OBJECTIVES: To investigate the role and mechanism of Brahma-related gene 1 (Brg1) in regulating the Wnt/β-catenin signaling pathway in a bronchopulmonary dysplasia (BPD) model. METHODS: Wild-type C57BL/6 and Brg1^f1/f1 mice were randomly divided into four groups: wild-type control, wild-type BPD, Brg1^f1/f1 control, and Brg1^f1/f1 BPD (n=5 each). Immortalized mouse pulmonary alveolar type 2 cells (imPAC2) were cultured, and Brg1 gene was knocked down using lentivirus transfection technology. Cells were divided into three groups: control, empty vector, and Brg1 knockdown. Hematoxylin and eosin staining and immunofluorescence were used to detect pathological changes in mouse lung tissue. Western blot and real-time fluorescent quantitative PCR were used to measure Brg1 protein and mRNA expression levels in mouse lung tissue. Western blot and immunofluorescence were used to detect the expression of homeodomain-containing protein homeobox (HOPX), surfactant protein C (SPC), and Wnt/β-catenin signaling pathway proteins in mouse lung tissue and imPAC2 cells. The CCK8 assay was used to assess the proliferation of imPAC2 cells, and co-immunoprecipitation was performed to verify the interaction between Brg1 and β-catenin proteins in imPAC2 cells. RESULTS: Compared to the Brg1^f1/f1 control group and wild-type BPD group, the Brg1^f1/f1 BPD group showed increased alveolar diameter and SPC protein expression, and decreased relative density of pulmonary vasculature and HOPX protein expression (P<0.05). Compared to the control group, the Brg1 knockdown group showed increased cell proliferation ability, protein expression levels of SPC, Wnt5a and β-catenin, and β-catenin protein fluorescence intensity, along with decreased HOPX protein expression (P<0.05). An interaction between Brg1 and β-catenin proteins was confirmed. CONCLUSIONS The Brg1 gene may promote the proliferation of alveolar type 2 epithelial cells by regulating the Wnt/β-catenin signaling pathway, thus influencing the occurrence and development of BPD.
Animals ; DNA Helicases/genetics* ; Transcription Factors/genetics* ; Wnt Signaling Pathway/physiology* ; Nuclear Proteins/genetics* ; Mice ; Bronchopulmonary Dysplasia/etiology* ; Mice, Inbred C57BL ; beta Catenin/physiology* ; Disease Models, Animal ; Cell Proliferation ; Lung/pathology* ; Male

OBJECTIVE: To investigate the expression and possible regulatory mechanism of miR-34a in the lung tissue of neonatal rat model of bronchopulmonary dysplasia (BPD) induced by hyperoxia. METHODS: In the study, 80 newborn SD rats were randomly divided into hyperoxia group (FiO₂=60%) and air group (FiO₂=21%) within 2 hours after birth, 40 rats per group. Lung tissue samples of the SD rats in each group were extracted on the 1st, 7th, 14th and 21st days after birth, and the pathological changes of lung tissue were observed under light microscope after HE staining. The number of radial alveolar counts (RAC) and the mean alveolar diameter (MAD) and the thickness of alveolar septal thickness (AST) were measured to evaluate the development of alveoli. Real-time fluorescence quantitative PCR was used to detect the expression of miR-34a, angiopoietin-1 (Ang-1) and tyrosine kinase receptor-2 (Tie-2) in lung tissue of rats in hyperoxia group and air group at different time points. Enzyme-linked immunosorbent assay (ELISA) was used to detect the proteins expression of Ang-1 and Tie-2 in the lung tissues of the two groups at different time points. RESULTS: The weight of rats in the hyperoxia group on the 7th, 14th and 21st days after birth was significantly lower than that in the air group (P all < 0.05). With the prolongation of oxygen exposure, the number of alveoli decreased, the volume increased, the structure simplified, the alveolar cavity enlarged obviously and the alveolar septum thickened in the hyperoxia group. On the 7th, 14th and 21st days after birth, the RAC in the hyperoxia group was significantly lower than that in the air group (P all < 0.05). Compared with the air group, MAD and AST increased significantly on the 7th, 14th and 21st days after birth in the hyperoxia group, and the difference was statistically significant (P all < 0.05). The expression level of miR-34a in lung tissue of hyperoxia group was significantly higher than that of air group on the 7th, 14th and 21st days after birth, and the difference was statistically significant (P all < 0.05). Compared with the air group at the same time point, the expression levels of Ang-1 and Tie-2 mRNA and protein in the hyperoxia group were lower than those in the air group on the 14th and 21st days after birth (P all < 0.05). CONCLUSION The new BPD model of newborn SD rats can be successfully established by continuous exposure to 60% hyperoxia. The expression of miR-34a was up-regulated in the lung tissue of the new BPD model of neonatal rats. MiR-34a may play an important role in the occurrence and development of BPD by regulating Ang-1/Tie-2 signal pathway.
Animals ; MicroRNAs/metabolism* ; Bronchopulmonary Dysplasia/genetics* ; Hyperoxia/metabolism* ; Rats, Sprague-Dawley ; Animals, Newborn ; Rats ; Angiopoietin-1/genetics* ; Disease Models, Animal ; Receptor, TIE-2/genetics* ; Lung/pathology* ; Male

OBJECTIVES: To investigate the changes and significance of type 2 innate lymphoid cells (ILC2), interleukin-33 (IL-33), interleukin-25 (IL-25), thymic stromal lymphopoietin (TSLP), interleukin-5 (IL-5), and interleukin-13 (IL-13) in peripheral blood of preterm infants with bronchopulmonary dysplasia (BPD). METHODS: A total of 76 preterm infants with a gestational age of <32 weeks and a length of hospital stay of ≥14 days who were admitted to the Department of Pediatrics of the Affiliated Hospital of Jiangsu University from September 2020 to December 2021 were enrolled. According to the diagnostic criteria for BPD, they were divided into a BPD group with 30 infants and a non-BPD group with 46 infants. The two groups were compared in terms of the percentage of ILC2 and the levels of IL-33, IL-25, TSLP, IL-5, and IL-13 in peripheral blood on days 1, 7, and 14 after birth. RESULTS: The BPD group had significantly lower birth weight and gestational age than the non-BPD group (P<0.05). On days 7 and 14 after birth, the BPD group had significantly higher levels of ILC2, IL-33, TSLP, and IL-5 than the non-BPD group (P<0.05), and these indices had an area under the curve of >0.7 in predicting the devolpment of BPD (P<0.05). Multivariate logistic regression analysis showed that after adjusting for gestational age and birth weight, peripheral blood IL-33, TSLP and IL-5 on days 7 and 14 after birth were closely related to the devolpment of BPD (P<0.05). CONCLUSIONS Early innate immune activation and upregulated expression of related factors may be observed in preterm infants with BPD. ILC2, IL-33, TSLP, and IL-5 may be used as biological indicators for early diagnosis of BPD.
Child ; Humans ; Infant ; Infant, Newborn ; Birth Weight ; Bronchopulmonary Dysplasia/pathology* ; Cytokines ; Immunity, Innate ; Infant, Premature ; Interleukin-13 ; Interleukin-33 ; Interleukin-5 ; Lymphocytes/pathology* ; Thymic Stromal Lymphopoietin

To analyze clinical characteristics and risk factors of very low birth weight and extremely low birth weight infants with bronchopulmonary dysplasia (BPD). A retrospective epidemiological study was performed in 768 neonates (376 males) with birth weights<1 500 g and gestational age ≤ 34 weeks who survived ≥28 days. Clinical data were obtained from the multi-center clinical database of neonatal intensive care units (NICU) in 19 hospitals of Jiangsu Province between January 1, 2017 and December 31, 2017. These infants were divided into non-BPD group and BPD group according to BPD diagnositic criteria. Clinical features and potential risk factors were compared between groups with Chi-square test or nonparametric test. Risk factors for BPD were analyzed with Logistic regression analysis. Among the total of 768 eligible neonates, 577 without BPD, 191 with BPD (24.9%). Mild, moderate and severe BPD accounted for 73.3% (140/191), 23.6% (45/191) and 3.1% (6/191) of all BPD cases respectively. There were significant differences in the average gestational age (29 (28, 30) 30 (29, 31) weeks) or the average birth weight (1 170 (990, 1 300) 1 300 (1 160, 1 400) g) between BPD group and non-BPD group (-9.959,-7.202, both 0.000). The incidences of BPD in the infants with gestational age of<28 weeks, 28-31 weeks and 32-34 weeks were 51.7% (46/89), 24.8% (139/561), 5.1% (6/118) respectively. The incidences of BPD in infants with birth weigh1 000 g, 1 000- 1 249 g and 1 250-1 500 g were 62.3% (48/77), 25.9% (70/270) and 17.3% (73/421) respectively. Proportion of male (55.5% (106/191) 46.8% (270/577)), rate and length of conventional mechanical ventilation (48.7% (93/191) 14.9% (86/577), 120 (72, 259) 80 (29, 144)h), initial inhaled oxygen concentration and maximum inhaled oxygen concentration (0.35 (0.30, 0.40) 0.30(0.25, 0.40), 0.40 (0.30, 0.50) 0.30 (0.30, 0.40)) and volume of red blood cell transfusion (53(30, 90) .38(28, 55) ml) were higher in BPD group than in non-BPD group (χ(2)=4.350, 91.640, -3.557, -2.848, -3.776, -4.677, all 0.05). Rate of continuous positive airway pressure (12.6%(24/191) 19.4%(112/577)) during neonatal resuscitation in delivery room was lower in BPD group than that in non-BPD group (χ(2)=4.614, 0.032). The incidences of complications in BPD group including severe asphyxia, neonatal respiratory distress syndrome (NRDS), persistent pulmonary hypertension in newborns (PPHN), patent ductus arteriosus, anemia of prematurity, early onset sepsis, clinical sepsis and ventilator associated pneumonia were higher than that in non-BPD group (15.2%(29/191) 4.5% (26/577), 91.1% (174/191) 56.7% (327/577), 2.6% (5/191) 0.2% (1/577), 43.5% (83/191) 34.2% (197/577), 88.0% (168/191) 58.8% (339/577), 15.7% (30/191) 9.9% (57/577), 42.9% (82/191) 18.6% (107/577), 14.1% (27/191) 2.3% (13/577); χ(2)=24.605, 74.993, 9.167, 5.373, 61.866, 4.557, 43.149, 34.315, all 0.05). Multivariate logistic regression analysis showed that NRDS (4.651, 95: 1.860-11.625), clinical sepsis (1.989, 95: 1.067-3.708), ventilator associated pneumonia (3.155, 95: 1.060-9.388), conventional mechanical ventilation (2.298, 95: 1.152-4.586), and volume of red blood cell transfusion (1.013, 95: 1.002-1.024) were risk factors of BPD. BPD is more common in very low birth weight infants of male with gestational age less than 32 weeks. Using CPAP in the delivery room, active treatment of NRDS, preventing nosocomial infection, and reducing invasive ventilation and red blood cell transfusion may decrease the incidence of BPD.
Birth Weight ; Bronchopulmonary Dysplasia ; complications ; epidemiology ; pathology ; Gestational Age ; Humans ; Infant ; Infant, Extremely Low Birth Weight ; Infant, Newborn ; Infant, Very Low Birth Weight ; Male ; Respiratory Distress Syndrome, Newborn ; Retrospective Studies ; Risk Factors

OBJECTIVETo study the effect of rhubarb on neonatal rats with bronchopulmonary dysplasia (BPD) induced by hyperoxia.

METHODSA total of 64 rats (postnatal day 4) were randomly divided into four groups: air control, rhubarb control, hyperoxia model, and hyperoxia+rhubarb (n=16 each). The rats in the hyperoxia model and hyperoxia+rhubarb groups were exposed to hyperoxia (60% O2) to establish a BPD model. The rats in the rhubarb control and hyperoxia+rhubarb groups were given rhubarb extract suspension (600 mg/kg) by gavage daily. The pathological changes of lung tissue were evaluated by hematoxylin-eosin staining on postnatal days 14 and 21. The content of malondialdehyde (MDA) and the activity of superoxide dismutase (SOD) were measured by spectrophotometry. The mRNA and protein expression levels of tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) were determined by RT-PCR and Western blot respectively.

RESULTSThe hyperoxia model group showed reduced alveolar number, increased alveolar volume, and simplified alveolar structure, which worsened over the time of exposure to hyperoxia. These pathological changes were significantly reduced in the hyperoxia+rhubarb group. On postnatal days 14 and 21, compared with the air control and rhubarb control groups, the hyperoxia model group had significantly reduced radical alveolar count (RAC), significantly reduced activity of SOD in the lung tissue, and significantly increased content of MDA and mRNA and protein expression levels of TNF-α and IL-6 (P<0.05). Compared with the hyperoxia model group, the hyperoxia+rhubarb group had significantly increased RAC, significantly increased activity of SOD in the lung tissue, and significantly reduced content of MDA and mRNA and protein expression levels of TNF-α and IL-6 (P<0.05).

CONCLUSIONSRhubarb may play a protective role in rats with BPD induced by hyperoxia through inhibiting inflammatory response and oxidative stress.

Animals ; Animals, Newborn ; Bronchopulmonary Dysplasia ; metabolism ; pathology ; prevention & control ; Disease Models, Animal ; Hyperoxia ; complications ; Lung ; metabolism ; pathology ; Plant Extracts ; therapeutic use ; Rats ; Rats, Sprague-Dawley ; Rheum ; Superoxide Dismutase ; metabolism ; Tumor Necrosis Factor-alpha ; genetics

OBJECTIVETo study the expression of SUMO-modified CCAAT enhancer binding protein α (C/EBPα) in preterm rat model of bronchopulmonary dysplasisa (BPD) induced by hyperoxia exposure and its role.

METHODSEighteen preterm rats were randomly divided into an air group and a hyperoxia group (n=9 each). The model of BPD was prepared in preterm rats exposed to hyperoxia. The rats from the two groups were sacrificed on postnatal days 4, 7 and 14 respectively (3 rats at each time) and lung tissues were harvested. Periodic acid-Schiff (PAS) staining was used to observe the differentiation of rat lung tissues. Ki67 expression was detected by immunohistochemistry. Western blot was used to measure the protein expression of small ubiquitin-related modifier-1(SUMO1) and C/EBPα. A co-immunoprecipitation assay was performed to measure the protein expression of SUMO-modified C/EBPα.

RESULTSCompared with the air group, the hyperoxia group showed a decreased glycogen content in the lung tissue on postnatal day 4, and an increased content on postnatal days 7 and 14. Over the time of hyperoxia exposure, the hyperoxia group showed an increased expression of Ki67 in the lung tissue compared with the air group at all time points. Compared with the air group, the protein expression of C/EBPα increased on postnatal day 4 and decreased on postnatal days 7 and 14 in the hyperoxia group (P<0.05). The hyperoxia group had significantly upregulated expression of SUMO1 and SUMO-modified C/EBPα compared with the air group at all time points (P<0.05). In the hyperoxia group, the protein expression of SUMO-modified C/EBPα was positively correlated with the glycogen content (r=0.529, P<0.05) and the expression of Ki67 (r=0.671, P<0.05).

CONCLUSIONSHyperoxia may induce over-proliferation and differentiation disorders of alveolar epithelial cells in preterm rat model of BPD, possibly through an increased expression of SUMO-modified C/EBP&alpha.

Animals ; Animals, Newborn ; Bronchopulmonary Dysplasia ; etiology ; metabolism ; pathology ; CCAAT-Enhancer-Binding Protein-alpha ; metabolism ; Cell Proliferation ; Disease Models, Animal ; Hyperoxia ; complications ; pathology ; Ki-67 Antigen ; analysis ; Pulmonary Alveoli ; pathology ; Rats ; Rats, Sprague-Dawley ; Sumoylation

OBJECTIVETo explore the expression of CASZ1 and its relationship with the pulmonary microvascular development in lung tissue of newborn rats exposed to hyperoxia which induced bronchopulmonary dysplasia (BPD).

METHODForty-eight newborn Sprague Dawley(SD) rats (male and female unlimited) were randomly divided into two groups: experimental group and control group according to random digits table with 24 in each.The rats in experimental group were exposed to high oxygen volume fraction of 800 ml/L and the rats in control group were exposed to normal air. Eight rats were randomly selected from each group on day 3 and 7 after oxygen exposure.The sections of lung were stained with HE method in order to assess lung histological changes, the alveolar development was evaluated by the number of radial alveolar count (RAC) and septal wall thickness. CD31 was detected by immunohistochemistry (IHC) method and the capillary density was calculated. The location, distribution and expression of CASZ1 in the lung tissue were detected by the immunohistochemistry, Western blotting, and quantitative PCR (qPCR).

RESULT(1) Stained by HE, lungs of experimental group showed destroyed alveoli, alveoli fusion and increased septal wall thickness, RAC were significantly lower than those in control group(14 d: septal wall thickness (12.69 ± 0.63) μm vs. (6.53 ± 0.16) μm, RAC 5.9 ± 0.4 vs. 8.4 ± 1.0, t = 19.046, 4.760, P both = 0.000). (2) CD31 protein was expressed predominantly in cytoplasm of pulmonary microvascular endothelial cells. The experimental group CD31 average optical density (AIOD) were decreased compared with control group((16.6 ± 1.6) × 10(3) vs.(40.1 ± 2.4) × 10(3), (18.1 ± 1.4) × 10(3) vs.(83.2 ± 5.2) × 10(3), (49.2 ± 5.4) × 10(3) vs.(136.2 ± 28.1) × 10(3), t=16.185, 16.066 and 6.078, P<0.01 for all comparisons). Capillary density in experimental group was also significantly decreased compared with control group ((3.84 ± 0.15)% vs.(6.01 ± 0.22)%, (4.17 ± 0.38)% vs.(6.15 ± 0.24)%, (5.43 ± 0.44)% vs. (9.13 ± 0.25)%, t = 16.124, 8.773 and 14.076, P all < 0.01). (3)RT-qPCR and Western blotting showed that the CASZ1 mRNA significantly increased in experimental group compared with control group(0.56 ± 0.17 vs. 1.00 ± 0.26, 0.32 ± 0.29 vs. 0.58 ± 0.14, 0.14 ± 0.22 vs. 0.56 ± 0.15, t=3.890, 3.303 and 2.388, P < 0.05 for all comparisons), and the protein expression of CASZ1 also significantly increased in experimental group compared with control group (0.65 ± 0.02 vs. 0.78 ± 0.23, 0.46 ± 0.03 vs. 0.75 ± 0.05, 0.34 ± 0.22 vs. 0.75 ± 0.04, t=6.200 and 10.485 and 14.998, P < 0.05 for all comparisons). (4)The protein level of CASZ1 in experimental group was positively correlated with capillary density (r=0.519, P<0.01).

CONCLUSIONCASZ1 is involved in the whole process of newborn rats BPD and may be linked to pulmonary microvascular dysplasia.

Animals ; Animals, Newborn ; Bronchopulmonary Dysplasia ; pathology ; Female ; Hyperoxia ; pathology ; Lung ; blood supply ; pathology ; Male ; Oxygen ; adverse effects ; Pulmonary Alveoli ; RNA, Messenger ; metabolism ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Transcription Factors ; metabolism

Conflicting results on the influences of histologic chorioamnionitis (HC) on neonatal morbidities might be partly originated from using different definition of HC. The aim of this study was to determine the relationship between HC and neonatal morbidities using definition of HC that reflects the site and extent of inflammation. This was a retrospective cohort study of 261 very low birth weight (VLBW) infants admitted at a tertiary academic center. Based on the site of inflammation, HC was categorized: any HC; amnionitis; funisitis; amnionitis+funisitis. The extent of inflammation in each site was reflected by sub-defining high grade (HG). The incidences of morbidities in infants with and without HC were compared. The bronchopulmonary dysplasia (BPD) rate was significantly higher in infants with amnionitis and the severe retinopathy of prematurity (ROP) rate was significantly higher in infants with any HC and funisitis. After adjustment for both gestational age and birth weight, the respiratory distress syndrome (RDS) rate was significantly lower in infants with all categories of HC except for HG amnionitis and HG funisitis, which are not associated with lower RDS rate. HG amnionitis was significantly associated with increased BPD rate but the association of HC with severe ROP disappeared. In conclusion, HC is significantly associated with decreased RDS and HG amnionitis with increased BPD while lacking association with other neonatal morbidities in VLBW infants. The association with HC and neonatal morbidities differs by the site and extent of chorioamnionitis.
Adult ; Birth Weight ; Bronchopulmonary Dysplasia/complications/*epidemiology ; Chorioamnionitis/classification/*epidemiology/pathology ; Cohort Studies ; Female ; Gestational Age ; Humans ; Infant, Newborn ; *Infant, Very Low Birth Weight ; Neutrophil Infiltration/immunology ; Placenta/pathology ; Pre-Eclampsia/*epidemiology/pathology ; Pregnancy ; Respiratory Distress Syndrome, Newborn/complications/*epidemiology ; Retinopathy of Prematurity/complications/*epidemiology ; Retrospective Studies ; Tertiary Care Centers

This study was done to evaluate respiratory syncytial virus (RSV) related readmission (RRR) and risk factors of RRR in preterm infants < 34 weeks gestational age (GA) within 1 yr following discharge from the neonatal intensive care unit (NICU). Infants (n = 1,140) who were born and admitted to the NICUs of 46 hospitals in Korea from April to September 2012, and followed up for > 1 yr after discharge from the NICU, were enrolled. The average GA and birth weight of the infants was 30(+5) +/- 2(+5) weeks and 1,502 +/- 474 g, respectively. The RRR rate of enrolled infants was 8.4% (96/1,140), and RSV accounted for 58.2% of respiratory readmissions of infants who had laboratory tests confirming etiological viruses. Living with elder siblings (odd ratio [OR], 2.68; 95% confidence interval [CI], 1.68-4.28; P < 0.001), and bronchopulmonary dysplasia (BPD) (OR, 2.95; 95% CI, 1.44-6.04; P = 0.003, BPD vs. none) increased the risk of RRR. Palivizumab prophylaxis (OR, 0.06; 95% CI, 0.03-0.13; P < 0.001) decreased the risk of RRR. The risk of RRR of infants of 32-33 weeks' gestation was lower than that of infants < 26 weeks' gestation (OR, 0.11; 95% CI, 0.02-0.53; P = 0.006). This was a nationwide study that evaluated the rate and associated risk factors of RRR in Korean preterm infants. Preterm infants with BPD or living with siblings should be supervised, and administration of palivizumab to prevent RRR should be considered.
Antiviral Agents/therapeutic use ; Birth Weight ; Bronchopulmonary Dysplasia/drug therapy/pathology ; Female ; Gestational Age ; Humans ; Infant ; Infant, Newborn ; Infant, Premature ; Intensive Care Units, Neonatal ; Male ; Odds Ratio ; Palivizumab/therapeutic use ; Patient Discharge ; Patient Readmission ; Republic of Korea ; Respiratory Syncytial Virus Infections/drug therapy/*pathology/virology ; Respiratory Syncytial Viruses/*isolation & purification ; Risk Factors ; Siblings

Fetal lung development normally occurs in a hypoxic environment. Hypoxia-inducible factor (HIF)-1alpha is robustly induced under hypoxia and transactivates many genes that are essential for fetal development. Most preterm infants are prematurely exposed to hyperoxia, which can halt hypoxia-driven lung maturation. We were to investigate whether the HIF-1alpha inducer, deferoxamine (DFX) can improve alveolarization in a rat model of bronchopulmonary dysplasia (BPD). A rat model of BPD was produced by intra-amniotic lipopolysaccharide (LPS) administration and postnatal hyperoxia (85% for 7 days), and DFX (150 mg/kg/d) or vehicle was administered to rat pups intraperitoneally for 14 days. On day 14, the rat pups were sacrificed and their lungs were removed and examined. A parallel in vitro study was performed with a human small airway epithelial cell line to test whether DFX induces the expression of HIF-1alpha and its target genes. Alveolarization and pulmonary vascular development were impaired in rats with BPD. However, DFX significantly ameliorated these effects. Immunohistochemical analysis showed that HIF-1alpha was significantly upregulated in the lungs of BPD rats treated with DFX. DFX was also found to induce HIF-1alpha in human small airway epithelial cells and to promote the expression of HIF-1alpha target genes. Our data suggest that DFX induces and activates HIF-1alpha, thereby improving alveolarization and vascular distribution in the lungs of rats with BPD.
Animals ; Bronchopulmonary Dysplasia/*drug therapy/*metabolism/pathology ; Deferoxamine/*administration & dosage ; Female ; Hypoxia-Inducible Factor 1, alpha Subunit/*metabolism ; Male ; Pulmonary Alveoli/drug effects/*growth & development/metabolism/pathology ; Pulmonary Veins/drug effects/*growth & development/pathology ; Rats ; Rats, Sprague-Dawley ; Treatment Outcome ; Up-Regulation/drug effects