Identification of a microRNA (miR-663a) induced by ER stress and its target gene PLOD3 by a combined microRNome and proteome approach

Huangqi Decoction, a compound Chinese herbal medicine, inhibits the proliferation and activation of hepatic stellate cells by regulating the long noncoding RNA-C18orf26-1/microRNA-663a/transforming growth factor-β axis

OBJECTIVE

Huangqi Decoction (HQD), a classical traditional Chinese medicine formula, has been used as a valid treatment for alleviating liver fibrosis; however, the underlying molecular mechanism is still unknown. Although our previous studies showed that microRNA-663a (miR-663a) suppresses the proliferation and activation of hepatic stellate cells (HSCs) and the transforming growth factor-β/small mothers against decapentaplegic (TGF-β/Smad) pathway, whether long noncoding RNAs (lncRNAs) are involved in HSC activation via the miR-663a/TGF-β/Smad signaling pathway has not yet reported. The present study aimed to investigate the roles of lncRNA lnc-C18orf26-1 in the activation of HSCs and the mechanism by which HQD inhibits hepatic fibrosis.

METHODS

The expression levels of lnc-C18orf26-1, miR-663a and related genes were measured by quantitative reverse transcription-polymerase chain reaction. HSCs were transfected with the miR-663a mimic or inhibitor and lnc-C18orf26-1 small interfering RNAs. The water-soluble tetrazolium salt-1 assay was used to assess the proliferation rate of HSCs. Changes in lncRNA expression were evaluated in miR-663a-overexpressing HSCs by using microarray to identify miR-663a-regulated lncRNAs. RNA hybrid was used to predict the potential miR-663a binding sites on lncRNAs. Luciferase reporter assays further confirmed the interaction between miR-663a and the lncRNA. The expression levels of collagen α-2(I) chain (COL1A2), α-smooth muscle actin (α-SMA) and TGF-β/Smad signaling pathway-related proteins were determined using Western blotting.

RESULTS

Lnc-C18orf26-1 was upregulated in TGF-β1-activated HSCs and competitively bound to miR-663a. Knockdown of lnc-C18orf26-1 inhibited HSC proliferation and activation, downregulated TGF-β1-stimulated α-SMA and COL1A2 expression, and inhibited the TGF-β1/Smad signaling pathway. HQD suppressed the proliferation and activation of HSCs. HQD increased miR-663a expression and decreased lnc-C18orf26-1 expression in HSCs. Further studies showed that HQD inhibited the expression of COL1A2, α-SMA, TGF-β1, TGF-β type I receptor (TGF-βRI) and phosphorylated Smad2 (p-Smad2) in HSCs, and these effects were reversed by miR-663a inhibitor treatment.

CONCLUSION

Our study identified lnc-C18orf26-1 and miR-663a as promising therapeutic targets for hepatic fibrosis. HQD inhibits HSC proliferation and activation at least partially by regulating the lnc-C18orf26-1/miR-663a/TGF-β1/TGF-βRI/p-Smad2 axis.

Shrimp pmo-miR-750 regulates the expression of sarcoplasmic calcium-binding protein facilitating virus infection in Penaeus monodon

MicroRNAs (miRNAs) regulate gene expression post-transcriptionally and play crucial roles in antiviral responses. Penaeus monodon miR-750 (pmo-miR-750) was found to be strongly up-regulated in the late phase of white spot syndrome virus (WSSV) infection, but its function remains uncharacterized. Herein, the targets that were translationally down-regulated in the shrimp stomach following a pmo-miR-750 mimic injection were identified using two-dimensional gel electrophoresis. Sarcoplasmic calcium-binding protein (Scp) and actin1 (Act1) were revealed to be down-regulated protein spots. The genuine binding of pmo-miR-750 mimic to Scp but not Act1 mRNA was validated in vitro. In addition, a negative correlation between the Scp transcript and pmo-miR-750 expression level in WSSV-infected P. monodon stomach implies that pmo-miR-750 regulates Scp expression in vivo. When injected into WSSV-infected shrimp, the pmo-miR-750 mimic suppressed Scp expression but significantly increased the WSSV copy number. Consistent with the miRNA mimic-mediated Scp suppression, the loss of function assay of Scp in WSSV-challenged shrimp by RNA interference revealed a decreased survival rate with a dramatic increase in viral copy number. Besides that, apoptosis was activated in the hemocytes of the Scp knockdown shrimp upon WSSV infection. Collectively, our findings reveal that up-regulated pmo-miR-750 suppresses Scp expression at both the transcript and protein levels in the late stage of WSSV infection, which contributes to modulating apoptosis and eventually enabling viral propagation.

PLOD Family: A Novel Biomarker for Prognosis and Personalized Treatment in Soft Tissue Sarcoma

Despite various treatment attempts, the heterogenous group of soft tissue sarcomata (STS) with more than 100 subtypes still shows poor outcomes. Therefore, effective biomarkers for prognosis prediction and personalized treatment are of high importance. The Procollagen-Lysine, 2-Oxoglutarate 5-Dioxygenase (PLOD) gene family, which is related to multiple cancer entities, consists of three members which encode important enzymes for the formation of connective tissue. The relation to STS, however, has not yet been explored. In this study, data from The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) databases were used to analyze the role of PLOD1–3 in STS. It was found that an overexpression of PLOD family members correlates with poor prognosis, which might be due to an increased infiltration of immune-related cells in the tumor microenvironment. In STS, the expression of PLOD genes could be a novel biomarker for prognosis and a personalized, more aggressive treatment in these patients.

PLOD3 regulates the expression of YAP1 to affect the progression of non-small cell lung cancer via the PKCδ/CDK1/LIMD1 signaling pathway

Procollagen-lysine, 2-oxoglutarate 5-dioxygenase (PLOD3) is a crucial oncogene in human lung cancer, whereas protein kinase C δ (PKCδ) acts as a tumor suppressor. In this study, we aimed to explore the regulation by PLOD3 on the expression of YAP1 to affect the progression of non-small cell lung cancer (NSCLC) via the PKCδ/CDK1/LIMD1 signaling pathway. We found that PLOD3, CDK1, and YAP1 were highly expressed, while LIMD1 was poorly expressed in NSCLC tissues. Mechanistic investigation demonstrated that silencing PLOD3 promoted the cleavage of PKCδ in a caspase-dependent manner to generate a catalytically active fragment cleaved PKCδ, enhanced phosphorylation levels of CDK1, and LIMD1 but suppressed nuclear translocation of YAP1. Furthermore, functional experimental results suggested that loss of PLOD3 led to increased phosphorylation levels of CDK1 and LIMD1 and downregulated YAP1, thereby suppressing the proliferation, colony formation, cell cycle entry, and resistance to apoptosis of NSCLC cells in vitro and inhibiting tumor growth in vivo. Taken together, these results show that PLOD3 silencing activates the PKCδ/CDK1/LIMD1 signaling pathway to prevent the progression of NSCLC, thus providing novel insight into molecular targets for treating NSCLC.

The Regulation of Collagen Processing by miRNAs in Disease and Possible Implications for Bone Turnover

This article describes several recent examples of miRNA governing the regulation of the gene expression involved in bone matrix construction. We present the impact of miRNA on the subsequent steps in the formation of collagen type I. Collagen type I is a main factor of mechanical bone stiffness because it constitutes 90-95% of the organic components of the bone. Therefore, the precise epigenetic regulation of collagen formation may have a significant influence on bone structure. We also describe miRNA involvement in the expression of genes, the protein products of which participate in collagen maturation in various tissues and cancer cells. We show how non-collagenous proteins in the extracellular matrix are epigenetically regulated by miRNA in bone and other tissues. We also delineate collagen mineralisation in bones by factors that depend on miRNA molecules. This review reveals the tissue variability of miRNA regulation at different levels of collagen maturation and mineralisation. The functionality of collagen mRNA regulation by miRNA, as proven in other tissues, has not yet been shown in osteoblasts. Several collagen-regulating miRNAs are co-expressed with collagen in bone. We suggest that collagen mRNA regulation by miRNA could also be potentially important in bone metabolism.

Polypeptide N-acetylgalactosaminyltransferase 18 retains in endoplasmic reticulum depending on its luminal regions interacting with ER resident UGGT1, PLOD3 and LPCAT1

Mucin-type O-glycosylation is initiated by the polypeptide: N-acetylgalactosaminyltransferase (ppGalNAc-T) family of enzymes, which consists of 20 members in humans. Among them, unlike other ppGalNAc-Ts located in Golgi apparatus, ppGalNAc-T18 distributes primarily in the endoplasmic reticulum (ER) and non-catalytically regulates ER homeostasis and O-glycosylation. Here, we report the mechanism for ppGalNAc-T18 ER localization and the function of each structural domain of ppGalNAc-T18. By using ppGalNAc-T18 truncation mutants, we revealed that the luminal stem region and catalytic domain of ppGalNAc-T18 are essential for ER localization, whereas the lectin domain and N-glycosylation of ppGalNAc-T18 are not required. In the absence of the luminal region (i.e., stem region, catalytic and lectin domains), the conserved Golgi retention motif RKTK within the cytoplasmic tail combined with the transmembrane domain ensure ER export and Golgi retention, as observed for other Golgi resident ppGalNAc-Ts. Results from coimmunoprecipitation assays showed that the luminal region interacts with ER resident proteins UGGT1, PLOD3 and LPCAT1. Furthermore, flow cytometry analysis showed that the entire luminal region is required for the non-catalytic O-GalNAc glycosylation activity of ppGalNAc-T18. The findings reveal a novel subcellular localization mechanism of ppGalNAc-Ts and provide a foundation to further characterize the function of ppGalNAc-T18 in the ER.

PERK Signaling Controls Myoblast Differentiation by Regulating MicroRNA Networks

The unfolded protein response (UPR) plays important roles in various cells that have a high demand for protein folding, which are involved in the process of cell differentiation and development. Here, we separately knocked down the three sensors of the UPR in myoblasts and found that PERK knockdown led to a marked transformation in myoblasts from a fusiform to a rounded morphology, which suggests that PERK is required for early myoblast differentiation. Interestingly, knocking down PERK induced reprogramming of C2C12 myoblasts into stem-like cells by altering the miRNA networks associated with differentiation and stemness maintenance, and the PERK-ATF4 signaling pathway transactivated muscle differentiation-associated miRNAs in the early stage of myoblast differentiation. Furthermore, we identified Ppp1cc as a direct target gene of miR-128 regulated by the PERK signaling pathway and showed that its repression is critical for a feedback loop that regulates the activity of UPR-associated signaling pathways, leading to cell migration, cell fusion, endoplasmic reticulum expansion, and myotube formation during myoblast differentiation. Subsequently, we found that the RNA-binding protein ARPP21, encoded by the host gene of miR-128-2, antagonized miR-128 activity by competing with it to bind to the 3' untranslated region (UTR) of Ppp1cc to maintain the balance of the differentiation state. Together, these results reveal the crucial role of PERK signaling in myoblast maintenance and differentiation and identify the mechanism underlying the role of UPR signaling as a major regulator of miRNA networks during early differentiation of myoblasts.

Roles of microRNAs in renal disorders related to primary podocyte dysfunction

Through the regulation of gene expression, microRNAs (miRNAs) are capable of modulating vital biological processes, such as proliferation, differentiation, and apoptosis. Several mechanisms control the function of miRNAs, including translational inhibition and targeted miRNA degradation. Through utilizing high-throughput screening methods, such as small RNA sequencing and microarray, alterations in miRNA expression of kidneys have recently been observed both in rodent models and humans throughout the development of chronic kidney disease (CKD) and acute kidney injury (AKI). The levels of miRNAs in urine supernatant, sediment, and exosomal fraction could predict novel biomarker candidates in different diseases of kidneys, including IgA nephropathy, lupus nephritis, and diabetic nephropathy. The therapeutic potential of administrating anti-miRNAs and miRNAs has also been reported recently. The present study is aimed at reviewing the state-of-the-art research with regards to miRNAs involved in renal disorders related to primary podocyte dysfunction by laying particular emphasis on Focal Segmental Glomerulosclerosis (FSGS), Minimal Change Disease (MCD) and Membranous Nephropathy (MN).

PERK-Mediated Unfolded Protein Response Activation and Oxidative Stress in PARK20 Fibroblasts

PARK20, an early onset autosomal recessive parkinsonism is due to mutations in the phosphatidylinositol-phosphatase Synaptojanin 1 (Synj1). We have recently shown that the early endosomal compartments are profoundly altered in PARK20 fibroblasts as well as the endosomal trafficking. Here, we report that PARK20 fibroblasts also display a drastic alteration of the architecture and function of the early secretory compartments. Our results show that the exit machinery from the Endoplasmic Reticulum (ER) and the ER-to-Golgi trafficking are markedly compromised in patient cells. As a consequence, PARK20 fibroblasts accumulate large amounts of cargo proteins within the ER, leading to the induction of ER stress. Interestingly, this stressful state is coupled to the activation of the PERK/eIF2α/ATF4/CHOP pathway of the Unfolded Protein Response (UPR). In addition, PARK20 fibroblasts reveal upregulation of oxidative stress markers and total ROS production with concomitant alteration of the morphology of the mitochondrial network. Interestingly, treatment of PARK20 cells with GSK2606414 (GSK), a specific inhibitor of PERK activity, restores the level of ROS, signaling a direct correlation between ER stress and the induction of oxidative stress in the PARK20 cells. All together, these findings suggest that dysfunction of early secretory pathway might contribute to the pathogenesis of the disease.

MicroRNA in osteoarthritis: physiopathology, diagnosis and therapeutic challenge

BACKGROUND

Osteoarthritis (OA) is the most orthopedic condition. The pattern of gene expression and the transcription factors that exert control of chondrogenesis have been extensively studied.

SOURCES OF DATA

A systematic search (up to July 2018) of articles assessing the role of microRNA (miRNA) in physiopathology, diagnosis and therapy of OA was performed, with the purpose of giving a critical perspective of the possibilities for diagnostic and therapeutic use of miRNA in the management of OA.

AREAS OF AGREEMENT

miRNAs are small noncoding RNAs that can regulate gene expression in human cells. miRNAs can be expressed in a different fashion in osteoarthritic compared to nonosteoarthritic cartilage.

AREAS OF CONTROVERSY

The mechanisms that produce alteration of gene expression in OA are still not completely understood. miRNAs may be involved in the diagnosis of OA as well as in its treatment.

GROWING POINTS

There are complex interactions between miRNAs and their multiple target genes. These interactions may be important in gene regulation and the control of homeostatic pathways in OA.

AREAS TIMELY FOR DEVELOPING RESEARCH

miRNA could be useful for diagnostic or management purposes, but the issue of delivery of miRNA targeting agents needs to be overcome before miRNA can be applied in clinical practice.

Recent advances in the molecular mechanism of sex disparity in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is more frequently observed and aggressive in men compared with women. Increasing evidence demonstrates that the sex disparity appears to be mediated by the stimulatory effects of androgens and the protective effects of estrogen in the development and progression of HCC. In the past few decades, studies on the sex difference of HCC mainly focused on the effect of sex hormones on the transactivation of hepatitis B virus X protein and the release of inflammatory cytokines, and these studies have further intensified in recent years. Sex hormones are also involved in genetic alterations and DNA damage repair in hepatocytes through binding to their specific cellular receptors and affecting the corresponding signaling pathways. Furthermore, the theory of sex chromosomes participating in HCC has been considered. The present review discussed the recent advances in the molecular mechanisms of sex disparity in HCC, with the aim of improving the understanding of the underlying critical factors and exploring more effective methods for the prevention and treatment of HCC.

PLOD3 suppression exerts an anti-tumor effect on human lung cancer cells by modulating the PKC-delta signaling pathway

Current lung cancer treatments are far from satisfactory; thus, finding novel treatment targets is crucial. We recently identified procollagen-lysine, 2-oxoglutarate 5-dioxygenase 3 (PLOD3), which is involved in fibrosis and tissue remodeling as a radioresistance-related protein in lung cancer cells; however, its mechanism is unclear. In this study, we designed human PLOD3-specific short interfering (si)RNAs and tested their effects on tumor growth inhibition in vitro and in vivo. PLOD3 knockdown overcame chemoresistance and decreased radioresistance by inducing caspase-3-dependent apoptosis in lung cancer cells. Furthermore, PLOD3 interacted with PKCδ to activate caspase-2,4-dependent apoptosis through ER-stress-induced IRE1α activation and the downstream unfolded-protein response pathway. In a mouse xenograft model, PLOD3 knockdown promoted radiation-induced tumor growth inhibition, without side effects. Moreover, lung cancer patients with high PLOD3 expression showed poorer prognosis than those with low PLOD3 expression upon radiotherapy, suggesting that PLOD3 promotes tumor growth. Therefore, PLOD3 siRNA suppresses radioresistance and chemoresistance by inducing apoptosis and renders PLOD3 as a candidate lung cancer biomarker. PLOD3 gene therapy might enhance the efficacy of radiotherapy or chemotherapy in lung cancer patients.

ZBTB7A, a miR-663a target gene, protects osteosarcoma from endoplasmic reticulum stress-induced apoptosis by suppressing LncRNA GAS5 expression

Many studies have uncovered the essential role of ZBTB7A in regulating tumourigenesis. However, its functional significance in cell responses to endoplasmic reticulum stress (ER stress) remains poorly understood. Here we report that ZBTB7A functions as an important prosurvival factor in osteosarcoma cells undergoing pharmacological ER stress-induced by tunicamycin (TM) or thapsigargin (TG). The downregulation of ZBTB7A expression by ER stress promoted cell apoptosis in vitro and in vivo. ZBTB7A expression levels were increased in osteosarcoma tissues and elevated ZBTB7A was associated with osteosarcoma metastasis. Further mechanistic studies revealed that miR-663a induced by ER stress directly bound to the 3'UTR of ZBTB7A and contributed to ER stress-induced ZBTB7A downregulation in osteosarcoma cells. Additionally, our data revealed that ZBTB7A bound to the promoter of LncRNA GAS5 and transcriptionally suppressed LncRNA GAS5 expression, leading to a decline in ER stress-induced cell apoptosis. Collectively, our findings reveal the prosurvival role of ZBTB7A in osteosarcoma adaptation to ER stress and suggest that the miR-663a-ZBTB7A-LncRNAGAS5 pathway is essential for the survival of human osteosarcoma cells under ER stress.

Single Cell Proteomics for Molecular Targets in Lung Cancer: High-Dimensional Data Acquisition and Analysis

In the proteomic and genomic era, lung cancer researchers are increasingly under challenge with traditional protein analyzing tools. High output, multiplexed analytical procedures are in demand for disclosing the post-translational modification, molecular interactions and signaling pathways of proteins precisely, specifically, dynamically and systematically, as well as for identifying novel proteins and their functions. This could be better realized by single-cell proteomic methods than conventional proteomic methods. Using single-cell proteomic tools including flow cytometry, mass cytometry, microfluidics and chip technologies, chemical cytometry, single-cell western blotting, the quantity and functions of proteins are analyzed simultaneously. Aside from deciphering disease mechanisms, single-cell proteomic techniques facilitate the identification and screening of biomarkers, molecular targets and promising compounds as well. This review summarized single-cell proteomic tools and their use in lung cancer.

Structural basis of antiviral activity of peptides from MPER of FIV gp36

Feline immunodeficiency virus (FIV) is a naturally occurring Lentivirus causing acquired immunodeficiency syndrome in felines. It is considered a useful non-primate model to study HIV infection, and to test anti-HIV vaccine. Similarly to HIV, FIV enters cells via a mechanism involving a surface glycoprotein named gp36. C8 is a short synthetic peptide corresponding to the residues 770WEDWVGWI777 of gp36 membrane proximal external region (MPER). It elicits antiviral activity by inhibiting the fusion of the FIV and host cell membrane. C8 is endowed with evident membrane binding property, inducing alteration of the phospholipid bilayer and membrane fusion. The presence and the position of tryptophan residues in C8 are important for antiviral activity: the C8 derivative C6a, obtained by truncating the N-terminal 770WE771 residues, exhibits conserved antiviral activity, while the C8 derivative C6b, derived from the truncation of the C-terminal 776WI777, is nearly inactive. To elucidate the structural factors that induce the different activity profiles of C6a and C6b, in spite of their similarity, we investigated the structural behaviour of the two peptides in membrane mimicking environments. Conformational data on the short peptides C6a and C6b, matched to those of their parent peptide C8, allow describing a pharmacophore model of antiviral fusion inhibitors. This includes the essential structural motifs to design new simplified molecules overcoming the pharmacokinetic and high cost limitations affecting the antiviral entry inhibitors that currently are in therapy.

Oncogenic miR-663a is associated with cellular function and poor prognosis in renal cell carcinoma

BACKGROUND

MicroRNA(miRNA) plays a key regulatory role in various stages of tumorigenesis, including cell growth, cell cycle control, apoptosis avoidance, tissue invasion, and metastasis. Several microRNAs are involved in the development of renal cell carcinoma (RCC) and the malignant transformation process. However, the effects of miR-663a on RCC have rarely been reported.

METHODS

In the present study, the expression of miR-663a was examined in RCC using matched normal kidney tissues and four cell lines (786-O, Caki-1, ACHN and HK-2). MicroRNA mimics were transiently transfected into RCC cells and the effects of over expression on proliferation, migration, invasion, and apoptosis was observed. In addition, the relationship between miR-663a expression in 42 formalin-fixed paraffin-embedded (FFPE) clear cell renal carcinoma (ccRCC) samples and clinical pathological variables and overall survival was investigated. We evaluated the prognostic value of miR-663a expression in ccRCC by experimental results.

RESULTS

The results showed that the expression of miR-663a was up-regulated in RCC cells and tissues and miR-663a was associated with proliferation, migration, invasion, and apoptosis of RCC. Cox proportional hazard regression analysis showed that a high expression of miR-663a patients had a significantly shorter overall survival in univariate and multivariate analysis. Kaplan-Meier survival curves showed that a high expression of miR-663a patients had a significantly shorter overall survival.

CONCLUSIONS

These results indicate that miR-663a can be used as an independent marker for the poor prognosis of ccRCC, and may also play an important role as a tumor oncogene in the occurrence and development of RCC.

Roles of PLODs in Collagen Synthesis and Cancer Progression

Collagen is the major component of extracellular matrix. Collagen cross-link and deposition depend on lysyl hydroxylation, which is catalyzed by procollagen-lysine, 2-oxoglutarate 5-dioxygenase (PLOD). Aberrant lysyl hydroxylation and collagen cross-link contributes to the progression of many collagen-related diseases, such as fibrosis and cancer. Three lysyl hydroxylases (LH1, LH2, and LH3) are identified, encoded by PLOD1, PLOD2, and PLOD3 genes. Expression of PLODs is regulated by multiple cytokines, transcription factors and microRNAs. Dysregulation of PLODs promotes cancer progression and metastasis, suggesting that targeting PLODs is potential strategy for cancer treatment. Here, we summarize the recent progress in the investigation of function and regulation of PLODs in normal tissue development and disease progression, especially in cancer.

Targeting the Endoplasmic Reticulum Unfolded Protein Response to Counteract the Oxidative Stress-Induced Endothelial Dysfunction

In endothelial cells, the tight control of the redox environment is essential for the maintenance of vascular homeostasis. The imbalance between ROS production and antioxidant response can induce endothelial dysfunction, the initial event of many cardiovascular diseases. Recent studies have revealed that the endoplasmic reticulum could be a new player in the promotion of the pro- or antioxidative pathways and that in such a modulation, the unfolded protein response (UPR) pathways play an essential role. The UPR consists of a set of conserved signalling pathways evolved to restore the proteostasis during protein misfolding within the endoplasmic reticulum. Although the first outcome of the UPR pathways is the promotion of an adaptive response, the persistent activation of UPR leads to increased oxidative stress and cell death. This molecular switch has been correlated to the onset or to the exacerbation of the endothelial dysfunction in cardiovascular diseases. In this review, we highlight the multiple chances of the UPR to induce or ameliorate oxidative disturbances and propose the UPR pathways as a new therapeutic target for the clinical management of endothelial dysfunction.

The isoprenoid end product N6-isopentenyladenosine reduces inflammatory response through the inhibition of the NFκB and STAT3 pathways in cystic fibrosis cells

Objective

N6-isopentenyladenosine (iPA) is an intermediate of the mevalonate pathway that exhibits various anti-cancer effects. However, studies on its anti-inflammatory activity are scarce and underlying molecular mechanisms are unknown. Therefore, we aimed to investigate the ability of iPA to exert anti-inflammatory effects in the human cystic fibrosis (CF) cell model of exacerbated inflammation.

Materials and methods

TNFα-stimulated CF cells CuFi-1 and its normal counterpart NuLi-1 were pre-treated with increasing concentrations of iPA and cell viability and proliferation were assessed by MTT and BrdU assays. The effect of iPA on IL-8 and RANTES secretion was determined by ELISA, and the activation and expression of signaling molecules and selenoproteins were studied by Western blot. To assess the direct effect of iPA on NFκB activity, luciferase assay was performed on TNFα-stimulated HEK293/T cells transfected with a NFκB reporter plasmid.

Results

We demonstrated for the first time that iPA prevents IL-8 and RANTES release in TNFα-stimulated CF cells and this effect is mediated by increasing the expression of the direct NFκB inhibitor IκBα and decreasing the levels of STAT3. Consistent with this, we showed that iPA inhibited TNFα-mediated NFκB activation in HEK/293T cells. Finally, we also found that iPA improved the levels of glutathione peroxidase 1 and thioredoxin reductase 1 only in CF cells suggesting its ability to maintain sufficient expression of these anti-oxidant selenoproteins.

Conclusions

Our findings indicate that iPA can exert anti-inflammatory activity especially in the cases of excessive inflammatory response as in CF.

Regulation of the unfolded protein response by noncoding RNA

Cells are exposed to various intrinsic and extrinsic stresses in both physiological and pathological conditions. To adapt to those conditions, cells have evolved various mechanisms to cope with the disturbances in protein demand, largely through the unfolded protein response (UPR) in the endoplasmic reticulum (ER), but also through the integrated stress response (ISR). Both responses initiate downstream signaling to transcription factors that, in turn, trigger adaptive programs and/or in the case of prolonged stress, cell death mechanisms. Recently, noncoding RNAs, including microRNA and long noncoding RNA, have emerged as key players in the stress responses. These noncoding RNAs act as both regulators and effectors of the UPR and fine-tune the output of the stress signaling pathways. Although much is known about the UPR and the cross talk that exists between pathways, the contribution of small noncoding RNA has not been fully assessed. Herein we bring together and review the current known functions of noncoding RNA in regulating adaptive pathways in both physiological and pathophysiological conditions, illustrating how they operate within the known UPR functions and contribute to diverse cellular outcomes.

Role of BAG3 in cancer progression: A therapeutic opportunity

BAG3 is a multifunctional protein that can bind to heat shock proteins (Hsp) 70 through its BAG domain and to other partners through its WW domain, proline-rich (PXXP) repeat and IPV (Ile-Pro-Val) motifs. Its intracellular expression can be induced by stressful stimuli, while is constitutive in skeletal muscle, cardiac myocytes and several tumour types. BAG3 can modulate the levels, localisation or activity of its partner proteins, thereby regulating major cell pathways and functions, including apoptosis, autophagy, mechanotransduction, cytoskeleton organisation, motility. A secreted form of BAG3 has been identified in studies on pancreatic ductal adenocarcinoma (PDAC). Secreted BAG3 can bind to a specific receptor, IFITM2, expressed on macrophages, and induce the release of factors that sustain tumour growth and the metastatic process. BAG3 neutralisation therefore appears to constitute a novel potential strategy in the therapy of PDAC and, possibly, other tumours.

Integration of microRNAome, proteomics and metabolomics to analyze arsenic-induced malignant cell transformation

Long-term exposure to arsenic has been linked to tumorigenesis in different organs and tissues, such as skin; however, the detailed mechanism remains unclear. In this present study, we integrated “omics” including microRNAome, proteomics and metabolomics to investigate the potential molecular mechanisms. Compared with non-malignant human keratinocytes (HaCaT), twenty-six miRNAs were significantly altered in arsenic-induced transformed cells. Among these miRNAs, the differential expression of six miRNAs was confirmed using Q-RT-PCR, representing potential oxidative stress genes. Two-dimensional gel electrophoresis (2D-PAGE) and mass spectrometry (MS) were performed to identify the differential expression of proteins in arsenic-induced transformed cells, and twelve proteins were significantly changed. Several proteins were associated with oxidative stress and carcinogenesis including heat shock protein beta-1 (HSPB1), peroxiredoxin-2 (PRDX2). Using ultra-performance liquid chromatography and Q-TOF mass spectrometry (UPLC/Q-TOF MS), 68 metabolites including glutathione, fumaric acid, citric acid, phenylalanine, and tyrosine, related to redox metabolism, glutathione metabolism, citrate cycle, met cycle, phenylalanine and tyrosine metabolism were identified and quantified. Taken together, these results indicated that arsenic-induced transformed cells exhibit alterations in miRNA, protein and metabolite profiles providing novel insights into arsenic-induced cell malignant transformation and identifying early potential biomarkers for cutaneous squamous cell carcinoma induced by arsenic.

The Endoplasmic Reticulum Unfolded Protein Response in Neurodegenerative Disorders and Its Potential Therapeutic Significance

In eukaryotic cells, the endoplasmic reticulum (ER) is the cell compartment involved in secretory protein translocation and quality control of secretory protein folding. Different conditions can alter ER function, resulting in the accumulation of unfolded or misfolded proteins within the ER lumen. Such a condition, known as ER stress, elicits an integrated adaptive response known as the unfolded protein response (UPR) that aims to restore proteostasis within the secretory pathway. Conversely, in prolonged cell stress or insufficient adaptive response, UPR signaling causes cell death. ER dysfunctions are involved and contribute to neuronal degeneration in several human diseases, including Alzheimer, Parkinson and Huntington disease and amyotrophic lateral sclerosis. The correlations between ER stress and its signal transduction pathway known as the UPR with neuropathological changes are well established. In addition, much evidence suggests that genetic or pharmacological modulation of UPR could represent an effective strategy for minimizing the progressive neuronal loss in neurodegenerative diseases. Here, we review recent results describing the main cellular mechanisms linking ER stress and UPR to neurodegeneration. Furthermore, we provide an up-to-date panoramic view of the currently pursued strategies for ameliorating the toxic effects of protein unfolding in disease by targeting the ER UPR pathway.