TRIM37 inhibits PDGF-BB-induced proliferation and migration of airway smooth muscle cells

TRIM7 knockdown protects against LPS-induced autophagy, ferroptosis, and inflammatory responses in human bronchial epithelial cells

Asthma is one of the most common respiratory diseases in pediatric department. Several asthma-associated events including inflammatory responses, autophagy, and ferroptosis have been identified as typical pathological processes. TRIM7 is a member of TRIM proteins family associated with several types of diseases. Nevertheless, its role in asthma is still elusive. The current research showed that TRIM7 was involved in the pathogenesis of asthma mainly by regulating the Akt signaling pathway. In detail, we found that TRIM7 was highly expressed in patients with asthma and in an in vitro model of asthma. The following analysis indicated that TRIM7 knockdown attenuated the expression and secretion of inflammatory cytokines including TNF-α, IL-1β and IL-6 in lipopolysaccharide (LPS)-exposed human bronchial epithelial cells (HBECs). Meanwhile, knockdown of TRIM7 exerted inhibitory effects on LPS-induced autophagy and ferroptosis. Further mechanistic studies showed that TRIM7 knockdown inhibited LPS-induced activation of Akt pathway, while overexpression of Akt attenuated the inhibitory effects of TRIM7 knockdown on LPS-exposed HBECs. Collectively, we reported here that TRIM7 knockdown inhibited LPS-induced autophagy, ferroptosis, and inflammatory cytokine secretion in HBECs via regulating the Akt pathway, providing a new insight into the strategies for improving asthma treatments.

Roles of Exosomal miRNAs in Asthma: Mechanisms and Applications

Asthma is a chronic inflammatory disorder of the airways, characterized by a complex interplay of genetic, environmental, and immunological factors that contribute to its onset and progression. Recent advances in researches have illuminated the critical role of exosomal microRNAs (miRNAs) in the pathogenesis and development of asthma. Exosomes are nano-sized extracellular vesicles that facilitate intercellular communication by transporting a variety of bioactive molecules, including miRNAs, and play a crucial role in regulating gene expression and immune responses, which are central to the inflammatory processes underlying asthma. Exosomal miRNAs are emerging as key players in asthma due to their involvement in various aspects of the disease, including the regulation of inflammation, airway hyperresponsiveness, and remodeling. Their ability to influence the behavior of target cells and tissues makes them valuable both as diagnostic biomarkers and as potential therapeutic targets. This review aims to provide a comprehensive overview of the biogenesis of exosomes, the functional roles of exosomal miRNAs in asthma, and their clinical potential. It will explore the mechanisms by which these miRNAs contribute to asthma pathophysiology, discuss their utility in diagnosing and monitoring the disease, and highlight ongoing research efforts to harness their therapeutic potential.

Trim27 aggravates airway inflammation and oxidative stress in asthmatic mice via potentiating the NLRP3 inflammasome

Asthma is a prevalent chronic respiratory disease, yet understanding its ecology and pathogenesis remains a challenge. Trim27, a ubiquitination ligase belonging to the TRIM (tripartite motif-containing) family, has been implicated in regulating multiple pathophysiological processes such as inflammation, oxidative stress, apoptosis, and cell proliferation. However, the role of Trim27 in asthma has not been investigated. Our study found that Trim27 expression significantly increases in the airway epithelium of asthmatic mice. Knockdown of Trim27 expression effectively relieved ovalbumin (OVA)-induced airway hyperresponsiveness (AHR) and lung tissue histopathological changes. Moreover, Trim27 knockdown exhibited a significant reduction in airway inflammation and oxidative stress in asthmatic mice, and in vitro analysis confirmed the favorable effect of Trim27 deletion on inflammation and oxidative stress in mouse airway epithelial cells. Furthermore, our study revealed that deletion of Trim27 in MLE12 cells significantly decreased NLRP3 inflammasome activation, as evidenced by reduced expression of NLRP3, ASC, and pro-IL-1β mRNA. This downregulation was reversed when Trim27, but not its mutant lacking ubiquitination ligase activity, was replenished in these cells. Consistent with these findings, protein levels of NLRP3, pro-caspase-1, pro-IL-1β, cleaved-caspase-1, and cleaved-IL-1β were higher in Trim27-replenished cells compared to cells expressing Trim27C/A. Functionally, the downregulation of IL-1β and IL-18 levels induced by Trim27 deletion was rescued by replenishing Trim27. Overall, our findings provide evidence that Trim27 contributes to airway inflammation and oxidative stress in asthmatic mice via NLRP3 inflammasome activation, providing crucial insights into potential therapeutic interventions targeting Trim27 as a way to treat asthma.

The Role of TRIM Proteins in Vascular Disease

There are more than 80 different tripartite motifs (TRIM) proteins within the E3 ubiquitin ligase subfamily, including proteins that regulate intracellular signaling, apoptosis, autophagy, proliferation, inflammation, and immunity through the ubiquitination of target proteins. Studies conducted in recent years have unraveled the importance of TRIM proteins in the pathophysiology of vascular diseases. In this review, we describe the effects of TRIM proteins on vascular endothelial cells, smooth muscle cells, heart, and lungs. In particular, we discuss the potential mechanisms by which TRIMs regulate diseases and shed light on the potential therapeutic applications of TRIMs.

Long noncoding RNA antisense noncoding RNA in the INK4 locus inhibition alleviates airway remodeling in asthma through the regulation of the microRNA-7-5p/early growth response factor 3 axis

Asthma, a chronic inflammatory disease of the airways, clinically manifests as airway remodeling. The purpose of this study was to probe the potential role of long noncoding RNA (lncRNA) antisense noncoding RNA in the INK4 locus (lncRNA ANRIL) in the proliferation and migration of airway smooth muscle cell (ASMC) and to explore its potential mechanisms in asthma. Serum samples were obtained from 30 healthy volunteers and 30 patients with asthma. Additionally, platelet-derived growth factor-BB (PDGF-BB) was used to induce airway remodeling in ASMCs. The level of lncRNA ANRIL and microRNA (miR)-7-5p in serum samples were measured by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). TargetScan predicted the binding site of miR-7-5p to early growth response factor 3 (EGR3) and validated the results using a dual-luciferase reporter assay. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) and Transwell assays were used to detect cellular proliferation and migration, respectively. Subsequently, changes in proliferation- and migration-related genes were verified using western blot analysis and qRT-PCR. These results indicate that lncRNA ANRIL was upregulated in the serum and PDGF-BB-induced ASMCs of patients with asthma, whereas miR-7-5p expression was reduced. EGR3 was a direct target of miR-7-5p. LncRNA ANRIL silencing inhibited the proliferation or migration of ASMCs induced by PDGF-BB through miR-7-5p upregulation. Mechanistic studies indicated that miR-7-5p inhibits the proliferation or migration of PDGF-BB-induced ASMCs by decreasing EGR3 expression. EGR3 upregulation reverses the role of miR-7-5p in airway remodeling. Thus, downregulation of lncRNA ANRIL inhibits airway remodeling through inhibiting the proliferation and migration of PDGF-BB-induced ASMCs by regulating miR-7-5p/EGR3 signaling.

2-Undecanone alleviates asthma by inhibiting NF-κB pathway

Asthma is characterized by airway inflammation and remodeling. 2-Undecanone (methyl nonyl ketone), a volatile organic compound originating from Houttuynia cordata, has the potential to ameliorate inflammatory diseases. This study aimed to explore potential benefits of 2-undecanone in asthma. 2-Undecanone (100, 200, or 400 mg/kg) was administered intragastrically to ovalbumin (OVA)-challenged BALB/c mice. Lung tissues were collected to observe histopathological changes, and bronchoalveolar lavage fluid (BALF) was collected for the detection of inflammatory cells and cytokine production. The results showed that 2-undecanone ameliorated OVA-induced pathologic changes of lungs, including reducing inflammatory cell infiltration, goblet cell hyperplasia, and airway smooth muscle thickness. The number of inflammatory cells and the levels of IL-4, IL-5, IL-13, and IgE in BALF were decreased by 2-undecanone in asthmatic mice. Furthermore, abnormal activation of NF-κB pathway in lung tissues of asthmatic mice was impeded by 2-undecanone. In vitro, 2-undecanone (12.5, 25, or 50 µM) suppressed platelet-derived growth factor-BB-induced proliferation and migration of primary airway smooth muscle cells (ASMCs), and inhibited the switching of ASMCs from contractile phenotype to synthetic phenotype. Consistently, 2-undecanone blocked NF-κB activation in ASMCs. Collectively, 2-undecanone relieves asthma through alleviating airway inflammation and remodeling, and this beneficial effect is achieved by inhibiting NF-κB pathway.

Immunoglobulin A promotes IL-6 and IL-8 production, proliferation, and migration by the human bronchial smooth muscle cells

Immunoglobulin A (IgA) is important in biological defense, mainly in the mucosal area, and plays pathogenic roles in various diseases by activating both inflammatory and structural cells. The current study aimed to validate the effects of IgA on the human bronchial smooth muscle cell (BSMC), which plays a major role in airway inflammation and remodeling. Serum IgA induced interleukin (IL)-6 and IL-8 production at both mRNA and protein levels, and enhanced cell proliferation and migration by the BSMCs. The synthetic phenotype markers were regulated and the contractile phenotype markers were downregulated by serum IgA. Mitogen-activated protein kinase, phosphatidylinositol 3-kinase/Akt, and nuclear factor-κB pathways were involved in IgA-induced IL-6 and IL-8 production. The BSMCs expressed transferrin receptor (TfR), and TfR siRNA transfection inhibited IL-6 and IL-8 production by serum IgA. In summary, serum IgA is a potent activator of the BSMCs at least partially via TfR.

Focus on long non-coding RNA MALAT1: Insights into acute and chronic lung diseases

Acute lung injury (ALI) is a pulmonary illness with a high burden of morbidity and mortality around the world. Chronic lung diseases also represent life-threatening situations. Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is a type of long non-coding RNA (lncRNA) and is highly abundant in lung tissues. MALAT1 can function as a competitive endogenous RNA (ceRNA) to impair the microRNA (miRNA) inhibition on targeted messenger RNAs (mRNAs). In this review, we summarized that MALAT1 mainly participates in pulmonary cell biology and lung inflammation. Therefore, MALAT1 can positively or negatively regulate ALI and chronic lung diseases (e.g., chronic obstructive pulmonary disease (COPD), bronchopulmonary dysplasia (BPD), pulmonary fibrosis, asthma, and pulmonary hypertension (PH)). Besides, we also found a MALAT1-miRNA-mRNA ceRNA regulatory network in acute and chronic lung diseases. Through this review, we hope to cast light on the regulatory mechanisms of MALAT1 in ALI and chronic lung disease and provide a promising approach for lung disease treatment.

TRIM36 inhibits tumorigenesis through the Wnt/β-catenin pathway and promotes caspase-dependent apoptosis in hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer and has an extremely poor prognosis. We aimed to determine the latent relationships between TRIM36 regulation of apoptosis and the Wnt/β-catenin pathway in HCC.

METHODS

Immunohistochemistry and western blotting were used to characterize the aberrant expression of TRIM36 in HCC and adjacent tissues. Clinical information was analyzed using Kaplan-Meier and Cox methods. RNA-seq of potential targets was conducted to detect the regulation of TRIM36. Apoptosis assays and cellular proliferation, invasion and migration were conducted in a loss- and gain-of-function manner in cultured cells to determine the biological functions of TRIM36. A rescue experiment was conducted to confirm the role of Wnt/β-catenin signaling in TRIM36 regulation. Finally, in vivo experiments were conducted using cell line-derived xenografts in nude mice to validate the central role of TRIM36 in HCC.

RESULTS

TRIM36 expression was significantly downregulated in HCC tissues compared to adjacent non-tumor tissues. TRIM36 repressed the proliferation, migration, and invasion of Huh7 and HCCLM3 cells, whereas it stimulated apoptosis. Wnt/β-catenin signaling was inhibited by TRIM36, and rescue experiments highlighted its importance in HCC proliferation, migration, and invasion. In vivo experiments further confirmed the effects of sh-TRIM36 on HCC tumorigenesis, inhibition of apoptosis, and promotion of Wnt/β-catenin signaling.

CONCLUSION

Our study is the first to indicate that TRIM36 acts as a tumor suppressor in HCC. TRIM36 activates apoptosis and inhibits cellular proliferation, invasion, and migration via the Wnt/β-catenin pathway, which may serve as an important biomarker and promising therapeutic target for HCC.

MiR-18a Inhibits PI3K/AKT Signaling Pathway to Regulate PDGF BB-Induced Airway Smooth Muscle Cell Proliferation and Phenotypic Transformation

The increased proliferation and migration of airway smooth muscle cells (ASMCs) is a key process in the formation of airway remodeling in asthma. In this study, we focused on the expression of mircoRNA-18a (miR-18a) in airway remodeling in bronchial asthma and its related mechanisms. ASMCs are induced by platelet-derived growth factor BB (PDGF-BB) for in vitro airway remodeling. The expression of miR-18a in sputum of asthmatic patients and healthy volunteers was detected by qRT-PCR. The expression of miR-18a was over-expressed or interfered with in PDGF-BB-treated ASMCs. Cell proliferation, apoptosis and migration were detected by MTT, flow cytometry and Transwell, respectively; the expression of contractile phenotype marker proteins (SM-22α, α-SM-actin, calponin) and key molecules of the phosphatidylinositol 3-kinase (PI3K)/AKT pathway (PI3K, p-PI3K, AKT and p-AKT) in ASMCs were detected by Western blot. The expression of miR-18a was down-regulated in the sputum and PDGF-BB-treated ASMCs of asthma patients. PDGF-BB could promote the proliferation and migration of ASMCs and inhibit their apoptosis; it could also promote the phenotypic transformation of ASMCs and activate the PI3K/AKT pathway. MiR-18a could inhibit the proliferation, migration ability and phenotypic transformation of ASMCs induced by PDGF-BB to a certain extent and alleviate the effect of PDGF-BB in supressing apoptosis, while miR-18a could inhibit the activation of the PI3K/AKT pathway. MiR-18a inhibits PDGF-BB-induced proliferation, migration and phenotypic conversion of ASMCs by inhibiting the PI3K/AKT pathway, thus attenuating airway remodeling in asthma.

MiR-18a Inhibits PI3K/AKT Signaling Pathway to Regulate PDGF BB-Induced Airway Smooth Muscle Cell Proliferation and Phenotypic Transformation

The increased proliferation and migration of airway smooth muscle cells (ASMCs) is a key process in the formation of airway remodeling in asthma. In this study, we focused on the expression of mircoRNA-18a (miR-18a) in airway remodeling in bronchial asthma and its related mechanisms. ASMCs are induced by platelet-derived growth factor BB (PDGF-BB) for in vitro airway remodeling. The expression of miR-18a in sputum of asthmatic patients and healthy volunteers was detected by qRT-PCR. The expression of miR-18a was over-expressed or interfered with in PDGF-BB-treated ASMCs. Cell proliferation, apoptosis and migration were detected by MTT, flow cytometry and Transwell, respectively; the expression of contractile phenotype marker proteins (SM-22alpha, alpha-SM-actin, calponin) and key molecules of the phosphatidylinositol 3-kinase (PI3K)/AKT pathway (PI3K, p-PI3K, AKT and p-AKT) in ASMCs were detected by Western blot. The expression of miR-18a was down-regulated in the sputum and PDGF-BB-treated ASMCs of asthma patients. PDGF-BB could promote the proliferation and migration of ASMCs and inhibit their apoptosis; it could also promote the phenotypic transformation of ASMCs and activate the PI3K/AKT pathway. MiR-18a could inhibit the proliferation, migration ability and phenotypic transformation of ASMCs induced by PDGF-BB to a certain extent and alleviate the effect of PDGF-BB in supressing apoptosis, while miR-18a could inhibit the activation of the PI3K/AKT pathway. MiR-18a inhibits PDGF-BB-induced proliferation, migration and phenotypic conversion of ASMCs by inhibiting the PI3K/AKT pathway, thus attenuating airway remodeling in asthma.

TRIM proteins in fibrosis

Fibrosis is an outcome of tissue repair after different types of injuries. The homeostasis of extracellular matrix is broken, and excessive deposition occurs, affecting the normal function of tissues and organs, which could become prostrated in serious cases.Finding a suitable target to regulate the repair process and reduce the damage caused by fibrosis is a hot research topic at present. The TRIM family is number of one of the E3 ubiquitin ligase subfamilies and participates in various biological processes including intracellular signal transduction, apoptosis, autophagy, and immunity by regulating the ubiquitination of target proteins. For the past few years, the important role of TRIM in the occurrence and development of fibrosis has been gradually revealed. In this review, we focus on the recent emerging topics on TRIM proteins in the regulation of fibrosis, fibrosis-related cytokines and pathways.

Galectin-1 inhibits PDGF-BB-induced proliferation and migration of airway smooth muscle cells through the inactivation of PI3K/Akt signaling pathway

Childhood asthma is one of the most common chronic childhood diseases. Platelet-derived growth factor BB (PDGF-BB) induced airway smooth muscle cell (ASMC) proliferation and migration are involved in the pathogenesis of asthma. Galectin-1 (Gal-1) is a glycan-binding protein that has been found to be involved in the progression of asthma. However, the mechanism remains unclear. In the current study, we aimed to evaluate the role of Gal-1 in regulating the phenotype switching of ASMCs, which is an important mechanism in the pathogenesis of asthma. Our results showed that Gal-1 was markedly down-regulated in the samples from asthma patients. In vitro study also proved that Gal-1 expression was decreased in PDGF-BB-stimulated ASMCs. In addition, Gal-1 overexpression significantly inhibited PDGF-BB-induced ASMCs proliferation and migration, while Gal-1 knockdown exhibits opposite effects of Gal-1 overexpression. The PDGF-BB-caused reductions in expressions of α-smooth muscle actin (α-SMA), specific muscle myosin heavy chain (SM-MHC), and calponin were elevated by Gal-1 overexpression, but were deteriorated by Gal-1 knockdown in ASMCs. Furthermore, overexpression of Gal-1 inhibited PDGF-BB-stimulated PI3K/Akt activation in ASMCs. Notably, treatment with IGF-1, an activator of PI3K, reversed the effects of Gal-1 on ASMCs proliferation, migration, and phenotype switching. In conclusion, these findings showed that Gal-1 exerted inhibitory effects on PDGF-BB-stimulated proliferation, migration, and phenotype switching of ASMCs via inhibiting the PI3K/Akt signaling pathway. Thus, Gal-1 might be a promising target for the treatment of asthma.

MicroRNA-221 Modulates Airway Remodeling via the PI3K/AKT Pathway in OVA-Induced Chronic Murine Asthma

Background

Airway remodeling is one of the most important pathological features of chronic asthma. This study aimed to determine whether microRNA-221 (hereafter, miR-221) can affect airway remodeling in a mouse model of ovalbumin (OVA)-induced chronic asthma.

Methods

Adeno-associated viruses (AAVs) “Bearing miR-221 sponges” were used to downregulate miR-221 in asthmatic mice. Staining with hematoxylin and eosin (H&E), Masson trichrome, and periodic acid–Schiff reagent was used to assess histological changes. The affected signaling pathway in mouse airway smooth muscle cells (ASMCs) was also identified by gene chip technology. A PI3K/AKT-inhibitor (LY294002) was used to confirm the role of the pathway in ASMCs.

Results

The inhibition of miR-221 in a murine asthma model was found to reduce airway hyper-responsiveness, mucus metaplasia, airway inflammation, and airway remodeling (p < 0.05). Furthermore, miR-221 was found to regulate collagen deposition in the extracellular matrix (ECM) of ASMCs. Bioinformatics analysis and western blot analysis confirmed that the PI3K-AKT pathway was involved in ECM deposition in ASMCs.

Conclusion

miR-221 might play a crucial role in the mechanism of remodeling via the PI3K/AKT pathway in chronic asthma and it could be considered as a potential target for developing therapeutic strategies.

Differential Wound Healing Capacity of Mesenchymal Stem Cell-Derived Exosomes Originated From Bone Marrow, Adipose Tissue and Umbilical Cord Under Serum- and Xeno-Free Condition

Exosomes are nano-scale and closed membrane vesicles which are promising for therapeutic applications due to exosome-enclosed therapeutic molecules such as DNA, small RNAs, proteins and lipids. Recently, it has been demonstrated that mesenchymal stem cell (MSC)-derived exosomes have capacity to regulate many biological events associated with wound healing process, such as cell proliferation, cell migration and blood vessel formation. This study investigated the regenerative potentials for cutaneous tissue, in regard to growth factors associated with wound healing and skin cell proliferation and migration, by exosomes released from primary MSCs originated from bone marrow (BM), adipose tissue (AD), and umbilical cord (UC) under serum- and xeno-free condition. We found crucial wound healing-mediated growth factors, such as vascular endothelial growth factor A (VEGF-A), fibroblast growth factor 2 (FGF-2), hepatocyte growth factor (HGF), and platelet-derived growth factor BB (PDGF-BB) in exosomes derived from all three MSC sources. However, expression levels of these growth factors in exosomes were influenced by MSC origins, especially transforming growth factor beta (TGF-β) was only detected in UCMSC-derived exosomes. All exosomes released by three MSCs sources induced keratinocyte and fibroblast proliferation and migration; and, the induction of cell migration is a dependent manner with the higher dose of exosomes was used (20 μg), the faster migration rate was observed. Additionally, the influences of exosomes on cell proliferation and migration was associated with exosome origins and also target cells of exosomes that the greatest induction of primary dermal fibroblasts belongs to BMMSC-derived exosomes and keratinocytes belongs to UCMSC-derived exosomes. Data from this study indicated that BMMSCs and UCMSCs under clinical condition secreted exosomes are promising to develop into therapeutic products for wound healing treatment.

TRIP6 accelerates the proliferation and migration of fetal airway smooth muscle cells by enhancing YAP activation

The thyroid receptor interactor protein 6 (TRIP6) has emerged as a key regulator for the proliferation and migration of various cells. However, whether TRIP6 is involved in regulating the proliferation and migration of airway smooth muscle (ASM) cells in the progression of pediatric asthma remains undetermined. The present study investigated the function of TRIP6 in regulating the proliferation and migration of fetal ASM cells induced by tumor necrosis factor (TNF)-α in vitro. The results revealed that TRIP6 expression was significantly upregulated in TNF-α-stimulated ASM cells. Loss-of-function experiments demonstrated that the knockdown of TRIP6 markedly suppressed TNF-α-proliferation and migration of ASM cells. By contrast, overexpression of TRIP6 had the opposite effect. In-depth research uncovered that TNF-α stimulation promoted the activation of yes-associated protein (YAP), which could be significantly reversed by TRIP6 silencing. Moreover, inactivation of YAP significantly reversed the promotion effect of TRIP6 overexpression on TNF-α-induced ASM cell proliferation and migration. Overall, these results reveal that upregulation of TRIP6 contributes to the proliferation and migration of fetal ASM cells by enhancing YAP activation, highlighting the importance of the TRIP6/YAP axis in the airway remodeling of pediatric asthma.

Identification of biomarkers in common chronic lung diseases by co-expression networks and drug-target interactions analysis

Background

asthma, chronic obstructive pulmonary disease (COPD), and idiopathic pulmonary fibrosis (IPF) are three serious pulmonary diseases that contain common and unique characteristics. Therefore, the identification of biomarkers that differentiate these diseases is of importance for preventing misdiagnosis. In this regard, the present study aimed to identify the disorders at the early stages, based on lung transcriptomics data and drug-target interactions.

Methods

To this end, the differentially expressed genes were found in each disease. Then, WGCNA was utilized to find specific and consensus gene modules among the three diseases. Finally, the disease-disease similarity was analyzed, followed by determining candidate drug-target interactions.

Results

The results confirmed that the asthma lung transcriptome was more similar to COPD than IPF. In addition, the biomarkers were found in each disease and thus were proposed for further clinical validations. These genes included RBM42, STX5, and TRIM41 in asthma, CYP27A1, GM2A, LGALS9, SPI1, and NLRC4 in COPD, ATF3, PPP1R15A, ZFP36, SOCS3, NAMPT, and GADD45B in IPF, LRRC48 and CETN2 in asthma-COPD, COL15A1, GIMAP6, and JAM2 in asthma-IPF and LMO7, TSPAN13, LAMA3, and ANXA3 in COPD-IPF. Finally, analyzing drug-target networks suggested anti-inflammatory candidate drugs for treating the above mentioned diseases.

Conclusion

In general, the results revealed the unique and common biomarkers among three chronic lung diseases. Eventually, some drugs were suggested for treatment purposes.

Upregulation of LncRNA Malat1 Induced Proliferation and Migration of Airway Smooth Muscle Cells via miR-150-eIF4E/Akt Signaling

The increased proliferation and migration of airway smooth muscle cells (ASMCs) are critical processes in the formation of airway remodeling in asthma. Long non-coding RNAs (lncRNAs) have emerged as key mediators of diverse physiological and pathological processes, and are involved in the pathogenesis of various diseases, including asthma. LncRNA Malat1 has been widely reported to regulate the proliferation and migration of multiple cell types and be involved in the pathogenesis of various human diseases. However, it remains unknown whether Malat1 regulates ASMC proliferation and migration. Here, we explored the function of Malat1 in ASMC proliferation and migration in vitro stimulated by platelet-derived growth factor BB (PDGF-BB), and the underlying molecular mechanism involved. The results showed that Malat1 was significantly upregulated in ASMCs treated with PDGF-BB, and knockdown of Malat1 effectively inhibited ASMC proliferation and migration induced by PDGF-BB. Our data also showed that miR-150 was a target of Malat1 in ASMCs, and inhibited PDGF-BB-induced ASMC proliferation and migration, whereas the inhibition effect was effectively reversed by Malat1 overexpression. Additionally, translation initiation factor 4E (eIF4E), an important regulator of Akt signaling, was identified to be a target of miR-150, and both eIF4E knockdown and Akt inhibitor GSK690693 inhibited PDGF-BB-induced ASMC proliferation and migration. Collectively, these data indicate that Malat1, as a competing endogenous RNA (ceRNA) for miR-150, derepresses eIF4E expression and activates Akt signaling, thereby being involved in PDGF-BB-induced ASMC proliferation and migration. These findings suggest that Malat1 knockdown may present a new target to limit airway remodeling in asthma.

TRIMming down to TRIM37: Relevance to Inflammation, Cardiovascular Disorders, and Cancer in MULIBREY Nanism

TRIpartite motif (TRIM) proteins are part of the largest subfamilies of E3 ligases that mediate the transfer of ubiquitin to substrate target proteins. In this review, we focus on TRIM37 in the normal cell and in pathological conditions, with an emphasis on the MULIBREY (MUscle-LIver-BRain-EYe) genetic disorder caused by TRIM37 mutations. TRIM37 is characterized by the presence of a RING domain, B-box motifs, and a coiled-coil region, and its C-terminal part includes the MATH domain specific to TRIM37. MULIBREY nanism is a rare autosomal recessive caused by TRIM37 mutations and characterized by severe pre- and postnatal growth failure. Constrictive pericarditis is the most serious anomaly of the disease and is present in about 20% of patients. The patients have a deregulation of glucose and lipid metabolism, including type 2 diabetes, fatty liver, and hypertension. Puzzlingly, MULIBREY patients, deficient for TRIM37, are plagued with numerous tumors. Among non-MULIBREY patients affected by cancer, a wide variety of cancers are associated with an overexpression of TRIM37. This suggests that normal cells need an optimal equilibrium in TRIM37 expression. Finding a way to keep that balance could lead to potential innovative drugs for MULIBREY nanism, including heart condition and carcinogenesis treatment.