, the aim of the present study was to further explore whether this effect could involve the modulation of gene expression of ECM components and their mediators as well as whether it could affect another two mechanisms involved in cardiac damage: mitochondrial dynamics and autophagic flux.

METHODS

Male Wistar rats were fed an atherogenic diet with a high content of saturated fat (35%). MI was induced by the ligation of left anterior descendant (LAD) coronary artery 6 weeks after and MCP (100mg/kg/day) or vehicle were administered for 4 weeks more. A group of rats fed a standard diet (5.3% fat) and subjected to a sham operation was used as controls.

RESULTS

Obese infarcted animals presented an increase in cross-linked collagen that was not affected by the administration of galectin-3 inhibitor. However, MCP reduced the increase in gene expression observed in obese infarcted rats of ECM components and mediators (collagen I, fibronectin, transforming growth factor-β and connective tissue growth factor), of components of endoplasmic reticulum stress (binding immunoglobulin protein, CCAAT-enhancer-binding homologous protein and activating transcription factor 4), of oxidative stress mediator (NADPH oxidase-4) and normalized those of the interleukin 33/ST2 system. MCP is also able to increase the levels of the mitochondrial protein Dynamin-1-like and those of both proteins involved in autophagic flux (p62 and LC3) that were reduced by the myocardial ischemia in the context of obesity.

CONCLUSIONS

The data show that the beneficial effect of the nutritional supplement MCP on the cardiac consequences associated with myocardial ischemia in the context of obesity could rely on its capacity to inhibit galectin-3 and to consequently modulate different downstream mechanisms, including inflammation, ER stress, oxidative stress, autophagy and mitochondrial function, which can facilitate fibrosis and cardiac remodeling in this pathological context.

Induction of Ca2+-dependent autophagy and concurrent lysosomal alkalinization underlies the cytotoxic effects of NNC-55-0396 on glioblastoma cells

Diverse agents targeting (macro)autophagy, a critical metabolic stress response in cancer cells, have been proposed for cancer therapy. In previous studies, we showed that NNC-55-0396 (NNC) induces glioblastoma cell death by activating the Unfolded Protein Response (UPR) of ER stress and increasing cytosolic Ca2+ levels. Here, we report that NNC affects both ends of the autophagy process, causing extensive cytoplasmic vacuolation. Our results show that: (1) NNC induces autophagy downstream of UPR and Ca2+ signaling pathways, thus silencing IRE1α/JNK1 or inhibiting Ca2+/IP3R signaling prevents NNC-induced vacuolation. (2) Silencing ATG5 delays cell death, indicating that autophagy induction plays a role in NNC's cytotoxic effects. (3) NNC and other Ca2+-mobilizing agents transcriptionally upregulate p62/SQSTM1, an autophagosome cargo receptor, highlighting a role for this protein in the response to NNC. (4) Studies using tandem fluorescent-tagged LC3 and electron microscopy, however, further reveal that NNC blocks late-stage autophagy that leads to enlarged degradative compartments accumulating ubiquitin-tagged cargoes. (5) Finally, NNC impedes pro-cathepsin-B processing, an effect that is reversed with a weak acid co-treatment, suggesting that lysosomal dysfunction due to increased intraluminal pH is the underlying cause of the autophagy blockade. Together, these findings underscore a multi-level dysregulation of autophagy that contributes to NNC's anti-tumoral effects.

Single-cell transcriptomic analysis reveals regulative mechanisms of follicular selection and atresia in chicken granulosa cells

Eggs are an important food source for people. Follicle selection and atresia are the two directions of pre-hierarchical follicles that affect egg production in chickens. Granulosa cells (GCs), the vital somatic cells in follicles, determine the fate of follicles. In this study, single-cell RNA sequencing was performed on the GC layers from five follicular stages (small white follicles, atretic small white follicles, small yellow follicles, atretic small yellow follicles, and F6) to map the cellular differentiation trajectories and explore the follicle fate-determining genes. The results showed that GCs were genetically heterogeneous and could be divided into four subtypes, and the presence of GCs-Ⅲ with a steroid-producing capacity in unselected small follicles is a novel finding that differs from conventional wisdom. In addition, degenerated GCs were annotated for the first time, and GC degeneration was found to be significantly related to lipid metabolism disorders. Many candidate switch genes had been marked out, among which the overexpression of transforming growth factor-beta 2 (TGFB2) and insulin like growth factor binding protein 5 (IGFBP5) could inhibit the proliferation and differentiation of GCs and induce their degeneration. This study provided new insights into the regulatory mechanisms of follicle selection and atresia, which have significant value for improving egg production and prolonging the laying period of laying hens.

Dual Role of Lysosome in Cancer Development and Progression

Lysosomes are essential intracellular catabolic organelles that contain digestive enzymes involved in the degradation and recycle of damaged proteins, organelles, etc. Thus, they play an important role in various biological processes, including autophagy regulation, ion homeostasis, cell death, cell senescence. A myriad of studies has shown that the dysfunction of lysosome is implicated in human aging and various age-related diseases, including cancer. However, what is noteworthy is that the modulation of lysosome-based signaling and degradation has both the cancer-suppressive and cancer-promotive functions in diverse cancers depending on stage, biology, or tumor microenvironment. This dual role limits their application as targets in cancer therapy. In this review, we provide an overview of lysosome and autophagy-lysosomal pathway and outline their critical roles in many cellular processes, including cell death. We highlight the different functions of autophagy-lysosomal pathway in cancer development and progression, underscoring its potential as a target for effective cancer therapies.

TMCO1 regulates energy metabolism and mitochondrial function of hepatocellular carcinoma cells through TOMM20, affecting the growth of subcutaneous graft tumors and infiltration of CAFs

This study mainly shows the role of endoplasmic reticulum transmembrane and coiled coil domains 1 (TMCO1) in the regulatory mechanism of hepatocellular carcinoma (HCC). Invasion and migration capacity were detected by Transwell and wound healing after TMCO1 and TOMM20 overexpression and knockdown, and mitochondrial function was detected through reactive oxygen species (ROS), mitochondrial permeability transition pore (mPTP), mitochondrial membrane potential (MMP), and ATP production. A model of subcutaneous tumor formation in nude mice was established to detect the effect of TMCO1 on tumor formation. The results showed that overexpression of TMCO1 significantly promoted HCC cell metastasis, promoted cell proliferation and ATP production, inhibited cell apoptosis, mPTP opening and ROS production, mediated the increase of MMP level and cytoskeletal remodeling. However, knocking down TMCO1 can have the opposite effect. More importantly, knocking down TOMM20 can block the regulation effect of TMCO1, and TOMM20 overexpression can alleviate the inhibitory effect of knocking down TMCO1 on the development of liver cancer cells. In animal models, knockdown of TMCO1 expression significantly inhibited the growth of subcutaneous implant tumors. This suggests that TMCO1 may be a potential and valuable therapeutic target for liver cancer.

Endoplasmic reticulum stress: The underlying mechanism of chronic pain

Chronic pain (CP) affects over 30 % of the global population, imposing significant financial burdens on individuals and society. However, existing treatments for CP offer limited efficacy and troublesome side effects, primarily owing to a lack of knowledge of its precise underlying mechanism. Pathological stimuli disrupt the intricate process of protein folding and endoplasmic reticulum (ER) homeostasis. This disruption leads to the accumulation of misfolded or unfolded proteins in the ER, generating a condition termed ER stress. Emerging data have indicated that ER stress, occurring in the peripheral and central nervous systems, contributes to the development and maintenance of CP. This review aimed to comprehensively explore the intersection of ER stress and CP within the lower and upper nervous systems and highlight the cell-specific contributions of the unfolded protein response in different CP types. We provide a comprehensive synthesis of evidence from animal models, examining neuronal and non-neuronal mechanisms and discuss the damaging ER stress-linked inflammation, autophagy, oxidative stress, and apoptosis, which collectively drive disease progression and contribute to a neurotoxic environment. However, the mechanisms through which ER stress influences the most advanced centre-of-pain projections in the brain remain unclear. Further investigation in this area is crucial to elucidate the relationship between ER stress and CP and facilitate the development of novel therapeutic drugs for this intractable dilemma.

The regulation of the thermal stability and affinity of the HSPA5 (Grp78/BiP) by clients and nucleotides is modulated by domains coupling

The HSPA5 protein (BiP/Grp78) serves as a pivotal chaperone in maintaining cellular protein quality control. As a member of the human HSP70 family, HSPA5 comprises two distinct domains: a nucleotide-binding domain (NBD) and a peptide-binding domain (PBD). In this study, we investigated the interdomain interactions of HSPA5, aiming to elucidate how these domains regulate its function as a chaperone. Our findings revealed that HSPA5-FL, HSPA5-T, and HSPA5-N exhibit varying affinities for ATP and ADP, with a noticeable dependency on Mg2+ for optimal interactions. Interestingly, in ADP assays, the presence of the metal ion seems to enhance NBD binding only for HSPA5-FL and HSPA5-T. Moreover, while the truncation of the C-terminus does not significantly impact the thermal stability of HSPA5, experiments involving MgATP underscore its essential role in mediating interactions and nucleotide hydrolysis. Thermal stability assays further suggested that the NBD-PBD interface enhances the stability of the NBD, more pronounced for HSPA5 than for the orthologous HSPA1A, and prevents self-aggregation through interdomain coupling. Enzymatic analyses indicated that the presence of PBD enhances NBD ATPase activity and augments its nucleotide affinity. Notably, the intrinsic chaperone activity of the PBD is dependent on the presence of the NBD, potentially due to the propensity of the PBD for self-oligomerization. Collectively, our data highlight the pivotal role of allosteric mechanisms in modulating thermal stability, nucleotide interaction, and ATPase activity of HSPA5, underscoring its significance in protein quality control within cellular environments.

The mechanisms of Ca2+ regulating autophagy and its research progress in neurodegenerative diseases: A review

Neurodegenerative diseases are complex disorders that significantly challenge human health, with their incidence increasing with age. A key pathological feature of these diseases is the accumulation of misfolded proteins. The underlying mechanisms involve an imbalance in calcium homeostasis and disturbances in autophagy, indicating a likely correlation between them. As the most important second messenger, Ca2+ plays a vital role in regulating various cell activities, including autophagy. Different organelles within cells serve as Ca2+ storage chambers and regulate Ca2+ levels under different conditions. Ca2+ in these compartments can affect autophagy via Ca2+ channels or other related signaling proteins. Researchers propose that Ca2+ regulates autophagy through distinct signal transduction mechanisms, under normal or stressful conditions, and thereby contributing to the occurrence and development of neurodegenerative diseases. This review provides a systematic examination of the regulatory mechanisms of Ca2+ in cell membranes and different organelles, as well as its downstream pathways that influence autophagy and its implications for neurodegenerative diseases. This comprehensive analysis may facilitate the development of new drugs and provide more precise treatments for neurodegenerative diseases.

The detrimental role of galectin-3 and endoplasmic reticulum stress in the cardiac consequences of myocardial ischemia in the context of obesity

The association between cardiac fibrosis and galectin-3 was evaluated in patients with acute myocardial infarction (MI). The role of galectin-3 and its association with endoplasmic reticulum (ER) stress activation in the progression of cardiovascular fibrosis was also evaluated in obese-infarcted rats. The inhibitor of galectin-3 activity, modified citrus pectin (MCP; 100 mg/kg/day), and the inhibitor of the ER stress activation, 4-phenylbutyric acid (4-PBA; 500 mg/kg/day), were administered for 4 weeks after MI in obese rats. Overweight-obese patients who suffered a first MI showed higher circulating galectin-3 levels, higher extracellular volume, and LV infarcted size, as well as lower E/e'ratio and LVEF compared with normal-weight patients. A correlation was observed between galectin-3 levels and extracellular volume. Obese-infarcted animals presented cardiac hypertrophy and reduction in LVEF, and E/A ratio as compared with control animals. They also showed an increase in galectin-3 gene expression, as well as cardiac fibrosis and reduced autophagic flux. These alterations were associated with ER stress activation characterized by enhanced cardiac levels of binding immunoglobulin protein, which were correlated with those of galectin-3. Both MCP and 4-PBA not only reduced cardiac fibrosis, oxidative stress, galectin-3 levels, and ER stress activation, but also prevented cardiac functional alterations and ameliorated autophagic flux. These results show the relevant role of galectin-3 in the development of diffuse fibrosis associated with MI in the context of obesity in both the animal model and patients. Galectin-3 in tandem with ER stress activation could modulate different downstream mechanisms, including inflammation, oxidative stress, and autophagy.

Pan-cancer bioinformatics analysis of hepatic leukemia factor and further validation in colorectal cancer

Background

Hepatic leukemia factor (HLF) is associated with cancer onset, growth, and progression; however, little is known regarding its biological role in pan-cancer. In order to further evaluate the diagnostic and prognostic value of HLF in pan-cancer and colorectal cancer (CRC), we performed comprehensive bioinformatics analyses of the molecular mechanism of HLF in pan-cancer, with subsequent verification in CRC.

Methods

We downloaded data (gene expression, clinical data, follow-up duration, and immune-related data) related to 33 solid tumor types from UCSC Xena (University of California Santa Cruz cancer database, https://xena.ucsc.edu/). HLF expression was analyzed in pan-cancer, and its diagnostic efficacy, prognostic value, and correlation with pathological stage and cancer immunity were determined. We also analyzed gene alterations in HLF and biological processes involved in its regulation in pan-cancer. Using CRC data in The Cancer Genome Atlas (TCGA), we assessed correlations between HLF and CRC diagnosis, prognosis, and drug sensitivity and performed functional enrichment analyses. Moreover, we constructed an HLF-related ceRNA regulatory network. Finally, we externally validated HLF expression and diagnostic and prognostic value in CRC using Gene Expression Omnibus (GEO) database, as well as by performing in vitro experiments.

Results

HLF expression was downregulated in most tumors, and HLF showed good predictive potential for pan-cancer diagnosis and prognosis. It was closely related to the clinicopathological stages of pan-cancer. Further, HLF was associated with tumor microenvironment and immune cell infiltration in many tumors. Analyses involving cBioPortal revealed changes in HLF amplifications and mutations in most tumors. HLF was also closely associated with microsatellite instability and tumor mutational burden in pan-cancer and involved in regulating various tumor-related pathways and biological processes. In CRC, HLF expression was similarly downregulated, with implications for CRC diagnosis and prognosis. Functional enrichment analysis indicated the association of HLF with many cancer-related pathways. Further, HLF was associated with drug (e.g., oxaliplatin) sensitivity in CRC. The ceRNA regulatory network showed multigene regulation of HLF in CRC. External validation involving GEO databases and quantitative real-time polymerase chain reaction (qRT-PCR) data substantiated these findings.

Conclusions

HLF expression generally exhibited downregulation in pan-cancer, contributing to tumor occurrence and development by regulating various biological processes and affecting tumor immune characteristics. HLF was also closely related to CRC occurrence and development. We believe HLF can serve as a reliable diagnostic, prognostic, and immune biomarker for pan-cancer.

Liquid-liquid phase separation in diseases

Liquid-liquid phase separation (LLPS), an emerging biophysical phenomenon, can sequester molecules to implement physiological and pathological functions. LLPS implements the assembly of numerous membraneless chambers, including stress granules and P-bodies, containing RNA and protein. RNA-RNA and RNA-protein interactions play a critical role in LLPS. Scaffolding proteins, through multivalent interactions and external factors, support protein-RNA interaction networks to form condensates involved in a variety of diseases, particularly neurodegenerative diseases and cancer. Modulating LLPS phenomenon in multiple pathogenic proteins for the treatment of neurodegenerative diseases and cancer could present a promising direction, though recent advances in this area are limited. Here, we summarize in detail the complexity of LLPS in constructing signaling pathways and highlight the role of LLPS in neurodegenerative diseases and cancers. We also explore RNA modifications on LLPS to alter diseases progression because these modifications can influence LLPS of certain proteins or the formation of stress granules, and discuss the possibility of proper manipulation of LLPS process to restore cellular homeostasis or develop therapeutic drugs for the eradication of diseases. This review attempts to discuss potential therapeutic opportunities by elaborating on the connection between LLPS, RNA modification, and their roles in diseases.

Decoding Organelle Interactions: Unveiling Molecular Mechanisms and Disease Therapies

Organelles, substructures in the cytoplasm with specific morphological structures and functions, interact with each other via membrane fusion, membrane transport, and protein interactions, collectively termed organelle interaction. Organelle interaction is a complex biological process involving the interaction and regulation of several organelles, including the interaction between mitochondria-endoplasmic reticulum, endoplasmic reticulum-Golgi, mitochondria-lysosomes, and endoplasmic reticulum-peroxisomes. This interaction enables intracellular substance transport, metabolism, and signal transmission, and is closely related to the occurrence, development, and treatment of many diseases, such as cancer, neurodegenerative diseases, and metabolic diseases. Herein, the mechanisms and regulation of organelle interactions are reviewed, which are critical for understanding basic principles of cell biology and disease development mechanisms. The findings will help to facilitate the development of novel strategies for disease prevention, diagnosis, and treatment opportunities.

Bidirectional regulation mechanism of TRPM2 channel: role in oxidative stress, inflammation and ischemia-reperfusion injury

Transient receptor potential melastatin 2 (TRPM2) is a non-selective cation channel that exhibits Ca2+ permeability. The TRPM2 channel is expressed in various tissues and cells and can be activated by multiple factors, including endogenous ligands, Ca2+, reactive oxygen species (ROS) and temperature. This article reviews the multiple roles of the TRPM2 channel in physiological and pathological processes, particularly on oxidative stress, inflammation and ischemia-reperfusion (I/R) injury. In oxidative stress, the excessive influx of Ca2+ caused by the activation of the TRPM2 channel may exacerbate cellular damage. However, under specific conditions, activating the TRPM2 channel can have a protective effect on cells. In inflammation, the activation of the TRPM2 channel may not only promote inflammatory response but also inhibit inflammation by regulating ROS production and bactericidal ability of macrophages and neutrophils. In I/R, the activation of the TRPM2 channel may worsen I/R injury to various organs, including the brain, heart, kidney and liver. However, activating the TRPM2 channel may protect the myocardium from I/R injury by regulating calcium influx and phosphorylating proline-rich tyrosine kinase 2 (Pyk2). A thorough investigation of the bidirectional role and regulatory mechanism of the TRPM2 channel in these physiological and pathological processes will aid in identifying new targets and strategies for treatment of related diseases.

NCX1/Ca2+ promotes autophagy and decreases bortezomib activity in multiple myeloma through non-canonical NFκB signaling pathway

Although bortezomib (BTZ) is the cornerstone of anti-multiple myeloma (MM) therapy, the inevitable primary and secondary drug resistance still seriously affects the prognosis of patients. New treatment strategies are in need. Sodium-calcium exchanger 1 (NCX1) is a calcium-permeable ion transporter on the membrane, and our previous studies showed that low NCX1 confers inferior viability in MM cells and suppressed osteoclast differentiation. However, the effect of NCX1 on BTZ sensitivity of MM and its possible mechanism remain unclear. In this study, we investigated the effect of NCX1 on BTZ sensitivity in MM, focusing on cellular processes of autophagy and cell viability. Our results provide evidence that NCX1 expression correlates with MM disease progression and low NCX1 expression increases BTZ sensitivity. NCX1/Ca2+ triggered autophagic flux through non-canonical NFκB pathway in MM cells, leading to attenuated the sensitivity of BTZ. Knockdown or inhibition of NCX1 could potentiate the anti-MM activity of BTZ in vitro and vivo, and inhibition of autophagy sensitized NCX1-overexpressing MM cells to BTZ. In general, this work implicates NCX1 as a potential therapeutic target in MM with BTZ resistance and provides novel mechanistic insights into its vital role in combating BTZ resistance.

Micronutrient Status and Breast Cancer: A Narrative Review

Breast cancer is one of the most common cancers worldwide, at the same time being one of the most prevalent causes of women's death. Many factors such as alcohol, weight fluctuations, or hormonal replacement therapy can potentially contribute to breast cancer development and progression. Another important factor in breast cancer onset includes micronutrient status. In this narrative review, we analyzed 23 micronutrients and their possible influence on breast cancer onset and progression. Further, the aim of this study was to investigate the impact of micronutrient status on the prevention of breast cancer and its possible influence on various therapeutic pathways. We researched meta-analyses, systemic and narrative reviews, retrospective studies, as well as original studies on human and animal models. The results of these studies indicate a possible correlation between the different levels of micronutrients and a decreased risk of breast cancer as well as a better survival rate. However, further studies are necessary to establish adequate doses of supplementation of the chosen micronutrients and the exact mechanisms of micronutrient impact on breast cancer therapy.

Optogenetically engineered calcium oscillations promote autophagy-mediated cell death via AMPK activation

Autophagy is a double-edged sword for cells; it can lead to both cell survival and death. Calcium (Ca2+) signalling plays a crucial role in regulating various cellular behaviours, including cell migration, proliferation and death. In this study, we investigated the effects of modulating cytosolic Ca2+ levels on autophagy using chemical and optogenetic methods. Our findings revealed that ionomycin and thapsigargin induce Ca2+ influx to promote autophagy, whereas the Ca2+ chelator BAPTA-AM induces Ca2+ depletion and inhibits autophagy. Furthermore, the optogenetic platform allows the manipulation of illumination parameters, including density, frequency, duty cycle and duration, to create different patterns of Ca2+ oscillations. We used the optogenetic tool Ca2+-translocating channelrhodopsin, which is activated and opened by 470 nm blue light to induce Ca2+ influx. These results demonstrated that high-frequency Ca2+ oscillations induce autophagy. In addition, autophagy induction may involve Ca2+-activated adenosine monophosphate (AMP)-activated protein kinases. In conclusion, high-frequency optogenetic Ca2+ oscillations led to cell death mediated by AMP-activated protein kinase-induced autophagy.

KCTD15 acts as an anti-tumor factor in colorectal cancer cells downstream of the demethylase FTO and the m6A reader YTHDF2

Potassium Channel Tetramerization Domain Containing 15 (KCTD15) participates in the carcinogenesis of several solid malignancies; however, its role in colorectal cancer (CRC) remains unclear. Here we find that KCTD15 exhibits lower expression in CRC tissues as compared to para-carcinoma tissues. Tetracycline (tet)-induced overexpression and knockdown of KCTD15 confirms KCTD15 as an anti-proliferative and pro-apoptotic factor in CRC both in vitro and in xenografted tumors. N6-methyladenosine (m6A) is known to affect the expression, stabilization, and degradation of RNAs with this modification. We demonstrate that upregulation of fat mass and obesity-associated protein (FTO), a classical m6A eraser, prevents KCTD15 mRNA degradation in CRC cells. Less KCTD15 RNA is recognized by m6A 'reader' YTH N6-Methyladenosine RNA Binding Protein F2 (YTHDF2) in FTO-overexpressed cells. Moreover, KCTD15 overexpression decreases protein expression of histone deacetylase 1 (HDAC1) but increases acetylation of critical tumor suppressor p53 at Lys373 and Lys382. Degradation of p53 is delayed in CRC cells post-KCTD15 overexpression. We further show that the regulatory effects of KCTD15 on p53 are HDAC1-dependent. Collectively, we conclude that KCTD15 functions as an anti-growth factor in CRC cells, and its expression is orchestrated by the FTO-YTHDF2 axis. Enhanced p53 protein stabilization may contribute to KCTD15's actions in CRC cells.

Advancements in Genetic and Biochemical Insights: Unraveling the Etiopathogenesis of Neurodegeneration in Parkinson's Disease

Parkinson's disease (PD) is the second most prevalent neurodegenerative movement disorder worldwide, which is primarily characterized by motor impairments. Even though multiple hypotheses have been proposed over the decades that explain the pathogenesis of PD, presently, there are no cures or promising preventive therapies for PD. This could be attributed to the intricate pathophysiology of PD and the poorly understood molecular mechanism. To address these challenges comprehensively, a thorough disease model is imperative for a nuanced understanding of PD's underlying pathogenic mechanisms. This review offers a detailed analysis of the current state of knowledge regarding the molecular mechanisms underlying the pathogenesis of PD, with a particular emphasis on the roles played by gene-based factors in the disease's development and progression. This study includes an extensive discussion of the proteins and mutations of primary genes that are linked to PD, including α-synuclein, GBA1, LRRK2, VPS35, PINK1, DJ-1, and Parkin. Further, this review explores plausible mechanisms for DAergic neural loss, non-motor and non-dopaminergic pathologies, and the risk factors associated with PD. The present study will encourage the related research fields to understand better and analyze the current status of the biochemical mechanisms of PD, which might contribute to the design and development of efficacious and safe treatment strategies for PD in future endeavors.

Investigation of nanotopography on SOCE mediated cell migration via live-cell : Imaging on opaque implant surface

The exploration of cell response to nanotopography has attracted considerable attentions for years. This article focuses on the influence of nanotopography on the intracellular Ca2+ dynamics, the most ubiquitous but ignored second messenger. The classic titanium nanotubes (NT) were fabricated by anodization to formulate nanoporous surfaces. Firstly, the store operative calcium entry (SOCE) in endoplasmic reticulum (ER) and functional Ca2+ release-activated Ca2+ (CRAC) channels were significantly enhanced on NT surfaces that revealed by live-cell Ca2+ imaging and fluorescence resonance energy transfer (FRET) identification of orai1-stim1 connection. To investigate the potential implication of Ca2+ elevation, the dynamic cell migration trajectory was monitored by a self-made holder, which could not only be suitable for the opaque implant surface but also guarantee the focus fields identical during samples shifting. The cell migration on NT surface was more vigorous and rapid, which was correlated with higher focal adhesion proteins expression, Ca2+-dependent calpain activity and stim1 level. In conclusion, this study has confirmed the novel ER Ca2+ hemostasis pathway on nanosurfaces and its crucial role in cell migration regulation, which may help for more biofavorable implant surface design.

Suberoylanilide hydroxamic acid upregulates reticulophagy receptor expression and promotes cell death in hepatocellular carcinoma cells

BACKGROUND

Hepatocellular carcinoma (HCC) is a common clinical condition with a poor prognosis and few effective treatment options. Potent anticancer agents for treating HCC must be identified. Epigenetics plays an essential role in HCC tumorigenesis. Suberoylanilide hydroxamic acid (SAHA), the most common histone deacetylase inhibitor agent, triggers many forms of cell death in HCC. However, the underlying mechanism of action remains unclear. Family with sequence similarity 134 member B (FAM134B)-induced reticulophagy, a selective autophagic pathway, participates in the decision of cell fate and exhibits anticancer activity. This study focused on the relationship between FAM134B-induced reticulophagy and SAHA-mediated cell death.

AIM

To elucidate potential roles and underlying molecular mechanisms of reticulophagy in SAHA-induced HCC cell death.

METHODS

The viability, apoptosis, cell cycle, migration, and invasion of SAHA-treated Huh7 and MHCC97L cells were measured. Proteins related to the reticulophagy pathway, mitochondria-endoplasmic reticulum (ER) contact sites, intrinsic mitochondrial apoptosis, and histone acetylation were quantified using western blotting. ER and lysosome colocalization, and mitochondrial Ca2+ levels were characterized via confocal microscopy. The level of cell death was evaluated through Hoechst 33342 staining and propidium iodide colocalization. Chromatin immunoprecipitation was used to verify histone H4 lysine-16 acetylation in the FAM134B promoter region.

RESULTS

After SAHA treatment, the proliferation of Huh7 and MHCC97L cells was significantly inhibited, and the migration and invasion abilities were greatly blocked in vitro. This promoted apoptosis and caused G1 phase cells to increase in a concentration-dependent manner. Following treatment with SAHA, ER-phagy was activated, thereby triggering autophagy-mediated cell death of HCC cells in vitro. Western blotting and chromatin immunoprecipitation assays confirmed that SAHA regulated FAM134B expression by enhancing the histone H4 lysine-16 acetylation in the FAM134B promoter region. Further, SAHA disturbed the Ca2+ homeostasis and upregulated the level of autocrine motility factor receptor and proteins related to mitochondria-endoplasmic reticulum contact sites in HCC cells. Additionally, SAHA decreased the mitochondrial membrane potential levels, thereby accelerating the activation of the reticulophagy-mediated mitochondrial apoptosis pathway and promoting HCC cell death in vitro.

CONCLUSION

SAHA stimulates FAM134B-mediated ER-phagy to synergistically enhance the mitochondrial apoptotic pathway, thereby enhancing HCC cell death.

Endoplasmic reticulum stress: a vital process and potential therapeutic target in chronic obstructive pulmonary disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD), a chronic and progressive disease characterized by persistent respiratory symptoms and progressive airflow obstruction, has attracted extensive attention due to its high morbidity and mortality. Although the understanding of the pathogenesis of COPD has gradually increased because of increasing evidence, many questions regarding the mechanisms involved in COPD progression and its deleterious effects remain unanswered. Recent advances have shown the potential functions of endoplasmic reticulum (ER) stress in causing airway inflammation, emphasizing the vital role of unfolded protein response (UPR) pathways in the development of COPD.

METHODS

A comprehensive search of major databases including PubMed, Scopus, and Web of Science was conducted to retrieve original research articles and reviews related to ER stress, UPR, and COPD.

RESULTS

The common causes of COPD, namely cigarette smoke (CS) and air pollutants, induce ER stress through the generation of reactive oxygen species (ROS). UPR promotes mucus secretion and further plays a dual role in the cell apoptosis-autophagy axis in the development of COPD. Existing drug research has indicated the potential of UPR as a therapeutic target for COPD.

CONCLUSIONS

ER stress and UPR activation play significant roles in the etiology, pathogenesis, and treatment of COPD and discuss whether related genes can be used as biomarkers and therapeutic targets.

Progranulin Protects against Hyperglycemia-Induced Neuronal Dysfunction through GSK3β Signaling

Type II diabetes affects over 530 million individuals worldwide and contributes to a host of neurological pathologies. Uncontrolled high blood glucose (hyperglycemia) is a major factor in diabetic pathology, and glucose regulation is a common goal for maintenance in patients. We have found that the neuronal growth factor progranulin protects against hyperglycemic stress in neurons, and although its mechanism of action is uncertain, our findings identified Glycogen Synthase Kinase 3β (GSK3β) as being potentially involved in its effects. In this study, we treated mouse primary cortical neurons exposed to high-glucose conditions with progranulin and a selective pharmacological inhibitor of GSK3β before assessing neuronal health and function. Whole-cell and mitochondrial viability were both improved by progranulin under high-glucose stress in a GSK3β-dependent manner. This extended to autophagy flux, indicated by the expressions of autophagosome marker Light Chain 3B (LC3B) and lysosome marker Lysosome-Associated Membrane Protein 2A (LAMP2A), which were affected by progranulin and showed heterogeneous changes from GSK3β inhibition. Lastly, GSK3β inhibition attenuated downstream calcium signaling and neuronal firing effects due to acute progranulin treatment. These data indicate that GSK3β plays an important role in progranulin's neuroprotective effects under hyperglycemic stress and serves as a jumping-off point to explore progranulin's protective capabilities in other neurodegenerative models.

A Deadly Liaison between Oxidative Injury and p53 Drives Methyl-Gallate-Induced Autophagy and Apoptosis in HCT116 Colon Cancer Cells

Methyl gallate (MG), which is a gallotannin widely found in plants, is a polyphenol used in traditional Chinese phytotherapy to alleviate several cancer symptoms. Our studies provided evidence that MG is capable of reducing the viability of HCT116 colon cancer cells, while it was found to be ineffective on differentiated Caco-2 cells, which is a model of polarized colon cells. In the first phase of treatment, MG promoted both early ROS generation and endoplasmic reticulum (ER) stress, sustained by elevated PERK, Grp78 and CHOP expression levels, as well as an upregulation in intracellular calcium content. Such events were accompanied by an autophagic process (16-24 h), where prolonging the time (48 h) of MG exposure led to cellular homeostasis collapse and apoptotic cell death with DNA fragmentation and p53 and γH2Ax activation. Our data demonstrated that a crucial role in the MG-induced mechanism is played by p53. Its level, which increased precociously (4 h) in MG-treated cells, was tightly intertwined with oxidative injury. Indeed, the addition of N-acetylcysteine (NAC), which is a ROS scavenger, counteracted the p53 increase, as well as the MG effect on cell viability. Moreover, MG promoted p53 accumulation into the nucleus and its inhibition by pifithrin-α (PFT-α), which is a negative modulator of p53 transcriptional activity, enhanced autophagy, increased the LC3-II level and inhibited apoptotic cell death. These findings provide new clues to the potential action of MG as a possible anti-tumor phytomolecule for colon cancer treatment.

Nifuroxazide induces the apoptosis of human non‑small cell lung cancer cells through the endoplasmic reticulum stress PERK signaling pathway

The aim of the present study was to investigate the molecular mechanism of nifuroxazide (NFZ) in the induction of apoptosis of NCI-H1299 human non-small cell lung cancer (NSCLC) cells through the reactive oxygen species (ROS)/Ca²⁺/protein kinase R-like ER kinase (PERK)-activating transcription factor 4 (ATF4)-DNA damage inducible transcript 3 (CHOP) signaling pathway. Morphological changes of cells were observed by microscopy, and the apoptosis and intracellular ROS levels of cells were observed by inverted fluorescence microscopy. Cell viability after the addition of the PERK inhibitor, GSK2606414, were detected by Cell Counting Kit-8 assay. Annexin V-FITC was used to detect cell apoptosis, Brite 670 was used to detect intracellular ROS and Fura Red AM was used to detect Ca²⁺ content. Western blotting was used to detect PERK, phosphorylated (P)-PERK, ATF4, CHOP, P-Janus kinase 2 and P-signal transducer and activator of transcription 3 expression levels. Compared with the dimethyl sulfoxide control group, NFZ inhibited the survival activity in the H1299 NSCLC cell line, in a time- and dose-dependent manner. However, GSK2606414 inhibited the NFZ-induced apoptosis of H1299 cells. GSK2606414 also inhibited the increase in ROS and Ca²⁺ in H1299 cells induced by NFZ. Western blotting results demonstrated that NFZ significantly increased the expression levels of P-PERK, ATF4 and CHOP, whereas GSK2606414 significantly reduced the NFZ-induced increase in these protein expression levels. In conclusion, NFZ may induce the apoptosis of H1299 NSCLC cells through the ROS/Ca²⁺/PERK-ATF4-CHOP signaling pathway.

Nobiletin inhibits de novo FA synthesis to alleviate gastric cancer progression by regulating endoplasmic reticulum stress

BACKGROUND

Gastric cancer (GC) is a common malignant tumor with limited treatment options. The natural flavonoid nobiletin (NOB) is a beneficial antioxidant that possesses anticancer activity. However, the mechanisms by which NOB inhibits GC progression remain unclear.

METHODS

A CCK-8 assay was performed to determine cytotoxicity. Cell cycle and apoptosis analyses were performed by flow cytometry. RNA-seq was performed to detect differential gene expression after NOB treatment. RT‒qPCR, Western blot and immunofluorescence staining were used to examine the underlying mechanisms of NOB in GC. Xenograft tumor models were constructed to verify the effect of NOB and its specific biological mechanism in GC.

RESULTS

NOB inhibited cell proliferation, caused cell cycle arrest and induced apoptosis in GC cells. KEGG classification identified that the inhibitory effect of NOB on GC cells mainly involved the lipid metabolism pathway. We further showed that NOB reduced de novo fatty acid (FA) synthesis, as evidenced by the decreased levels of neutral lipids and the expression levels of ACLY, ACACA and FASN, and ACLY abrogated the effect of NOB on lipid deposits in GC cells. In addition, we also found that NOB triggered endoplasmic reticulum (ER) stress by activating the IRE-1α/GRP78/CHOP axis, but overexpression of ACLY reversed ER stress. Mechanistically, inhibiting ACLY expression with NOB significantly reduced neutral lipid accumulation, thereby inducing apoptosis by activating IRE-1α-mediated ER stress and inhibiting GC cell progression. Finally, in vivo results also demonstrated that NOB inhibited tumor growth by decreasing de novo FA synthesis.

CONCLUSION

NOB could inhibit the expression of ACLY to activate IRE-1α-induced ER stress, which ultimately led to GC cell apoptosis. Our results provide novel insight into the use of de novo FA synthesis for GC treatment and are the first to reveal that NOB inhibits GC progression by ACLY-dependent ER stress.

Magnetic Control of Protein Expression via Magneto-mechanical Actuation of ND-PEGylated Iron Oxide Nanocubes for Cell Therapy

Engineered cells used as smart vehicles for delivery of secreted therapeutic proteins enable effective treatment of cancer and certain degenerative, autoimmune, and genetic disorders. However, current cell-based therapies use mostly invasive tools for tracking proteins and do not allow for controlled secretion of therapeutic proteins, which could result in unconstrained killing of surrounding healthy tissues or ineffective killing of host cancer cells. Regulating the expression of therapeutic proteins after success of therapy remains elusive. In this study, a noninvasive therapeutic approach mediated by magneto-mechanical actuation (MMA) was developed to remotely regulate the expression of the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) protein, which is secreted by transduced cells. Stem cells, macrophages, and breast cancer cells were transduced with a lentiviral vector encoding the SGpL2TR protein. SGpL2TR comprises TRAIL and GpLuc domains optimized for cell-based applications. Our approach relies on the remote actuation of cubic-shape highly magnetic field responsive superparamagnetic iron oxide nanoparticles (SPIONs) coated with nitrodopamine PEG (ND-PEG), which are internalized within the cells. Cubic ND-PEG-SPIONs actuated by superlow frequency alternating current magnetic fields can translate magnetic forces into mechanical motion and in turn spur mechanosensitive cellular responses. Cubic ND-PEG-SPIONs were artificially designed to effectively operate at low magnetic field strengths (<100 mT) retaining approximately 60% of their saturation magnetization. Compared to other cells, stems cells were more sensitive to the interaction with actuated cubic ND-PEG-SPIONs, which clustered near the endoplasmic reticulum (ER). Luciferase, ELISA, and RT-qPCR analyses revealed a marked TRAIL downregulation (secretion levels were depleted down to 30%) when intracellular particles at 0.100 mg/mL Fe were actuated by magnetic fields (65 mT and 50 Hz for 30 min). Western blot studies indicated actuated, intracellular cubic ND-PEG-SPIONs can cause mild ER stress at short periods (up to 3 h) of postmagnetic field treatment thus leading to the unfolded protein response. We observed that the interaction of TRAIL polypeptides with ND-PEG can also contribute to this response. To prove the applicability of our approach, we used glioblastoma cells, which were exposed to TRAIL secreted from stem cells. We demonstrated that in the absence of MMA treatment, TRAIL essentially killed glioblastoma cells indiscriminately, but when treated with MMA, we were able to control the cell killing rate by adjusting the magnetic doses. This approach can expand the capabilities of stem cells to serve as smart vehicles for delivery of therapeutic proteins in a controlled manner without using interfering and expensive drugs, while retaining their potential to regenerate damaged tissue after treatment. This approach brings forth new alternatives to regulate protein expression noninvasively for cell therapy and other cancer therapies.

Association of dietary calcium with mortality from all causes, cardiovascular disease and cancer in people with hypertension

Association between calcium intake and premature mortality in the general population has been well studied, but little is known about the association among specific populations. The authors aim to evaluate the association among people with hypertension and to provide a proper reference range of dietary calcium intake. This prospective cohort study included 8534 US adults with hypertension from National Health and Nutrition Examination Survey cycles 2003-2014. Dietary calcium intakes were self-reported and mortality status was ascertained by National Death Index records. During a median follow-up of 5.9 years, 1357 death occurred. Compared with participants of dietary calcium intake in quintile 1, participants in quintiles 2 and 4 had a 27% (HR: 0.73, 95% CI: 0.60-0.89) and a 29% lower risk (HR: 0.71, 95% CI: 0.57-0.88) of all-cause mortality respectively. The authors also observed a 34% lower risk (HR: 0.66, 95% CI: 0.45-0.97) of CVD death among participants in quintile 3 and a 37% lower risk (HR: 0.63, 95% CI: 0.40-0.99) of cancer-related death in participants in quintile 4 respectively. Restricted cubic spline (RCS) regression revealed a consistent protective effect of dietary calcium in participants with a daily intake of over 1000 mg, but a daily intake over 1200 mg fails to show further protective effect. Our findings suggest that elevated dietary calcium was associated with lower mortality risk from all-causes, cardiovascular disease (CVD) and cancer, and supplying sufficient dietary calcium intake, between 1000 and 1200 mg per day, in people with hypertension may be considered cost-effective to decrease risk of premature death.

Regulation of Autophagy via Carbohydrate and Lipid Metabolism in Cancer

Metabolic changes are an important component of tumor cell progression. Tumor cells adapt to environmental stresses via changes to carbohydrate and lipid metabolism. Autophagy, a physiological process in mammalian cells that digests damaged organelles and misfolded proteins via lysosomal degradation, is closely associated with metabolism in mammalian cells, acting as a meter of cellular ATP levels. In this review, we discuss the changes in glycolytic and lipid biosynthetic pathways in mammalian cells and their impact on carcinogenesis via the autophagy pathway. In addition, we discuss the impact of these metabolic pathways on autophagy in lung cancer.

Molecular interplay between NOX1 and autophagy in cadmium-induced prostate carcinogenesis

Chronic exposure to cadmium (Cd), a class I carcinogen, leads to malignant transformation of normal prostate epithelial cells (RWPE-1). The constant generation of Cd-induced ROS and resulting ER stress induces cellular responses that are needed for cell survival, and autophagy has an important role in this process. However, the mechanisms that regulate Cd-induced ROS and how these differ in terms of acute and chronic cadmium exposure remain unexplained. Here, we show that acute or chronic Cd exposure facilitates NOX1 assembly by activating its cytosolic regulators p47phox and p67phox in RWPE-1 cells. Upregulation of NOX1 complex proteins and generation of ROS activates unfolded protein response (UPR) via phosphorylation of protein kinase RNA-like endoplasmic reticulum kinase (PERK), eukaryotic initiation factor 2 alpha (eIF2α), and selective translation of activating transcription factor 4 (ATF4). Chronic Cd exposure constantly activates NOX1 complex and generates consistent ROS and ER stress that led to defective autophagy, wherein ATG5 expression is downregulated in contrast to acute Cd exposure. As a result, selective/defective autophagy creates depletion of autophagosome-lysosome fusion that gives a survival advantage to transforming cells, which is not available to RWPE-1 cells acutely exposed to Cd. Knockdown of key molecules in a lockstep manner directly affects the most downstream autophagy pathways in transforming cells. Overall, this study demonstrates that assembly of NOX1 complex proteins is indispensable for Cd-induced persistent ROS and controls ER stress-induced defective autophagy in mice and humans.

Porcine reproductive and respiratory syndrome virus infection triggers autophagy via ER stress-induced calcium signaling to facilitate virus replication

Calcium (Ca2+), a ubiquitous second messenger, plays a crucial role in many cellular functions. Viruses often hijack Ca2+ signaling to facilitate viral processes such as entry, replication, assembly, and egress. Here, we report that infection by the swine arterivirus, porcine reproductive and respiratory syndrome virus (PRRSV), induces dysregulated Ca2+ homeostasis, subsequently activating calmodulin-dependent protein kinase-II (CaMKII) mediated autophagy, and thus fueling viral replication. Mechanically, PRRSV infection induces endoplasmic reticulum (ER) stress and forms a closed ER–plasma membrane (PM) contacts, resulting the opening of store operated calcium entry (SOCE) channel and causing the ER to take up extracellular Ca2+, which is then released into the cytoplasm by inositol trisphosphate receptor (IP3R) channel. Importantly, pharmacological inhibition of ER stress or CaMKII mediated autophagy blocks PRRSV replication. Notably, we show that PRRSV protein Nsp2 plays a dominant role in the PRRSV induced ER stress and autophagy, interacting with stromal interaction molecule 1 (STIM1) and the 78 kDa glucose-regulated protein 78 (GRP78). The interplay between PRRSV and cellular calcium signaling provides a novel potential approach to develop antivirals and therapeutics for the disease outbreaks.

Current and potential roles of RNA modification-mediated autophagy dysregulation in cancer

Autophagy, a cellular lysosomal degradation and survival pathway, supports nutrient recycling and adaptation to metabolic stress and participates in various stages of tumor development, including tumorigenesis, metastasis, and malignant state maintenance. Among the various factors contributing to the dysregulation of autophagy in cancer, RNA modification can regulate autophagy by directly affecting the expression of core autophagy proteins. We propose that autophagy disorder mediated by RNA modification is an important mechanism for cancer development. Therefore, this review mainly discusses the role of RNA modification-mediated autophagy regulation in tumorigenesis. We summarize the molecular basis of autophagy and the core proteins and complexes at different stages of autophagy, especially those involved in cancer development. Moreover, we describe the crosstalk of RNA modification and autophagy and review the recent advances and potential role of the RNA modification/autophagy axis in the development of multiple cancers. Furthermore, the dual role of the RNA modification/autophagy axis in cancer drug resistance is discussed. A comprehensive understanding and extensive exploration of the molecular crosstalk of RNA modifications with autophagy will provide important insights into tumor pathophysiology and provide more options for cancer therapeutic strategies.

Polylactic acid microplastics induce higher biotoxicity of decabromodiphenyl ethane on earthworms (Eisenia fetida) compared to polyethylene and polypropylene microplastics

Decabromodiphenyl ethane (DBDPE) and microplastics (MPs), such as fossil-based polymers polyethylene (PE), polypropylene (PP), and bio-based plastics polylactic acid (PLA) are abundant in e-waste dismantling areas. However, the information on the effects of DBDPE combined with MPs (DBDPE-MPs) on earthworms is still limited. In this study, we explored the impacts of DBDPE-MPs on neurotoxic biomarkers, tissue damage, and transcriptomics of Eisenia fetida by simulating different exposure patterns of 10 mg kg^-1 DBDPE and 10 mg kg^-1 DBDPE-MPs (PLA, PP, and PE). Results showed that the activities of acetylcholinesterase, Na⁺/K⁺-ATPase, Ca²⁺/Mg²⁺-ATPase, carboxylate enzyme, and the contents of calcium and glutamate were significantly stimulated. DBDPE-MP co-exposure caused more severe damage to the epidermis, muscles, and tissues. Transcriptomic analysis revealed that differentially expressed genes (DEGs) of DBDPE-MPs were mainly related to inflammation, the immune system, digestive system, endocrine system, and metabolism. DBDPE and PP-MPs had similar influences on immunity and metabolism. However, DBDPE-PLA and DBDPE-PE further affected the endocrine system and signaling pathways. Specific DEGs showed that detoxification systems in the case of MPs were significantly upregulated. The study indicated that MPs exacerbated DBDPE toxicity in the nervous system, epidermis, and gene regulation of E. fetida, helping to assess the ecological risks of e-wastes and microplastics in soil.

Autophagy is induced by swine acute diarrhea syndrome coronavirus through the cellular IRE1-JNK-Beclin 1 signaling pathway after an interaction of viral membrane-associated papain-like protease and GRP78

Autophagy plays an important role in the infectious processes of diverse pathogens. For instance, cellular autophagy could be harnessed by viruses to facilitate replication. However, it is still uncertain about the interplay of autophagy and swine acute diarrhea syndrome coronavirus (SADS-CoV) in cells. In this study, we reported that SADS-CoV infection could induce a complete autophagy process both in vitro and in vivo, and an inhibition of autophagy significantly decreased SADS-CoV production, thus suggesting that autophagy facilitated the replication of SADS-CoV. We found that ER stress and its downstream IRE1 pathway were indispensable in the processes of SADS-CoV-induced autophagy. We also demonstrated that IRE1-JNK-Beclin 1 signaling pathway, neither PERK-EIF2S1 nor ATF6 pathways, was essential during SADS-CoV-induced autophagy. Importantly, our work provided the first evidence that expression of SADS-CoV PLP2-TM protein induced autophagy through the IRE1-JNK-Beclin 1 signaling pathway. Furthermore, the interaction of viral PLP2-TMF451-L490 domain and substrate-binding domain of GRP78 was identified to activate the IRE1-JNK-Beclin 1 signaling pathway, and thus resulting in autophagy, and in turn, enhancing SADS-CoV replication. Collectively, these results not only showed that autophagy promoted SADS-CoV replication in cultured cells, but also revealed that the molecular mechanism underlying SADS-CoV-induced autophagy in cells.

Calcium and Reactive Oxygen Species Signaling Interplays in Cardiac Physiology and Pathologies

Mitochondria are key players in energy production, critical activity for the smooth functioning of energy-demanding organs such as the muscles, brain, and heart. Therefore, dysregulation or alterations in mitochondrial bioenergetics primarily perturb these organs. Within the cell, mitochondria are the major site of reactive oxygen species (ROS) production through the activity of different enzymes since it is one of the organelles with the major availability of oxygen. ROS can act as signaling molecules in a number of different pathways by modulating calcium (Ca2+) signaling. Interactions among ROS and calcium signaling can be considered bidirectional, with ROS regulating cellular Ca2+ signaling, whereas Ca2+ signaling is essential for ROS production. In particular, we will discuss how alterations in the crosstalk between ROS and Ca2+ can lead to mitochondrial bioenergetics dysfunctions and the consequent damage to tissues at high energy demand, such as the heart. Changes in Ca2+ can induce mitochondrial alterations associated with reduced ATP production and increased production of ROS. These changes in Ca2+ levels and ROS generation completely paralyze cardiac contractility. Thus, ROS can hinder the excitation-contraction coupling, inducing arrhythmias, hypertrophy, apoptosis, or necrosis of cardiac cells. These interplays in the cardiovascular system are the focus of this review.

Retinal protective effect of curcumin metabolite hexahydrocurcumin against blue light-induced RPE damage

BACKGROUND

Age-related macular degeneration (AMD) is a disease of retinal pigment epithelium (RPE) cells. We have previously demonstrated that blue light can damage RPE cells and their underlying mechanisms. We found that hexahydrocurcumin (HHC), a metabolite of curcumin, had better retinal protection than curcumin. However, the involved mechanisms remain unclear.

METHODS

By exposing ARPE-19 human RPE cells and mouse primary RPE cells to blue light, the intracellular mechanisms of HHC in cells were investigated, including the proliferation of RPE cells and the effects of HHC on activating intracellular protective mechanisms and related factors. Next-generation sequencing (NGS) RNA sequencing revealed the underlying mechanisms involved in the induction and regulation of HHC treatment following blue light exposure.

RESULTS

HHC promoted autophagy by enhancing autophagic flux, reduced oxidative stress and endoplasmic reticulum (ER) stress, and effectively reversed blue light-induced cell death. RNA sequencing-based bioinformatics approaches comprehensively analyze HHC-mediated cellular processes.

CONCLUSION

Our findings elucidate the mechanisms of HHC against blue light damage in RPE cells and are beneficial for the development of natural metabolite-based preventive drugs or functional foods.

Glucotropaeolin Promotes Apoptosis by Calcium Dysregulation and Attenuates Cell Migration with FOXM1 Suppression in Pancreatic Cancer Cells

Pancreatic ductal adenocarcinoma (PDAC) has naturally aggressive characteristics including postoperative recurrence, resistance to conventional treatment, and metastasis. Surgical resection with chemotherapeutic agents has been conducted as the major treatment for PDAC. However, surgical treatment is ineffective in the case of advanced cancer, and conventional adjuvant chemotherapy, including gemcitabine and 5-fluorouracil, show low effectiveness due to the high drug resistance of PDAC to this type of treatment. Therefore, the development of innovative therapeutic drugs is crucial to solving the present limitation of conventional drugs. Glucotropaeolin (GT) is a glucosinolate that can be isolated from the Brassicaceae family. GT has exhibited a growth-inhibitory effect against liver and colon cancer cells; however, there is no study regarding the anticancer effect of GT on PDAC. In our study, we determined the antiproliferative effect of GT in PANC-1 and MIA PaCa-2, representative of PDAC. We revealed the intracellular mechanisms underlying the anticancer effect of GT with respect to cell viability, reactive oxygen species (ROS) accumulation, alteration of mitochondrial membrane potential (MMP), calcium dysregulation, cell migration, and the induction of apoptosis. Moreover, GT regulated the signaling pathways related to anticancer in PDAC cells. Finally, the silencing of the forkhead box protein M, a key factor regulating PDAC progression, contributes to the anticancer property of GT in terms of the induction of apoptosis and cell migration. Therefore, GT may be a potential therapeutic drug against PDAC.

Inactivation of CACNA1H induces cell apoptosis by initiating endoplasmic reticulum stress in glioma

Background

Ca²⁺ channels are abnormally expressed in various tumor cells and are involved in the progression of human glioma. Here, we explored the role of a calcium channel, voltage-dependent, T-type, alpha 1H subunit (CACNA1H), which encodes T-type Ca²⁺ channel Cav3.2 in glioma cells.

Methods

Cell viability and apoptosis were detected using cell-counting kit-8 and flow cytometry, respectively. The expression of target protein was determined using western blot analysis.

Results

Cell viability of U251 cells was inhibited significantly after the knockdown of CACNA1H. The apoptosis of U251 cells was enhanced significantly after the knockdown of CACNA1H. Importantly, knockdown of CACNA1H decreased the levels of p-PERK, GRP78, CHOP, and ATF6, indicating that CACNA1H knockdown activated endoplasmic reticulum stress (ERS) in U251 cells. In addition, T-type Ca²⁺ channel inhibitor NNC55-0396 also induced apoptosis through the activation of ERS in U251 cells. ERS inhibitor UR906 could block CACNA1H inhibitor ABT-639-induced apoptosis.

Conclusion

Suppression of CACNA1H activated the ERS and thus induced apoptosis in glioma cells. T-type Ca²⁺ channel inhibitors ABT-639 and NNC55-0396 also induced apoptosis through ERS in glioma cells. Our data highlighted the effect of CACNA1H as an oncogenic gene in human glioma.

The Emerging Role of Ferroptosis in Liver Cancers

Liver cancer represents a global health challenge with worldwide growth. Hepatocellular carcinoma (HCC) is the most common type of liver cancer. Indeed, approximately 90% of HCC cases have a low survival rate. Moreover, cholangiocarcinoma (CC) is another malignant solid tumor originating from cholangiocytes, the epithelial cells of the biliary system. It is the second-most common primary liver tumor, with an increasing course in morbidity and mortality. Tumor cells always show high metabolic levels, antioxidant modifications, and an increased iron uptake to maintain unlimited growth. In recent years, alterations in iron metabolism have been shown to play an important role in the pathogenesis of HCC. Several findings show that a diet rich in iron can enhance HCC risk. Hence, elevated iron concentration inside the cell may promote the development of HCC. Growing evidence sustains that activating ferroptosis may potentially block the proliferation of HCC cells. Even in CC, it has been shown that ferroptosis plays a crucial role in the treatment of tumors. Several data confirmed the inhibitory effect in cell growth of photodynamic therapy (PDT) that can induce reactive oxygen species (ROS) in CC, leading to an increase in malondialdehyde (MDA) and a decrease in intracellular glutathione (GSH). MDA and GSH depletion/modulation are crucial in inducing ferroptosis, suggesting that PDT may have the potential to induce this kind of cell death through these ways. A selective induction of programmed cell death in cancer cells is one of the main treatments for malignant tumors; thus, ferroptosis may represent a novel therapeutic strategy against HCC and CC.

Emerging links between endoplasmic reticulum stress responses and acute kidney injury

All cell types must maintain homeostasis under periods of stress. To prevent the catastrophic effects of stress, all cell types also respond to stress by inducing protective pathways. Within the cell, the endoplasmic reticulum (ER) is exquisitely stress-sensitive, primarily because this organelle folds, posttranslationally processes, and sorts one-third of the proteome. In the 1990s, a specialized ER stress response pathway was discovered, the unfolded protein response (UPR), which specifically protects the ER from damaged proteins and toxic chemicals. Not surprisingly, UPR-dependent responses are essential to maintain the function and viability of cells continuously exposed to stress, such as those in the kidney, which have high metabolic demands, produce myriad protein assemblies, continuously filter toxins, and synthesize ammonia. In this mini-review, we highlight recent articles that link ER stress and the UPR with acute kidney injury (AKI), a disease that arises in ∼10% of all hospitalized individuals and nearly half of all people admitted to intensive care units. We conclude with a discussion of prospects for treating AKI with emerging drugs that improve ER function.

Prx1 Regulates Thapsigargin-Mediated UPR Activation and Apoptosis

Endoplasmic reticulum (ER) stress activates the unfolded protein response (UPR) signaling via the accumulation of unfolded and misfolded proteins. ER stress leads to the production of reactive oxygen species (ROS), which are necessary to maintain redox homeostasis in the ER. Although peroxiredoxin 1 (Prx1) is an antioxidant enzyme that regulates intracellular ROS levels, the link between Prx1 and ER stress remains unclear. In this study, we investigated the role of Prx1 in X-box binding protein 1 (XBP-1) activation, the C/EBP homologous protein (CHOP) pathway, and apoptosis in response to ER stress. We observed that Prx1 overexpression inhibited the nuclear localization of XBP-1 and the expression of XBP-1 target genes and CHOP after thapsigargin (Tg) treatment to induce ER stress. In addition, Prx1 inhibited apoptosis and ROS production during ER stress. The ROS scavenger inhibited ER stress-induced apoptosis but did not affect XBP-1 activation and CHOP expression. Therefore, the biological role of Prx1 in ER stress may have important implications for ER stress-related diseases.

Cadmium exposure induces autophagy via PLC-IP3 -IP3 R signaling pathway in duck renal tubular epithelial cells

Cadmium (Cd) is detrimental to animals, but nephrotoxic effects of Cd on duck have not been fully elucidated. To evaluate the impacts of Cd on Ca homeostasis and autophagy via PLC-IP₃ -IP₃ R pathway, primary duck renal tubular epithelial cells were exposed to 2.5 μM and 5.0 μM Cd, and combination of 5.0 μM Cd and 10.0 μM 2-APB or 0.125 μM U-73122 for 12 h (U-73122 pretreated for 1 h). These results evidenced that Cd induced [Ca²⁺ ]_c overload mainly came from intracellular Ca store. Cd caused [Ca²⁺ ]_mit and [Ca²⁺ ]_c overload with [Ca²⁺ ]_ER decrease, elevated Ca homeostasis related factors (GRP78, GRP94, CRT, CaN, CaMKII, and CaMKKβ) expression, PLC and IP₃ activities and IP₃ R expression, but subcellular Ca²⁺ redistribution was reversed by 2-APB. PLC inhibitor U-73122 dramatically relieved the changes of the above indicators induced by Cd. Additionally, U-73122 obviously reduced the number of autophagosomes and LC3 accumulation spots, Atg5, LC3A, LC3B mRNA levels and LC3II/LC3I, Beclin-1 protein levels induced by Cd, and markedly elevated p62 mRNA and protein levels. Overall, the results verified that Cd induced [Ca²⁺ ]_c overload mainly originated from ER Ca²⁺ release mediated by PLC-IP₃ -IP₃ R pathway, then triggered autophagy in duck renal tubular epithelial cells.

Exposure to phenanthrene affects oocyte meiosis by inducing mitochondrial dysfunction and endoplasmic reticulum stress

OBJECTIVES

Phenanthrene (PHE) is one of the most abundant polycyclic aromatic hydrocarbons (PAHs), which is a widespread environmental contaminant. Various studies showed that PHE has adverse impacts on animals and human health. It has been shown that PHE exposure induced follicular atresia and endocrine dyscrasia in female mice. However, the potential mechanism regarding how PHE affects female reproductive system especially the oocyte quality has not been elucidated.

METHODS AND RESULTS

In this study, we set up PHE exposure model and found that PHE exposure compromised oocytes maturation competence by inhibiting spindle assembly and chromosomes alignment. Moreover, PHE exposure induced mitochondrial dysfunction and endoplasmic reticulum (ER) stress, leading to increased reactive oxygen species (ROS) and aberrant calcium levels in cytoplasm, eventually induced oxidative stress and DNA damage in oocytes. Furthermore, we found that oral administration of PHE caused the occurrence of oxidative stress and apoptosis in female ovary. In addition, the oocyte exhibited aberrant spindle morphology and failure of actin cap formation in metaphase II oocytes.

CONCLUSIONS

Taken together, our study demonstrated that mitochondrial dysfunction and ER stress-induced oxidative stress and DNA damage are the major cause of poor oocyte quality after PHE exposure.

Inhibition of Ca2+ entry by capsazepine analog CIDD-99 prevents oral squamous carcinoma cell proliferation

Oral cancer patients have a poor prognosis, with approximately 66% of patients surviving 5-years after diagnosis. Treatments for oral cancer are limited and have many adverse side effects; thus, further studies are needed to develop drugs that are more efficacious. To achieve this objective, we developed CIDD-99, which produces cytotoxic effects in multiple oral squamous cell carcinoma (OSCC) cell lines. While we demonstrated that CIDD-99 induces ER stress and apoptosis in OSCC, the mechanism was unclear. Investigation of the Bcl-family of proteins showed that OSCC cells treated with CIDD-99 undergo downregulation of Bcl-XL and Bcl-2 anti-apoptotic proteins and upregulation of Bax (pro-apoptotic). Importantly, OSCC cells treated with CIDD-99 displayed decreased calcium signaling in a dose and time-dependent manner, suggesting that blockage of calcium signaling is the key mechanism that induces cell death in OSCC. Indeed, CIDD-99 anti-proliferative effects were reversed by the addition of exogenous calcium. Moreover, electrophysiological properties further established that calcium entry was via the non-selective TRPC1 channel and prolonged CIDD-99 incubation inhibited STIM1 expression. CIDD-99 inhibition of calcium signaling also led to ER stress and inhibited mitochondrial complexes II and V in vitro. Taken together, these findings suggest that inhibition of TRPC mediates induction of ER stress and mitochondrial dysfunction as a part of the cellular response to CIDD-99 in OSCC.

ER Stress Response and Induction of Apoptosis in Malignant Pleural Mesothelioma: The Achilles Heel Targeted by the Anticancer Ruthenium Drug BOLD-100

Simple Summary

Malignant mesothelioma is a rare cancer arising from the serosal surfaces of the body, mainly from the pleural layer. This cancer, strongly linked to asbestos exposure, shows a very inauspicious prognosis. In fact, there is no efficient therapeutic treatment for malignant pleural mesothelioma (MPM). Thus, there is an urgent need to develop novel therapeutic approaches to treat this form of cancer. Our previous study showed the importance of GRP78 in MPM survival. BOLD-100 is a specific modulator of GRP78 and we have observed that it shows cytotoxicity against MPM cells. In particular, we describe that BOLD-100 increases oxidative stress and deregulates the calcium homeostasis leading to cell stress and, ultimately, to cell death. Our in vitro data strongly suggest that BOLD-100 inhibits the growth of MPM cell lines, proposing the application as a single agent, or in combination with other standard-of-care drugs, to treat MPM.

Abstract

Malignant mesothelioma is a rare cancer arising from the serosal surfaces of the body, mainly from the pleural layer. This cancer is strongly related to asbestos exposure and shows a very inauspicious prognosis, because there are scarce therapeutic options for this rare disease. Thus, there is an urgent need to develop novel therapeutic approaches to treat this form of cancer. To explore the biology of malignant pleural mesothelioma (MPM), we previously observed that MPM cell lines show high expression of the GRP78 protein, which is a chaperone protein and the master regulator of the unfolded protein response (UPR) that resides in the endoplasmic reticulum (ER). Based on our previous studies showing the importance of GRP78 in MPM, we observed that BOLD-100, a specific modulator of GRP78 and the UPR, shows cytotoxicity against MPM cells. Our studies demonstrated that BOLD-100 increases ROS production and Ca²⁺ release from the ER, leading to ER stress activation and, ultimately, to cell death. Our in vitro data strongly suggest that BOLD-100 inhibits the growth of MPM cell lines, proposing the application as a single agent, or in combination with other standard-of-care drugs, to treat MPM.

Prostate Cancer Secretome and Membrane Proteome from Pten Conditional Knockout Mice Identify Potential Biomarkers for Disease Progression

Prostate cancer (PCa) is the second most common cause of mortality among men. Tumor secretome is a promising strategy for understanding the biology of tumor cells and providing markers for disease progression and patient outcomes. Here, transcriptomic-based secretome analysis was performed on the PCa tumor transcriptome of Genetically Engineered Mouse Model (GEMM) Pb-Cre4/Pten^f/f mice to identify potentially secreted and membrane proteins—PSPs and PMPs. We combined a selection of transcripts from the GSE 94574 dataset and a list of protein-coding genes of the secretome and membrane proteome datasets using the Human Protein Atlas Secretome. Notably, nine deregulated PMPs and PSPs were identified in PCa (DMPK, PLN, KCNQ5, KCNQ4, MYOC, WIF1, BMP7, F3, and MUC1). We verified the gene expression patterns of Differentially Expressed Genes (DEGs) in normal and tumoral human samples using the GEPIA tool. DMPK, KCNQ4, and WIF1 targets were downregulated in PCa samples and in the GSE dataset. A significant association between shorter survival and KCNQ4, PLN, WIF1, and F3 expression was detected in the MSKCC dataset. We further identified six validated miRNAs (mmu-miR-6962-3p, mmu-miR- 6989-3p, mmu-miR-6998-3p, mmu-miR-5627-5p, mmu-miR-15a-3p, and mmu-miR-6922-3p) interactions that target MYOC, KCNQ5, MUC1, and F3. We have characterized the PCa secretome and membrane proteome and have spotted new dysregulated target candidates in PCa.

Phillygenin ameliorates nonalcoholic fatty liver disease via TFEB-mediated lysosome biogenesis and lipophagy

BACKGROUND

Lipophagy is an autophagic process, which delivers the intracellular lipid droplets to the lysosomes for degradation. Recent studies revealed that the impairment of lysosomal biogenesis and autophagic flux led to dysregulation of lipophagy in hepatocytes, which exacerbated the development of nonalcoholic fatty liver disease (NAFLD). Therefore, agents restoring autophagic flux and lipophagy in hepatocytes may have therapeutic potential against this increasingly prevalent disease. Phillygenin (PHI), a lignin extracted from Forsythia suspense, exerts hepatoprotective and anti-inflammatory effects. However, the effect of PHI on NAFLD remains unknown.

PURPOSE

This study aimed to investigate the protective effect of PHI on NAFLD and elucidate the underlying mechanism.

METHODS

The effects of PHI were examined in palmitate (PA)-stimulated AML12 cells and primary hepatocytes, as well as in NAFLD mice induced by a high-fat diet (HFD). We also used transcription factor EB (TFEB) knockdown hepatocytes and hepatocyte-specific TFEB knockout (TFEB^Δhep) mice for mechanistic studies. In vivo and in vitro studies were performed using western blots, immunofluorescence techniques, and transmission electron microscopy.

RESULTS

Our results indicated that autophagic flux and lysosome biogenesis in PA-stimulated hepatocytes were impaired. PHI alleviated lipid deposition by increasing lysosomal biogenesis and autophagic flux. It also stimulated the release of endoplasmic reticulum Ca²⁺ to activate calcineurin, which regulated TFEB dephosphorylation and nuclear translocation, and promoted lysosomal biogenesis. In addition, PHI blocked the NLRP3 inflammasome pathway and improved hepatocyte inflammation in an autophagy-dependent manner. Consistent with the in vitro results, PHI improved hepatic steatosis and inflammation in HFD mice, but these beneficial effects were eliminated in hepatocyte-specific TFEB knockout mice.

CONCLUSION

Despite PHI has been reported to have anti-hepatic fibrosis effects, whether it has a hepatoprotective effects against NAFLD and the underlying molecular mechanism remain unclear. Herein, we found that PHI restored lipophagy and suppressed lipid accumulation and inflammation by regulating the Ca²⁺-calcineurin-TFEB axis in hepatocytes. Thus, PHI represents a therapeutic candidate for the treatment of NAFLD.

Drug Discovery Using Evolutionary Similarities in Chemical Binding to Inhibit Patient-Derived Hepatocellular Carcinoma

Drug resistance causes therapeutic failure in refractory cancer. Cancer drug resistance stems from various factors, such as patient heterogeneity and genetic alterations in somatic cancer cells, including those from identical tissues. Generally, resistance is intrinsic for cancers; however, cancer resistance becomes common owing to an increased drug treatment. Unfortunately, overcoming this issue is not yet possible. The present study aimed to evaluate a clinical approach using candidate compounds 19 and 23, which are sarcoplasmic/endoplasmic reticulum calcium ATPase (SERCA) inhibitors, discovered using the evolutionary chemical binding similarity method. mRNA sequencing indicated SERCA as the dominant marker of patient-derived anti-cancer drug-resistant hepatocellular carcinoma (HCC), but not of patient-derived anti-cancer drug-sensitive HCC. Candidate compounds 19 and 23 led to significant tumor shrinkage in a tumor xenograft model of anti-cancer drug-resistant patient-derived HCC cells. Our results might be clinically significant for the development of novel combinatorial strategies that selectively and efficiently target highly malignant cells such as drug-resistant and cancer stem-like cells.

Role of miR-451 in mediating cadmium induced head kidney injury in common carp via targeting cacna1ab through autophagy pathways

Cadmium (Cd) is a common environmental pollutant, which leads to Cd residue in aquatic animals. The Cd in aquatic animals will be enriched into the human body through the food chain and seriously harm human health. The research aims to investigate the molecular mechanism of Cd poisoning in common carps. Our previous studies have confirmed that 23 differentially expressed miRNAs were potential biomarkers for Cd exposure in common carp head kidney lymphocytes. Herein, based on the prediction of the website and previous studies, miR-451 and cacna1ab were selected and their targeting relationship was verified again by dual-luciferase. Subsequently, we established the miR-451 overexpression/knockdown models and miR-451 inhibitor, cacna1ab co-knockdown models in common carp head kidney lymphocytes respectively. Immunofluorescence staining, MDC staining, calcium staining, qRT-PCR (Quantitative Real-time PCR) and western blot were used to detect the levels of autophagy. Our results demonstrated that Cd significantly decreased the expression of miR-451, miR-451 suppression thereby induced increased cacna1ab and the expression of ATG5, LC3-I, LC3-II and Beclin 1, while significantly inhibiting the expression of mTOR, P62 and Bcl-2, which indicated that autophagy was triggered. Moreover, the miR-451 knockdown group activated the expression of autophagy related factors as well as the Cd group. However, cacna1ab knockdown can reduce autophagy activation induced by miR-451 knockdown. Our results indicated that Cd induced autophagy in head kidney lymphocytes through the inhibition of miR-451 and the excitation of cacna1ab.