PIWI-interacting RNA (piRNA) is a class of recently discovered small non-coding RNA molecules with a length of 18–33 nt that interacts with the PIWI protein to form the piRNA/PIWI complex. The PIWI family is a subfamily of Argonaute (AGO) proteins that also contain the AGO family which bind to microRNA (miRNA). Recently studies indicate that piRNAs are not specific to in the mammalian germline, they are also expressed in a tissue-specific manner in a variety of human tissues and participated in various of diseases, such as cardiovascular, neurological, and urinary tract diseases, and are especially prevalent in malignant tumors in these systems. However, the functions and abnormal expression of piRNAs in respiratory tract diseases and their underlying mechanisms remain incompletely understood. In this review, we discuss current studies summarizing the biogenetic processes, functions, and emerging roles of piRNAs in respiratory tract diseases, providing a reference value for future piRNA research.

Abstract Background The burden of chronic respiratory diseases has changed over three decades.To describe the spatiotemporal trends of prevalence, mortality and disability adjusted life years (DALY) due to chronic respiratory diseases(CRDs), across the globe during 1990–2019 using data from the Global Burden of Disease Study 2019(GBD 2019). Methods The prevalence, mortality and DALY attributable to CRDs, and risk factors from 1990 to 2019 were estimated. We also assessed the driving factors and potentiality for improvement by decomposition analyses and frontier analyses. Results In 2019, 454.56 (95% uncertainty interval(UI): 417.35-499.14) million individuals worldwide had a CRD, showing a 39·8% increase compared with 1990. Deaths due to CRDs numbered 3.97(95% UI: 3.58–4.30) million, and DALY in 2019 was 103.53 (95% UI:94.79-112.27) million. Declines by average annual percent change(AAPC) were observed in age-standardized prevalence rates(ASPR) (0.64% decrease), age-standardized mortality rates(ASMR) (1.92%), and age-standardized DALY rates(ASDR) (1.72%) globally and in 5 socio-demographic index (SDI) regions. Decomposition analyses represented that the increase in overall CRDs DALY was driven by aging and population growth. Chronic obstructive pulmonary disease (COPD) was the leading drivers globally. Frontier analyses witnessed significant improvement opportunities at all levels of the development spectrum. Smoking remained a leading risk factor(RF) for the mortality and DALY, although, it showed a downward trend. Air pollution, a growing factor especially in relatively low SDI regions, deserves our attention. Conclusion Our study clarified that CRDs remain a leading cause of prevalence, mortality and DALY worldwide, with growth in absolute numbers but declines in several age-standardized estimators since 1990. The estimated contribution of risk factors to mortality and DALY supports the need for urgent measures to improve them.

Objective To analyze the disease burden of interstitial lung disease and pulmonary sarcoidosis （ILD＆） and its trend in China from 1990 to 2019， and provide theoretical evidence for the prevention and control of ILD＆PS. Methods Based on the data of Global Burden of Disease （GBD） Study 2019， the prevalence， mortality and absolute number of disability-adjusted life years （DALYs） of ILD＆PS in China from 1990 to 2019 were obtained， including age-standardized rate （ASR）. Joinpoint linear regression model was used to calculate average annual percent change （AAPC） and analyze the change trends of prevalence， mortality and DALYs of ILD＆PS. Age-period-cohort （APC） model was used to analyze the effects of age， period and cohort on changes in the mortality. Results The prevalence， mortality and absolute number of DALYs of ILD＆PS showed increasing trends in China from 1990 to 2019. In 2019， there were 722410 cases （95%UI 586951～872704），8181 deaths （95% UI 5796～10302） of ILD＆PS，and the absolute number of DALYs was 240576 person years （95% UI 189934～299740）. In general， the age-standardized prevalence rate （ASPR）（AAPC=0.58%，P＜0.05）showed an upward trend， while the age-standardized mortality rate （ASMR）（AAPC=-0.07%，P＞0.05）and age-standardized DALYs rate （ASDR） （AAPC=-0.20%，P＜0.05）showed downward trends， from 1990 to 2019. The trends in women were similar to the general trends， but the ASMR（AAPC=0.23%，P＜0.05）and ASDR（AAPC=0.04%，P＞0.05）in men showed upward trends. The prevalence， mortality and absolute number of DALYs of ILD＆PS generally increased first and then decreased with age， with the peaks at about 70 years old. Except for the sustained growth of ASMR， ASPR and ASDR increased first and then decreased with age. The mortality APC model suggested that the net drift value during 1990-2019 was negative （-0.50%，P＜0.05）， the death risk increased with age， and the risk of death decreased in the period after 2010 and in birth cohort after 1955. But the risk of death was higher in men. Conclusion Although the overall ASMR and ASDR of ILD＆PS showed downward trends in China from 1990 to 2019， and APC analysis also showed a downtrend in mortality rate， the prevalence， ASPR， mortality and absolute number of DALYs still showed gradual increase trends. The burden of ILD＆PS remains heavy， especially in men. So more works are need to do in the prevention and treatment of ILD＆PS in China.

Lung adenocarcinoma (LUAD) is associated with poor prognosis. Identifying novel cancer targets and helpful therapeutic strategies remains a serious clinical challenge. This study detected differentially expressed genes in The Cancer Genome Atlas (TCGA) LUAD data collection. We also identified a predictive DNA biomarker, G protein-coupled receptor 37 (GPR37), which was verified as a prognostic biomarker with a critical role in tumor progression. In human LUAD specimens and microarray analyses, we determined that GPR37 was significantly upregulated and associated with a poor prognosis. GPR37 downregulation markedly inhibited the proliferation and migration of LUAD both in vitro and in vivo. Mechanistically, GPR37 could bind to CDK6, thereby facilitating tumor progression in LUAD by inducing cell cycle arrest at the G1 phase. GPR37 also facilitates tumorigenesis in xenograft tumors in vivo. High-throughput screening for GPR37-targeted drugs was performed using the Natural Products Library, which revealed the potential of Hypocrellin B to inhibit GPR37 and cell growth in LUAD. We demonstrated that Hypocrellin B suppressed LUAD cell proliferation and migration both in vitro and in vivo via GPR37 inhibition. Collectively, our findings reveal the role of GPR37 in LUAD progression and migration and the potential of GPR37 as a target for the treatment of LUAD. Thus, the specific inhibition of GPR37 by the natural product Hypocrellin B may possess the potential for the treatment of LUAD.

Background. Sustained hypoxia can trigger a progressive rise in pulmonary artery pressure and cause serious pulmonary diseases. Macrophages play important roles along the progression of pulmonary hypertension. However, the state of macrophage polarization during the early stage of pulmonary hypertension is unclear. Methods. Unlike traditional sequencing method, single-cell sequencing can accurately distinguish among cell types and better understand cell-to-cell relationships. In this study, we investigated the polarization of macrophages in pulmonary hypertension via single-cell RNA-sequencing in a mice hypoxia model, which was then validated in patients with pulmonary hypertension. Results. We identified that the intermittent exposure to hypoxic conditions could lead to the production of more M2-type macrophages than M1-type macrophages in a mouse model. Further validation analysis was performed by analyzing lung tissue of patients with pulmonary hypertension, revealing that the number of disease-associated M2 macrophages was substantially increased. Conclusions. In this study, the active anti-inflammatory response of macrophage involved in pulmonary hypertension has been identified, suggesting that intervention against the polarization of macrophages to the M2 type may be a potential way to reduce chronic pulmonary inflammation, pulmonary vascular remodeling, and artery pressure. Thus, investigation of macrophage polarization associated with hypoxia could help us better understand disease mechanism and craft effective prevention strategies and approaches.

Abstract: Dihydroartemisinin (DHA) is an active form of artemisinin extracted from the traditional Chinese medicine Artemisia annua, which is used to treat malaria. Previous studies have shown that DHA has a therapeutic effect on pulmonary hypertension (PH), but its specific mechanism has not been fully elucidated. In this study, a hypoxia-induced PH mouse model was established and DHA was administered as a therapeutic intervention. We measured hemodynamics and right ventricular hypertrophy and observed hematoxylin and eosin staining of lung tissue sections, proving the therapeutic effect of DHA on PH. Furthermore, cell counting kit-8 and 5-ethynyl-2′-deoxyuridine (EdU) cell proliferation assay kit were performed to examine cell proliferation of pulmonary artery smooth muscle cells cultured in hypoxia or in normoxia. Transwell migration chamber assay was performed to examine cell migration of the same cell model. Consistent with the therapeutic effect in vivo, DHA inhibited hypoxia-induced cell proliferation and migration. Through high-throughput sequencing of mouse lung tissue, we screened embryonic lethal abnormal vision-like 2 (ELAVL2) as a key RNA binding protein in PH. Mechanistically, DHA inhibited the proliferation and migration of pulmonary artery smooth muscle cells by promoting the expression of ELAVL2 and regulating the miR-503/PI3K/AKT pathway. The binding relationship between ELAVL2 and pre-miR-503 was verified by RNA binding protein immunoprecipitation assay. In conclusion, we first propose that DHA alleviates PH through the ELAVL2/miR-503/PI3K/AKT pathway, which may provide a basis for new therapeutic strategies of PH.

Dihydroartemisinin (DHA) is a traditional antimalarial drug. DHA plays a crucial role in preventing pulmonary hypertension (PH); however, its regulatory function on microRNAs (miRNAs) in PH remains unclear. This study aimed to investigate whether DHA exerts its protective functions by regulating miR-335 in PH. Hypoxia-induced PH models were induced both in vitro and in vivo. Mice were treated with various concentrations of DHA, and pulmonary arterial smooth muscle cells (PASMCs) were treated with DHA, miR-335 inhibitor, miR-335 mimic, or Van Gogh-like 2 (Vangl2) plasmid. The expression of miR-335 and Vangl2, pulmonary arterial remodeling index; right ventricular hypertrophy index; and proliferation and migration indexes were measured. DHA improved pulmonary vascular remodeling and alleviated PH in vivo. miRNA sequencing and real-time PCR results further show that the increase in hypoxia-induced miR-335 was avoided by DHA administration, and miR-335 increased the hypoxia-induced PASMC proliferation and migration. MiRNA databases and dual-luciferase reporter assay show that miR-335 directly targets Vangl2, and Vangl2 decreased the hypoxia-induced PASMC proliferation and migration. The miR-335 inhibitor failed to inhibit hypoxia-induced proliferation and migration upregulation in Vangl2 knockdown PASMCs, and the effect of DHA can be blocked by miR-335 upregulation. In hypoxic PH, MiR-335 is increased, whereas Vangl2 is decreased. MiR-335 can significantly promote the hypoxia-induced proliferation and migration of PASMCs by targeting the Vangl2 gene. DHA effectively reverses the hypoxia-induced upregulation of miR-335 expression, avoiding the miR-335-mediated downregulation of Vangl2 and thereby promoting the expression of Vangl2 to prevent PH.

Methylenetetrahydrofolate dehydrogenase 2 (MTHFD2) is a bifunctional enzyme located in the mitochondria. It has been reported to be overexpressed in several malignancies. However, the relationship between the expression of MTHFD2 and non-small cell lung cancer (NSCLC) remains largely unknown. In this study, we found that MTHFD2 was significantly overexpressed in NSCLC tissues and cell lines. Knockdown of MTHFD2 resulted in reduced cell growth and tumorigenicity in vitro and in vivo. Besides, the mRNA and protein expression level of cell cycle genes, such as CCNA2, MCM7 and SKP2, was decreased in MTHFD2 knockdown H1299 cells. Our results indicate that the inhibitory effect of MTHFD2 knockdown on NSCLC may be mediated via suppressing cell cycle-related genes. These findings delineate the role of MTHFD2 in the development of NSCLC and may have potential applications in the treatment of NSCLC.

AIM:To study whether salidroside plays a protective role in hypoxia-induced pulmonary hyperten-sion by suppressing oxidative stress.METHODS: Sprague-Dawley rats were randomly divided into 4 groups: normoxia (N)group,hypoxia for 4 weeks(H4)group,low-dose salidroside(hypoxia for 4 weeks and treatment with salidroside at 16 mg/kg,H4S16)group and high-dose salidroside(hypoxia for 4 weeks and treatment with salidroside at 32 mg/kg, H4S32)group.The mean pulmonary arterial pressure(mPAP), the weight ratio of right ventricle/(left ventricle+sep-tum)[RV/(LV+S)]and vessel wall area/vessel total area(WA/TA)were evaluated.The levels of malondialdehyde (MDA)in the serum and lung tissues were detected by colorimetric method.The levels of 8-iso-prostaglandin F2α(8-iso-PGF2α)in the serum and lung tissues were measured by ELISA.The activity of superoxide dismutase(SOD)in the serum was analyzed by hydroxylamine method.The expression of NAPDH oxidase 4(NOX4)and SOD1 in the lung tissues was determined by Western blot.RESULTS:Compared with N group,the levels of mPAP,RV/(LV+S)and WA/TA in H4 group were significantly increased,which were apparently attenuated by salidroside injection in a dose-dependent manner. Meanwhile,salidroside administration apparently decreased the levels of MDA and 8-iso-PGF2αin the serum and lung tis-sues,as well as the expression of NOX 4 in the lung tissues.Besides,compared with N group, the activity of SOD in the serum and the expression of SOD1 in the lung tissues in H4group were significantly decreased,while administration of sali-droside increased the activity of SOD in the serum and the expression of SOD 1 in the lung tissues in a dose-dependent man-ner.CONCLUSION:Salidroside protects the pulmonary vessels from remodeling and attenuates hypoxia -induced pulmo-nary hypertension by inhibiting oxidative stress.

Background Baicalin is a flavonoid compound that exerts specific pharmacological effect in attenuating the proliferation, migration, and apoptotic resistance of hypoxia-induced pulmonary artery smooth muscle cells (PASMCs). However, the underlying mechanism has not been fully elucidated yet. Although our previous studies had indicated that activation of A2aR attenuates CXCR expression, little is known about the relationship between A2aR and SDF-1/CXCR4 axis in hypoxic PASMCs. In this study, we aimed to investigate the effect of A2aR on the SDF-1/CXCR4 axis in hypoxic PASMCs, the mechanism underlying this effect, and whether baicalin exerts its protective functions though A2aR. Methods Rat PASMCs were cultured under normoxia/hypoxia and divided into nine groups: normoxia, hypoxia, hypoxia + AMD3100 (a CXCR4 antagonist), hypoxia + baicalin, hypoxia + negative virus, normoxia + A2aR knockdown, hypoxia + A2aR knockdown, hypoxia + CGS21680 (an A2aR agonist), and hypoxia + A2aR knockdown + baicalin. Lentiviral transfection methods were used to establish the A2aR knockdown model in PASMCs. Cells were incubated under hypoxic conditions for 24 h. Expression levels of A2aR, SDF-1, and CXCR4 were detected using RT-qPCR and western blot. The proliferation and migration rate were observed via CCK-8 and Transwell methods. Cell cycle distribution and cell apoptosis were measured by flow cytometry (FCM) and the In-Situ Cell Death Detection kit (Fluorescein). Results Under hypoxic conditions, levels of A2aR, SDF-1, and CXCR4 were significantly increased compared to those under normoxia. The trend of SDF-1 and CXCR4 being inhibited when A2aR is up-regulated was more obvious in the baicalin intervention group. Baicalin directly enhanced A2aR expression, and A2aR knockdown weakened the function of baicalin. SDF-1 and CXCR4 expression levels were increased in the hypoxia + A2aR knockdown group, as were the proliferation and migration rates of PASMCs, while the apoptotic rate was decreased. Baicalin and CGS21680 showed opposite effects. Conclusions Our data indicate that baicalin efficiently attenuates hypoxia-induced PASMC proliferation, migration, and apoptotic resistance, as well as SDF-1 secretion, by up-regulating A2aR and down-regulating the SDF-1/CXCR4 axis.

Pulmonary arterial hypertension (PAH) is a devastating disease characterized by high pulmonary artery pressure. It is reported that microRNA-204 (miR-204) plays an important role in the development of PAH. Calcitriol [1,25-dihydroxyvitamin D3, 1,25(OH)2D3] mediates multiple pathophysiological processes. The aim of the current study was to explore the role of 1,25(OH)2D3 in PAH. PAH was induced in rats and rat pulmonary arterial endothelial cells (PAECs) were isolated as in vitro PAH model. The mean pulmonary artery pressure, morphologic changes, and expressions of transforming growth factor-beta1 (Tgfbr2), Smad2/7, alpha smooth muscle actin (α-SMA), and p21 were then measured. Furthermore, the effect of 1,25(OH)2D3 on rat PAECs with or without hypoxia treatment was also assessed by measuring the proliferation, migration, and cell cycle distribution of PAECs. The potential targets of miR-204 were also predicted and validated with a dual-luciferase reporter system. Then the role of miR-204 and Tgfbr2 in the anti-PAH effect of 1,25(OH)2D3 was further explored by modulating the expression of the two genes. The overall pulmonary hypertension and hypoxia-induced proliferation and migration of PAECs were attenuated by administration of 1,25(OH)2D3, which was associated with the suppressed expressions of Tgfbr2, α-SMA, and Smad7 and induced expressions of miR-204, p21 and Smad2 both in vitro and in vivo. Moreover, the luciferase reporter assay identified Tgfbr2 as a novel direct target of miR-204. Both overexpression of miR-204 and inhibition of Tgfbr2 would strengthen the effect of 1,25(OH)2D3 administration. Findings outlined in the current study demonstrated that 1,25(OH)2D3 was a promising therapeutic modality for treatment of PAH, function of which was exerted through miR-204 mediated Tgfbr2 signaling.

急性胰腺炎（ AP）是消化系统最常见的急腹症之一，发病急、病程长、并发症多，总的病死率约5％［1］，其中重症急性胰腺炎（SAP）的病死率高达36％～50％［2］，因此早期评价AP患者病情的严重程度对患者的治疗和监护具有十分重要的临床意义。2008年提出的AP 床旁严重度指数（ bedside index for severity in AP ， BISAP ）是一种简便、准确的评分系统，已被广泛应用于临床。文献报道红细胞比容（ HCT ）≥44％可作为预测SAP的重要指标［3-4］，入院时HCT升高可以预测AP并发感染［5］。早期快速补液以降低HCT可改善AP患者的预后［6-7］。本研究回顾性分析温州医科大学附属第一医院近2年来资料完整的AP患者586例，分析BISAP评分联合HCT预测SAP患者预后的临床价值。