IL-33 regulates adipogenesis via Wnt/ß-catenin/PPAR-γ signaling pathway in preadipocytes.

Interleukin-33 (IL-33), an emerging cytokine within the IL-1 family, assumes a pivotal function in the control of obesity. However, the specific mechanism of its regulation of obesity formation remains unclear. In this study, we found that the expression level of IL-33 increased in visceral adipose tissue in mice fed with a high-fat diet (HFD) compared with that in mice fed with a normal diet (ND). In vitro, we also found the expression level of IL-33 was upregulated during the adipogenesis of 3T3-L1 cells. Functional test results showed that knockdown of IL-33 in 3T3-L1 cells differentiation could promote the accumulation of lipid droplets, the content of triglyceride and the expression of adipogenic-related genes (i.e. PPAR-γ, C/EBPα, FABP4, LPL, Adipoq and CD36). In contrast, overexpression of IL-33 inhibits adipogenic differentiation. Meanwhile, the above tests were repeated after over-differentiation of 3T3-L1 cells induced by oleic acid, and the results showed that IL-33 played a more significant role in the regulation of adipogenesis. To explore the mechanism, transcriptome sequencing was performed and results showed that IL-33 regulated the PPAR signaling pathway in 3T3-L1 cells. Further, Western blot and confocal microscopy showed that the inhibition of IL-33 could promote PPAR-γ expression by inhibiting the Wnt/ß-catenin signal in 3T3-L1 cells. This study demonstrated that IL-33 was an important regulator of preadipocyte differentiation and inhibited adipogenesis by regulating the Wnt/ß-catenin/PPAR-γ signaling pathway, which provided a new insight for further research on IL-33 as a new intervention target for metabolic disorders.

The Association Between Hyperuricemia and Obesity Metabolic Phenotypes in Chinese General Population: A Retrospective Analysis.

Purpose: Serum uric acid (UA) not only affects the development of obesity but also alters the metabolic status in obese subjects; thus we investigated the relationship between serum UA and the overweight/obese metabolic phenotypes. Methods: The demographic, biochemical, and hematological data were collected for 12,876 patients undergoing routine physical examination, and 6,912 participants were enrolled in our study. Participants were classified into four obesity metabolic phenotypes according to their BMI and the presence of metabolic syndrome: metabolically healthy overweight/obese (MHOO), metabolically healthy and normal weighted (MHNW), metabolically abnormal and overweight/obese (MAOO), and metabolically abnormal but normal weighted (MANW). Univariate and multivariate logistic regression analysis, stratified analysis, and also interaction analysis were conducted to analyze the relationship between serum UA and obesity metabolic phenotypes. Results: Multivariable logistic regression analysis showed that hyperuricemia was positively associated with MHOO, MANW, and MAOO phenotypes relative to MHNW. After adjusting for the confounding factors, the odds ratios (OR) for individuals with hyperuricemia to be MHOO, MANW, and MAOO phenotypes were 1.86 (1.42-2.45), 2.30 (1.44-3.66), and 3.15 (2.34-4.24), respectively. The ORs for having MHOO, MANW, and MAOO increased 6% [OR: 1.06 (1.05-1.07), P < 0.0001], 5% [OR: 1.05 (1.03-1.07), P < 0.0001], and 11% [OR: 1.11 (1.10-1.13), P < 0.0001] for each 10 unit (µmol/L) of increase in serum UA level. Stratification analysis as well as an interaction test showed that sex and age did not interfere with the association of hyperuricemia with each metabolic phenotype. In terms of the components of the metabolic syndrome, after adjusting for other confounding factors including all of the metabolic indicators except itself, hyperuricemia was positively associated with increased BMI [OR: 1.66 (1.32-2.09), P < 0.0001], hypertriglyceridemia [OR: 1.56 (1.21-2.02), P = 0.0006], and hypertension [OR: 1.22 (1.03-1.46), P = 0.0233], while it had no significant association with hyperglycemia and low HDL-C (all P > 0.05). Conclusion: In our study, we discovered that hyperuricemia was positively associated with MHOO, MANW, and MAOO phenotypes, and this relationship was independent of sex and age.

Influence of Serum Albumin on HbA1c and HbA1c-Defined Glycemic Status: A Retrospective Study.

Background: Glycated hemoglobin (HbA1c) is commonly used in the diagnosis and evaluation of glycemic control in diabetes, and it may be influenced by several non-glycemic and glycemic factors, including albumin. This retrospective study investigated the influence of albumin on HbA1c and HbA1c-defined glycemic status. Methods: The demographic, hematological, and biochemical data were collected for 11,922 patients undergoing routine physical examination. Univariate and multivariate linear regression analyses, stratified analyses and interaction analyses, and multiple logistic regression were conducted to identify the association between albumin and HbA1c in people with different glycemic status. Results: HbA1c levels were inversely associated with serum albumin level (P < 0.0001) in all participants. Risk factors leading to the association included age > 45 years, high fasting plasma glucose (≥7.0 mmol/L), and anemia. The negative association between HbA1c and albumin was curved (P < 0.0001) and had a threshold effect in the HbA1c-defined diabetic population; the association was significantly stronger when the albumin level fell below 41.4 g/L (ß: -0.31, 95% CI: -0.45 to -0.17, P < 0.0001). A 2 g/L increase in albumin reduced the odds of HbA1c-defined dysglycemia, diabetes, and poor glycemia control by 12% to 36%, after adjustment for all possible confounders. Conclusions: HbA1c was inversely associated with albumin level in all participants, and the association was significantly stronger in people with diabetes (defined by HbA1c criteria). For diabetic patients with lower albumin level, there was an increased risk of an erroneous HbA1c-based identification and management of glycemic status.

Bioinformatic prediction of immunodominant regions in spike protein for early diagnosis of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

BACKGROUND: To contain the pandemics caused by SARS-CoV-2, early detection approaches with high accuracy and accessibility are critical. Generating an antigen-capture based detection system would be an ideal strategy complementing the current methods based on nucleic acids and antibody detection. The spike protein is found on the outside of virus particles and appropriate for antigen detection. METHODS: In this study, we utilized bioinformatics approaches to explore the immunodominant fragments on spike protein of SARS-CoV-2. RESULTS: The S1 subunit of spike protein was identified with higher sequence specificity. Three immunodominant fragments, Spike56-94, Spike199-264, and Spike577-612, located at the S1 subunit were finally selected via bioinformatics analysis. The glycosylation sites and high-frequency mutation sites on spike protein were circumvented in the antigen design. All the identified fragments present qualified antigenicity, hydrophilicity, and surface accessibility. A recombinant antigen with a length of 194 amino acids (aa) consisting of the selected immunodominant fragments as well as a universal Th epitope was finally constructed. CONCLUSION: The recombinant peptide encoded by the construct contains multiple immunodominant epitopes, which is expected to stimulate a strong immune response in mice and generate qualified antibodies for SARS-CoV-2 detection.

Circulating levels of IL-33 are elevated by obesity and positively correlated with metabolic disorders in Chinese adults.

BACKGROUND: Interleukin-33 (IL-33) plays a pivotal role in regulating innate immune response and metabolic homeostasis. However, whether its circulating level is correlated with obesity and metabolic disorders in humans remains largely unknown. We aimed to address this gap by determining IL-33 serum level and its downstream type 2 inflammatory cytokines interleukin-5 (IL-5) and interleukin-13 (IL-13) in overweight/obese population, and analyzing the specific associations between IL-33 and obesity metabolic phenotypes. METHODS: 217 subjects were enrolled and divided into three groups: healthy control (HC) subjects, metabolically healthy overweight/obese (MHOO) subjects and metabolically unhealthy overweight/obese (MUOO) subjects. Circulating levels of IL-33, IL-5 and IL-13 were measured using ELISA analyses. Multivariate regression analyses were further performed to determine the independent association between IL-33 and obesity metabolic phenotypes. RESULTS: Circulating levels of IL-33 were significantly elevated in subjects of MUOO group compared with HC group and MHOO group, while no significant difference was observed between the latter two groups in IL-33 levels. Consistent with this, serum levels of IL-5/13 were higher in the MUOO group compared with HC and MHOO groups. After adjusted for all confounders, MUOO phenotype was significantly associated with increased IL-33 serum levels (OR = 1.70; 95% CI 1.09-2.64; p = 0.019). With the MHOO group as the reference population, higher circulating level of IL-33 was also positively associated with MUOO phenotype after adjusting for confounders (OR = 1.50; 95% CI 1.20-1.88; p = 2.91E-4). However, there was no significant association between MHOO phenotype and IL-33 levels (p = 0.942). Trend analysis further confirmed the positive correlation between MUOO phenotype and IL-33 level (p for trend = 0.019). Additionally, IL-33 was significantly and positively correlated with diastolic blood pressure (DBP), total cholesterol (TC), alanine aminotransferase (ALT), aspartate aminotransferase (AST), white blood cell (WBC), neutrophil and IL-5 only in MUOO group, while inversely correlated with high density lipoprotein cholesterol (HDL-C) in MHOO subjects. CONCLUSION: Circulating levels of IL-33 were significantly elevated in overweight/obese Chinese adults with metabolic disorders. Increased levels of IL-33 were positively associated with metabolically unhealthy overweight/obese phenotype and several metabolic syndrome risk factors.

Immunodominant regions prediction of nucleocapsid protein for SARS-CoV-2 early diagnosis: a bioinformatics and immunoinformatics study.

COVID-19 caused by SARS-CoV-2 is sweeping the world and posing serious health problems. Rapid and accurate detection along with timely isolation is the key to control the epidemic. Nucleic acid test and antibody-detection have been applied in the diagnosis of COVID-19, while both have their limitations. Comparatively, direct detection of viral antigens in clinical specimens is highly valuable for the early diagnosis of SARS-CoV-2. The nucleocapsid (N) protein is one of the predominantly expressed proteins with high immunogenicity during the early stages of infection. Here, we applied multiple bioinformatics servers to forecast the potential immunodominant regions derived from the N protein of SARS-CoV-2. Since the high homology of N protein between SARS-CoV-2 and SARS-CoV, we attempted to leverage existing SARS-CoV immunological studies to develop SARS-CoV-2 diagnostic antibodies. Finally, N229-269, N349-399, and N405-419 were predicted to be the potential immunodominant regions, which contain both predicted linear B-cell epitopes and murine MHC class II binding epitopes. These three regions exhibited good surface accessibility and hydrophilicity. All were forecasted to be non-allergen and non-toxic. The final construct was built based on the bioinformatics analysis, which could help to develop an antigen-capture system for the early diagnosis of SARS-CoV-2.

Higher Serum Neuropeptide Y Levels Are Associated with Metabolically Unhealthy Obesity in Obese Chinese Adults: A Cross-Sectional Study.

OBJECTIVE: Neuropeptide Y (NPY), an orexigenic peptide known to cause hyperphagia, has been involved in the occurrence and development of obesity. However, differences in the distribution of serum NPY levels in obese phenotypes (including metabolically unhealthy obesity (MUO) phenotype and metabolically healthy obesity (MHO) phenotype) and the association of NPY with MUO phenotype have not been unequivocally established. We therefore determined associations of serum NPY levels with MUO phenotype in obese Chinese adults. METHODS: A cross-sectional study was conducted from 400 obese adults in Hunan province, who underwent a health examination in the Second Xiangya Hospital, and 164 participants were finally enrolled in the study and divided into MHO and MUO groups. Serum NPY levels were examined; univariate and multivariate analyses as well as smooth curve fitting analyses were conducted to measure the association of NPY serum levels with the MUO phenotype. RESULTS: Serum NPY levels were significantly elevated in the MUO group compared with the MHO group ((667.69 ± 292.90) pg/mL vs. (478.89 ± 145.53) pg/mL, p < 0.001). A threshold and nonlinear association between serum NPY levels and MUO was found (p = 0.001). When serum NPY levels exceeded the turning point (471.5 pg/mL), each 10 pg/mL increment in the NPY serum level was significantly associated with an 18% increased odds ratio of MUO phenotype (OR: 1.18, 95% CI: 1.07-1.29, p = 0.0007) after adjusted for confounders. CONCLUSIONS: Higher NPY serum levels were positively correlated with MUO phenotype in obese Chinese adults.

Cadmium exposure during prenatal development causes progesterone disruptors in multiple generations via steroidogenic enzymes in rat ovarian granulosa cells.

Exposure to the heavy metal cadmium (Cd) in the environment is linked to adverse health. To fully understand the adverse effects of this important endocrine-disrupting compound (EDC) requires studies that address multigenerational effects and epigenetic mechanisms. The present study orally dosed pregnant SD rats with Cd from gestation day 1 until birth. First filial generation (F1) female rats were mated with untreated males to generate the secondary filial generation (F2). Ovarian granulosa cells (OGCs) were collected at postnatal day (PND) 56 from both generations after prenatal Cd exposure, and hormone secretion examinations showed a progesterone disorder. Significant decreases in steroidogenic enzymes (steroidogenic acute regulatory protein (StAR) and P450 cholesterol side-chain cleavage enzyme (CYP11A1)) were observed in F1 and F2 rats. However, F1 and F2 rats had different patterns of mRNA and protein expression of steroidogenic factor 1 (SF-1). We also found that microRNAs were significantly changed using a microarray, and miR-10b-5p and miR-27a-3p were upregulated in F1 and F2 rats. The COV434 cell line microRNA-knockdown model showed that these two important microRNAs regulated the StAR-induced Cd effect on progesterone secretion. Overall, the results of this study indicate that prenatal Cd exposure causes cytotoxicity problems, progesterone disorder and microRNAs expression changed in a multigenerational manner. And progesterone disorder may interfere with the steroidogenic enzymes in offspring. The present study also revealed that environmental pollution produces multigenerational effects.

Roles of Mitogen-Activating Protein Kinase Kinase Kinase Kinase-3 (MAP4K3) in Preterm Skeletal Muscle Satellite Cell Myogenesis and Mammalian Target of Rapamycin Complex 1 (mTORC1) Activation Regulation.

BACKGROUND Preterm skeletal muscle genesis is a paradigm for myogenesis. The role of mitogen-activating protein kinase kinase kinase kinase-3 (MAP4K3) in preterm skeletal muscle satellite cells myogenesis or its relationship to mammalian target of rapamycin complex 1 (mTORC1) activity have not been previously elaborated. MATERIAL AND METHODS Small interfering RNA (siRNA) interference technology was used to inhibit MAP4K3 expression. Leucine stimulation experiments were performed following MAP4K3-siRNA interference. The differentiation of primary preterm skeletal muscle satellite cells was observed after siRNA-MAP4K3 interference. Western blot analysis was used to determine the expression of MAP4K3, MyHC, MyoD, myogenin, p-mTOR, and p-S6K1. The immunofluorescence fusion index of MyHC and myogenin were detected. MAP4K3 effects on preterm rat satellite cells differentiation and its relationship to mTORC1 activity are reported. RESULTS MAP4K3 siRNA knockdown inhibited myotube formation and both MyoD and myogenin expression in primary preterm rat skeletal muscle satellite cells, but MAP4K3 siRNA had no effect on the activity of mTORC1. In primary preterm rat skeletal muscle satellite cells, MAP4K3 knockdown resulted in significantly weaker, but not entirely blunted, leucine-induced mTORC1 signaling. CONCLUSIONS MAP4K3 positively regulates preterm skeletal muscle satellite cell myogenesis, but may not regulate mTORC1 activity. MAP4K3 may play a role in mTORC1 full activation in response to leucine.

Analysis of In-hospital Neonatal Death in the Tertiary Neonatal Intensive Care Unit in China: A Multicenter Retrospective Study.

BACKGROUND: Globally, the proportion of child deaths that occur in the neonatal period remains a high level of 37-41%. Differences of cause in neonate death exist in different regions as well as in different economic development countries. The specific aim of this study was to investigate the causes, characteristics, and differences of death in neonates during hospitalization in the tertiary Neonatal Intensive Care Unit (NICU) of China. METHODS: All the dead neonates admitted to 26 NICUs were included between January l, 2011, and December 31, 2011. All the data were collected retrospectively from clinical records by a designed questionnaire. Data collected from each NICU were delivered to the leading institution where the results were analyzed. RESULTS: A total of 744 newborns died during the 1-year survey, accounting for 1.2% of all the neonates admitted to 26 NICUs and 37.6% of all the deaths in children under 5 years of age in these hospitals. Preterm neonate death accounted for 59.3% of all the death. The leading causes of death in preterm and term infants were pulmonary disease and infection, respectively. In early neonate period, pulmonary diseases (56.5%) occupied the largest proportion of preterm deaths while infection (27%) and neurologic diseases (22%) were the two main causes of term deaths. In late neonate period, infection was the leading cause of both preterm and term neonate deaths. About two-thirds of neonate death occurred after medical care withdrawal. Of the cases who might survive if receiving continuing treatment, parents' concern about the long-term outcomes was the main reason of medical care withdrawal. CONCLUSIONS: Neonate death still accounts for a high proportion of all the deaths in children under 5 years of age. Our study showed the majority of neonate death occurred in preterm infants. Cause of death varied with the age of death and gestational age. Accurate and prompt evaluation of the long-term outcomes should be carried out to guide the critical decision.

Mortality and Morbidity of Extremely Low Birth Weight Infants in the Mainland of China: A Multi-center Study.

BACKGROUND: With the progress of perinatal medicine and neonatal technology, more and more extremely low birth weight (ELBW) survived all over the world. This study was designed to investigate the short-term outcomes of ELBW infants during their Neonatal Intensive Care Unit (NICU) stay in the mainland of China. METHODS: All infants admitted to 26 NICUs with a birth weight (BW) < l000 g were included between January l, 2011 and December 31, 2011. All the data were collected retrospectively from clinical records by a prospectively designed questionnaire. The data collected from each NICU transmitted to the main institution where the results were aggregated and analyzed. Categorical variables were performed with Pearson Chi-square test. Binary Logistic regression analysis was used to detect risk factors. RESULTS: A total of 258 ELBW infants were admitted to 26 NICUs, of whom the mean gestational age (GA) was 28.1 ± 2.2 weeks, and the mean BW was 868 ± 97 g. The overall survival rate at discharge was 50.0%. Despite aggressive treatment 60 infants (23.3%) died and another 69 infants (26.7%) died after medical care withdrawal. Furthermore, the survival rate was significantly higher in coastal areas than inland areas (53.6% vs. 35.3%, P = 0.019). BW < 750 g and GA < 28 weeks were the largest risk factors, and being small for gestational age was a protective factor related to mortality. Respiratory distress syndrome was the most common complication. The incidence of patent ductus arteriosus, intraventricular hemorrhage, periventricular leukomalacia, bronchopulmonary dysplasia, retinopathy of prematurity was 26.2%, 33.7%, 6.7%, 48.1%, and 41.4%, respectively. Ventilator associated pneumonia was the most common hospital acquired infection during hospitalization. CONCLUSIONS: Our study was the first survey that revealed the present status of ELBW infants in the mainland of China. The mortality and morbidity of ELBW infants remained high as compared to other developed countries.

Leucine Promotes Proliferation and Differentiation of Primary Preterm Rat Satellite Cells in Part through mTORC1 Signaling Pathway.

Signaling through the mammalian target of rapamycin (mTOR) in response to leucine modulates many cellular and developmental processes. However, in the context of satellite cell proliferation and differentiation, the role of leucine and mTORC1 is less known. This study investigates the role of leucine in the process of proliferation and differentiation of primary preterm rat satellite cells, and the relationship with mammalian target of rapamycin complex 1 (mTORC1) activation. Dissociation of primary satellite cells occurred with type I collagenase and trypsin, and purification, via different speed adherence methods. Satellite cells with positive expression of Desmin were treated with leucine and rapamycin. We observed that leucine promoted proliferation and differentiation of primary satellite cells and increased the phosphorylation of mTOR. Rapamycin inhibited proliferation and differentiation, as well as decreased the phosphorylation level of mTOR. Furthermore, leucine increased the expression of MyoD and myogenin while the protein level of MyoD decreased due to rapamycin. However, myogenin expressed no affect by rapamycin. In conclusion, leucine may up-regulate the activation of mTORC1 to promote proliferation and differentiation of primary preterm rat satellite cells. We have shown that leucine promoted the differentiation of myotubes in part through the mTORC1-MyoD signal pathway.

[Effects of extensively hydrolyzed protein formula on feeding and growth in preterm infants: a multicenter controlled clinical study].

OBJECTIVE: To study the effects of extensively hydrolyzed protein formula (eHF) on the feeding and growth in preterm infants through a multicenter controlled clinical study. METHODS: Preterm infants admitted to eight upper first-class hospitals in China between February 2012 and December 2013 were randomly selected. They were divided into two observation groups and two control groups. The first observation group consisted of preterm infants with a gestational age of <32 weeks, who were fed with eHF for 10-14 days after birth and then with standard preterm formula (SPF) until discharge. The second observation group consisted of preterm infants with a gestational age of 32-34 weeks, who were fed with SPF after birth, but were switched to eHF (7-14 days) if suffering feeding intolerance at 6-8 days after birth. The two control groups with corresponding gestational ages kept to be fed with SPF after birth. Clinical data were recorded to compare feeding condition, physical growth, blood biochemical indices, and major complications between different groups. RESULTS: A total of 328 preterm infants were enrolled. Preterm infants with a gestational age of <32 weeks in the observation group had a significantly shorter meconium evacuation time than in the corresponding control group (P<0.05). They also had significantly lower levels of serum total bilirubin at weeks 1 and 2 after birth compared with the control group (P<0.05). The observation group needed more time in reaching enteral nutrition (EN) basic energy uptake of 50 kcal/(kg·d), partial parenteral nutrition (PPN), hospitalization, and corrected gestational age at discharge compared with the controlled infants (P<0.05). There was no difference in the incidence of extrauterine growth retardation (EUGR) at discharge between the two groups (P>0.05). Preterm infants with a gestational age of 32-34 weeks in the observation group had significantly lower serum total bilirubin levels at 2 weeks after birth compared with the corresponding control group (P<0.05). They required more time in achieving EN basic energy and PPN than in the control group (P<0.05). There was no difference in the incidence of EUGR at discharge between the two groups (P>0.05). CONCLUSIONS: For preterm infants, eHF can improve gastrointestinal motility, accelerate bilirubin metabolism and excretion and does not increase the incidence of EUGR.

Successful management of congenital chylous ascites in a premature infant using somatostatin analogue.

Congenital chylous ascites (CCA) is a rare disease defined as the accumulation of chylomicron-rich lymphatic fluid within the peritoneal cavity, resulting from maldevelopment of the intra-abdominal lymphatic system. Cases unresponsive to conservative treatment usually require surgical intervention. We report a case of CCA in a premature neonate, who was treated successfully with intravenous infusion of octreotide, a synthetic somatostatin analogue after failure to response to traditional supportive therapies.

[A follow-up study on children conceived through intracytoplasmic sperm injection].

OBJECTIVE: To investigate the perinatal complications, birth defects and growth of children conceived through intracytoplasmic sperm injection (ICSI). METHODS: A total of 575 children conceived by ICSI in our reproductive medical center, were studied. The follow-up study would include items as pregnant complications, neonatal complications, birth defects in perinatal period, subsequently detected birth defects, body weight and body length/height growth. RESULTS: Prematurity and low birth weight of ICSI children were higher in the multiple births than in the singleton births. The rates of materal gestational hypertension, neonatal asphyxia, respiratory distress syndrome, infection diseases were higher in the multiple pregnancies than in the singleton pregnancies (P < 0.05). Eleven ICSI children had died. Ten of them died in the neonatal period and they were preterm infants. One fullterm singleton ICSI child died of hepatoblastoma at the age of 2. The rate of birth defects in perinatal period was higher in ICSI children of multiple pregnancies than in the general population (P < 0.05). The body weight and body length/height of most ICSI children had obtained the standard range between 1 to 3 year-olds. CONCLUSION: The higher rates of perinatal complications in ICSI children were closely related to multiple pregnancies.

Impaired growth hormone receptor signaling during non-catch-up growth in rats born small for gestational age.

BACKGROUND/AIMS: Non-catch-up growth (NCG) in children born small for gestational age (SGA) is associated with growth hormone (GH) resistance, although the mechanisms of this association are unknown. Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling is involved in GH signal transduction. This study examined the role of JAK/STAT signaling in GH resistance of SGA rats. METHODS: NCG-SGA was induced by uterine artery ligation in pregnant rats. NCG-SGA rats were treated with GH for 7 days and rats appropriate for gestational age (AGA) served as controls. Phosphorylation of JAK2/STAT5 and expression of GH receptor, suppressor of cytokine signaling 2 (SOCS-2) and cytokine-inducible SH2-containing protein (CIS) in the liver were determined by Western blotting. The expression of insulin-like growth factor 1 (IGF-1) mRNA was examined by the reverse transcription-polymerase chain reaction. RESULTS: GH treatment significantly increased body weight and length growth rate in AGA but not in NCG-SGA rats. The increase in serum IGF-1 level and expression of IGF-1 mRNA in response to GH treatment in NCG-SGA rats was significantly less than in AGA rats. GH-induced increase in phosphorylation of JAK2/STAT5 in response to acute GH stimulation was significantly lower in NCG-SGA rats compared to AGA controls. SOCS-2 and CIS expressions significantly increased in NCG-SGA rats following GH treatment. CONCLUSION: GH resistance in NCG-SGA rats is associated with impaired JAK/STAT signaling and upregulated SOCS-2 and CIS expression.

[Role of minocycline in an immature rat model of hypoxic-ischemic brain damage].

OBJECTIVE: To establish a model of immature rat hypoxic-ischemic brain damage (HIBD) which was expected to be similar to periventricular leukomalacia in human preterm infants pathologically and neuroethologically, and to investigate the role of minocycline (MN) in this model. METHOD: Totally 192 Sprague-Dawley rats (postnatal day 2, P(2)), of either sex, were randomly divided into 4 groups: normal-group, sham operation group, HIBD-group, HIBD + MN group, each group had 48 rats. HIBD group and HIBD + MN group survived the left common carotid artery (CCA) ligation followed by 4h exposure to 8% O(2). Rats in sham operation group only survived the left CCA isolation. Rats in normal group were not treated with anything. In HIBD + MN group, the rats were treated with intraperitoneal injection of minocycline 45 mg/kg, immediately after HI and every 24 h for 2 days. Brain tissues were collected on day 3, 1 week, 2 weeks, 4 weeks after HI, for hematoxylin-eosin staining and histological scoring. Frozen sections of the brains were stained with anti-O4, anti-O1 immunohistochemistry on day 3 after HI, and MBP immunohistochemistry 2 weeks after HI. Rats in the four groups underwent neuroethologic examination 4 weeks after HI. RESULT: In the HIBD group, there were pathological changes in the periventricular white matter. The pathological changes were milder in HIBD + MN group; There was no statistically significant difference between the normal group and HIBD + MN group in the number of positively stained O4 cell (P > 0.05). The number of positively stained O4 cell in the HIBD group was significantly reduced, compared with that of normal group, sham operation group, and HIBD + MN group (23.67 ± 12.00 vs. 52.89 ± 10.68, 39.28 ± 11.78, 41.63 ± 8.41, P < 0.05). The differences in the number of positively stained O1 cell among the normal group, sham operation group, HIBD group and HIBD + MN group had no statistical significance (P = 0.093). The numbers of myelin basic protein (MBP) positively immunostained fiber bundles in the HIBD + MN group were significantly less than that of the normal group and sham operation group (P < 0.05). The numbers of MBP positively immunostained fiber bundles in the HIBD group were significantly less than that of the normal group, sham operation group, and HIBD + MN group (14.71 ± 7.42 vs. 36.67 ± 6.50, 35.50 ± 3.24, 26.33 ± 5.92, P < 0.05). The HIBD group had long-term neuroethologic abnormality. There was no statistically significant difference in the inclined plane test, hanging test and cylinder test among the HIBD + MN group, normal group, and sham operation group (P > 0.05). The scores of the HIBD group had statistical significantly among the normal group, sham operation group and HIBD + MN group (P < 0.05). In the open field test, there was no statistically significant difference between the HIBD group and HIBD + MN group (P = 0.772), but there was significant difference between these two groups and the normal group, sham operation group (P < 0.05). CONCLUSION: Minocycline protects the pre-oligodendrocyte and has protective effects in terms of long-term neuroethology.

[Long-term effects of early hyperbaric oxygen therapy on neonatal rats with hypoxic-ischemic brain damage].

OBJECTIVE: The application and therapeutic effect of hyperbaric oxygen (HBO) in hypoxic-ischemic brain damage (HIBD) remains controversial. Previous studies have focused on the early pathological and biochemical outcomes and there is a lack of long-term functional evaluation. This study was designed to evaluate the long-term pathological and behavioral changes of early HBO therapy on neonatal rats with HIBD. METHODS: Postnatal 7 days (PD7) rat pups were randomly assigned into Control (n=18), HIBD (n=17) and HBO treatment groups (n=17). HIBD was induced by ligating the left common carotid, followed by 2 hrs hypoxia exposure in the HIBD and HBO treatment groups. The Control group was sham-operated and was not subjected to hypoxia exposure. The HBO therapy with 2 atmosphere absolutes began 0.5-1 hr after HIBD in the HIBD treatment group, once daily for 2 days. The spatial learning and memory ability were evaluated by the Morris water maze test at PD37 to PD41. The morphological and histological changes of the brain, including brain weight, survival neurons, AchE positive unit and NOS positive neurons in hippocampal CA1 region, were detected at PD42. RESULTS: The rats in the HIBD group displayed significant morphological and histological deficits, as well as severe spatial learning and memory disability. In the Morris water maze test, the mean escape latency were longer (56.35 +/- 22.37 s vs 23.07 +/- 16.28 s; P < 0.05) and the probe time and probe length were shorter in the HIBD group (29.29 +/- 6.06 s vs 51.21 +/- 4.59 s and 548 +/- 92 cm vs 989 +/- 101 cm; both P < 0.05) compared with the Control group. The left brain weight in the HIBD group was lighter than that in the Control group (0.601 +/- 0.59 g vs 0.984 +/- 0.18 g; P < 0.05). The survival neurons in the hippocampal CA1 region were less (100 +/- 27/mm vs 183 +/- 8/mm; P < 0.05), as well as the AchE-positive unit and NOS-positive neurons (18.50 +/- 2.24% vs 27.50 +/- 2.18% and 19.25 +/- 4.33 vs 33.75 +/- 5.57 respectively; P < 0.05) after HIBD. Early HBO treatment improved the abilities of spatial learning and alleviated the morphological and histological damage. The mean escape latency (39.17 +/- 21.20 s) was shortened, the probe time (36.84 +/- 4.36 s) and the probe length (686 +/- 76 cm) were longer, and the brain weight (0.768 +/- 0.85 g), the survival neurons (133 +/- 25/mm) and the AchE-positive unit (21.94 +/- 2.73%) increased significantly compared with those of the HIBD group (P < 0.05). CONCLUSIONS: Early HBO treatment resulted in a protective effect against HIBD-induced long-term brain morphological and histological deficits and spatial learning and memory disability.