The Porcine Pulmonary Surfactant Protein A (pSP-A) Immunogenicity Evaluation in the Murine Model

This paper investigated the porcine surfactant protein A (pSP-A) immunogenicity in murine model. Many elegant stu-dies about SP-A therapeutic applications are available however specific studies about its exogenous immunogenicity were not easily assumed. Therefore, we investigated the immunogenicity of this porcine protein in mice. The mice re-ceived pSP-A subcutaneously on days 0 and 7. The animals were observed during 90 days and the blood was collected on days 30, 60 and 90 for assessment the immunogenic potential of pSP-A. Some animals showed circulating antibodies above the screening cut point, which was calculated based on control mice sera signals. However, those antibodies were considered false positive read-outs by the performed competitive inhibition assay. Also no neutralizing antibodies were detected able to avoid the porcine protein ability to promote lipid aggregation. So far in this model, porcine surfactant protein-A could be considered not immunogenic.

Pulmonary Immunohistochemical Detection of Surfactant Protein A (SP-A) in Fatal Drowning

Drowning still remains one of the most difficult diagnoses in forensic pathology because macroscopic and microscopic autopsy findings are unspecific. An ideal diagnostic marker for drowning still needs to be developed, but some authors have recently studied SP-A as a marker of asphyxiation and drowning. The aim of this study is to compare the histopathological features and the SP-A immunohistochemical expression in lung tissue in the case of drowning with those determined by other causes to discriminate between cadaver submersion and drowning.

ISOFLURANE REDUCES THE SYNTHESIS OF SURFACTANT-RELATED PROTEIN A OF ALVEOLAR TYPE II CELLS INJURED BY H_2O_2

Objective To explore the influence of isoflurane(Iso) on the synthesis of surfactant-related protein(SP-A) of alveolar type II cells(AT II cells) cultured in primary and injured by hydrogen peroxide(H2O2).Methods AT II cells were isolated from adult SD rats and used for experiments after 32h in primary culture and randomized into six groups: control group,0.28 mM Iso group,2.8mM Iso group,75 μM H2O2 group,75 μM H2O2 +0.28 mM Iso group and 75 μM H2O2 +2.8 mM Iso group. Each group was continuously incubated for 3 h after administration of Iso or/and H2O2. The intracellular SP-A and the SP-A of cultured medium were measured with an enzyme-linked immunosorbent assay(ELISA).Results Iso significantly decreased SP-A content of cultured medium and the intracellular,and aggravated the decrease of SP-A content induced by H2O2 in a dose-dependent manner.Conclusion Iso itself may decrease SP-A synthesis of AT II cells in vitro,and aggravate the damage of AT II cells especially under peroxidation condition.

The roles of surfactant protein D during Aspergillus fumigatus infection in human corneal epithelial cells

AIM: To investigate roles of surfactant protein D (SP-D) and relative cytokines in human corneal epithelial (HCE) cells Exposed to aspergillus fumigatus (AF) antigens. METHODS: HCE cells cultured 47 in vitro with AF antigens and sampled at 0, 0.5, 1 hour, 2, 4, 6 and 8 hours. The Expression of SP-D mRNA was evaluated by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR).The expression of SP-D protein was shown by ELISA and immunocytochemistry SP methods. The expression of NF-kappa B and relative downstream cytokines such as TNF-alpha, IL-1 beta, IL-8 and IL-10 in supernatant fluid were measured by ELISA. RESULTS: SP-D mRNA and protein were detected in untreated HCE cells. The expression of SP-D and the relative downstream cytokines rose after being stimulated with AF antigens. SP-D mRNA began to rise at 0.5 hour and the most significantly peak was in 2 hours. The protein of SP-D in supernatant fluid had the same trend with mRNA. Immunocytochemistry of SP-D showed positive expression and gradually increased to 6 hours, and then the expression began to decline. NF-kappa B was activated after treated by AF antigens and the changes had correlation with SP-D. TNF-alpha, IL-1 beta, IL-8 and IL-10 began to rise after given AF antigens 1 hour and were 1.82, 1.43, 1.12 and 1.28 times higher than the untreated HCE cells separately. The expression of TNF-alpha and IL-1 beta reached the peak at 2 hours, separately 2.80 and 2.86 times than the untreated. The expression of IL-8 and IL-10 gradually increased with a time-dependent manner. ' CONCLUSION: HCE cells exists SP-D and it may play a significant role in pathogenesis of keratomycosis. AF may induce human corneal epithelial cells to express inflammatory cytokines via SP-D and NF-kappa B pathway. SP-D possibly mediates the recognition to AF mycelium.

Surfactant Protein B 1580 Polymorphism Is Associated with Susceptibility to Chronic Obstructive Pulmonary Disease in Chinese Han Population

Summary: Whether surfactant protein B (SP-B)-18A/C and 1580C/T polymorphism were associated with susceptibility to chronic obstructive pulmonary disease (COPD) in Chinese Han population was investigated. After genomic DNA was isolated from blood of COPD smokers and control smokers, the genotypes of SP-B-18A/C and SP-B1580C/T polymorphism loci were determined by polymerase chain reaction-restriction fragment length polymorphism analysis (PCR-RFLP) respectively. The results showed that there was significant difference in genotypes distribution frequency of SP-B1580C/T polymorphism locus between COPD smokers and control smokers. C→T mutation rate (including TT homozygote and CT heterozygote) in COPD smokers was higher than in control smokers (57.9 % vs 41.7 %, χ2=4.93, P<0.05), whereas there was no significant difference in genotypes distribution frequency of SP-B1580-18A/C locus between COPD smokers and control smokers. The allele frequency (29.1 %) of SP-B1580-18A/C locus is lower than T allele (70.9 %) in Chinese Han Population, and the distribution was different from that in Mexican, in which, the A and T allele frequencies were 85 % and 15 % respectively. It was concluded that SP-B1580 T allele was probably associated with increased susceptibility to COPD in Chinese Han population; The polymorphism of SP-B-18A/C locus maybe varied with race.

Early expression of surfactant proteins D in Fusarium solani infected rat cornea

AIM: To investigate the early expression of surfactant proteins D(SP-D) in Fusarium solani infected rat cornea. METHODS: Wistar rats were divided into group A, B and C randomly. The right eyes were chosen as the experiment one. Group A was control group. Group B was not inoculated with Fusarium solani. Group C was taken as fusarium solani keratitis model. Five rats in group B and C were executed randomly at 6, 12, 24, 48 and 96 hours respectively after the experimental model being established. The expression of SP-D was assessed through immunohistochemistry and reverse transcription polyrnerase chain reaction(RT-PCR). RESULTS: RT-PCR detected that the SP-D mRNA expression was low in the corneal of normal rats and group B. The expression of fungal infected cornea increased gradually and reached the peak at 24 hours in group C. The synchronous expression of group B and C were in significant difference (P<0.01). Immunohistochemisty discovered the protein of SP-D expression was increased gradually from 12 hours and reached the peak at 48 hours in group C. The synchronous expression of group B and C were also in significant difference (P<0.01). CONCLUSION: There exists SP-D in rat corneal tissue and the expression is significantly increased at the early period of fusarium solani infected cornea. SP-D may play a role in the early innate immunity response of the corneal resistance to Fusarium solani infection.

Association of Surfactant Protein B Gene Polymorphisms (C/A-18, C/T1580, Intron 4 and A/G9306) and Haplotypes with Bronchopulmonary Dysplasia in Chinese Han Population

Summary： This study aimed to investigate the association between surfactant protein B （SP-B） pol- ymorphisms and bronchopulmonary dysplasia （BPD） in Chinese Han infants. We performed a case- control study including 86 infants with BPD and 156 matched controls. Genotyping was performed by sequence specific primer-polymerase chain reaction （PCR） and haplotypes were reconstructed by the fastPHASE software. The results showed that significant differences were detected in the geno- type distribution of C/A-18 and intron 4 polymorphisms of SP-B gene between cases and controls. No significant differences were detected in fhe genotype distribution of C/T1580 or A/G9306 be- tween the two groups. Haplotype analysis revealed that the frequency of A-del-C-A haplotype was higher in case group （0.12 to 0.05, P=0.003）, whereas the frequency of C-inv-C-A haplotype was higher in control group （0.19 to 0.05, P=0.000）. In addition, a significant difference was observed in the frequency of C-inv-T-A haplotype between the two groups. It was concluded that the polymor- phisms of SP-B intron 4 and C/A-18 could be associated with BPD in Chinese Han infants, and the del allele of intron 4 and A allele of C/A-18 might be used as markers of susceptibility in the disease. Haplotype analysis indicated that the gene-gene interactions would play an important part in deter- mining susceptibility to BPD.

Surfactant Protein A Polymorphism Is Associated with Susceptibility to Chronic Obstructive Pulmonary Disease (COPD) in Chinese Uighur Population

This study investigatedexamined the correlation between surfactant protein-A (SP-A) polymorphism and the susceptibility of cvhronic obstructive pulmonary disease (COPD) in Xinjiang Uighurs. Genomic DNA was extracted from peripheral blood of 194 COPD smokers and 201 healthy smokers of Uighur who were hospitalized in or paid a visit to one of the four Xingjiang-based hospi-tals involved in the study, betweenfrom March 2009 to December 2010. Single nucleotide polymor-phisms (SNPs) were studied on A/G atwithin amino acid aa62 (CCA/CCG rs1136451) and C/T within aa219 (CGG/TGG, rs4253527) in SP-A. Genotypes were determined by using the TaqMan polymerase chain reaction (PCR). Our results showed that genotype frequencies were different be-tween the COPD and normal smokers infor aa62 (χx2=6.852, P=0.033). There were also significant differences in allele genotype frequencies between the COPD and the control and allele G might de-crease the risk COPD (χx2=6.545, P=0.011; OR=0.663; 95% CI: 0.484–0.909). The result suggested We were led to conclude that polymorphism of aa62 (CCA/CCG, rs1136451) of SP-A may be asso-ciated with the susceptibility to COPD in Xingjiang Uighurs.

Expression of Peroxiredoxins and Pulmonary Surfactant Protein A Induced by Silica in Rat Lung Tissue

Silicosis is one of the most serious occupational diseases in China and dates back to centuries ago. In this study, we successfully established a rat model of silicosis by intratracheal silica injection for 28 days and determined hydroxyproline levels to evaluate collagen metabolism in lung homogenates. Oxidative stress status was evaluated by detecting catalase and glutathione peroxidase activities.

Changes of Tumor Necrosis Factor, Surfactant Protein A, and Phospholipids in Bronchoalveolar Lavage Fluid in the Development and Progression of Coal Workers’ Pneumoconiosis

Objective To evaluate the alterations of biomarkers in the development and progression of coal workers＇ pneumoconiosis （CWP）. Methods The type and number of cells, and the levels of tumor necrosis factor-alpha （TNF-α）, pulmonary surfactant protein, phospholipids and fibronectin in bronchoalveolar lavage fluid were assayed in 14 health active coal miners, 21 coal miners without CWP and 13 miners with CWP of 0/1 to 1/1. Results Compared to active coal miners without CWP （8,23μg/mL）, TNF-α concentration was gradually decreased when dust exposure was stopped （5.90 μg/mL）. Elevated surfactant protein A （SP-A） level and phosphatidylglycerol （PG） to phosphatidylinositol （PI） ratio were found in miners actively exposed to coal dust （6528 μg/mL for SP-A and 10. for PG/P1）, and both parameters decreased when CWP progressed from CWP （0/1） （3419μg/mL for SP-A and 5.9 for PG/PI） to CWP （1/1） （1654 μg/mL for SP-A and 5.5 for PG/PI）. Conclusion Biomarkers in bronchoalveolar lavage fluid can be used to screen coal miners at high risk of developing coal workers＇ pneumoconiosis.

Mass Spectrometry-based Deep Coverage Proteome:Evaluation of Cellular Protein Extraction Methods

The current study comprehensively evaluates four different protein extraction methods based on urea,sodium dodecyl sulfate(SDS),anionic surfactants(BT),and total RNA extractor(Trizol),aiming to optimize the sample preparation workflow for mass spectrometry-based proteomics.Using HeLa cells as an example,we found that the method employing the mass spectrometry-compatible surfactant BT reagent significantly reduces the total time consumed for protein extraction and minimizes protein losses during the sample preparation process.Further integrating the four protein extraction methods,we identified over 7000 proteins from HeLa cells without relying on pre-fractionation techniques,and 2990 of them were quantified using label-free quantification.It is worth noting that the BT and SDS methods demonstrate higher efficiency in extracting membrane proteins,while the Urea and Trizol methods are more effective in extracting proteins from nuclear and cytoplasmic fractions.In summary,this study provides a novel solution for deep proteome coverage,particularly in the context of cellular protein extraction,by integrating mass spectrometry-compatible surfactants with traditional extraction methods to effectively enhance protein identification numbers.

<i>Stachybotrys chartarum</i>(<i>atra</i>) spore extract alters surfactant protein expression and surfactant function in isolated fetal rat lung epithelial cells, fibroblasts and human A549 cells

Moulds, notably Stachybotrys chartarum (atra), are constant contributors to air pollution particularly to air quality in buildings. The spores themselves or their volatile organic products are present in variable amounts in almost all environments, particularly in buildings affected by flooding. These moulds and products can account for the sick building syndrome and have been tied to such occurrences as the outbreak of pulmonary hemosiderosis and hemorrhage in infants in Cleveland, Ohio. The present study was designed to investigate the effects of S. chartarum extracts on surfactant protein expression, surfactant quality and cell survival in the developing lung. S. chartarum extracts were incubated with cultures of several cell types;isolated fetal lung type II cells and fetal lung fibroblasts, and human lung A549 cells, a continuously growing cell line derived from surfactant producing type II alveolar cells. MTT formazan assays were employed to test cell viability. The synthesis and release of the predominant surfactant protein A (SP-A), which is involved in the regulation of surfactant turnover and metabolism, and surfactant protein B (SP-B) involved in shuttling phospholipids between surfactant subcompartments was also assessed. Antibodies to these proteins and western blotting results were used to assess the quantity of protein produced by the various cell types. A novel approach utilizing captive bubble surfactometry was employed to investigate the quality of surfactant in terms of surface tension and bubble volume measurements. Electron microscopy was used to examine changes in cellular structure of control and S. chartarum-treated cells. Results of the study showed that exposure to the S. chartarum extracts had deleterious effects on fetal lung epithelial cell viability and their ability to produce pulmonary surfactant. S. chartarum extracts also induced deleterious changes to the developing fetal lung cells in terms of expression of SP-A and SP-B as well as to the surface tension reducing abilities of the pulmonary surfactant. Ultrastructurally, spore toxin associated changes were apparent in the isolated lung cells most notably in the lamellar bodies of fetal rat lung alveolar type II and human A549 cells. This study has demonstrated the potential damage to surfactant production and function which may be induced by inhaling S. chartarum toxins.

Efficient Protein Refolding Using Surfactants at High Final Protein Concentration

The refolding of denatured hen egg white lysozyme (HEWL) was examined by surfactants at a high final refolded HEWL concentration (1 mg/mL). Hexadecyltrimethylammonium bromide (CTAB) and sucrose fatty acid monoester (DK-SS) were used to dissolve denatured HEWL without denaturants such as guanidine hydrochloride (GuHCl) and urea. When denatured HEWL was perfectly dissolved in buffer solutions containing surfactants and dithiothreitol (DTT), the concentration of CTAB was about one-twentieth times less than that of DK-SS. The concentration of CTAB strongly affected the refolding yield, and the maximum refolding yield was obtained at 0.88 mM CTAB, which is around the critical micelle concentration of CTAB. The refolding yield was influenced by the molar ratio of oxidized glutathione (GSSG) to DTT, and the maximum refolding yield was obtained when [GSSG]/[DTT] was 1.5. The refolding yield was markedly dependent upon the solution pH of HEWL, and exhibited 80% at pH 5.2.

The Expression of Surfactant Proteins A and D in the Intestines and Pancreas of Murine Fetuses

Purpose: Surfactant proteins exist in the digestive tract and may play an important role in the host defense. However, the expression of surfactant proteins in the premature digestive system remains unclear. The aim of this study was to investigate the expression of surfactant proteins in the intes-tines and pancreas of murine fetuses. Methods: Immunostaining for SP-A and SP-D was assessed in the small intestine and pancreas of ICR murine fetuses on days 15, 16, 17 and 18 of gestation (normal duration of pregnancy: 19 - 21 days). RT-PCR was performed to detect the expression of spa and spd mRNA in the small intestine and pancreas on day 16, 17 and 18 of gestation. Results: Immunoreactivity for SP-A and SP-D in the acinar cells of pancreas and intestinal mucosal surface were positive on day 16 of gestation onward. RT-PCR revealed that the expression of spa and spd mRNA was significant in the pancreas but weak in the small intestine. Conclusions: Our data revealed that surfactant proteins are present in the fetal intestines and pancreas and that a significant expression of spa and spd mRNA is detected in the fetal pancreas. Pancreas may be a possible organ involved in the synthesis and secretion of surfactant proteins into the intestinal lumen.

Surfactant Protein D for Pathological Evaluation of Infant Acute Respiratory Distress Syndrome Caused by Respiratory Syncytial Virus Infection

Pediatric respiratory syncytial viral infection (RS) usually shows relatively good outcome;however, when it accompanies acute respiratory distress syndrome (ARDS), this becomes fatal. We experienced three pediatric patients with RS + ARDS, with all showing good outcome with steroid pulse therapy. We wish to emphasize;1) steroid pulse therapy may become an option for this condition, and 2) plasma KL-6 and surfactant protein D levels may become a biomarker reflecting the disease progression/condition. Patients were, aged 1 month, 1 year 5 months, and 1 year 11 months. In all three, the respiratory condition deteriorated rapidly, requiring invasive ventilator management. Although the effectiveness of steroid treatment for ARDS is controversial, very severe condition prompted us to employ steroid pulse therapy, after which, oxygenation rapidly improved without adverse events. Plasma KL-6 and surfactant protein D levels were measured during exacerbations of ARDS, steroid pulse therapy, and recovery. Surfactant protein D levels were closely associated with oxygenation, suggesting this substance level might be a biomarker of ARDS caused by the disruption of the alveolar epithelial lining and to understand oxygenation without time lag.

Correlation of neonatal pulmonary surfactant protein A gene polymorphism with pneumonia susceptibility and inflammatory response

Objective:To study the correlation of neonatal pulmonary surfactant protein A gene polymorphism with pneumonia susceptibility and inflammatory response.Methods:Neonates who were born and diagnosed with pneumonia in Zigong Maternity and Child Healthcare Hospital between September 2015 and February 2017 were selected as pneumonia group, and neonates without infection were selected as control group. SP-A gene rs1059054 and rs1136454 loci polymorphism, the contents of inflammatory cytokines in serum as well as the expression of inflammatory transcription factors in peripheral blood were determined.Results:The constituent ratio of rs1059054 loci CC genotype of pneumonia group was significantly higher than that of control group while the constituent ratio of CT and TT genotypes were significantly lower than those of control group;the constituent ratio of rs1136454 loci AA genotype was significantly lower than that of control group while the constituent ratio of AG and GG genotypes were significantly higher than those of control group. PCT, sTREM1, TNF-α and IL-6 levels in serum as well as RORγt mRNA expression in peripheral blood of pneumonia children with SP-A gene rs1059054 loci CC genotype were significantly higher than those of pneumonia children with CT genotype and TT genotype while SOCS1 and Foxp3 mRNA expression in peripheral blood were significantly lower than those of pneumonia children with CT genotype and TT genotype;PCT, sTREM1, TNF-α and IL-6 levels in serum as well as RORγt mRNA expression in peripheral blood of pneumonia children with SP-A gene rs1136454 loci AA genotype were significantly lower than those of pneumonia children with AG genotype and GG genotype while SOCS1 and Foxp3 mRNA expression in peripheral blood were significantly higher than those of pneumonia children with AG genotype and GG genotype.Conclusion: Neonatal SP-A gene rs1059054 loci CC genotype can increase the pneumonia susceptibility and aggravate inflammatory response, and rs1136454 loci AA genotype can decrease pneumonia susceptibility and relieve inflammatory response.

Establishment of Surfactant-associated Protein A Suicide Gene System and Analysis of Its Activity

Summary： Alveolar epithelial type II （AT II） cells are essential for lung development and remodeling, as they are precursors for type I cells and also produce other non-repair cells （fibroblasts）. Progenitor ceils are believed to possess capability of multi-potent transdifferentiation, which is closely related to the niche, suggesting the importance of establishment of a lung progenitor cell niche model. We hypothesized that pulmonary surfactant-associated protein A （SPA） suicide gene system would cause AT II cell to kill itself through apoptosis and leave its niche. In vitro, the recombinant adeno-associated virus vectors-SPA-thymidine kinase （rAAV-SPA-TK） system was established to get targeted apoptotic AT II cells. The apoptosis of AT II cells was detected by using MTT. The results showed that cloned SPA gene promoter had specific transcriptional activity in SPA high expression cells, and SPA high expression cells （H441） transfected with TK gene had higher sensitivity to ganciclovir （GCV） than SPA low expression cells （A549）. In vivo, increased apoptosis of AT II cells induced by GCV in rAAV-SPA-TK system was observed by TUNEL. Finally, the successful packaging and application of rAAV-SPA-TK system provide experimental basis to get specific lung progenitor cell （AT II） niche in vitro and in vivo.

儿童支原体肺炎患者血清CCL-2、IL-6、TGF-β_(1)、SP-A变化及与疾病严重程度的关系

目的探讨儿童支原体肺炎(MPP)患者血清趋化因子配体2(CCL-2)、白介素-6(IL-6)、转化生长因子-β_(1)(TGF-β_(1))、肺表面活性物质相关蛋白A(SP-A)水平变化及与疾病严重程度的关系。方法纳入100例2019年6月至2022年6月入院且经检测诊断为MPP儿童患者为研究对象(MMP组),根据临床表现及影像学表现分为轻症组(62例)、重症组(38例)。选择同期来院健康体检的儿童患者为参照对象(健康组,100例)。采集两组儿童静脉血样,检测并比较MPP组与健康组儿童血清CCL-2、IL-6、TGF-β_(1)、SP-A水平,并分析其与MPP严重程度的关系,绘制ROC曲线分析单独检测和四者联合检测对MMP严重程度诊断的效能。结果MPP组患儿血清中CCL-2、IL-6、TGF-β_(1)、SP-A水平较健康组升高,且MPP患儿重症组中的水平较轻症组更高,差异有统计学意义(P<0.05);Pearson相关分析显示,CCL-2、IL-6、TGF-β_(1)、SP-A与儿童MPP严重程度呈正相关(P<0.05);ROC曲线结果显示,四者联合检测诊断儿童MPP的AUC为0.940,高于单独检测(P<0.05)。结论CCL-2、IL-6、TGF-β_(1)、SP-A水平在MPP患儿血清中升高,并与MPP严重程度相关,四者联合检测更有利于对MPP严重程度进行临床诊断。

托法替布联合醋酸泼尼松对间质性肺疾病的应用效果及对动脉血气指标、肺功能、肺泡灌洗液中KL-6、SP-A水平的影响

目的探讨托法替布联合醋酸泼尼松对间质性肺疾病的应用效果及对动脉血气指标、肺功能及肺泡灌洗液中人Ⅱ型肺泡细胞表面抗原(Human TypeⅡAlveolar Cell Surface Antigen,KL-6)、人肺表面活性物质相关蛋白A(Human Pulmonary Surfactant Associated Protein A,SP-A)水平的影响。方法前瞻性随机选取2021年1月—2023年7月南平市第一医院收治的100例间质性肺疾病患者作为研究对象,根据治疗方法不同分为两组,各50例。所有患者均进行常规对症治疗,对照组采取醋酸泼尼松治疗,观察组采取托法替布联合醋酸泼尼松治疗,对比两组疗效、血气指标、肺功能及肺泡灌洗液中KL-6、SP-A水平。结果观察组总有效率为96.00%,高于对照组的80.00%,差异有统计学意义(χ^(2)=6.061,P<0.05)。治疗后,观察组血氧分压高于对照组,动脉血二氧化碳分压低于对照组,差异有统计学意义(P均<0.05)。治疗后,观察组第1秒用力呼气容积、用力肺活量及第1秒用力呼气容积/用力肺活量高于对照组,差异有统计学意义(P均<0.05)。治疗后,观察组肺泡灌洗液中KL-6、SP-A水平低于对照组,差异有统计学意义(P均<0.05)。结论托法替布联合醋酸泼尼松对间质性肺疾病疗效显著,可改善患者动脉血气指标,提升肺功能,降低肺泡灌洗液中KL-6、SP-A表达水平。

miR-4433b-5p及SP-A在老年COPD患者病情严重程度及频繁加重风险中的价值

目的分析青海地区老年慢性阻塞性肺疾病(COPD)患者血浆miR-4433b-5p、基质金属蛋白酶(MMP)-2及肺泡表面活性蛋白(SP)-A表达水平变化及其临床意义。方法随机选取出院后定期随访的60岁以上COPD患者和健康体检者作为COPD组及对照组。所有受试者采集清晨空腹静脉血留取血浆。选择5例对照组及COPD组患者进行高通量测序。选择两组各35例为对照验证组和COPD验证组,收集血浆提取RNA后用qRT-聚合酶链反应(PCR)检测miR-4433b-5p表达,用酶联免疫吸附试验(ELISA)检测血浆中MMP-2及SP-A的浓度,完善肺功能检查并进行为期1年的随访。结果以P值≤0.05且差异倍数(FC)≥2为判断标准,共筛选出老年COPD患者差异表达的miRNAs 159个,其中上调53个,下调106个,差异表达miRNAs靶基因信号通路主要富集于神经生长因子(NGF)等信号通路;与对照验证组相比,COPD验证组血浆MMP-2及SP-A浓度明显升高(P<0.05);血浆miR-4433b-5p与第1秒用力呼力量占预计值百分比(FEV1%)预计值呈显著正相关(r=0.429,P<0.05),而与1年急性加重次数呈显著负相关(r=-0.455,P<0.05);血浆MMP-2及SP-A与FEV1%预计值呈显著负相关(r=-0.462、-0.422,P<0.01、P<0.05),与1年急性加重次数呈显著正相关(r=-0.422、0.429,均P<0.05);二元Logistic回归分析显示,血浆miR-4433b-5p及SP-A可作为老年COPD频繁加重风险评估指标;受试者工作特征(ROC)曲线下面积(AUC)结果显示血浆miR-4433b-5p及SP-A联合预测AUC、灵敏度分别为0.866、82.6%,在预测老年COPD频繁加重风险评估中优于单标志物。结论老年COPD血浆中miR-4433b-5p表达降低,血浆miR-4433b-5p及SP-A可作为老年COPD患者严重程度评估及未来急性加重风险的危险因素。miR-4433b-5p可能通过调控MMP-2调控COPD病理学过程。