Association of Insulin-like Growth Factors with Lung Development in Neonatal Rats

To explore the relationship between Insulin-like growth factor (IGF)- Ⅰ, -Ⅱ and lung development in neonatal rats. 80 timed pregnant Sprague-Dawley ( SD) rats were randomly divided into 4 groups (n=20): group A (Control group), group B (Dexamethasone (DEX) 1 group), group C (DEX 2 group), group D (retinoic acid (RA) group). 20 pregnant rats in group A, B and D were injected subcutaneously or intraperitoneally with vehicle (NS), DEX, or RA respectively during gestational day 16 to 18. All newborn rats in group C were subcutaneously injected with DEX at day 1 to 3 after birth. The lung tissue was obtained at the following times: fetuses at gestational ages of 18, 20 and 21 days, and 1, 3, 5, 7, 10, 14 and 21 days after birth. Lung tissues were used for histopathological study, the polypeptides analysis of IGF-Ⅰ, -Ⅱ (immunohistochemistry and Western blot) and mRNA analysis ( RT- PCR). The results showed that the strongest expression of IGF-Ⅰ in group A and D occurred at ages of 5-7 days (alveolar stage). The stronger their expressions, the better the alveolar develop. The peak stage of expression in group B occurred earlier, on the day 3 after birth. Compared with group A, the expression of IGF-Ⅰ during gestation age of 18 days to age of 3 days in group B were significantly higher (P<0.01), but significantly lower at other time points (P<0.01). The expression of IGF-Ⅰ was lower in group C all the time and always higher in group D than those in group A (P<0.01). The peak expression of IGF-Ⅱ took place at the gestation age of 18 days, then gradually dropped to trace. During 18 days of gestation to age of 3 days, the expression of IGF-Ⅱ in group B was significantly higher than that in group A (P<0.01). No difference was found among all other groups. The change in the expression of IGF-Ⅰ, -Ⅱ mRNA in all 4 groups was similar to that of their polypeptides. The results suggested that there is a close linking between IGF-Ⅰ, -Ⅱ and lung development in newborns. The IGF-Ⅱ works at early stage and the that of IGF-Ⅰ works at the stage of new septa formation and alveoli maturation. The stronger their expressions, the more mature the lung development.

Blood Lead Dynamics of Lead-Exposed Pregnant Women and Its Effects on Fetus Development

The dynamics of blood lead (Pb-B) and blood zinc protoporphyrin (ZPP-B) of women in early pregnancy and parturient women with lead exposure and the effects on fetus development were investigated. Pb-B of lead-exposed women was high: 0.984 μmol/L (20.38 μg/dl) and ZPP was 84.52μg/dl. Cord blood Pb-B was 0.896 μmol/L(18.56μg/dl)and cord blood ZPP was 69.24μg/dl. In the control group, Pb-B was 0.261μmol/L(5.41μg/dl), ZPP-B, 37.59 μg/dl, cord blood, Pb-B 0.34 μmol/L (7.93 μg/dl), and cord ZPP-B 49.0μg/dl. There was a significant correlation between blood lead and blood ZPP, maternal Pb-B and cord Pb-B, maternal Pb-B and cord ZPP-B. The significance of the consistency of high level Pb-B and the effects on fetus development is discussed.

Effects of Hyperoxia on the Dynamic Expression of Aquaporin5 in Premature Rats Lung Development

To explore the dynamic expression and role of Aquaporin5 ( AQP5) in lung development and hyperoxia lung injury, gestation 21-day Sprague-Dawley (SD) rats (term=22 days) were ran- domly assigned to air group and hyperoxia group within 12-24 h after birth. The rats in hypreoxia group were continuously exposed to about 85% oxygen and those in air group to room air. After 1 to 14 days of exposure, total lung RNA was extracted and the expression of AQP5 mRNA was detected by reverse transcription polymerase chain reaction (RT-PCR). Immunohistochemistry and west- ern-blot were used to detect the expression of AQP5 protein. The results showed that the expression of AQP5 in premature rats lung could be detected at various time points after birth, and the positive staining was restricted to the type Ⅰ alveolar epithelial cells. In air group, the AQP5 expression was detected in a very low level at day 1, but exhibited a persistent increase after birth. Compared with the air group, the expression of AQP5 in hyperoxia group was increased at day 1, and had significant difference in mRNA level (P<0.05), but decreased significantly in mRNA and protein levels after 4 to 14 days (P<0.01 or P<0.05 respectively). It was concluded that AQP5 might play a key role in the alveolar period of premature rats by regulating the lung water balance. Hyperoxia exposure leads to a down-regulation of the AQP5 expression, which may be an important factor for the development of hyperoxia lung injury.

Growth factors and fetal lung development mediated by mechanical forces

Incomplete development of the lung secondary to extreme prematurity or pulmonary hypoplasia causes significant morbidity and mortality during the neonatal period. Currently, the management is primarily supportive with no specific treatment to stimulate the growth and development of the lung. Mechanical forces generated inside the fetal lung by constant distention pressure and "breathing-like movements" are a major determinant of fetal lung development. However, the mechanisms by which lung cells sense these mechanical signals to promote lung development are not well-defined. Tracheal ligation has been used not only experimentally but also in human fetuses affected by severe congenital diaphragmatic hernia to stimulate lung growth and decrease the degree of pulmonary hypoplasia. Past investigations suggested that the increase of intratracheal pressure after tracheal ligation releases soluble factors that are critical for lung development. Studies from our laboratory have shown that mechanical strain of fetal type Ⅱ epithelial cells, simulating mechanical forces in utero, promotes differentiation via release of epidermal growth factor receptor ligands heparin binding epidermal growth factor-like growth factor and transforming growth factor alpha. The identification of growth factors released by mechanical forces that are importantfor normal lung development could lead to novel treatments to accelerate lung development.

Effect of Retinoic acid on Platelet-derived Growth Factorand Lung Development in Newborn Rats

Summary: The influence of platelet-derived growth factor (PDGF) on lung development in newborn rats and the effect of retinoic acid (RA) on PDGF in lung development were investigated. Newborn Sprague-Dawley (SD) rats were randomly assigned to two groups: control group and RA group. The rats in RA group was intraperitoneally injected with all trans-retinoic acid (500 μg/kg every day) for consecutive 3 days after birth, while those in the control group were not subjected to intervention. Immunohistochemical assay was performed to locate the expression of PDGF. mRNA levels of PDGF were measured by reverse transcription polymerase chain reaction (RT-PCR) at age of 1, 3, 5, 7, 10, 14, 21 days. The method of radial alveolar counts (RAC) was used to measure the amount of the alveoli of the lungs. It was found that with increasing days, levels of PDGF-A and PDGF-B changed to verying degrees. RA could elevate significantly the expression levels of PDGF-A mRNA and protein (P<0.01), but not affect the expression levels of PDGF-B mRNA and protein markedly (P>0.05). It is suggested that PDGF might play an important role in lung development. RA can stimulate lung development through increasing the expression levels of PDGF-A mRNA and protein.

Lung development:AT1 and AT2 property

The human respiratory system consists of the upper and the lower respiratory tracts.Anatomically,the lower respiratory tract consists of the trachea,bronchi,bronchioles(terminal bronchioles and respiratory bronchioles),alveolar duct,alveolar duct sacs,and alveoli.Alveoli are composed of two epithelial cell types,cuboidal alveolar type 2(AT2)cells that secrete surfactant to prevent alveolar collapse and function as stem cells to regenerate alveolar type 1(AT1)cells during damage repair,and squamous AT1 cells that cover most of the surface area of the alveoli and mediate gas exchange.Previous studies mainly focused on AT2 cells;this review summarizes the current studies on lung development and property of AT1 cells.

Development of a new choroidal metastasis in resistance to crizotinib therapy in anaplastic lymphoma kinaserearranged non-small cell lung cancer

INTRODUCTION Non-small cell lung cancer（NSCLC）is a common malignant disease with an extremely poor prognosis.Lung cancer has been reported to metastasize to the eye in 0.2%to7%of patients based on clinical studies,and in 6%to 7%of patients based on postmortem histopathologic studies.

Initial research of cord blood leptin, adiponectin and IGF-I with fetus growth and development

Objective:In order to reveal the relationship between cord blood leptin,adiponectin and insulin-like growth factor-I(IGF-I)and the fetus growth and development,and discuss the interaction and clinical significance on fetus growth and development.Methods:The levels of cord blood leptin,adiponectin,IGF-I in 86 newborns were examined by radio immunoassay,according to gestation age and birth weight percentile relation,the objects were divided into the SGA group(n=16),the AGA group(n=41),the LGA group(n=29),meanwhile,neonatal birth weight,body length,head circumference,foot length,and placental weight were measured,and body mass index(BMI)was computed.Dependability analysis was taken.Results:The levels of cord blood leptin,adiponectin and IGF-I were as follows:LGA group>AGA group>SGA group.The level of cord blood adiponectin was positively correlated with birth weight,placental weight and BMI(p<.05).Cord blood leptin and IGF-I concentrations were positively correlated with their birth weight,body length,head circumference,foot length,placental weight and BMI,respectively(p<.01),cord blood leptin was positively correlated with adiponectin and IGF-I(p<.01).The levels of cord blood leptin and adiponectin had no statistical significance with neonatal sexuality and deliver style(p>.05);the levels of cord blood IGF-I had no statistical significance with neonatal sexuality(p>.05),but had statistical significance with deliver style(p<.05).Conclusions:Cord blood leptin,adiponectin and IGF-I played an important part in adjusting fetus growth and development as well as participating in the process of fetus growth and development,and could be regarded as one of the clinical indexes to evaluate fetus growth and development or state of nutrition.The abnormal level of cord blood leptin and IGF-I might be one of the reasons to cause intrauterine growth retardation and fetal macrosomia.

TEMPORAL EXPRESSION OF NOTCH RECEPTORS DURING LUNG DEVELOPMENT IN RAT

Objective To investigate the temporal expression of Notch receptors in developing lungs of rats and to explore the regulating role of Notch in lung development. Methods We studied the expression of Notch1,2,3 isforms in embryonic days 18,20,21 and postnatal days 1,4,7,14, 21 rat lungs. Six rats of each group were used to assess lung histologic changes by HE staining and expression of Notch in lungs by immunohistochemistry. Total RNA was extracted by Trizol reagent from the frozen lung tissues. mRNA levels of Notch were measured by reverse transcription polymerase chain reaction (RT-PCR). Results It is showed that Notch_ 1-3 mainly localized in the airway surface epithelium、alveolar epithelium during the psdueoglandular stage, and reached the peaks at canalicular period. The expression patterns of Notch_ 1-3 were changed with the fetal age. Conclusion These results support multiple roles for Notch1,2,and 3 receptor activation during lung development, probably not only modulating the process of branching morphogenesis but also involved in determining the cell differentiation fate in fetal alveolar epithelium.

Expression of Lung Surfactant Proteins SP-B and SP-C and Their Modulating Factors in Fetal Lung of FGR Rats

This study investigated the expression of lung surfactant proteins SP-B and SP-C, and their modulating factors TTF-1 and PLAGL2 in the fetal lung of rats with fetal growth restriction（FGR）. The rat FGR model was established by prenatal hypoxia in the first stage of pregnancy, 180 rats for experiment served as hypoxia group, and 197 healthy rats served as normal control group. The FGR incidence in hypoxia was compared with that in normal control group. The histological changes in the fetal lung were observed under the light microscope and electronic microscope in two groups. The SP-B, SP-C, TTF-1 and PLAGL2 proteins were determined in the fetal lung of two groups immunohistochemically. The expression levels of SP-B, SP-C, TTF-1 and PLAGL2 protein and m RNA in the fetal lung of two groups were detected by using Western blotting and RT-PCR respectively. The FGR rat model was successfully established by using hypoxia. Pathologically the fetal lung developed slowly, and the expression levels of SP-B, SP-C, TTF-1 and PLAGL2 protein and mR NA in the fetal lung were significantly reduced in hypoxia group as compared with those in normal control group. It was suggested that maternal hypoxia in the first stage of pregnancy could induce FGR, and reduce the expression of SP-B and SP-C, resulting in the disorder of fetal lung development and maturation.

Discovering myeloid cell heterogeneity in the lung by means of next generation sequencing

The lung plays a vital role in maintaining homeostasis,as it is responsible for the exchange of oxygen and carbon dioxide.Pulmonary homeostasis is maintained by a network of tissue-resident cells,including epithelial cells,endothelial cells and leukocytes.Myeloid cells of the innate immune system and epithelial cells form a critical barrier in the lung.Recently developed unbiased next generation sequencing(NGS)has revealed cell heterogeneity in the lung with respect to physiology and pathology and has reshaped our knowledge.New phenotypes and distinct gene signatures have been identified,and these new findings enhance the diagnosis and treatment of lung diseases.Here,we present a review of the new NGS findings on myeloid cells in lung development,homeostasis,and lung diseases,including acute lung injury(ALI),lung fibrosis,chronic obstructive pulmonary disease(COPD),and lung cancer.

Expression of Lung Surfactant Proteins SP-B and SP-C and Their Regulatory Factors in Fetal Lung of GDM Rats

This study investigated the expression of lung surfactant proteins (SP-B and SP-C),and regulatory factors [forkhead box A2(FOXA2)and nitrolyogenic FOXA2 (N-FOXA2)]in the fetal lung of rats with gestational diabetes mellitus (GDM)in order to study the mechanism of pulmonary dysplasia.The rat GDM model was established by using streptozotocin intraperitoneally in the first stage of pregnancy.There were 10 rats in the GDM group,and 10 healthy rats in normal control group without any treatment.Fetal lungs of two groups were taken at day 21 of pregnancy.Blood glucose levels of maternal rats and fetal rats were measured by Roche blood glucose meter.The histological changes in the fetal lung were observed under the light microscope in both groups.The SP-B,SP-C and FOXA2were determined in the fetal lung of two groups immunohistochemically. The expression levels of SP-B,SP-C,total FOXA2,FOXA2 in nucleus (n-FOXA2), N-FOXA2 proteins were detected by Western blotting,and the relative expression levels of SP-B,SP-C,FOXA2 mRNA in the fetal lung of two groups were detected by RT-PCR.The results showed that blood glucose levels of maternal rats and fetal rats in GDM group were higher than those in control group.The light microscope revealed fetal lung development retardation in GDM group.The expression of SP-B and SP-C in GDM group was significantly reduced as compared with control group (P<0.05).As compared with control group,the n-FOXA2 expression was significantly decreased in the fetal lung tissue,and N-FOXA2 was significantly increased in control group (P<0.05),but there was no significant changes in the total FOXA2(P>0.05).It was concluded that GDM can cause fetal lung development and maturation disorders,and FOXA2 in fetal lung tissue decreases while nitrocellulose FOXA2 increases.

Effect of Retinoic Acid on Lung Injury in Hyperoxia-Exposed Newborn Rats

To investigate whether treatment with retinoic acid (RA) could improve level of lung alveolarization and influence lung collagen in newborn rats exposed to hyperoxia, newborn Sprague-Dawley rats aged 2 days were randomly assigned to 8 groups:(1) air, (2) O 2, (3) air+NS, (4) O 2+NS, (5) air+dex, (6) O 2+dex, (7) air+RA and (8) O 2+RA. Group 2, 4 6 and 8 were kept in chambers containing 85 % oxygen, the values were checked 3 times a day. The other 4 groups were exposed to room air. Level of alveolarization and lung collagen were analyzed at age of 14 or 21 days through radial alveolar counts, alveolar airspace measurements, type Ⅰ, Ⅲ collagen immunohistochemical methods (SP method) and image processing system. Transforming growth factor-β receptors and procollagen mRNA accumulation were examined at age of 14 days through immunohistochemical methods and in situ hybridization. Our results showed that radial alveolar counts were increased and distal airspace was enlarged in group 8. TypeⅠcollagen was markedly increased, and transforming growth factor-β receptors and procollagen mRNA were decreased by retinoic acid in bronchial epithelial cells, alveolar epithelial cells and alveolar intersitium. It is concluded that retinoic acid can partially reverse lung development arrest during exposure to hyperoxia by increasing lung collagen.

Application of lung microphysiological systems to COVID-19 modeling and drug discovery:a review

There is a pressing need for effective therapeutics for coronavirus disease 2019(COVID-19),the respiratory disease caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)virus.The process of drug development is a costly and meticulously paced process,where progress is often hindered by the failure of initially promising leads.To aid this chal-lenge,in vitro human microphysiological systems need to be refined and adapted for mechanistic studies and drug screening,thereby saving valuable time and resources during a pandemic crisis.The SARS-CoV-2 virus attacks the lung,an organ where the unique three-dimensional(3D)structure of its functional units is critical for proper respiratory function.The in vitro lung models essentially recapitulate the distinct tissue structure and the dynamic mechanical and biological interactions between different cell types.Current model systems include Transwell,organoid and organ-on-a-chip or microphysiological systems(MPSs).We review models that have direct relevance toward modeling the pathology of COVID-19,including the processes of inflammation,edema,coagulation,as well as lung immune function.We also consider the practical issues that may influence the design and fabrication of MPS.The role of lung MPS is addressed in the context of multi-organ models,and it is discussed how high-throughput screening and artificial intelligence can be integrated with lung MPS to accelerate drug development for COVID-19 and other infectious diseases.

Role of SOX2 in foregut development in relation to congenital abnormalities

The uptake of the two essential ingredients for life, oxygen and nutrients, occurs primarily through the oral cavity, but these two lifelines need to be separated with high accuracy once inside the body. The two systems, the gas exchange pulmonary system and the gastro-intestinal feeding system, are derived from the same primitive embryonic structure during development, the foregut, which need to be separated before birth. In certain newborns, this separation occurs not or insufficiently, leading to life threatening conditions, sometimes incompatible with life. The development of the foregut, trachea and lungs is influenced and coordinated by a multitude of signaling cascades and transcription factors. In this review, we will highlight the development of the foregut and pulmonary system and focus on associated congenital abnormalities in light of known genetic alterations with specific attention to the transcription factor SOX2.

Missing the Target?—Targeted Therapy in Small Cell Lung Cancer

Small cell lung cancer [SCLC] is a devastating form of cancer, with most patients harbouring extensive disease at diagnosis and survival of less than 5% at five years. Progress in novel therapies has been limited. This specialist review explores current targeted therapy options and potential areas of development.

Investigating the correlation of Fgf signaling and Wnt signaling pathway with interuterine hyperglycemia-induced fetal lung heteroplasia

Pregnancy with diabetes mellitus(PGDM)has been known to affect the em br yonic development of various systems.No doubt that it has a negative impact on the respiratory system,but the specific pathogenesis is not clear.In this study,firstly we demonstrated that the fetuses had immature lung development in PGDM,including pulmonary epithelial cell decreased and fibrous tissue increased.Secondly,we show Fgf signaling and Wnt signal would be activated in PGDM.For further study,we used in vitro experiments showed that the transcription factor GATA6,lung epithelial related-factors gene was down-regulated in high glucose groups,and the expression of Wnt signal-related and Fgf signal-related gene were up-regulated in high glucose groups;Treated with high glucose and used the inhibitor of Wnt and Fgf signal,the expression of GATA6 and epithelial related-factors gene were up-regulated,while the expression of fibrosis-related genes was down-regulated.

Comparison of protective effects of electroacupuncture and moxibustion at Zusanli(ST 36)on perinatal nicotine exposure-induced lung phenotype in rat offspring

Objective:To compare the effects of electroacupuncture(EA)and moxibustion at Zusanli(ST 36)on the lung phenotype of rat offspring exposed to nicotine during the perinatal period.Methods:Pregnant Sprague-Dawley rats were randomly divided into 4 groups:the control group(saline only),the model group(nicotine only),the EA group(nicotine+EA at ST 36 acupoints bilaterally),and the moxibustion group(nicotine+moxibustion at ST 36 acupoints bilaterally).n=6 rats per group.On postnatal day 21,the body weight,lung weight,and pulmonary function were determined and lung morphometry was performed.Peroxisome proliferator-activated receptor gamma andβ-catenin levels in the lung tissue of offspring were also determined.Results:Perinatal nicotine exposure(PNE)results in decreased body and lung weights of offspring rats,abnormal lung tissue morphology,and significantly altered pulmonary function,showing an increase in total airway resistance and a decrease in tidal volume,minute ventilation,total airway compliance,and peak expiratory flow.Bilateral EA at ST 36 acupoints could block all of these perinatal nicotine-induced effects.Although moxibustion also had protective effects in nicotine-induced offspring lungs,some of these effects did not reach statistical significance,e.g.,protection against the upregulation ofβ-catenin,the downregulation of PPARγsignaling,and the increase in peak expiratory flow.Conclusion:Maternal EA at ST 36 blocked the PNE-induced changes in key developmental signaling pathways,prevented the PNE-induced changes in lung morphology,and protected pulmonary function.Moxibustion at ST 36 showed similar but weaker protective effects against the PNE-induced changes in the exposed offspring.It is important to note that the mechanism underlying the protective effects of moxibustion at ST 36 may be different from those of EA at ST 36,and further research is needed to understand these differences.

Cigarette Smoke Induces Apoptosis by Activation of Caspase-3 in Isolated Fetal Rat Lung Type II Alveolar Ep-ithelial Cells <i>in Vitro</i>

Smoking during pregnancy is a major source of fetal exposure to numerous harmful agents present in tobacco smoke. Lung development involves complex biochemical processes resulting in dramatic changes which continue even after birth. In addition to type I cells which form the blood-air barrier, type II alveolar epithelial (AE) cells have important and diverse functions related to immunological protection and stabilization of the alveolus through synthesis and secretion of the pulmonary surfactant. Apoptosis or programmed cells death is an important physiological process during lung embryogenesis and for the proper maintenance of homeostasis. Caspases are proteases that play important roles in regulating apoptosis. Caspase-3 is the key executioner caspase in the cascade of events leading to cell death by apoptosis. We explored the hypothesis that cigarette smoke extract (CSE) induces apoptosis in fetal rat lung type II AE cells by activation of caspase-3. To analyze these factors, isolated fetal rat lung type II AE cells were used. The cells were exposed to different concentrations of CSE (5%, 10% or 15%) (v/v) for 60 min. The results of the present study showed that CSE induced apoptosis in fetal rat lung type II AE cells with a significant increase (p 0.05) in caspase-3 activity and decrease in cell proliferation at CSE concentrations of 10% and 15% (v/v). These observations indicate that cigarette smoke extract induces apoptosis by activation of caspase-3 in fetal rat lung type II AE cells in a dose-dependent manner and may potentially alter the regulated development of the lung and the appearance of the surfactant-producing type II alveolar cells which are critical for the establishment of adequate gas exchange at birth.