• Tuberculosis and Respiratory Diseases
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• 제38권3호
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• pp.228-235
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• 1991

Pulmonary surfactant is a lipoprotein complex composed primarily of phospholipid and lungspecific apoproteins that reduces surface tension in the alveolus and maintains alveolar stability at low lung volume. Three families of lung-specific apoproteins have been described: SP-A, a glycoprotein with a reduced molecular weight of 28~36 KDa. SP-B a hydrophobic protein with a nonreduced molecular weight of 18 KDa, and SP-C a hydrophobic protein with a non-reduced molecular weight of 5~8 KDa. Surfactant proteins have important roles in regulating surfactant metabolism as well as in determining its physical properties. The synthesis of the active surfactant peptides appears to be modulated by system with considerable complexity, including numerous levels of regulation such as cell-specific, hormonal and developmental controls. Endotoxin appears to alter surfactant protein mRNAs differentially. It is hoped that the elucidation of the factors controlling the synthesis and metabolism of the surfactant proteins will aid in understanding the pathogenesis of hyaline membrane disease and offer new avenues for the therapy and diagnosis of ther pulmonary disorders as well.

• Tuberculosis and Respiratory Diseases
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• 제48권4호
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• pp.513-521
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• 2000

Background : TNF may play an important role(central mediator) in the development of an acute respiratory distress syndrome. Since TNF induced lung injury in the acute respiratory distress syndrome and abnormalities in surfactant function have been described in acute respiratory distress syndrome, the authors investigated the effects of TNF on the regulation of surfactant protein A, B and C mRNA accumulation. Methods : The effects of TNF on gene expression of surfactant protein A, B, and C were analyzed using filter hybridization, 12 and 24 hours after intravenous injection of TNF in rats. Results : 1. The accumulation of SP-A mRNA in the TNF treated group (12 and 24 hours after TNF injection) was significantly decreased by 22.9% and 27.4%, respectively, compared to the control group (P<.025, P<.025). 2. The accumulation of SP-B mRNA in 24 hours after TNF treated group was significantly decreased by 20.5% compared to that of the control group(P<.01). 3. The accumulation of SP-C mRNA in 12 hours after TNF treated group was significantly decreased by 31% the compared to that of the control group(P<.01). Conclusions : These findings indicate the marked inhibitory effects of tumor necrosis factor on surfactant proteins expression in vivo. This finding. in turn, supports the idea of inhibitory effects of tumor necrosis factor on surfactant proteins expression as it relates to pathogenesis of acute respiratory distress syndrome.

• The Korean Journal of Physiology
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• 제28권1호
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• pp.71-77
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• 1994

In the animal model of acute respiratory distress syndrome (ARDS) induced by N-nitroso-N-methylurethane (NNNMU) the secretory activity of alveolar type H cells during acute alveolar injury was investigated by determining phospholipid and pulmonary surfactant associated proteins in crude surfactant. The mechanism of the secretory change was studied by determination of DNA and RNA levels in the lung tissue. After induction of acute alveolar injury with NNNMU, pulmonary hemorrhage, atelectasis and gross hypertrophy were observed. Seven days after NNNMU treatment the level of total DNA in lung homogenate was increased markedly indicating that a hypertrophy was induced by cellular proliferation. Although the total DNA level increased, the RNA/DNA ratio was gradually decreased after NNNMU treatment. Seven days after NNNMU treatment the RNA/DNA ratio returned to the normal control level. During the acute alveolar injury, phospholipid and surfactant associated proteins were reduced significantly as compared with the control, implying that the secretory activity of alveolar type II cells was altered during acute alveolar injury induced by NNNMU. The protein content in crude surfactant during peak injury(7 days after NNNMU) was decreased significantly but phospholipid/protein ratios were identical in both control and NNNMU treatment groups. SDS-PAGE of proteins in crude pulmonary surfactant showed a decrease in major surfactant associated protein(M.W. 38,000) during acute alveolar injury. The present study may suggest that while alveolar type H cells proliferate markedly, transcription of alveolar type ll cell gene was inhibited by an unknown mechanism such as DNA methylation induced by NNNMU. Such an inhibition of transcriptional activity is thought to be associated with the decreased secretory activity of alveolar type ll cells, which may lead to pulmonary atelectasis and edema during the acute alveolar injury.

• Food Science and Biotechnology
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• 제14권1호
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• pp.131-136
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• 2005

The selective extraction behavior of lactoferrin (Lf) from whey protein mixture was examined using reverse micelles formed by the cationic surfactant, cetyldimethylammonium bromide (CDAB). The major whey proteins, including ${\beta}$-lactoglobulin, ${\alpha}$-lactalbumin and bovine serum albumin, were solubilized from aqueous phase to organic phase while Lf was recovered in the aqueous phase. The solubilization behaviors of the proteins were manipulated by the process parameters such as the pH and salt concentration of the aqueous phase and the surfactant concentration in the organic phase. Efficient forward extraction was achieved with sodium borate buffer (50 mM, pH 9) containing 50 mM KCl and organic phase containing 100 mM CDAB. Based on SDS-PAGE and densitometry, about 96% of the initial Lf remained in the aqueous phase after forward extraction. The dialyzed Lf fully maintained its bacteriostatic activity against E. coli O157:H7.

• Clinical and Experimental Pediatrics
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• 제57권4호
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• pp.157-163
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• 2014

Respiratory distress syndrome (RDS) among preterm infants is typically due to a quantitative deficiency of pulmonary surfactant. Aside from the degree of prematurity, diverse environmental and genetic factors can affect the development of RDS. The variance of the risk of RDS in various races/ethnicities or monozygotic/dizygotic twins has suggested genetic influences on this disorder. So far, several specific mutations in genes encoding surfactant-associated molecules have confirmed this. Specific genetic variants contributing to the regulation of pulmonary development, its structure and function, or the inflammatory response could be candidate risk factors for the development of RDS. This review summarizes the background that suggests the genetic predisposition of RDS, the identified mutations, and candidate genetic polymorphisms of pulmonary surfactant proteins associated with RDS.

• 한국응용과학기술학회지
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• 제19권2호
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• pp.79-85
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• 2002

The cutaneous tolerability of detergent formulations can be improved by means of suitable additives. They complex the surfactant molecules lowering the concentration of their free monomeric species. Proteins derivatives used as additives for detergency are usually prepared by partial hydrolysis of plant reserve proteins. The main purpose of the hydrolytic cleavage is to make them water soluble and suitable for liquid products. Water solubility and stability are obtained by means of complexation with surfactants which also increase their actual hydrophobicity, an important parameter affecting cosmetic properties of proteins. Transepidermal water loss (TEWL) and electric capacitance (EC) have been adopted as investigation technigues to evaluate the skin integrity/damage in vitro tests, The performance of native wheat protein / surfactant complexes has been compared with traditional protein hydrolysates as detergent additives. The results show a noticeable reduction of skin irritation in surfactant formulations with addition of native wheat protein.

• Clinical and Experimental Pediatrics
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• 제62권5호
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• pp.155-161
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• 2019

Following the first successful trial of surfactant replacement therapy for preterm infants with respiratory distress syndrome (RDS) by Fujiwara in 1980, several animal-derived natural surfactants and synthetic surfactants have been developed. Synthetic surfactants were designed to overcome limitations of natural surfactants such as cost, immune reactions, and infections elicited by animal proteins contained in natural surfactants. However, first-generation synthetic surfactants that are protein-free have failed to prove their superiority over natural surfactants because they lack surfactant protein (SP). Lucinactant, a second-generation synthetic surfactant containing the SP-B analog, was better or at least as effective as the natural surfactant, suggesting that lucinactant could act an alternative to natural surfactants. Lucinactant was approved by the U. S. Food and Drug Administration in March 2012 as the fifth surfactant to treat neonatal RDS. CHF5633, a second-generation synthetic surfactant containing SP-B and SP-C analogs, was effective and safe in a human multicenter cohort study for preterm infants. Many comparative studies of natural surfactants used worldwide have reported different efficacies for different preparations. However, these differences are believed to due to site variations, not actual differences. The more important thing than the composition of the surfactant in improving outcome is the timing and mode of administration of the surfactant. Novel synthetic surfactants containing synthetic phospholipid incorporated with SP-B and SP-C analogs will potentially represent alternatives to natural surfactants in the future, while improvement of treatment modalities with less-invasive or noninvasive methods of surfactant administration will be the most important task to be resolved.

• Journal of Plant Biotechnology
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• 제48권3호
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• pp.165-172
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• 2021

식물과 동물 모두 단백질체 분석을 위해 계면활성제를 사용하여 단백질을 효과적으로 가용화 하는 것은 매우 중요하다. 여러 계면활성제 중 광분해성의 Azo는 MS 분석에 적합하며 단백질을 효과적으로 잘 가용화 하는 등의 여러 이점을 보여주었다. 그러나 대부분이 동물 단백질체 분석에 적용되어 있었으며 식물 단백질체 분석에의 적용은 미비하였다. 따라서 본 연구에서는 벼 잎의 단백질체 분석을 위한 계면활성제로 Azo를 사용하여 SDS와 비교 분석을 수행하였다. 비표지 단백질체 정량 분석, 단백질 기능 분석, 세포내 단백질체의 위치 확인 분석 및 KEGG 경로 분석을 수행하였으며, 그 결과 SDS와 비교하였을 때 Azo의 단백질 가용화 효율이 전혀 떨어지지 않음을 확인하였다. 이는 앞으로 벼 뿐만 아니라 식물단백질체 분석 시에 광분해성 계면활성제인 Azo의 적용 가능성이 무궁무진함을 의미 한다.

• Tuberculosis and Respiratory Diseases
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• 제39권3호
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• pp.242-247
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• 1992

연구배경 : Surfactant 단백은 surfactant의 물리학적 성상의 결정 및 대사를 조절하는데 있어서 중요한 역할을 한다. 유전자 발현의 조절을 연구하기 위하여서는 cDNA의 탐지자에 의한 mRNA의 정량측정이 중요하다. 방법 : 쥐의 surfactant 단백 B의 cDNA에 대한 coding 부위를 PGem 3Z 또는 4Z에 subclone하여 SP6 RNA polymerase 효소를 이용하여 antisense와 sense을 얻었다. Sense을 이용한 filter hybridization올 시행하여 정상곡선을 얻었다. Antisense는 $^{32}P$를 표지시켜 탐지자로 이용하였다. 결과 : SP-B에 대한 sense 복사체의 정상곡선은 Y=2034.9X+159.1(X=SP-BmRNA 복사체, Y=CPM)이고, 상관계수는 1.0이었다. 결론 : 이상의 결과로 filter hybridization 방법은 mRNA을 정량측정 하는데 있어서 빠르고, 재현성이 높으며, 많은 시료를 한꺼번에 시행할 수 있는 유용한 방법이다.

• Tuberculosis and Respiratory Diseases
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• 제54권5호
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• pp.510-521
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• 2003

연구배경 : 내독소인 lipopolysaccharide는 조직 내에 많이 존재하는 대식세포를 활성화시키고 활성화된 대식세포는 폐손상의 중요한 매개체로 알려진 많은양의 TNF를 형성한다. Thiourea는 폐장의 미세혈관의 혈역동학적 변화와 투과성의 변화를 초래하여 폐부종을 유발하는 약물이며, 모세혈관의 내피세포의 장벽 상실을 초래해 모세혈관의 투과성을 증가시켜 간질 또는 폐포내 부종을 초래한다. 표면활성물질은 ARDS의 병태생리적인면에 있어서 중요한 역할을 하며 SP는 표면활성물질의 물리학적 성상의 결정 및 대사를 결정하는데 있어서 중요하다. SP는 염증성 cytokine들에 의하여 조절되며, SP들은 ARDS발생 시 감소한다. SP-B와 SP-C는 배수성 단백이며 표면활성물질의 신속한 film형성에 관여한다. 이에 저자들은 폐손상의 서로 다른 원인물질인 내독소와 thiourea를 실험동물의 복강 내로 유사한 조건하, 동일시간에 각각 투여하여 내독소와 thiourea의 투여후 시간경과에 따른 SP-B와 C유전자가 폐손상의 원인에 따른 발현의 차이가 있는지를 비교 관찰하기 위하여 이 연구를 시행하였다. 방법 : 저자들은 내독소와 thiourea를 백서에 각각 투여후 SP-B와 C의 유전자 발현양상을 filter hybridization방법으로 검색하고 내독소와 thiourea의 투여 후 시간경과에 따른 SP-B와 C의 유전자 발현의 변동을 비교 관찰하였다. 결과 : 내독소를 1일 5mg/kg를 투여하고 6시간 경과 후 SP-B mRNA양은 대조군에 비하여 26.1%가 감소하였다(P<0.01). 내독소를 1일 5mg/kg를 투여하고 24시간 경과 후 SP-B mRNA양은 대조군에 비하여 50%가 감소하였다(P<0.001). Thiourea를 1일 3.5mg/kg를 투여하고 6시간 및 24시간 경과 후 SP-B mRNA양은 대조군에 비하여 각각 9.8% 및 12.5%가 감소하였다. 내독소를 1일 5mg/kg를 투여하고 6시간 경과 후 SP-C mRNA양은 대조군에 비하여 38.7%가 감소하였다(P<0.01). 내독소를 1일 5mg/kg를 투여하고 24시간 경과 후 SP-C mRNA양은 대조군에 비하여 53.6%가 감소하였다(P<0.001). Thiourea를 1일 3.5mg/kg를 투여하고 6시간 경과 후 SP-C mRNA양은 대조군에 비하여 22.8%가 감소하였다(P<0.05). 결론 : SP-B와 SP-C mRNA에 대한 폐손상의 서로 다른 원인인 내독소와 thiourea의 유사한 조건하 투여후 시간경과에 따른 동물실험내 SP-B와 SP-C의 유전자발현이 각각 특이하게 상이하게 감소하는 것을 알 수 있었고 배수성 SP에 대한 영향은 thiourea보다 내독소 투여시 더 감소가 있었다.