Nestin represents a potential marker of pulmonary vascular remodeling in pulmonary arterial hypertension associated with congenital heart disease

Distribution, contribution and regulation of nestin+ cells

BACKGROUND

Nestin is an intermediate filament first reported in neuroepithelial stem cells. Nestin expression could be found in a variety of tissues throughout all systems of the body, especially during tissue development and tissue regeneration processes.

AIM OF REVIEW

This review aimed to summarize and discuss current studies on the distribution, contribution and regulation of nestin+ cells in different systems of the body, to discuss the feasibility ofusing nestin as a marker of multilineage stem/progenitor cells, and better understand the potential roles of nestin+ cells in tissue development, regeneration and pathological processes.

KEY SCIENTIFIC CONCEPTS OF REVIEW

This review highlights the potential of nestin as a marker of multilineage stem/progenitor cells, and as a key factor in tissue development and tissue regeneration. The article discussed the current findings, limitations, and potential clinical implications or applications of nestin+ cells. Additionally, it included the relationship of nestin+ cells to other cell populations. We propose potential future research directions to encourage further investigation in the field.

Expression of Markers Ki-67, Nestin, VEGF, CD34 and Apoptosis in Relatively Healthy Lung Tissue with Non-Changed and Metaplastic Bronchial Epithelium

BACKGROUND

Knowledge about the occurrence of processes such as proliferation, apoptosis and angiogenesis in healthy lung tissues with different bronchial epitheliums is limited, and further exploration can contribute to a better understanding of the physiological renewal of lung tissues. The processes mentioned above occur with the help of important tissue factors; therefore, the aim of the study was to determine the expression of markers Ki-67, nestin, CD34 and vascular endothelial growth factor (VEFG) and detect apoptotic cells in relatively healthy lung tissue.

METHODS

Samples of relatively healthy lung tissue were obtained from 19 patients and divided into groups of patients with non-changed and patients with metaplastic bronchial epithelium. Tissue samples were examined by hematoxylin and eosin staining. Ki-67, nestin, VEGF and CD34-positive cells were detected by the immunohistochemistry method. Terminal deoxynucleotidyl transferase (TdT) dUTP nick-end labeling (TUNEL) assay was carried out to detect apoptotic cells. The number of positive structures was counted semi-quantitatively by microscopy.

RESULTS

Ki-67-positive cells were detected in only one case. An occasional to moderate number of nestin-positive structures was found in various tissues of relatively healthy lungs with different bronchial epitheliums. No apoptotic cells were seen in non-changed bronchial epithelium, compared with few apoptotic cells in metaplastic bronchial epithelium. Metaplastic bronchial epithelium contained more VEGF-positive cells than non-changed bronchial epithelium. Samples with non-changed, and metaplastic bronchial epithelium both contained a similar number of CD34-positive structures.

CONCLUSIONS

Proliferative activity and programmed cell death are not prominent events in normal lung tissue. A moderate number of nestin-positive cells in the alveolar epithelium and cartilage of bronchi with pseudostratified ciliated epithelium suggests a significant role of neuronal origin cells in these structures, to be intensified in metaplastic bronchial epithelium. A practically non-changed number of CD34-positive cells excludes any difference in stimulation of endothelial origin cells between lungs with different types of epithelium, while an increase in VEGF in structures with metaplastic epithelium suggests the presence/influence of tissue ischemia impact on possible development/maintenance of metaplasia.

Protective effects of calcyclin-binding protein against pulmonary vascular remodeling in flow-associated pulmonary arterial hypertension

BACKGROUND

Pulmonary arterial hypertension associated with congenital heart disease (CHD-PAH) is recognized as a cancer-like disease with a proliferative and pro-migratory phenotype in pulmonary artery smooth muscle cells (PASMCs). Calcyclin-binding protein/Siah-1-interacting protein (CacyBP/SIP) has been implicated in the progression of various cancers; however, it has not been previously studied in the context of CHD-PAH. Here, we aimed to examine the function of CacyBP/SIP in CHD-PAH and explore its potential as a novel regulatory target for the disease.

METHODS

The expression of CacyBP/SIP in PASMCs was evaluated both in the pulmonary arterioles of patients with CHD-PAH and in high-flow-induced PAH rats. The effects of CacyBP/SIP on pulmonary vascular remodeling and PASMC phenotypic switch, proliferation, and migration were investigated. LY294002 (MedChemExpress, NJ, USA) was used to block the phosphoinositide 3-kinase/protein kinase B (PI3K/AKT) pathway to explore changes in PASMC dysfunction induced by low CacyBP/SIP levels. Hemodynamics and pulmonary arterial remodeling were further explored in rats after short-interfering RNA-mediated decrease of CacyBP/SIP expression.

RESULTS

CacyBP/SIP expression was markedly reduced both in the remodeled pulmonary arterioles of patients with CHD-PAH and in high-flow-induced PAH rats. Low CacyBP/SIP expression promoted hPASMC phenotypic switch, proliferation, and migration via PI3K/AKT pathway activation. Our results indicated that CacyBP/SIP protected against pulmonary vascular remodeling through amelioration of hPASMC dysfunction in CHD-PAH. Moreover, after inhibition of CacyBP/SIP expression in vivo, we observed increased right ventricular hypertrophy index, poor hemodynamics, and severe vascular remodeling.

CONCLUSIONS

CacyBP/SIP regulates hPASMC dysfunction, and its increased expression may ameliorate progression of CHD-PAH.

Transgelin exacerbates pulmonary artery smooth muscle cell dysfunction in shunt-related pulmonary arterial hypertension

AIMS

Orchestrating the transition from reversible medial hypertrophy to irreversible plexiform lesions is crucial for pulmonary arterial hypertension related to congenital heart disease (CHD-PAH). Transgelin is an actin-binding protein that modulates pulmonary arterial smooth muscle cell (PASMC) dysfunction. In this study, we aimed to probe the molecular mechanism and biological function of transgelin in the pathogenesis of CHD-PAH.

METHODS AND RESULTS

Transgelin expression was detected in lung tissues from both CHD-PAH patients and monocrotaline (MCT)-plus aortocaval (AV)-induced PAH rats by immunohistochemistry. In vitro, the effects of transgelin on the proliferation, migration, and apoptosis of human PASMCs (HPASMCs) were evaluated by the cell count and EdU assays, transwell migration assay, and TUNEL assay, respectively. And the effect of transgelin on the expression of HPASMC phenotype markers was assessed by the immunoblotting assay. (i) Compared with the normal control group (n = 12), transgelin expression was significantly overexpressed in the pulmonary arterioles of the reversible (n = 15) and irreversible CHD-PAH group (n = 4) (reversible group vs. control group: 18.2 ± 5.1 vs. 13.6 ± 2.6%, P < 0.05; irreversible group vs. control group: 29.9 ± 4.7 vs. 13.6 ± 2.6%, P < 0.001; irreversible group vs. reversible group: 29.9 ± 4.7 vs. 18.2 ± 5.1, P < 0.001). This result was further confirmed in MCT-AV-induced PAH rats. Besides, the transgelin expression level was positively correlated with the pathological grading of pulmonary arteries in CHD-PAH patients (r = 0.48, P = 0.03, n = 19). (ii) Compared with the normal control group (n = 12), TGF-β1 expression was notably overexpressed in the pulmonary arterioles of the reversible (n = 15) and irreversible CHD-PAH group (n = 4) (reversible group vs. control group: 14.8 ± 4.4 vs. 6.0 ± 2.5%, P < 0.001; irreversible group vs. control group: 20.1 ± 4.4 vs. 6.0 ± 2.5%, P < 0.001; irreversible group vs. reversible group: 20.1 ± 4.4 vs. 14.8 ± 4.4, P < 0.01). The progression-dependent correlation between TGF-β1 and transgelin was demonstrated in CHD-PAH patients (r = 0.48, P = 0.04, n = 19) and MCT-AV-induced PAH rats, which was further confirmed at sub-cellular levels. (iii) Knockdown of transgelin diminished proliferation, migration, apoptosis resistance, and phenotypic transformation of HPASMCs through repressing the TGF-β1 signalling pathway. On the contrary, transgelin overexpression resulted in the opposite effects.

CONCLUSIONS

These results indicate that transgelin may be an indicator of CHD-PAH development via boosting HPASMC dysfunction through positive regulation of the TGF-β1 signalling pathway, as well as a potential therapeutic target for the treatment of CHD-PAH.

Synemin promotes pulmonary artery smooth muscle cell phenotypic switch in shunt-induced pulmonary arterial hypertension

AIMS

Although considerable progress has been made in the diagnosis and treatment of congenital heart disease-associated pulmonary heart hypertension (CHD-PAH), the clinical prognosis and overall survival of patients with CHD-PAH remain poor. Therefore, the molecular pathogenesis of CHD-PAH requires further investigation. The intermediate filament protein synemin (SYN) is reported to modulate phenotypic alterations and varicose vein development, but there is little understanding of its exact functions in CHD-PAH.

METHODS AND RESULTS

SYN expression in the pulmonary arterioles of CHD-PAH patients and shunt-induced PAH rat models was evaluated using immunohistochemistry and western blot. Cell counts and Transwell migration assays were used to assess the effect of SYN on the proliferation and migration capability of human pulmonary smooth muscle cells (hPASMCs). Adeno-associated viruses (AAVs) have been used to suppress SYN expression in the pulmonary arterioles of rats. Such rats were further used to construct a shunt-induced PAH animal model to investigate the function of SYN in PAH and pulmonary vascular remodelling. Compared with the normal control group, SYN expression was found to be clearly up-regulated in the remodelled pulmonary arterioles of CHD-PAH and shunt-induced PAH rat models. In addition, SYN suppression increased the expression of hPASMC contractile-phenotype markers and decreased the expression of synthetic phenotype markers, in contrast to the control group. SYN suppression also dramatically attenuated the proliferation and migration capability of hPASMCs. Conversely, SYN overexpression promoted phenotypic switch, proliferation, and migration of hPASMCs, whereas these effects were notably alleviated by the protein kinase B (AKT) inhibitor MK-2206. Furthermore, we confirmed that SYN suppression mitigated PAH and pulmonary vascular remodelling induced by high blood flow in vivo.

CONCLUSIONS

Our findings indicated that SYN may represent a promising therapeutic target in the treatment of CHD-PAH.

Identification of candidate biomarkers and pathways associated with type 1 diabetes mellitus using bioinformatics analysis

Type 1 diabetes mellitus (T1DM) is a metabolic disorder for which the underlying molecular mechanisms remain largely unclear. This investigation aimed to elucidate essential candidate genes and pathways in T1DM by integrated bioinformatics analysis. In this study, differentially expressed genes (DEGs) were analyzed using DESeq2 of R package from GSE162689 of the Gene Expression Omnibus (GEO). Gene ontology (GO) enrichment analysis, REACTOME pathway enrichment analysis, and construction and analysis of protein–protein interaction (PPI) network, modules, miRNA-hub gene regulatory network and TF-hub gene regulatory network, and validation of hub genes were performed. A total of 952 DEGs (477 up regulated and 475 down regulated genes) were identified in T1DM. GO and REACTOME enrichment result results showed that DEGs mainly enriched in multicellular organism development, detection of stimulus, diseases of signal transduction by growth factor receptors and second messengers, and olfactory signaling pathway. The top hub genes such as MYC, EGFR, LNX1, YBX1, HSP90AA1, ESR1, FN1, TK1, ANLN and SMAD9 were screened out as the critical genes among the DEGs from the PPI network, modules, miRNA-hub gene regulatory network and TF-hub gene regulatory network. Receiver operating characteristic curve (ROC) analysis confirmed that these genes were significantly associated with T1DM. In conclusion, the identified DEGs, particularly the hub genes, strengthen the understanding of the advancement and progression of T1DM, and certain genes might be used as candidate target molecules to diagnose, monitor and treat T1DM.

Nestin-Expressing Cells in the Lung: The Bad and the Good Parts

Nestin is a member of the intermediate filament family, which is expressed in a variety of stem or progenitor cells as well as in several types of malignancies. Nestin might be involved in tissue homeostasis or repair, but its expression has also been associated with processes that lead to a poor prognosis in various types of cancer. In this article, we review the literature related to the effect of nestin expression in the lung. According to most of the reports in the literature, nestin expression in lung cancer leads to an aggressive phenotype and resistance to chemotherapy as well as radiation treatments due to the upregulation of phenomena such as cell proliferation, angiogenesis, and metastasis. Furthermore, nestin may be involved in the pathogenesis of some non-cancer-related lung diseases. On the other hand, evidence also indicates that nestin-positive cells may have a role in lung homeostasis and be capable of generating various types of lung tissues. More research is necessary to establish the true value of nestin expression as a prognostic factor and therapeutic target in lung cancer in addition to its usefulness in therapeutic approaches for pulmonary diseases.

Fatty acid-binding protein 5 aggravates pulmonary artery fibrosis in pulmonary hypertension secondary to left heart disease via activating wnt/β-catenin pathway

INTRODUCTION

Pulmonary hypertension secondary to left heart disease (PH-LHD) is a common and fatal disease. However, no effective therapeutic targets have been identified.

OBJECTIVES

Here, we set out to illustrate the functional role and underlying mechanisms of fatty acid-binding protein 5 (FABP5) in PH-LHD development.

METHODS

We performed a systematic analysis of datasets GSE84704 and GSE16624 to identify differentially expressed genes and then constructed protein-protein interaction network for significant modules. Potential target genes in the modules were validated by RT-qPCR and western blot in a PH-LHD mouse model. PH-LHD or sham mice were treated with FABP5 antagonist SBFI-26 or DMSO for 28 days. The role of FABP5 on cardiac function was determined by echocardiography, its impact on pulmonary vascular remodelling were evaluated with right heart catheter, histological analysis and western blot. In vitro, primary pulmonary adventitial fibroblasts were used to investigate the pro-fibrotic mechanisms involving in FABP5.

RESULTS

FABP5 was the only one dramatically upregulated along with increased protein expression in the established PH-LHD mouse model. Inhibition of FABP5 by SBFI-26 injection abrogated pulmonary artery remodelling in PH-LHD and improved cardiac function. In vitro, SBFI-26 or FABP5 siRNA blunted the TGF-β1-induced fibrotic response in cultured pulmonary adventitial fibroblasts. Mechanistically, FABP5 knockdown inhibited GSK3β phosphorylation and increased β-catenin phosphorylation. The wnt/β-catenin agonist SKL2001 diminished the antifibrotic effect of FABP5 knockdown on pulmonary adventitial fibroblasts under TGF-β1 stimulation.

CONCLUSION

FABP5 is an important mediator of pulmonary artery remodelling and a potential therapeutic target for PH-LHD.

CYLD mediates human pulmonary artery smooth muscle cell dysfunction in congenital heart disease-associated pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a common complication of congenital heart disease (CHD). Deubiquitinase cylindromatosis (CYLD) has been reported to significantly aggravate vascular smooth muscle cell (VSMC) phenotypic transformation, proliferation, and migration. Here, we aimed to further investigate its roles and underlying mechanisms in the CHD-PAH development. The expression of CYLD in the lung tissues from CHD-PAH patients and monocrotaline (MCT) plus aortocaval (AV)-induced PAH rats, pulmonary artery smooth muscle cells (PASMCs) from MCT-AV-induced PAH rats, and human PASMCs (HPASMCs) was evaluated. After infection with CYLD siRNA or pcNDA3.1-CYLD, the proliferation, migration, and apoptosis of HPASMCs were measured using an EdU assay, transwell and scratch wound healing assays, and flow cytometric assay, respectively. An adeno-associated virus (AAV) vector encoding CYLD was used to suppress CYLD expression by being intratracheally instilled in rats 7 days before MCT-AV treatment. The results showed that CYLD was increased in the lung tissues from CHD-PAH patients and MCT-AV-induced PAH rats, and in PASMCs from MCT-AV-induced PAH rats. The contractile-type HPASMCs expressed low levels of CYLD, while the proliferative synthetic-type HPASMCs expressed high levels of CYLD. In addition, CYLD could mediate HPASMC dysfunction, which regulated HPASMC phenotypic transformation and proliferation via the modulation of p38 and ERK activation, while CYLD regulated HPASMC migration via the modulation of p38 activation. In vivo results demonstrated that the local suppression of CYLD expression could attenuate the increased levels of PAH and its associated pulmonary vascular remodeling in MCT-AV-induced PAH rats. Collectively, these results indicated that CYLD might be a potential novel therapeutic target for the prevention of PAH and pulmonary vascular remodeling in CHD-PAH through the modulation of HPASMC dysfunction.