Jinjin Zhang

Analysing the relationship between lncRNA and protein-coding gene and the role of lncRNA as ceRNA in pulmonary fibrosis.

Long non‐coding RNAs (lncRNAs) are involved in various pathophysiologic processes and human diseases. However, their dynamics and corresponding functions in pulmonary fibrosis remain poorly understood. In this study, portions of lncRNAs adjacent or homologous to protein‐coding genes were determined by searching the UCSC genome bioinformatics database. This was found to be potentially useful for exploring lncRNA functions in disease progression. Previous studies showed that competing endogenous RNA (ceRNA) hypothesis is another method to predict lncRNA function. However, little is known about the function of ceRNA in pulmonary fibrosis. In this study, we selected two differentially expressed lncRNAs MRAK088388 and MRAK081523 to explore their regulatory mechanisms. MRAK088388 and MRAK081523 were analysed as long‐intergenic non‐coding RNAs (lincRNAs), and identified as orthologues of mouse lncRNAs AK088388 and AK081523, respectively. qRT‐PCR and in situ hybridization (ISH) showed that they were significantly up‐regulated, and located in the cytoplasm of interstitial lung cells. We also showed that MRAK088388 and N4bp2 had the same miRNA response elements (MREs) for miR‐200, miR‐429, miR‐29, and miR‐30, whereas MRAK081523 and Plxna4 had the same MREs for miR‐218, miR‐141, miR‐98, and let‐7. Moreover, the expression levels of N4bp2 and Plxna4 significantly increased in fibrotic rats, and were highly correlated with those of MRAK088388 and MRAK081523, respectively. Among their shared miRNAs, miR‐29b‐3p and let‐7i‐5p decreased in the model group, and were negatively correlated with the expression of MRAK088388 and MRAK081523, respectively. MRAK088388 and MRAK081523 could regulate N4bp2 and Plxna4 expression by sponging miR‐29b‐3p and let‐7i‐5p, respectively, and possessed regulatory functions as ceRNAs. Thus, our study may provide insights into the functional interactions of lncRNA, miRNA and mRNA, and lead to new theories for the pathogenesis and treatment of pulmonary fibrosis.

Differential expression of long non-coding RNAs in bleomycin-induced lung fibrosis.

Recent studies suggest that long non‑coding RNAs (lncRNAs) are more involved in human diseases than previously realized. A growing body of evidence links lncRNA mutation and dysregulation to diverse human diseases. However, the association of lncRNAs with the pathogenesis of lung fibrosis remains poorly understood. In this study, we detected changes in hydroxyproline and collagen levels, as well as the ultrastructure of lung tissue to develop a rat model of lung fibrosis. The differentially expressed lncRNAs and mRNA profiles between fibrotic lung and normal lung tissue were analyzed using microarrays. Gene Ontology analysis and pathway analysis were performed for further research. Two differentially expressed lncRNAs, namely, AJ005396 and S69206, were detected by in situ hybridization to validate the microarray data. The results revealed that the number of collagen fibers in the interstitial lung tissue significantly increased in the model group compared with the normal group. In total, 210 and 358 lncRNAs were upregulated and downregulated, respectively, along with 415 upregulated and 530 downregulated mRNAs in the rats with lung fibrosis. AJ005396 and S69206 were upregulated in the fibrotic lung tissue, consistent with the microarray data, and were located in the cytoplasm of the interstitial lung cells. In conclusion, the expression profile of the lncRNAs was significantly altered in the fibrotic lung tissue and these transcripts are potential molecular targets for inhibiting the development of lung fibrosis.

Astaxanthin prevents pulmonary fibrosis by promoting myofibroblast apoptosis dependent on Drp1-mediated mitochondrial fission.

Promotion of myofibroblast apoptosis is a potential therapeutic strategy for pulmonary fibrosis. This study investigated the antifibrotic effect of astaxanthin on the promotion of myofibroblast apoptosis based on dynamin‐related protein‐1 (Drp1)‐mediated mitochondrial fission in vivo and in vitro. Results showed that astaxanthin can inhibit lung parenchymal distortion and collagen deposition, as well as promote myofibroblast apoptosis. Astaxanthin demonstrated pro‐apoptotic function in myofibroblasts by contributing to mitochondrial fission, thereby leading to apoptosis by increasing the Drp1 expression and enhancing Drp1 translocation into the mitochondria. Two specific siRNAs were used to demonstrate that Drp1 is necessary to promote astaxanthin‐induced mitochondrial fission and apoptosis in myofibroblasts. Drp1‐associated genes, such as Bcl‐2‐associated X protein, cytochrome c, tumour suppressor gene p53 and p53‐up‐regulated modulator of apoptosis, were highly up‐regulated in the astaxanthin group compared with those in the sham group. This study revealed that astaxanthin can prevent pulmonary fibrosis by promoting myofibroblast apoptosis through a Drp1‐dependent molecular pathway. Furthermore, astaxanthin provides a potential therapeutic value in pulmonary fibrosis treatment.

Astaxanthin ameliorates lung fibrosis in vivo and in vitro by preventing transdifferentiation, inhibiting proliferation, and promoting apoptosis of activated cells.

Astaxanthin, a member of the carotenoid family, is the only known ketocarotenoid transported into the brain by transcytosis through the blood-brain barrier. However, whether astaxanthin has antifibrotic functions is unknown. In this study, we investigated the effects of astaxanthin on transforming growth factor β1-mediated and bleomycin-induced pulmonary fibrosis in vitro and in vivo. The results showed that astaxanthin significantly improved the structure of the alveoli and alleviated collagen deposition in vivo. Compared with the control group, the astaxanthin-treated groups exhibited downregulated protein expressions of α-smooth muscle actin, vimentin, hydroxyproline, and B cell lymphoma/leukemia-2 as well as upregulated protein expressions of E-cadherin and p53 in vitro and in vivo. Astaxanthin also inhibited the proliferation of activated A549 and MRC-5 cells at median inhibitory concentrations of 40 and 30 μM, respectively. In conclusion, astaxanthin could relieve the symptoms and halt the progression of pulmonary fibrosis, partly by preventing transdifferentiation, inhibiting proliferation, and promoting apoptosis of activated cells.

Changes in cell ultrastructure and inhibition of JAK1/STAT3 signaling pathway in CBRH-7919 cells with astaxanthin

Astaxanthin (AST), a xanthophylls carotenoid, possesses significant anticancer effects. However, to date, the molecular mechanism of anticancer remains unclear. In the present research, we studied the anticancer mechanism of AST, including the changes in cell ultrastructure, such as the mitochondrion, rough endoplasmic reticulum (RER), Golgi complex, and cytoskeleton, the inhibition of Janus kinase 1(JAK1)/transduction and the activators of the transcription-3 (STAT3) signaling pathway using rat hepatocellular carcinoma CBRH-7919 cells. Cell apoptosis was evaluated and the expressions of JAK1, STAT3, non-metastasis23-1 (nm23-1), and apoptotic gene like B-cell lymphoma/leukemia-2 (bcl-2), B-cell lymphoma-extra large (bcl-xl), proto-oncogene proteins c myc (c-myc) and bcl-2- associated X (bax) were also examined. The results showed that AST could induce cancer cell apoptosis. Under transmission electron microscope, the ultrastructure of treated cells were not clearly distinguishable, the membranes of the mitochondrion, RER, Golgi complex were broken or loosened, and the endoplasmic reticulum (ER) was degranulated. Cytoskeleton depolymerization of the microtubule system led to the collapse of extended vimentin intermediate filament bundles into short agglomerations with disordered distributions. AST inhibited the expression of STAT3, its upstream activator JAK1, and the STAT3 target antiapoptotic genes bcl-2, bcl-xl, and c-myc. Conversely, AST enhanced the expressions of nm23-1 and bax. Overall, our findings demonstrate that AST could induce the apoptosis of CBRH-7919 cells, which are involved in cell ultrastructure and the JAK1/STAT3 signaling pathway.

MiRNA‐30a inhibits AECs‐II apoptosis by blocking mitochondrial fission dependent on Drp‐1

Apoptosis of type II alveolar epithelial cells (AECs‐II) is a key determinant of initiation and progression of lung fibrosis. However, the mechanism of miR‐30a participation in the regulation of AECs‐II apoptosis is ambiguous. In this study, we investigated whether miR‐30a could block AECs‐II apoptosis by repressing mitochondrial fission dependent on dynamin‐related protein‐1 (Drp‐1). The levels of miR‐30a in vivo and in vitro were determined through quantitative real‐time PCR (qRT‐PCR). The inhibition of miR‐30a in AECs‐II apoptosis, mitochondrial fission and its dependence on Drp‐1, and Drp‐1 expression and translocation were detected using miR‐30a mimic, inhibitor‐transfection method (gain‐ and loss‐of‐function), or Drp‐1 siRNA technology. Results showed that miR‐30a decreased in lung fibrosis. Gain‐ and loss‐of‐function studies revealed that the up‐regulation of miR‐30a could decrease AECs‐II apoptosis, inhibit mitochondrial fission, and reduce Drp‐1 expression and translocation. MiR‐30a mimic/inhibitor and Drp‐1 siRNA co‐transfection showed that miR‐30a could inhibit the mitochondrial fission dependent on Drp‐1. This study demonstrated that miR‐30a inhibited AECs‐II apoptosis by repressing the mitochondrial fission dependent on Drp‐1, and could function as a novel therapeutic target for lung fibrosis.

miR-30a as Potential Therapeutics by Targeting TET1 through Regulation of Drp-1 Promoter Hydroxymethylation in Idiopathic Pulmonary Fibrosis

Several recent studies have indicated that miR-30a plays critical roles in various biological processes and diseases. However, the mechanism of miR-30a participation in idiopathic pulmonary fibrosis (IPF) regulation is ambiguous. Our previous study demonstrated that miR-30a may function as a novel therapeutic target for lung fibrosis by blocking mitochondrial fission, which is dependent on dynamin-related protein1 (Drp-1). However, the regulatory mechanism between miR-30a and Drp-1 is yet to be investigated. Additionally, whether miR-30a can act as a potential therapeutic has not been verified in vivo. In this study, the miR-30a expression in IPF patients was evaluated. Computational analysis and a dual-luciferase reporter assay system were used to identify the target gene of miR-30a, and cell transfection was utilized to confirm this relationship. Ten–eleven translocation 1 (TET1) was validated as a direct target of miR-30a, and miR-30a mimic and inhibitor transfection significantly reduced and increased the TET1 protein expression, respectively. Further experimentation verified that the TET1 siRNA interference could inhibit Drp-1 promoter hydroxymethylation. Finally, miR-30a agomir was designed and applied to identify and validate the therapeutic effect of miR-30a in vivo. Our study demonstrated that miR-30a could inhibit TET1 expression through base pairing with complementary sites in the 3′untranslated region to regulate Drp-1 promoter hydroxymethylation. Furthermore, miR-30a could act as a potential therapeutic target for IPF.

SMND-309 promotes neuron survival through the activation of the PI3K/Akt/CREB-signalling pathway

Abstract Context In clinical practice, the promotion of neuron survival is necessary to recover neurological functions after the onset of stroke. Objective This study aimed to investigate the post-ischaemic neuroprotective effect of SMND-309, a novel metabolite of salvianolic acid, on differentiated SH-SY5Y cells. Materials and methods SH-SY5Y cells were differentiated by pre-treating with 5 μM all-trans-retinoic acid for 6 d. The differentiated SH-SY5Y cells were exposed to oxygen–glucose deprivation (OGD) for 2 h and reperfusion (R) for 24 h to induce OGD/R injury. After OGD injury, differentiated SH-SY5Y cells were treated with or without SMND-309 (5, 10, 20 μM) for another 24 h. Cell viability was detected through Cell counting kit-8 assay and lactate dehydrogenase leakage assay. Apoptosis was evaluated through flow cytometry, caspase-3 activity assay. Changes in protein levels were assessed through Western blot. Results SMND-309 ameliorated the degree of injury in the differentiated SH-SY5Y cells by increasing cell viabilities (5 μM, 65.4% ± 4.1%; 10 μM, 69.8% ± 3.7%; 20 μM, 75.3% ± 5.1%) and by reducing LDH activity (20 μM, 2.5 fold) upon OGD/R stimulation. Annexin V-fluorescein isothiocyanate/propidium iodide staining results suggested that apoptotic rate of differentiated SH-SY5Y cells decreased from 43.8% induced by OGD/R injury to 19.2% when the cells were treated with 20 μM SMND-309. SMND-309 significantly increased the Bcl-2 level of the injured differentiated SH-SY5Y cells but decreased the caspase-3 activity of these cells by 1.6-fold. In contrast, SMND-309 did not affect the Bax level of these cells. SMND-309 evidently increased the protein expression of BDNF when Akt and CREB were activated. This function was antagonized by the addition of LY294002. Conclusion SMND-309 can prevent neuronal cell death in vitro. This process may be related to the activation of the PI3K/Akt/CREB-signalling pathway.

A novel lnc-PCF promotes the proliferation of TGF- β 1-activated epithelial cells by targeting miR-344a-5p to regulate map3k11 in pulmonary fibrosis

Emerging evidence suggests that microRNA (miRNA) and long noncoding RNA (lncRNA) play important roles in disease development. However, the mechanism underlying mRNA interaction with miRNA and lncRNA in idiopathic pulmonary fibrosis (IPF) remains unknown. This study presents a novel lnc-PCF that promotes the proliferation of TGF-β1-activated epithelial cells through the regulation of map3k11 by directly targeting miR-344a-5p during pulmonary fibrogenesis. Bioinformatics and in vitro translation assay were performed to confirm whether or not lnc-PCF is an actual lncRNA. RNA fluorescent in situ hybridization (FISH) and nucleocytoplasmic separation showed that lnc-PCF is mainly expressed in the cytoplasm. Knockdown and knockin of lnc-PCF indicated that lnc-PCF could promote fibrogenesis by regulating the proliferation of epithelial cells activated by TGF-β1 according to the results of xCELLigence real-time cell analysis system, flow cytometry, and western blot analysis. Computational analysis and a dual-luciferase reporter system were used to identify the target gene of miR-344a-5p, whereas RNA pull down, anti-AGO2 RNA immunoprecipitation, and rescue experiments were conducted to confirm the identity of this direct target. Further experiments verified that lnc-PCF promotes the proliferation of activated epithelial cells that were dependent on miR-344a-5p, which exerted its regulatory functions through its target gene map3k11. Finally, adenovirus packaging sh-lnc-PCF was sprayed into rat lung tissues to evaluate the therapeutic effect of lnc-PCF. These findings revealed that lnc-PCF can accelerate pulmonary fibrogenesis by directly targeting miR-344a-5p to regulate map3k11, which may be a potential therapeutic target in IPF.

MicroRNA-708-3p as a potential therapeutic target via the ADAM17-GATA/STAT3 axis in idiopathic pulmonary fibrosis

MicroRNAs (miRNAs) are important diagnostic markers and therapeutic targets for many diseases. However, the miRNAs that control the pathogenesis of idiopathic pulmonary fibrosis (IPF) and act as potential therapeutic targets for the disease are rarely studied. In the present study, we analyzed the function and regulatory mechanism of microRNA-708-3p (miR-708-3p) and evaluated this marker’s potential as a therapeutic target in IPF. The clinical and biological relevance of fibrogenesis for miR-708-3p was assessed in vivo and in vitro, specifically in matching plasma and tissue samples from 78 patients with IPF. The data showed that the miR-708-3p levels decreased during fibrosis and inversely correlated with IPF. The experiments showed that the decreased miR-708 promoter activity and primer-miR-708(pri-miR-708) expression were the potential causes. By computational analysis, a dual luciferase reporter system, rescue experiments and a Cignal Finder 45-Pathway system with siADAM17 and a miR-708-3p mimic, we identified that miR-708-3p directly regulates its target gene, a disintegrin and metalloproteinase 17 (ADAM17), through a binding site in the 3′ untranslated region, which depends on the GATA/STAT3 signaling pathway. Finally, an miR-708-3p agomir was designed and used to test the therapeutic effects of the miR-708-3p in an animal model. Small-animal imaging technology and other experiments showed that the dynamic image distribution of the miR-708-3p agomir was mainly concentrated in the lungs and could block fibrogenesis. In conclusion, the miR-708-3p–ADAM17 axis aggravates IPF, and miR-708-3p can serve as a potential therapeutic target for IPF.