Histomorphometric analysis of the endometrium in an ectopic model of endometriosis in mice

Objective: Evaluate histomorphometry of ectopic and eutopic endometrial tissues in receptor mice. Method: Eighteen female Balb/c were divided into 3 groups, 6 animals each: GI Control, no procedure; GII - Sham, animals that had the same procedures as GIII without receiving the ectopic endometrial implant. Instead, they received saline solution; GIII - endometriosis model, animals had surgical intervention with an ectopic endometrial implant. GI and GIII mice were treated with 17β-estradiol, 100 µg/kg each. All animals were euthanized to collect uterine horns, which were fixed in 4% paraformaldehyde, embedded in paraffin, stained with Hematoxilin and Eosin and submitted to histomorphometric analyzes. Data underwent one-way ANOVA followed by Tukey's test. Results: Local tissue growth, showing important lesions and adhesions, as well as dark cysts were noticed. In GIII group, there was an increase in number of blood vessels and glands (GIII ≥ GI and GIII p > .001). Thickening of the GIII endometrial epithelial was also evident (GIII ≥ GI and GIII. p > .001). We also noticed an increase in the number of eosinophils (GIII (GIII ≥ GI and GIII. p > .001). Conclusion: Easy to perform model, capable of reproducing morphological endometriosis characteristics. From our findings, there was an increase of endometrial thickness as well as an increase in the eosinophils population.

环状RNA在炎症所致早产小鼠脑损伤中的作用及机制初步研究

OBJECTIVE

To determine the association of circular RNA (circRNA) and circRNA-microRNA (miRNA) network regulation with brain injury induced by inflammation in preterm mice.

METHODS

Pregnant mice were treated with intraperitoneally injected lipopolysaccharide to establish a preterm mouse model of brain injury induced by inflammation (inflammation preterm group with 3 mice). Preterm mice born to normal pregnant mice by cesarean section were selected as controls (non-inflammation preterm group with 3 mice). The gene microarray technique was used to screen out the circRNAs associated with brain injury in preterm mice. The miRNA target prediction software was used to predict the binding sites between circRNAs and miRNAs and analyze the regulatory mechanism.

RESULTS

A total of 365 differentially expressed circRNAs were screened out between the inflammation preterm and non-inflammation preterm groups (fold change > 1.5, P < 0.05), among which there were 206 upregulated circRNAs and 159 downregulated circRNAs. Further analysis of the circRNAs with a fold change of > 4 showed that these circRNAs could bind to miRNAs and regulate their activity, thereby regulating the expression of the genes associated with the nervous system.

CONCLUSIONS

Inflammation induces a significant change in the expression profile of circRNAs in the brain tissue of mice, and the change in the expression of circRNAs plays an important role in brain injury induced by inflammation and subsequent brain development in preterm mice.

组蛋白去乙酰化酶在小鼠神经元发育中的作用与机制研究

OBJECTIVE

To study the role and mechanism of histone deacetylase 1 (HDAC1) and histone deacetylase 2 (HDAC2) in mouse neuronal development.

METHODS

The mice with Synapsin1-Cre recombinase were bred with HDAC1&2^flox/flox mice to obtain the mice with neuron-specific HDAC1&2 conditional knockout (knockout group), and their littermates without HDAC1&2 knockout were used as the control group. The general status of the mice was observed and survival curves were plotted. Brain tissue samples were collected from the knockout group and the control group. Western blot and immunohistochemistry were used to measure the protein expression of related neuronal and axonal markers, neuronal nuclear antigen (NeuN), non-phosphorylated neurofilament heavy chain (np-NF200), and phosphorylated neurofilament heavy chain (p-NF200), as well as the downstream effector of the mTOR signaling pathway, phosphorylated S6 ribosomal protein (p-S6).

RESULTS

The mice with HDAC1&2 conditional knockout usually died within one month after birth and were significantly smaller than those in the control group, with motor function abnormalities such as tremor and clasping of hindlimbs. Compared with the control group, the knockout group had significant reductions in the protein expression levels of NeuN, np-NF200, p-NF200, and p-S6 (P < 0.05; n=3).

CONCLUSIONS

Deletion of HDAC1 and HDAC2 in mouse neurons results in reduced neuronal maturation and axonal dysplasia, which may be associated with the mTOR signaling pathway.

[Effect of mogroside VI on acute liver injury induced by sepsis in mice and related mechanisms]

OBJECTIVE

To study the effect of mogroside VI (MVI) on acute liver injury induced by sepsis in mice and its possible mechanisms. Methods A total of 60 male C57BL/6 mice were randomly divided into five groups: sham-operation, model, low-dose MVI (25 mg/kg), high-dose MVI (100 mg/kg), peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) inhibitor (100 mg/kg MVI+30 mg/kg PGC-1α inhibitor SR-18292), with 12 mice in each group. Cecal ligation and puncture were performed to establish a mouse model of sepsis. The drugs were given by intraperitoneal injection after the model was established, once a day for 3 consecutive days. ELISA was used to measure the serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Colorimetry was used to measure the levels of malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) in liver tissue. Hematoxylin-eosin staining was used to observe liver histopathological changes. Liver mitochondrial respiratory function was measured, and mitochondrial respiratory control rate was calculated. RT-PCR was used to measure the copy number of mitochondrial DNA (mtDNA) in liver tissue and the mRNA expression levels of PGC-1α, nuclear respiratory factor-1 (NRF-1), and mitochondrial transcription factor A (TFAM) in liver tissue. Western blot was used to measure the protein expression levels of PGC-1α, NRF-1, and TFAM in liver tissue.

RESULTS

Compared with the sham-operation group, the model group had significant increases in the serum levels of ALT and AST and the content of MDA in liver tissue (P<0.05) and significant reductions in the activities of GSH-Px and SOD in liver tissue (P<0.05). The model group had also severe liver histopathological injury and significant reductions in the mitochondrial respiratory control rate, the copy number of mtDNA, and the mRNA and protein expression levels of PGC-1α, NRF-1, and TFAM in liver tissue (P<0.05). Compared with the model group, the high-dose group had significant reductions in the serum levels of ALT and AST and the content of MDA in liver tissue (P<0.05), significant increases in the activities of GSH-Px and SOD in liver tissue (P<0.05), significant improvement in liver histopathological injury, and significant increases in the mitochondrial respiratory control rate, the copy number of mtDNA, and the mRNA and protein expression levels of PGC-1α, NRF-1, and TFAM in liver tissue (P<0.05). There were no significant differences in the above indicators between the low-dose and model groups (P>0.05). The PGC-1α inhibitor SR-18292 significantly inhibited the intervention effect of high-dose MVI (P<0.05).

CONCLUSIONS

MVI can effectively alleviate acute liver injury caused by sepsis in mice, possibly by enhancing mitochondrial biosynthesis mediated by PGC-1α.

[Association of age distribution with the expression of angiotensin-converting enzyme 2 in lung tissues in severe acute respiratory syndrome coronavirus 2 infection: reflections from the study of RAS pathway expression in mice]

OBJECTIVE

To study the expression of angiotensin-converting enzyme 2 (ACE2) and other key molecules of the RAS pathway in normal mice at different developmental stages, and to provide ideas for understanding the infection mechanism of coronavirus disease 2019 (COVID-19) as well as the diagnosis and treatment of children with COVID-19.

METHODS

The mice at different developmental stages were enrolled, including fetal mice (embryonic days 14.5 and 18.5), neonatal mice (0, 3, 7, 14, and 21 days old), young mice (28 and 42 days old), and adult mice (84 days old). The lung tissues of all fetal mice from 4 pregnant mice were collected at each time point in the fetal group. Four mice were sampled in other age groups at each time point. Whole transcriptome resequencing was used to measure the mRNA expression of AGT, ACE, ACE2, Renin, Agtr1a, Agtr1b, Agtr2, and Mas1 in mouse lung tissue.

RESULTS

The expression of ACE2 in the lungs showed changes from embryonic stage to adult stage. It increased gradually after birth, reached a peak on day 3 after birth, and reached a nadir on day 14 after birth (P<0.05). The expression of AGT reached a peak on days 0 and 7 after birth and reached a nadir on day 21 after birth (P<0.05). The expression of ACE increased rapidly after birth and reached a peak on day 21 after birth (P<0.05). Agtr1a expression reached a peak on day 21 after birth (P<0.05). Agtr2 expression gradually decreased to a low level after birth. Renin, Agtr1b, and Mas1 showed low expression in lung tissues at all developmental stages.

CONCLUSIONS

At different developmental stages of mice, ACE2 has dynamic expression changes, with high expression in early neonatal and adult mice. The other key molecules of the RAS pathway have their own expression patterns. These suggest that the difference in clinical features between children and adults with COVID-19 might be associated with the different expression levels of ACE2 in the different stages, and further studies are needed for the mechanism.

[Continuous expression and functional prediction of circular RNA in mouse lung development]

OBJECTIVE

To study the continuous expression and potential function of circular RNA (circRNA), circ4:150439343|150477468 and circ15:73330849|73343359, in mouse lung development.

METHODS

According to the stage of lung development, lung tissue samples were collected from mice on embryonic day 16.5 (E16.5), embryonic day 18.5 (E18.5), and postnatal day 2 (P2). Hematoxylin and eosin staining was performed to observe the morphology of lung tissue. Quantitative real-time PCR (qRT-PCR) was used to measure the mRNA expression of circ4:150439343|150477468 and circ15:73330849|73343359 during late lung development; miRanda and TargetScan were used to predict the target miRNAs of circRNAs, and then GO and KEGG analysis was performed for the target genes to predict the potential function of circRNAs.

RESULTS

Type II alveolar epithelial cells were observed in the lung slices of E16.5 mice, with a gradual increase in number. On P2, the pulmonary alveoli expanded rapidly, the pulmonary interstitium became thinner, and the alveolar structure gradually became mature. The results of qRT-PCR showed that the relative expression of circ4:150439343|150477468 was continuously upregulated over time and the relative expression of circ15:73330849|73343359 was first downregulated and then upregulated (P<0.05). The KEGG and GO analysis showed that circRNAs were involved in the Notch, PI3K-Akt, and NF-κB signaling pathways.

CONCLUSIONS

Circ4:150439343|150477468 and circ15:73330849|73343359 can participate in lung development through the Notch signaling pathway.

[Association of age distribution with the expression of angiotensin-converting enzyme 2 in lung tissues in severe acute respiratory syndrome coronavirus 2 infection: reflections from the study of RAS pathway expression in mice]

OBJECTIVE

To study the expression of angiotensin-converting enzyme 2 (ACE2) and other key molecules of the RAS pathway in normal mice at different developmental stages, and to provide ideas for understanding the infection mechanism of coronavirus disease 2019 (COVID-19) as well as the diagnosis and treatment of children with COVID-19.

METHODS

The mice at different developmental stages were enrolled, including fetal mice (embryonic days 14.5 and 18.5), neonatal mice (0, 3, 7, 14, and 21 days old), young mice (28 and 42 days old), and adult mice (84 days old). The lung tissues of all fetal mice from 4 pregnant mice were collected at each time point in the fetal group. Four mice were sampled in other age groups at each time point. Whole transcriptome resequencing was used to measure the mRNA expression of AGT, ACE, ACE2, Renin, Agtr1a, Agtr1b, Agtr2, and Mas1 in mouse lung tissue.

RESULTS

The expression of ACE2 in the lungs showed changes from embryonic stage to adult stage. It increased gradually after birth, reached a peak on day 3 after birth, and reached a nadir on day 14 after birth (P<0.05). The expression of AGT reached a peak on days 0 and 7 after birth and reached a nadir on day 21 after birth (P<0.05). The expression of ACE increased rapidly after birth and reached a peak on day 21 after birth (P<0.05). Agtr1a expression reached a peak on day 21 after birth (P<0.05). Agtr2 expression gradually decreased to a low level after birth. Renin, Agtr1b, and Mas1 showed low expression in lung tissues at all developmental stages.

CONCLUSIONS

At different developmental stages of mice, ACE2 has dynamic expression changes, with high expression in early neonatal and adult mice. The other key molecules of the RAS pathway have their own expression patterns. These suggest that the difference in clinical features between children and adults with COVID-19 might be associated with the different expression levels of ACE2 in the different stages, and further studies are needed for the mechanism.

[Value of ginsenoside Rb1 in alleviating coronary artery lesion in a mouse model of Kawasaki disease]

OBJECTIVE

To study the effect and related signaling pathways of ginsenoside Rb1 in the treatment of coronary artery lesion (CAL) in a mouse model of Kawasaki disease (KD).

METHODS

BALB/c mice were randomly divided into a control group, a model group, an aspirin group, a low-dose ginsenoside Rb1 group (50 mg/kg), and a high-dose ginsenoside Rb1 group (100 mg/kg), with 12 mice in each group. All mice except those in the control group were given intermittent intraperitoneal injection of 10% bovine serum albumin to establish a mouse model of KD. The mice in the aspirin group, the low-dose ginsenoside Rb1 group, and the high-dose ginsenoside Rb1 group were given the corresponding drug by gavage for 20 days after modeling. Hematoxylin and eosin staining was used to observe the pathological changes of coronary artery tissue. ELISA was used to measure the levels of the inflammatory cytokines tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-1β (IL-1β) in serum and coronary artery tissue. Western blot was used to measure the relative expression levels of proteins involved in the regulation of the AMPK/mTOR autophagy signaling pathway and the PI3K/Akt oxidative stress signaling pathway in coronary artery tissue.

RESULTS

The observation of pathological sections showed that compared with the model group, the high-dose ginsenoside Rb1 group had significant improvement in the symptoms of vascular wall thickening, intimal edema, fiber rupture, and inflammatory infiltration of endothelial cells. Compared with the control group, the model and low-dose ginsenoside Rb1 groups had significant increases in the levels of TNF-α, IL-6, and IL-1β in serum and coronary artery tissue (P<0.05); the model group had significant increases in the expression levels of P-AMPK/AMPK, P-mTOR/mTOR, and P-P70S6/P70S6 in coronary artery tissue (P<0.05) and significant reductions in the expression levels of P-PI3K/PI3K, P-AKT/AKT, and P-GSK-3β/GSK-3β in coronary artery tissue (P<0.05). Compared with the model group, the aspirin group and the high-dose ginsenoside Rb1 group had significant reductions in the levels of TNF-α, IL-6, and IL-1β (P<0.05); the low- and high-dose ginsenoside Rb1 groups had significant reductions in the expression levels of P-AMPK/AMPK, P-mTOR/mTOR, and P-P70S6/P70S6 (P<0.05) in a dose-dependent manner between the two groups (P<0.05); the low-dose ginsenoside Rb1 group had no significant change in the expression level of P-PI3K/PI3K (P>0.05) and had significant increases in the expression levels of P-AKT/AKT and P-GSK-3β/GSK-3β (P<0.05), while the high-dose ginsenoside Rb1 group had significant increases in the relative protein expression levels of the above three proteins (P<0.05). Compared with the low-dose ginsenoside Rb1 group, the aspirin group and the high-dose ginsenoside Rb1 group had significant reductions in the levels of TNF-α, IL-6, and IL-1β (P<0.05); the high-dose ginsenoside Rb1 group had significant increases in the expression levels of P-PI3K/PI3K and P-AKT/AKT (P<0.05).

CONCLUSIONS

Ginsenoside Rb1 can effectively alleviate CAL in a mouse model of KD in a dose-dependent manner, possibly by regulating the AMPK/mTOR/P70S6 autophagy signaling pathway to inhibit CAL inflammation and regulating the PI3K/AKT/GSK-3β oxidative stress signaling pathway to exert a biological activity of protection against coronary artery endothelial cell injury.

[Value of ginsenoside Rb1 in alleviating coronary artery lesion in a mouse model of Kawasaki disease]

OBJECTIVE

To study the effect and related signaling pathways of ginsenoside Rb1 in the treatment of coronary artery lesion (CAL) in a mouse model of Kawasaki disease (KD).

METHODS

BALB/c mice were randomly divided into a control group, a model group, an aspirin group, a low-dose ginsenoside Rb1 group (50 mg/kg), and a high-dose ginsenoside Rb1 group (100 mg/kg), with 12 mice in each group. All mice except those in the control group were given intermittent intraperitoneal injection of 10% bovine serum albumin to establish a mouse model of KD. The mice in the aspirin group, the low-dose ginsenoside Rb1 group, and the high-dose ginsenoside Rb1 group were given the corresponding drug by gavage for 20 days after modeling. Hematoxylin and eosin staining was used to observe the pathological changes of coronary artery tissue. ELISA was used to measure the levels of the inflammatory cytokines tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-1β (IL-1β) in serum and coronary artery tissue. Western blot was used to measure the relative expression levels of proteins involved in the regulation of the AMPK/mTOR autophagy signaling pathway and the PI3K/Akt oxidative stress signaling pathway in coronary artery tissue.

RESULTS

The observation of pathological sections showed that compared with the model group, the high-dose ginsenoside Rb1 group had significant improvement in the symptoms of vascular wall thickening, intimal edema, fiber rupture, and inflammatory infiltration of endothelial cells. Compared with the control group, the model and low-dose ginsenoside Rb1 groups had significant increases in the levels of TNF-α, IL-6, and IL-1β in serum and coronary artery tissue (P<0.05); the model group had significant increases in the expression levels of P-AMPK/AMPK, P-mTOR/mTOR, and P-P70S6/P70S6 in coronary artery tissue (P<0.05) and significant reductions in the expression levels of P-PI3K/PI3K, P-AKT/AKT, and P-GSK-3β/GSK-3β in coronary artery tissue (P<0.05). Compared with the model group, the aspirin group and the high-dose ginsenoside Rb1 group had significant reductions in the levels of TNF-α, IL-6, and IL-1β (P<0.05); the low- and high-dose ginsenoside Rb1 groups had significant reductions in the expression levels of P-AMPK/AMPK, P-mTOR/mTOR, and P-P70S6/P70S6 (P<0.05) in a dose-dependent manner between the two groups (P<0.05); the low-dose ginsenoside Rb1 group had no significant change in the expression level of P-PI3K/PI3K (P>0.05) and had significant increases in the expression levels of P-AKT/AKT and P-GSK-3β/GSK-3β (P<0.05), while the high-dose ginsenoside Rb1 group had significant increases in the relative protein expression levels of the above three proteins (P<0.05). Compared with the low-dose ginsenoside Rb1 group, the aspirin group and the high-dose ginsenoside Rb1 group had significant reductions in the levels of TNF-α, IL-6, and IL-1β (P<0.05); the high-dose ginsenoside Rb1 group had significant increases in the expression levels of P-PI3K/PI3K and P-AKT/AKT (P<0.05).

CONCLUSIONS

Ginsenoside Rb1 can effectively alleviate CAL in a mouse model of KD in a dose-dependent manner, possibly by regulating the AMPK/mTOR/P70S6 autophagy signaling pathway to inhibit CAL inflammation and regulating the PI3K/AKT/GSK-3β oxidative stress signaling pathway to exert a biological activity of protection against coronary artery endothelial cell injury.

[Establishment of an ovalbumin-induced bronchial asthma model in mice with intrauterine growth retardation]

OBJECTIVE

To establish and evaluate an ovalbumin (OVA)-induced bronchial asthma model in mice with intrauterine growth retardation (IUGR), and to explore the molecular mechanism of relationship between IUGR and asthma.

METHODS

A total of 16 pregnant BALB/c female mice were divided into a low-protein diet group (n=8) and a normal-protein diet group (n=8), which were fed with low-protein (8%) diet and normal-protein (20%) diet respectively. The neonatal mice were weighed 6 hours after birth. Sixteen male neonatal mice with IUGR were randomly chosen from the low-protein diet group and enrolled in the IUGR group, and 16 male neonatal mice from the normal-protein diet group were enrolled in the control group. Blood samples were collected from the mice in both groups for testing of blood glucose. Enzyme-linked immunosorbent assay (ELISA) was used to determine serum insulin level. The mice in the control group were randomized into a control + PBS group and a control + OVA group (n=8 each). The mice in the IUGR group were randomized into an IUGR + PBS group and an IUGR + OVA group (n=8 each). Six-week-old mice in the control + OVA and IUGR + OVA groups were subjected to intraperitoneal injection of 2 mg/mL OVA for sensitization and aerosol inhalation of 1% OVA for challenge. Mice in the control + PBS group and the IUGR + PBS group were treated with an equivalent amount of PBS. ELISA was used to determine serum IgE level in the mice in each group. Bronchoalveolar lavage fluid (BLF) was collected from the mice in each group for cell counting. The lung tissue of the mice in each group was stained with hematoxylin and eosin to observe pathological changes.

RESULTS

The body weight at 6 hours after birth was significantly lower for neonatal mice in the low-protein diet group compared with those in the normal-protein diet group (P<0.01). The IUGR group had a significantly lower serum insulin level than the control group (P<0.01). The IUGR + PBS group had a significantly lower IgE level than the control + PBS group (P<0.01). Compared with the control + PBS and IUGR + PBS groups, the control + OVA and IUGR + OVA groups had a significantly increased IgE level, and the IgE level was significantly higher in the IUGR + OVA group than in the control + OVA group (P<0.01). Compared with the control + PBS and IUGR + PBS groups, the control + OVA and IUGR + OVA groups had significantly increased counts of leukocytes, eosinophils, lymphocytes, and macrophages in the BLF (P<0.01). The pulmonary alveoli of OVA-induced IUGR mice showed massive inflammatory cell infiltration and damage of intercellular continuity. Meanwhile, airway epithelial cell proliferation, bronchial wall thickening, bronchial lumen narrowing, and massive inflammatory cell infiltration around the bronchi and the vascular wall were observed.

CONCLUSIONS

An OVA-induced bronchial asthma model has been successfully established in the mice with IUGR induced by low-protein diet, which provides a basis for further study of the molecular mechanism of relationship between IUGR and airway inflammation.

[Establishment of an ovalbumin-induced bronchial asthma model in mice with intrauterine growth retardation]

OBJECTIVE

To establish and evaluate an ovalbumin (OVA)-induced bronchial asthma model in mice with intrauterine growth retardation (IUGR), and to explore the molecular mechanism of relationship between IUGR and asthma.

METHODS

A total of 16 pregnant BALB/c female mice were divided into a low-protein diet group (n=8) and a normal-protein diet group (n=8), which were fed with low-protein (8%) diet and normal-protein (20%) diet respectively. The neonatal mice were weighed 6 hours after birth. Sixteen male neonatal mice with IUGR were randomly chosen from the low-protein diet group and enrolled in the IUGR group, and 16 male neonatal mice from the normal-protein diet group were enrolled in the control group. Blood samples were collected from the mice in both groups for testing of blood glucose. Enzyme-linked immunosorbent assay (ELISA) was used to determine serum insulin level. The mice in the control group were randomized into a control + PBS group and a control + OVA group (n=8 each). The mice in the IUGR group were randomized into an IUGR + PBS group and an IUGR + OVA group (n=8 each). Six-week-old mice in the control + OVA and IUGR + OVA groups were subjected to intraperitoneal injection of 2 mg/mL OVA for sensitization and aerosol inhalation of 1% OVA for challenge. Mice in the control + PBS group and the IUGR + PBS group were treated with an equivalent amount of PBS. ELISA was used to determine serum IgE level in the mice in each group. Bronchoalveolar lavage fluid (BLF) was collected from the mice in each group for cell counting. The lung tissue of the mice in each group was stained with hematoxylin and eosin to observe pathological changes.

RESULTS

The body weight at 6 hours after birth was significantly lower for neonatal mice in the low-protein diet group compared with those in the normal-protein diet group (P<0.01). The IUGR group had a significantly lower serum insulin level than the control group (P<0.01). The IUGR + PBS group had a significantly lower IgE level than the control + PBS group (P<0.01). Compared with the control + PBS and IUGR + PBS groups, the control + OVA and IUGR + OVA groups had a significantly increased IgE level, and the IgE level was significantly higher in the IUGR + OVA group than in the control + OVA group (P<0.01). Compared with the control + PBS and IUGR + PBS groups, the control + OVA and IUGR + OVA groups had significantly increased counts of leukocytes, eosinophils, lymphocytes, and macrophages in the BLF (P<0.01). The pulmonary alveoli of OVA-induced IUGR mice showed massive inflammatory cell infiltration and damage of intercellular continuity. Meanwhile, airway epithelial cell proliferation, bronchial wall thickening, bronchial lumen narrowing, and massive inflammatory cell infiltration around the bronchi and the vascular wall were observed.

CONCLUSIONS

An OVA-induced bronchial asthma model has been successfully established in the mice with IUGR induced by low-protein diet, which provides a basis for further study of the molecular mechanism of relationship between IUGR and airway inflammation.

[Role of apoptosis signal-regulating kinase 1 in left ventricular remodeling in mice]

OBJECTIVE

To study the changes and significance of apoptosis signal-regulating kinase 1 (ASK1) in left ventricular remodeling in FVB/N mice.

METHODS

A total of 54 FVB/N mice were randomly divided into 4 groups: 0 d group with 8 mice, 7 d group with 10 mice, 14 d group with 16 mice, and 21 d group with 20 mice. A model of cardiac remodeling was established by intraperitoneal injection of isoproterenol (ISO) at a daily dose of 30 mg/kg, and the 7 d, 14 d, and 21 d groups were injected for 7, 14, and 21 consecutive days respectively. The 0 d group was given intraperitoneal injection of an equal volume of normal saline. Echocardiography was used to measure left ventricular posterior wall thickness at end diastole (dLVPW) and the ratio of heart weight to tibia length (HW/TL) was measured. Hematoxylin-eosin staining was used to measure left ventricular myocardial fiber diameter. Picric-Sirius red staining was used to measure myocardial collagen deposition area in the left ventricle. Quantitative real-time PCR was used to measure the mRNA expression of ASK1, type I collagen (collagen I), and B-type natriuretic peptide (BNP). The mortality rate was observed for each group.

RESULTS

There were gradual increases in HW/TL, myocardial fiber diameter, and dLVPW after 0, 7, and 14 days of ISO injection (P<0.05). There were no significant changes in HW/TL ratio and dLVPW from days 14 to 21 of ISO injection (P>0.05), while there was a significant reduction in myocardial fiber diameter (P<0.05), which was similar to the value on day 7 (P>0.05). There were significant increases in myocardial collagen deposition area and the mRNA expression of collagen I, ASK1, and BNP after 0, 7, 14, and 21 days of ISO injection, which reached the peaks on day 21 (P<0.01). The mRNA expression of ASK1 was positively correlated with myocardial collagen deposition area and the mRNA expression of collagen I and BNP and had a weak correlation with HW/TL, myocardial fiber diameter, and dLVPW. There was a significant increase in the mortality rate of the mice over the time of ISO injection.

CONCLUSIONS

The expression of ASK1 in the myocardium is closely associated with left ventricular remodeling. The increase of ASK1 expression may lead to the aggravation of left ventricular remodeling, and the mechanism of which needs further study.

干扰素α对乙型肝炎病毒X蛋白诱导小鼠足细胞系凋亡的影响及分子机制研究

OBJECTIVE

To investigate the effect and molecular mechanism of interferon-α (INF-α) on the apoptosis of the mouse podocyte cell line MPC5 induced by hepatitis B virus X (HBx) protein.

METHODS

MPC5 cells were transfected with the pEX plasmid carrying the HBx gene. RT-PCR was used to measure the mRNA expression of HBx at different time points. MPC5 cells were divided into 4 groups: control group (MPC5 cells cultured under normal conditions), INF-α group (MPC5 cells cultured with INF-α), HBx group (MPC5 cells induced by HBx), and HBx+INF-α group (MPC5 cells induced by HBx and cultured with INF-α). After 48 hours of intervention under different experimental conditions, flow cytometry was used to measure the apoptosis of MPC5 cells, and quantitative real-time PCR and Western blot were used to measure the mRNA and protein expression of slit diaphragm-related proteins (nephrin, CD2AP, and synaptopodin) and the cytoskeleton-related protein transient receptor potential cation channel 6 (TRPC6).

RESULTS

MPC5 cells transfected by pEX-HBx had the highest expression of HBx mRNA at 48 hours after transfection (P<0.05). Compared with the control, INF-α and HBx+INF-α groups, the HBx group had a significant increase in the apoptosis rate of MPC5 cells (P<0.05). Compared with the control and INF-α groups, the HBx group had significant reductions in the mRNA and protein expression of nephrin, synaptopodin, and CD2AP and significant increases in the mRNA and protein expression of TRPC6 (P<0.05). Compared with the HBx group, the HBx+INF-α group had significant increases in the mRNA and protein expression of nephrin, synaptopodin, and CD2AP and significant reductions in the mRNA and protein expression of TRPC6 (P<0.05).

CONCLUSIONS

INF-α can inhibit the apoptosis of podocytes induced by HBx, possibly through improving the abnormal expression of slit diaphragm-related proteins (CD2AP, nephrin, and synaptopodin) and cytoskeleton-related protein (TRPC6) induced by HBx.

[Protective effect of early intervention with lipoxin A4 on septic mice]

OBJECTIVE

To study the effect of early intervention with lipoxin A4 (LXA4) on septic mice.

METHODS

Healthy male Balb/c mice aged 6-8 weeks were randomly divided into sham-operation group, sepsis group, 1-hour intervention group (intervention at 1 hour after sepsis), and 6-hour intervention group (intervention at 6 hours after sepsis) (n=8 each). A sepsis model was prepared by cecal ligation and puncture. The intervention groups received LXA4 at 0.01 μg/g body weight 1 or 6 hours after the model was established. Blood was taken from eyeballs at 24 hours after operation. Peritoneal lavage fluid and liver and lung tissue samples were collected. The bacterial colonies of whole blood and peritoneal lavage fluid were counted by dilution plating. The serum levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and monocyte chemoattractant protein-1 (MCP-1) were determined by cytometric bead array. The serum level of high mobility group box-1 (HGMB1) was determined using ELISA. The percentages of macrophages and neutrophils in peritoneal lavage fluid were determined by flow cytometry. Paraffin sectioning and hematoxylin-eosin staining were performed for the liver and lung tissue samples to observe pathological damage.

RESULTS

Compared with the sham-operation group, the sepsis group had a significantly decreased percentage of macrophages and a significantly increased percentage of neutrophils in peritoneal lavage fluid (P<0.05), as well as significantly increased serum levels of IL-6, TNF-α, MCP-1, and HMGB1 (P<0.05); in addition, the sepsis group showed more vacuolar degeneration, hepatocyte swelling, and inflammatory cell infiltration in liver tissue, and more capillary congestion, pulmonary septal thickening, inflammatory cell infiltration, and partial tissue destruction in lung tissue. Compared with the sepsis group, the 1-hour and 6-hour intervention groups had a significantly increased percentage of macrophages in peritoneal lavage fluid (P<0.05) and significantly reduced bacterial load in whole blood (P<0.05), serum levels of IL-6, TNF-α, MCP-1, and HMGB1 (P<0.05), and degree of liver and lung tissue damage and inflammatory cell infiltration, but there was no significant difference in the percentage of neutrophils and bacterial load in peritoneal lavage fluid (P>0.05). Compared with the 6-hour intervention group, the 1-hour intervention group had a significantly decreased serum level of HMGB1 (P<0.05), but there was no significant difference in other indicators between the two groups (P>0.05).

CONCLUSIONS

Early intervention with LXA4 may attenuate liver and lung injuries in septic mice, which may be explained by the decrease in serum levels of IL-6, TNF-α, MCP-1, and HMGB1, and it also may reduce the bacterial dissemination in the whole blood of septic mice, which may be explained by the increase in the percentage of peritoneal macrophages.

[Expression and significance of tight junction proteins in the kidney in a mouse model of renal ischemia-reperfusion injury]

OBJECTIVE

To study the expression and significance of tight junction proteins (claudin-2, claudin-10, and claudin-17) in a mouse model of renal ischemia-reperfusion injury.

METHODS

A total of 152 male C57BL/6 mice were randomly assigned to control group (n=8), sham-operation group (n=72), and model group (n=72). The renal pedicles at both sides were clamped for 30 minutes to establish a mouse model of renal ischemia-reperfusion injury. According to the time points of reperfusion (0, 3, 6, 12, 24, 48, and 72 hours and 5 and 7 days), the sham-operation group and the model group were further divided into 9 subgroups, with 8 mice in each subgroup. RT-PCR and immunohistochemistry were used to measure the mRNA and protein expression of claudin-2, claudin-10, and claudin-17 in renal tissue.

RESULTS

The control and sham-operation groups had no significant changes in the mRNA and protein expression of claudin-2, claudin-10, and claudin-17 in renal tissue over the time of reperfusion (P>0.05). Compared with the control and sham-operation groups, the model group had decreased mRNA and protein expression of claudin-2 and claudin-10 after reperfusion, and the expression decreased gradually over the time of reperfusion, with the lowest levels at 24 hours of reperfusion (P<0.05). Compared with the control and sham-operation groups, the model group had increased mRNA and protein expression of claudin-17 after reperfusion, and the expression increased gradually over the time of reperfusion, with the highest mRNA level at 12 hours and the highest protein level at 24 hours of reperfusion (P<0.05).

CONCLUSIONS

Renal ischemia-reperfusion injury is closely associated with abnormal expression of tight junction proteins claudin-2, claudin-10, and claudin-17.

[Expression and significance of tight junction proteins in the kidney in a mouse model of renal ischemia-reperfusion injury]

OBJECTIVE

To study the expression and significance of tight junction proteins (claudin-2, claudin-10, and claudin-17) in a mouse model of renal ischemia-reperfusion injury.

METHODS

A total of 152 male C57BL/6 mice were randomly assigned to control group (n=8), sham-operation group (n=72), and model group (n=72). The renal pedicles at both sides were clamped for 30 minutes to establish a mouse model of renal ischemia-reperfusion injury. According to the time points of reperfusion (0, 3, 6, 12, 24, 48, and 72 hours and 5 and 7 days), the sham-operation group and the model group were further divided into 9 subgroups, with 8 mice in each subgroup. RT-PCR and immunohistochemistry were used to measure the mRNA and protein expression of claudin-2, claudin-10, and claudin-17 in renal tissue.

RESULTS

The control and sham-operation groups had no significant changes in the mRNA and protein expression of claudin-2, claudin-10, and claudin-17 in renal tissue over the time of reperfusion (P>0.05). Compared with the control and sham-operation groups, the model group had decreased mRNA and protein expression of claudin-2 and claudin-10 after reperfusion, and the expression decreased gradually over the time of reperfusion, with the lowest levels at 24 hours of reperfusion (P<0.05). Compared with the control and sham-operation groups, the model group had increased mRNA and protein expression of claudin-17 after reperfusion, and the expression increased gradually over the time of reperfusion, with the highest mRNA level at 12 hours and the highest protein level at 24 hours of reperfusion (P<0.05).

CONCLUSIONS

Renal ischemia-reperfusion injury is closely associated with abnormal expression of tight junction proteins claudin-2, claudin-10, and claudin-17.

[Interactive regulatory effect of histone H3K9ac acetylation and histone H3K9me3 methylation on cardiomyogenesis in mice]

OBJECTIVE

To study the interactive regulatory effect of histone acetylation and methylation on cardiomyogenesis, and to provide a theoretical basis for the prevention and treatment of congenital heart disease.

METHODS

A total of 24 Kunming mice were randomly divided into embryo day 14.5 (ED 14.5) group, embryo day 16.5 (ED 16.5) group, postnatal day 0.5 (PND 0.5) group, and postnatal day 7 (PND 7) group, with 6 mice in each group, and the heart tissue of fetal and neonatal mice was collected. Colorimetry was used to measure the activities of histone acetylases (HATs) and histone methyltransferases (HMTs) in the myocardium. Western blot was used to measure the expression of H3K9ac and H3K9me3 in the myocardium.

RESULTS

Colorimetry showed that the activities of HATs and HMTs were higher before birth and were lower after birth. There was a significant difference in the activity of HATs in the myocardium between the PND 0.5 and PND 7 groups and the ED 14.5 group (P<0.05), as well as between the PND 7 group and the ED 16.5 group (P<0.05). There was also a significant difference in the activity of HMTs in the myocardium between the PND 7 group and the ED 14.5 and ED 16.5 groups (P<0.05). Western blot showed higher expression of H3K9ac and H3K9me3 before birth and lower expression of H3K9ac and H3K9me3 after birth, and there were significant differences in the expression H3K9ac and H3K9me3 in the myocardium between the PND 0.5 and PND 7 groups and the ED 14.5 and ED 16.5 groups (P<0.05).

CONCLUSIONS

The dynamic expression of HATs, HMTs, H3K9ac, and H3K9me3 is observed during cardiomyogenesis, suggesting that histone H3K9ac acetylation and histone H3K9me3 methylation mediated by HATs and HMTs may play a role in interactive regulation during cardiomyogenesis.

[Analysis of orthologous lncRNAs in humans and mice and their species-specific epigenetic target genes]

OBJECTIVE

To identify orthologous lncRNAs in human and mice and the species specificity of their epigenetic regulatory functions.

METHODS

The human/mouse whole-genome pairwise alignment (hg19/mm10, genome.UCSC.edu) was used to identify the orthologues in 13 562 and 10 481 GENCODE-annotated human and mouse lncRNAs. The Infernal program was used to search the orthologous sequences of all the exons of the 13562 human lncRNAs in mouse genome (mm10) to identify the highly conserved orthologues in mice. LongTarget program was used to predict the DNA binding sites of the orthologous lncRNAs in their local genomic regions. Gene Ontology analysis was carried out to examine the functions of genes.

RESULTS

Only 158 orthologous lncRNAs were identified in humans and mice, and many of these orthologues had species-specific DNA binding sites and epigenetic target genes. Some of the epigenetic target genes executed important functions in determining human and mouse phenotypes.

CONCLUSION

s Only a few human and mouse lncRNAs are orthologues, and most of lncRNAs are species-specific. The orthologous lncRNAs have species-specific epigenetic target genes, and species-specific epigenetic regulation greatly contributes to the differences between humans and mice.

[Effects of bacterial lysates and all trans-retinoic acid on airway inflammation in asthmatic mice]

OBJECTIVE

To observe the effects of bacterial lysates (OM-85BV) and all trans-retinoic acid (ATRA) on airway inflammation in asthmatic mice, and to investigate the immunoregulatory mechanism of OM-85BV and ATRA for airway inflammation in asthmatic mice.

METHODS

Forty female BALB/c mice were randomly divided into five groups: normal control, model, OM-85BV, ATRA, and OM-85BV+ATRA. A bronchial asthma model was established by intraperitoneal injection of ovalbumin (OVA) for sensitization and aerosol challenge in all mice except those in the normal control group. On days 25-34, before aerosol challenge, the model, OM-85BV, ATRA, and OM-85BV+ATRA groups were given normal saline, OM-85BV, ATRA, and OM-85BV+ATRA respectively by gavage. Normal saline was used instead for sensitization, challenge, and pretreatment before challenge in the normal control group. These mice were anesthetized and dissected at 24-48 hours after the final challenge. Bronchoalveolar lavage fluid (BALF) was collected from the right lung to measure the levels of interleukin-10 (IL-10) and interleukin-17 (IL-17) by ELISA. The left lung was collected to observe histopathological changes by hematoxylin-eosin staining. The relative expression of ROR-γT mRNA was measured by quantitative real-time PCR.

RESULTS

Compared with the normal control group, the model group showed contraction of the bronchial cavity, increased bronchial secretions, and a large number of infiltrating inflammatory cells around the bronchi and alveolar walls, as well as a significantly reduced level of IL-10 (P<0.05) and significantly increased levels of IL-17 and ROR-γT mRNA (P<0.05). Compared with the model group, the OM-85BV, ATRA, and OM-85BV+ATRA groups showed a significant reduction in infiltrating inflammatory cells around the bronchi and alveolar walls; the OM-85BV group showed a significant increase in the level of IL-10 in BALF (P<0.05) and significant reductions in the levels of IL-17 and ROR-γT mRNA (P<0.05); the ATRA group showed significant reductions in the levels of IL-17 and ROR-γT mRNA (P<0.05). Compared with the OM-85BV group, the OM-85BV+ATRA group had significantly increased relative expression of ROR-γT mRNA (P<0.05). Compared with the ATRA group, the OM-85BV+ATRA group had significantly increased levels of IL-10 and IL-17 in BALF (P<0.05).

CONCLUSIONS

Both OM-85BV and ATRA can reduce respiratory inflammation in asthmatic mice. However, a combination of the two drugs does not have a better effect than them used alone.

[Establishment of cardiac remodeling model in FVB/N mice by intraperitoneal injection of isoproterenol]

OBJECTIVE

To explore the feasibility of intraperitoneal injection of isoproterenol (ISO) to induce cardiac remodeling in FVB/N mice.

METHODS

Forty-eight FVB/N mice were divided into back subcutaneous saline group (subcutaneous saline group), intraperitoneal saline group, back subcutaneous ISO group (subcutaneous ISO group), and intraperitoneal ISO group according to the route of administration of saline or ISO. ISO (30 μg/g body weight/day) was given to the subcutaneous ISO group and the intraperitoneal ISO group, twice daily with an interval of 12 hours, for 14 consecutive days. The subcutaneous saline group and the intraperitoneal saline group were injected with an equal volume of saline. The left ventricular end-diastolic posterior wall thickness was measured by echocardiography, and the ratio of heart weight to tibia length was determined. Hematoxylin-eosin staining was used to determine the myocardial fiber diameter. Picric-sirius red staining was used to determine the myocardial collagen deposition area. Quantitative real-time PCR was used to measure the mRNA expression of collagen I.

RESULTS

Compared with the subcutaneous ISO, subcutaneous saline, and intraperitoneal saline groups, the intraperitoneal ISO group had increased sizes of the cardiac cavity and the heart. Compared with the subcutaneous saline and intraperitoneal saline groups, the subcutaneous ISO group showed no significant changes in the gross morphology of the cardiac cavity and the heart. The intraperitoneal ISO group showed significant increases in the ratio of heart weight to tibia length, myocardial fiber diameter, left ventricular end-diastolic posterior wall thickness, myocardial collagen area percentage, and the mRNA expression of collagen I compared with the subcutaneous ISO, subcutaneous saline, and intraperitoneal saline groups (P<0.01). There were no significant differences in the above five indices between the subcutaneous ISO group and the subcutaneous saline and intraperitoneal saline groups (P>0.05). No significant difference in the mortality rate was found between the subcutaneous ISO and intraperitoneal ISO groups (P>0.05).

CONCLUSIONS

Intraperitoneal injection of ISO can induce cardiac hypertrophy and fibrosis in FVB/N mice.

[Effects of raloxifene at two different doses for ovulation induction on endometrial pinopodes in mice during the implantation window]

OBJECTIVE

To compare the expression of pinopodes, the marker of endometrial receptivity, during the implantation window in Kunming mice stimulated with two different doses of raloxifene (RAL).

METHODS

Forty-eight 8-week-old female Kunming mice were randomly divided into 4 groups (n=12), namely saline group, clomiphene citrate (CC, 18 mg/kg) group, RAL (33 mg/kg) group and RAL (44 mg/kg group). In each group, the mice received intragastric administration of 1 mL of normal saline containing CC or RAL at the specified doses or saline only as indicated for ovulation induction, once daily for 2 days. The mice received then injection with 5 IU human chorionic gonadotropin (HCG) and mated and on day 4.5 of gestation, the pregnant mice were sacrificed for examination of the uterus with scanning electron microscopy.

RESULTS

Abundant and well developed pinopodes were observed in the endometrium of the mice in the 2 RAL groups and in the saline control group. The mice in CC group showed obviously reduced endometrial pinopodes with poor development.

CONCLUSIONS

RAL at two different doses does not obviously affect the expression of pinopodes in the uterine epithelium of mice, suggesting the safety of RAL at these two doses for ovulation induction without causing adverse effects on endometrial receptivity.

[Effects of Toll-like receptor blockers on intestinal mucosal injury in mice with endotoxemia]

OBJECTIVE

To investigate the effects of Toll-like receptor blockers TLR2-Ab and TLR4-Ab on the tight junction protein ZO-1 in intestinal epithelial cells in mice, as well as their effects on nuclear factor-kappa B (NF-κB) and tumor necrosis factor-α (TNF-α).

METHODS

A total of 32 BALB/C mice were divided into control group, model group, TLR4 treatment group, and TLR2 treatment group, with 8 mice in each group. A mouse model of endotoxemia was established by intraperitoneal injection of lipopolysaccharide. The mice in the TLR4 treatment group and the TLR2 treatment group were given intraperitoneal injection of TLR4 antibody and TLR2 antibody (10 μg each mouse), respectively, and those in the control group were given normal saline. The distal small intestinal tissue was collected, and RT-PCR and immunohistochemistry were used to measure the mRNA and protein expression of ZO-1, NF-κBp65, and TNF-α.

RESULTS

Compared with the control group, the model group had significantly lower mRNA and protein expression of ZO-1 and significantly higher mRNA expression of NF-κBp65 and TNF-α (P<0.05). Compared with the model group, the TLR4 treatment group and the TLR2 treatment group had significantly higher mRNA and protein expression of ZO-1 and significantly lower mRNA and protein expression of NF-κBp65 and TNF-α (P<0.05). There were no significant differences in the mRNA and protein expression of ZO-1, NF-κBp65, and TNF-α between the TLR4 treatment group and the TLR2 treatment group (P>0.05).

CONCLUSIONS

Anti-TLR2 and anti-TLR4 monoclonal antibodies can reduce the activation of nuclear transcription factors, inhibit the secretion of inflammatory factors, and protect tight junction protein, which is expected to provide new ideas for the treatment of enterogenous infectious diseases.

[Effects of Toll-like receptor blockers on intestinal mucosal injury in mice with endotoxemia]

OBJECTIVE

To investigate the effects of Toll-like receptor blockers TLR2-Ab and TLR4-Ab on the tight junction protein ZO-1 in intestinal epithelial cells in mice, as well as their effects on nuclear factor-kappa B (NF-κB) and tumor necrosis factor-α (TNF-α).

METHODS

A total of 32 BALB/C mice were divided into control group, model group, TLR4 treatment group, and TLR2 treatment group, with 8 mice in each group. A mouse model of endotoxemia was established by intraperitoneal injection of lipopolysaccharide. The mice in the TLR4 treatment group and the TLR2 treatment group were given intraperitoneal injection of TLR4 antibody and TLR2 antibody (10 μg each mouse), respectively, and those in the control group were given normal saline. The distal small intestinal tissue was collected, and RT-PCR and immunohistochemistry were used to measure the mRNA and protein expression of ZO-1, NF-κBp65, and TNF-α.

RESULTS

Compared with the control group, the model group had significantly lower mRNA and protein expression of ZO-1 and significantly higher mRNA expression of NF-κBp65 and TNF-α (P<0.05). Compared with the model group, the TLR4 treatment group and the TLR2 treatment group had significantly higher mRNA and protein expression of ZO-1 and significantly lower mRNA and protein expression of NF-κBp65 and TNF-α (P<0.05). There were no significant differences in the mRNA and protein expression of ZO-1, NF-κBp65, and TNF-α between the TLR4 treatment group and the TLR2 treatment group (P>0.05).

CONCLUSIONS

Anti-TLR2 and anti-TLR4 monoclonal antibodies can reduce the activation of nuclear transcription factors, inhibit the secretion of inflammatory factors, and protect tight junction protein, which is expected to provide new ideas for the treatment of enterogenous infectious diseases.

[Mechanism of action of BET bromodomain inhibitor JQ1 in treating airway remodeling in asthmatic mice]

OBJECTIVE

To investigate the molecular mechanism of action of BET bromodomain inhibitor JQ1 in treating airway remodeling in asthmatic mice.

METHODS

A total of 24 mice were randomly divided into control group, ovalbumin (OVA)-induced asthma group (OVA group), and JQ1 intervention group (JQ1+OVA group), with 8 mice in each group. OVA sensitization/challenge was performed to establish a mouse model of asthma. At 1 hour before challenge, the mice in the JQ1+OVA group were given intraperitoneal injection of JQ1 solution (50 μg/g). Bronchoalveolar lavage fluid (BALF) and lung tissue samples were collected at 24 hours after the last challenge, and the total number of cells and percentage of eosinophils in BALF were calculated. Pathological staining was performed to observe histopathological changes in lung tissue. RT-PCR and Western blot were used to measure the mRNA and protein expression of E-cadherin and vimentin during epithelial-mesenchymal transition (EMT).

RESULTS

Compared with the control group, the OVA group had marked infiltration of inflammatory cells in the airway, thickening of the airway wall, increased secretion of mucus, and increases in the total number of cells and percentage of eosinophils in BALF (P<0.01). Compared with the OVA group, the JQ1+OVA group had significantly alleviated airway inflammatory response and significant reductions in the total number of cells and percentage of eosinophils in BALF (P<0.01). Compared with the control group, the OVA group had significant reductions in the mRNA and protein expression of E-cadherin and significant increases in the mRNA and protein expression of vimentin (P<0.01); compared with the OVA group, the JQ1+OVA group had significant increases in the mRNA and protein expression of E-cadherin and significant reductions in the mRNA and protein expression of vimentin (P<0.01); there were no significant differences in these indices between the JQ1+OVA group and the control group (P>0.05).

CONCLUSIONS

Mice with OVA-induced asthma have airway remodeling during EMT. BET bromodomain inhibitor JQ1 can reduce airway inflammation, inhibit EMT, and alleviate airway remodeling, which provides a new direction for the treatment of asthma.

[Protective effects of rutin against obesity-induced reproductive impairment in male mice]

OBJECTIVE

To study the effect of rutin on body weight and obesity-induced reproductive impairment in male mice.

METHODS

Twenty-four male mice were randomized equally into normal control group, high-fat diet group (HFD group), and HFD + rutin intervention group (HRU group). After 28 days of treatments, the testes and epididymis of the mice were collected for detection of total cholesterol (TC) and triglycerides (TG) levels and for pathological examinations with HE staining. The expressions of related genes was detected with real-time PCR, and Western blotting was used to detect the expression of Ucp1 protein in the samples.

RESULTS

After 28 days of treatments, the mean body weight was lower in mice with rutin intervention than in those in HFD group. The mice in HFD group showed significantly higher TG levels in the testis and epididymis and higher TC levels in the epididymis than those in the control and HRU groups. In HFD group, the testis and the epididymis displayed loosened structures with abnormalcell structure, and the number ofmature spermatozoa in the lumen was decreased and the mobility of the sperms was reduced; all these changes were significantly alleviated in HRU group. The expression levels of Ucp1 mRNA and protein increased (P<0.05) and the expressions of Mcp1 and TNF-α decreased significantly in the mice after rutin treatment (P<0.05).

CONCLUSION

Rutin can effectively inhibit rapid increase of body weight and protect against obesity-induced reproductive impairment in obese mice.

[Effect of high-fat diet on expression of transient receptor potential vanilloid 1 in respiratory tract and dorsal root ganglion of mice]

OBJECTIVE

To investigate the effect of high-fat diet on the expression of transient receptor potential vanilloid 1 (TRPV1) in the respiratory system and the dorsal root ganglion (DRG) of mice, as well as its effect on the excitability of sensory neurons.

METHODS

A total of 20 C57BL/6 mice were randomly divided into normal-diet (ND) group and high-fat diet (HFD) group, with 10 mice in each group. The mice were given corresponding diets and body weights were monitored. After 7 weeks of feeding, lung tissue, bronchial tissue, and DRG at thoracic segments 3-4 were collected and immunohistochemical staining was performed. A patch clamp was used to measure the number of action potentials and TRPV1 current intensity in the DRG.

RESULTS

After 7 weeks of feeding, the HFD group had significantly greater mean weight gain than the ND group (6.4±2.6 g vs 2.3±0.5 g; P<0.001). The HFD group had significantly higher expression of TRPV1 in the bronchus, pulmonary alveoli, and DRG than the ND group (P<0.05). Compared with the ND group, the HFD group had significant increases in the TRPV1 current intensity and number of action potentials in the DRG (P<0.05).

CONCLUSIONS

High-fat diet induces a significant increase in body weight and leads to high expression of TRPV1 and high excitability in the respiratory system and the peripheral sensory neurons. This suggests that TRPV1 may be an important factor in the physiopathological mechanisms of bronchial hyperresponsiveness.

[Effects of vasoactive intestinal peptide on airway inflammation and Th17/Treg balance in asthmatic mice]

OBJECTIVE

To investigate the effects of vasoactive intestinal peptide (VIP) on the airway inflammation and its regulatory effect on Th17/Treg imbalance in asthmatic mice.

METHODS

A total of 30 BALB/c mice were equally and randomly divided into three groups: control, asthma, and VIP. An acute asthmatic mouse model was established by sensitization and challenge with ovalbumin (OVA). The control group received normal saline instead of OVA. Before the challenge with OVA, the VIP group was administered VIP (20 μg/mL) by aerosol inhalation for 30 minutes. The bronchoalveolar lavage fluid (BALF) and the lung tissue were collected from mice. The pathological changes in the lung tissue were observed by hematoxylin and eosin staining. The levels of Th17/Treg-related cytokines in BALF were measured by enzyme-linked immunosorbent assay. The expression of retinoid-related orphan receptor gamma t (RORγt) and forkhead box P3 (Foxp3) were measured by real-time fluorescence quantitative PCR and immunohistochemistry.

RESULTS

The histopathological results showed that the VIP group had milder symptoms of airway inflammation than the asthma group. The level of IL-17 in BALF in the asthma group was significantly higher than that in the control group and the VIP group (P<0.01), but the level of IL-17 in the control group was significantly lower than that in the VIP group (P<0.01). The level of IL-10 in BALF in the asthma group was significantly lower than that in the control group and the VIP group (P<0.01, but the level of IL-10 in the VIP group was significantly higher than that in the control group (P<0.01). The asthma group showed significantly higher expression levels of RORγt mRNA and protein in the lung tissue and significantly lower expression levels of Foxp3 mRNA and protein than the control group (P<0.01). The VIP group had significantly lower expression levels of RORγt mRNA and protein in the lung tissue and significantly higher expression levels of Foxp3 mRNA and protein than the asthma group (P<0.05).

CONCLUSIONS

The Th17/Treg imbalance may be closely related to the airway inflammation in asthmatic mice. VIP can improve airway inflammation by regulating the Th17/Treg imbalance in asthmatic mice.

[Effects of recombinant fusion protein interleukin-18 on expression of immune-inflammatory factors in mice infected with Staphylococcus aureus]

OBJECTIVE

To observe the effects of recombinant fusion protein interleukin (IL)-18 on the expression of immune-inflammatory factors in the mice infected with Staphylococcus aureus (SA), and to investigate the mechanism of action of IL-18 in defense of SA infection in vivo.

METHODS

A total of 40 specific pathogen-free female BLAB/c mice were randomly divided into four groups: control, SA infection, immunized, and intervention. A mouse model of SA infection was established by nasal inoculation with SA liquid. The immunized group and the intervention group were intranasally given IL-18 before SA modeling, and then the SA infection group and the intervention group received the nasal inoculation with SA liquid; the control group was treated with phosphate buffered saline instead. The levels of IL-4, interferon (IFN)-γ, tumor necrosis factor (TNF), granulocyte colony-stimulating factor (G-CSF), IgM in the serum and bronchoalveolar lavage fluid (BALF) of mice were measured by enzyme-linked immunosorbent assay. The expression of macrophage inflammatory protein (MIP)-1α mRNA and MIP-2β mRNA in the lung tissue of mice were determined by real-time fluorescent quantitative PCR.

RESULTS

Compared with the control group, the SA infection group and the immunized group had significantly higher levels of IL-4, G-CSF, and IgM in the serum and BALF and expression of MIP-1α mRNA and MIP-2β mRNA in the lung tissue (P<0.05); the SA infection group had a significantly lower level of IFN-γ and a significantly higher level of TNF in the serum and BALF (P<0.05); the immunized group had a significantly higher level of IFN-γ in the serum and BALF (P<0.05). Compared with the SA infection group, the intervention group had significantly higher levels of IL-4, IFN-γ, G-CSF, and IgM in the serum and BALF and expression of MIP-1α mRNA in the lung tissue. In contrast, the intervention group showed a significantly lower level of TNF in the serum and BALF and expression of MIP-2β mRNA in the lung tissue (P<0.05). All the above indicators in the intervention group were significantly higher than those in the control group (P<0.05), except the serum level of IFN-γ.

CONCLUSIONS

In the mice infected with SA, the recombinant fusion protein IL-18 by mucosal immunity can affect inflammatory factors in the serum and BALF and the expression of MIP-1α mRNA and MIP-2β mRNA in the lung tissue to promote the anti-infective immune response and enhance the ability to clear pathogens.

脂肪间充质干细胞及非甲基化胞嘧啶鸟嘌呤核苷酸对食物过敏幼鼠外周血中CD4+CD25+Treg的影响

OBJECTIVE

To investigate the effects of adipose-derived stem cells (ADSC) and non-methylated CpG-oligodeoxynucleotides (CpG-ODN) on the expression of peripheral blood CD4⁺CD25⁺ regulatory T (Treg) cells in young mice with food allergy, as well as their immune intervention effects.

METHODS

A total of 40 female BALB/c mice were randomly divided into control group, allergic group, ADSC treatment group, and CpG-ODN treatment group, with 10 mice in each group. A mouse model of food allergy was established by intraperitoneal injection and intragastric administration of ovalbumin (OVA) for sensitization and challenge. The mice in the control group were treated with normal saline at the same dose; the mice in the ADSC treatment group were given intraperitoneal injection of ADSC (1×10⁶ cells for each mouse) before and after OVA challenge, and those in the CpG-ODN treatment group were given intraperitoneal injection of non-methylated CpG-ODN solution (40 μg for each mouse) at 1 hour before challenge by gavage. The allergic symptom scores were determined for each group after model establishment. ELISA was used to measure the serum level of OVA-IgE. Flow cytometry was used to measure the percentage of peripheral blood CD4⁺CD25⁺ Treg cells. Hematoxylin and eosin staining was used for the pathological analysis of the jejunum.

RESULTS

The allergic group had significantly higher allergic symptom scores and serum level of OVA-IgE than the control group (P<0.05). There were no significant differences in the allergic symptom score and the serum level of OVA-IgE between the ADSC treatment group and the CpG-ODN treatment group (P>0.05), but these two groups had significantly lower allergic symptom scores and serum level of OVA-IgE than the allergic group and significantly higher allergic symptom scores and serum level of OVA-IgE than the control group (P<0.01). The allergic group had a significantly lower percentage of peripheral blood CD4⁺CD25⁺ Treg cells than the control group (P<0.05). The ADSC treatment group and the CpG-ODN treatment group had a significantly higher percentage of peripheral blood CD4⁺CD25⁺ Treg cells than the allergic group (P<0.05); there were no significant differences between these two groups or between them and the control group (P>0.05). Pathological results showed structural damage and edema in the jejunal villi, a large number of eosinophils, and lymphocyte infiltration in the allergic group, while the ADSC treatment group and the CpG-ODN treatment group had less structural damage and edema in the jejunal villi, a lower number of eosinophils, and less lymphocyte infiltration.

CONCLUSIONS

ADSC and non-methylated CpG-ODN have a certain effect in the treatment of food allergy and can increase the percentage of peripheral blood CD4⁺CD25⁺ Treg cells and reduce the level of OVA-IgE. They may be associated with the induction of immune tolerance and these two treatment have comparable effects. Detailed mechanisms of action still need further investigation.

[Effects of adipose-derived stem cells and non-methylated CpG-oligodeoxynucleotides on peripheral blood CD4+CD25+ regulatory T cells in young mice with food allergy]

OBJECTIVE

To investigate the effects of adipose-derived stem cells (ADSC) and non-methylated CpG-oligodeoxynucleotides (CpG-ODN) on the expression of peripheral blood CD4+CD25+ regulatory T (Treg) cells in young mice with food allergy, as well as their immune intervention effects.

METHODS

A total of 40 female BALB/c mice were randomly divided into control group, allergic group, ADSC treatment group, and CpG-ODN treatment group, with 10 mice in each group. A mouse model of food allergy was established by intraperitoneal injection and intragastric administration of ovalbumin (OVA) for sensitization and challenge. The mice in the control group were treated with normal saline at the same dose; the mice in the ADSC treatment group were given intraperitoneal injection of ADSC (1×106 cells for each mouse) before and after OVA challenge, and those in the CpG-ODN treatment group were given intraperitoneal injection of non-methylated CpG-ODN solution (40 μg for each mouse) at 1 hour before challenge by gavage. The allergic symptom scores were determined for each group after model establishment. ELISA was used to measure the serum level of OVA-IgE. Flow cytometry was used to measure the percentage of peripheral blood CD4+CD25+ Treg cells. Hematoxylin and eosin staining was used for the pathological analysis of the jejunum.

RESULTS

The allergic group had significantly higher allergic symptom scores and serum level of OVA-IgE than the control group (P<0.05). There were no significant differences in the allergic symptom score and the serum level of OVA-IgE between the ADSC treatment group and the CpG-ODN treatment group (P>0.05), but these two groups had significantly lower allergic symptom scores and serum level of OVA-IgE than the allergic group and significantly higher allergic symptom scores and serum level of OVA-IgE than the control group (P<0.01). The allergic group had a significantly lower percentage of peripheral blood CD4+CD25+ Treg cells than the control group (P<0.05). The ADSC treatment group and the CpG-ODN treatment group had a significantly higher percentage of peripheral blood CD4+CD25+ Treg cells than the allergic group (P<0.05); there were no significant differences between these two groups or between them and the control group (P>0.05). Pathological results showed structural damage and edema in the jejunal villi, a large number of eosinophils, and lymphocyte infiltration in the allergic group, while the ADSC treatment group and the CpG-ODN treatment group had less structural damage and edema in the jejunal villi, a lower number of eosinophils, and less lymphocyte infiltration.

CONCLUSIONS

ADSC and non-methylated CpG-ODN have a certain effect in the treatment of food allergy and can increase the percentage of peripheral blood CD4+CD25+ Treg cells and reduce the level of OVA-IgE. They may be associated with the induction of immune tolerance and these two treatment have comparable effects. Detailed mechanisms of action still need further investigation.

[Immunoprotective effect of combined pneumococcal endopeptidase O and pneumococcal surface adhesin A vaccines against Streptococcus pneumoniae infection]

OBJECTIVE

To investigate the prokaryotic expression of proteins pneumococcal endopeptidase O (PepO) and pneumococcal surface adhesin A (PsaA) in Streptococcus pneumoniae and their immunoprotective effect as vaccine candidate proteins.

METHODS

Specific primers of target gene fragments were designed, and then PCR amplification was performed to establish recombinant plasmids pET28a(+)-pepO and pET28a(+)-psaA, which were transformed into host cells, Escherichia coli BL21 and DE3, respectively, to induce expression. Highly purified target proteins PepO and PsaA were obtained after purification. Mucosal immunization was performed for BALB/c mice and specific antiserum was prepared. ELISA was used to measure the antibody titer, and Western blot was used to analyze the specificity of the antiserum of target proteins. The mice were randomly divided into negative control group, PepO group, PsaA group, and PepO+PsaA combined immunization group, with 18 mice in each group. The models of different serotypes of Streptococcus pneumoniae infection were established to evaluate the immunoprotective effect of target proteins used alone or in combination.

RESULTS

The target proteins PepO and PsaA were successfully obtained and Western blot demonstrated that the antiserum of these proteins had good specificity. There was no significant difference in the titers of IgA in saliva and IgG in serum between the PepO group and the combined immunization group (P>0.05); however, these two groups had significantly higher antibody titers than the PsaA group (P<0.05). The PepO, PsaA, and combined immunization groups had significantly higher protection rates for mice infected with Streptococcus pneumoniae D39 and CMCC31436 in the nasal cavity than the negative control group (P<0.05). The PepO and combined immunization groups had a significantly higher protection rate for mice infected with Streptococcus pneumoniae D39 than the PsaA group (P<0.05). The results of colonization experiment showed that compared with the control group, the PepO, PsaA, and combined immunization groups showed a significant reduction in the colonization of Streptococcus pneumoniae (CMCC31693 and CMCC31207) in the nasopharynx and lung (P<0.05). The combined immunization group showed a better effect on reducing the colonization of CMCC31207 in the lung than the PepO and PsaA alone groups.

CONCLUSIONS

Combined PepO/PsaA vaccines may produce a better protective effect by mucosal immunization compared with the vaccine used alone in mice. The combined vaccines can effectively reduce the colonization of Streptococcus pneumoniae in the nasopharynx and lung. Therefore, such protein vaccines may have a great potential for research and development.

[Effect of histone acetylation/deacetylation imbalances on key gene of planar cell polarity pathway]

OBJECTIVE

To investigate the effect of histone acetylation/deacetylation imbalances on embryonic hearts of mice and its effect on key genes of planar cell polarity (PCP) pathway-Vangl2, Scrib and Rac1 in H9C2 cells.

METHODS

Forty pregnant C57/B6 mice were randomly assigned into three groups: blank group (n=10), vehicle group (n=10), and valproic acid (VPA)-treated group (n=20). In the VPA-treated group, VPA, a histone deacetylase (HDAC) inhibitor, was administered to each individual dam intraperitoneally at a single dose of 700 mg/kg on embryonic day 10.5 (E10.5). The vehicle and blank groups received equivalent saline or no interventions, respectively. Dams were sacrificed on E15.5, and death rates of embryos were evaluated. Subsequently, embryonic hearts of survival fetus were removed to observe cardiac abnormalities by hematoxylin-eosin (HE) staining. H9C2 cells were cultured and allotted to the blank, vehicle, and VPA-treated groups: the VPA treated group received VPA exposure at concentrations of 2.0, 4.0 and 8.0 mmol/L; the vehicle and blank groups received equivalent saline or no interventions, respectively. HDAC1-3 as well as Vangl2, Scrib and Rac1 mRNA and protein expression levels were determined by quantitative real-time PCR and Western blot, respectively. The total HDAC activity was analyzed by colorimetric assay.

RESULTS

The fetus mortality rate after VPA treatment was 31.7%, with a significantly higher rate of cardiac abnormalities in comparison with the controls (P<0.05). In comparison with the blank and vehicle groups, HDAC1 mRNA was significantly increased at various concentrations of VPA treatment at all time points of exposure (P<0.05), together with a reduction of protein level after 48 and 72 hours of exposure (P<0.05). The inhibition of HDAC2 mRNA after various concentrations of VPA incubation was pronounced at 24 hours of exposure (P<0.05), while the protein levels were reduced at all time points (P<0.05). HDAC3 mRNA was prominently induced by VPA (4.0 and 8.0 mmol/L) at all time points of treatment (P<0.05). In contrast, the protein level was inhibited after VPA treatment (P<0.05). In comparison with the blank and vehicle groups, Vangl2 mRNA as well as Scrib mRNA/protein expression levels were markedly reduced after 48 and 72 hours of VPA treatment (P<0.05), together with a reduction of protein level in Vangl2 at 72 hours (P<0.05). Compared with the blank and vehicle groups, a significant repression in the total HDAC activity was observed in the VPA-treated group at concentrations of 4.0 and 8.0 mmol/L after 24 hours of treatment (P<0.05), and the effect persisted up to 48 and 72 hours, exhibiting pronounced inhibition at all concentrations (P<0.05).

CONCLUSIONS

VPA might result in acetylation/deacetylation imbalances by inhibiting HDAC1-3 protein expression and total HDAC activity, leading to the down-regulation of mRNA and protein expression of Vangl2 and Scrib. This could be one of the mechanisms contributing to congenital heart disease.

[Effect of heat shock factor 1 on airway hyperresponsiveness and airway inflammation in mice with allergic asthma]

OBJECTIVE

To investigate the effect of heat shock factor 1 (HSF1) on airway hyperresponsiveness and airway inflammation in mice with asthma and possible mechanisms.

METHODS

A total of 36 mice were randomly divided into four groups: control, asthma, HSF1 small interfering RNA negative control (siHSF1-NC), and siHSF1 intervention (n=9 each). Ovalbumin (OVA) sensitization and challenge were performed to induce asthma in the latter three groups. The mice in the siHSF1-NC and siHSF1 groups were treated with siHSF1-NC and siHSF1, respectively. A spirometer was used to measure airway responsiveness at 24 hours after the last challenge. The direct count method was used to calculate the number of eosinophils. ELISA was used to measure the serum level of OVA-specific IgE and levels of interleukin-4 (IL-4), interleukin-5 (IL-5), interleukin-13 (IL-13), and interferon-γ (IFN-γ) in lung tissues and bronchoalveolar lavage fluid (BALF). Quantitative real-time PCR was used to measure the mRNA expression of HSF1 in asthmatic mice. Western blot was used to measure the protein expression of HSF1, high-mobility group box 1 (HMGB1), and phosphorylated c-Jun N-terminal kinase (p-JNK).

RESULTS

The asthma group had significant increases in the mRNA and protein expression of HSF1 compared with the control group (P<0.05). The siHSF1 group had significantly reduced mRNA and protein expression of HSF1 compared with the siHSF1-NC group (P<0.05). The knockdown of HSF1 increased airway wall thickness, airway hyperresponsiveness, OVA-specific IgE content, and the number of eosinophils (P<0.05). Compared with the siHSF1-NC group, the siHSF1 group had significantly increased levels of IL-4, IL-5, and IL-13 and significantly reduced expression of IFN-γ in lung tissues and BALF (P<0.05), as well as significantly increased expression of HMGB1 and p-JNK (P<0.05).

CONCLUSIONS

Knockdown of HSF1 aggravates airway hyperresponsiveness and airway inflammation in asthmatic mice, and its possible mechanism may involve the negative regulation of HMGB1 and JNK.

[Expression of long non-coding RNA NANCI in lung tissues of neonatal mice with hyperoxia-induced lung injury and its regulatory effect on NKX2.1]

OBJECTIVE

To investigate the expression of long non-coding RNA NANCI in lung tissues of neonatal mice with hyperoxia-induced lung injury and its regulatory effect on NKX2.1.

METHODS

A total of 48 neonatal C57BL/6J mice were randomly divided into an air group and a hyperoxia group, with 24 mice in each group. Each group was further divided into 7-day, 14-day, and 21-day subgroups, with 8 mice in each subgroup. The mice in the air group were fed in the indoor environment (FiO²=21%) and those in the hyperoxia group were fed in a high-oxygen box (oxygen concentration: >95%). The mice were sacrificed at each time point and lung tissue samples were collected. Hematoxylin and eosin staining was used to observe pathological changes in lung tissues. RT-qPCR and Western blot were used to measure the mRNA and protein expression of NANCI and NKX2.1.

RESULTS

The air group had the highest mRNA expression of NANCI and NKX2.1 at 7 days and the same level of mRNA expression at 14 and 21 days. Compared with the air group, the hyperoxia group had significant reductions in the degree of alveolarization and radial alveolar count (RAC) in lung tissues (P<0.05), and in the hyperoxia group, RAC gradually decreased over the time of hyperoxia exposure (P<0.05). The hyperoxia group had significantly lower mRNA and protein expression of NANCI and NKX2.1 than the air group at all time points (P<0.05). In both groups, the relative mRNA and protein expression of NANCI and NKX2.1 gradually decreased over the time of hyperoxia exposure (P<0.05). The expression of NKX2 was positively correlated with that of NANCI (r=0.585, P=0.003), and the expression of NKX2 and NANCI was positively correlated with RAC in the hyperoxia group (r=0.655 and 0.541 respectively, P<0.05).

CONCLUSIONS

NANCI may be involved in the development of immature lung tissues. Lung injury is gradually aggravated over the time of hyperoxia exposure. The levels of NANCI and NKX2.1 are associated with the severity of lung injury, suggesting that the NANCI/NKX2.1 target gene signaling pathway might be involved in the development of hyperoxia-induced lung injury in neonatal mice.

[HMGB1/TLR4/NF-κB signaling pathway and role of vitamin D in asthmatic mice]

OBJECTIVE

To investigate the changes in the mRNA and protein expression of high-mobility group box 1 (HMGB1), Toll-like receptor 4 (TLR4), and nuclear factor-kappa B (NF-κB) in lung tissues of asthmatic mice and the interventional effect of vitamin D.

METHODS

A total of 48 BALB/c mice were randomly divided into control group, asthma group, and 1,25-(OH)₂D₃ intervention group, with 16 mice in each group. An animal model of asthma was established, and lung tissue samples were taken in each group at weeks 1 and 2 of ovalbumin challenging. Conventional hematoxylin-eosin staining was used to measure airway wall thickness. Immunohistochemical staining was used to observe the expression of HMGB1, TLR4, and NF-κB in lung tissues. Quantitative real-time PCR and Western blot were used to investigate the changes in the mRNA and protein expression of HMGB1, TLR4, and NF-κB.

RESULTS

At weeks 1 and 2 of ovalbumin challenging, compared with the control group, the asthma group had a significant increase in airway wall thickness and the intervention group had a significant reduction compared with the asthma group (P<0.05). The asthma group had significantly higher mRNA expression of HMGB1, TLR4, and NF-κB in lung tissues than the control group, and the intervention group had significantly lower mRNA expression of TLR4 and NF-κB than the asthma group (P<0.05). At week 1 of ovalbumin challenging, there was no significant difference in the mRNA expression of HMGB1 between the intervention group and the asthma group (P>0.05). At week 2, the intervention group had a significant reduction in the mRNA expression of HMGB1 compared with the asthma group (P<0.05). At weeks 1 and 2 of ovalbumin challenging, the asthma group had significantly higher protein expression of HMGB1, TLR4, and NF-κB in lung tissues than the control group, and the intervention group had significantly lower expression than the asthma group (P<0.05). Airway wall thickness was positively correlated with the mRNA expression of HMGB1, TLR4, and NF-κB in lung tissues (r=0.804, 0.895, and 0.834; P<0.05).

CONCLUSIONS

The HMGB1/TLR4/NF-κB signaling pathway plays an important role in the pathogenesis of asthma, and an appropriate amount of 1,25-(OH)₂D₃ has a regulatory effect on this pathway and may prevent the progression of asthma. Therefore, 1,25-(OH)₂D₃ is expected to become a new choice for the treatment of asthma.

[HMGB1/TLR4/NF-κB signaling pathway and role of vitamin D in asthmatic mice]

OBJECTIVE

To investigate the changes in the mRNA and protein expression of high-mobility group box 1 (HMGB1), Toll-like receptor 4 (TLR4), and nuclear factor-kappa B (NF-κB) in lung tissues of asthmatic mice and the interventional effect of vitamin D.

METHODS

A total of 48 BALB/c mice were randomly divided into control group, asthma group, and 1,25-(OH)2D3 intervention group, with 16 mice in each group. An animal model of asthma was established, and lung tissue samples were taken in each group at weeks 1 and 2 of ovalbumin challenging. Conventional hematoxylin-eosin staining was used to measure airway wall thickness. Immunohistochemical staining was used to observe the expression of HMGB1, TLR4, and NF-κB in lung tissues. Quantitative real-time PCR and Western blot were used to investigate the changes in the mRNA and protein expression of HMGB1, TLR4, and NF-κB.

RESULTS

At weeks 1 and 2 of ovalbumin challenging, compared with the control group, the asthma group had a significant increase in airway wall thickness and the intervention group had a significant reduction compared with the asthma group (P<0.05). The asthma group had significantly higher mRNA expression of HMGB1, TLR4, and NF-κB in lung tissues than the control group, and the intervention group had significantly lower mRNA expression of TLR4 and NF-κB than the asthma group (P<0.05). At week 1 of ovalbumin challenging, there was no significant difference in the mRNA expression of HMGB1 between the intervention group and the asthma group (P>0.05). At week 2, the intervention group had a significant reduction in the mRNA expression of HMGB1 compared with the asthma group (P<0.05). At weeks 1 and 2 of ovalbumin challenging, the asthma group had significantly higher protein expression of HMGB1, TLR4, and NF-κB in lung tissues than the control group, and the intervention group had significantly lower expression than the asthma group (P<0.05). Airway wall thickness was positively correlated with the mRNA expression of HMGB1, TLR4, and NF-κB in lung tissues (r=0.804, 0.895, and 0.834; P<0.05).

CONCLUSIONS

The HMGB1/TLR4/NF-κB signaling pathway plays an important role in the pathogenesis of asthma, and an appropriate amount of 1,25-(OH)2D3 has a regulatory effect on this pathway and may prevent the progression of asthma. Therefore, 1,25-(OH)2D3 is expected to become a new choice for the treatment of asthma.

[Expression and significance of mTOR/4EBP1/HIF-1α/VEGF signaling pathway in lung tissues of asthmatic mice]

OBJECTIVE

To study the expression and significance of the mammalian target of rapamycin (mTOR)/eukaryote initiating factor 4E binding protein 1(4EBP1)/hypoxia inducible factor-1α (HIF-1α)/vascular endothelial growth factor (VEGF) signaling pathway in asthmatic mice.

METHODS

Forty SPF level 6-8 week-old female Balb/C mice were randomly divided into control, asthma, budesonide and mTOR inhibitor (rapamycin) intervention groups (n=10 each). The asthmatic mouse model was prepared via OVA induction and challenge test. The intervention groups were administered with rapamycin at the dosage of 3 mg/kg by an intraperitoneal injection or budesonide suspension at the dosage of l mg by aerosol inhalation respectively 30 minutes before the OVA challenge. The control and asthma groups were treated with normal saline instead. The concentrations of HIF-1α and VEGF in bronchoalveolar lavage fluid (BALF) were examined using ELISA 24 hours after the last challenge. The pathological changes of lung tissue were observed by hematoxylin-eosin (HE) staining. The p-mTOR and p-4EBP1 from the lung tissues were detected by immunohistochemistry and Western blot. Pearson analysis was used to study the correlation between p-mTOR, p-4EBP1, HIF-1α, and VEGF expression.

RESULTS

Compared with the control group, inflammatory cell infiltration and secretions in the trachea increased in the asthma group. The levels of HIF-1α and VEGF in BALF and p-mTOR and p-4EBP1 expression in lung tissues also increased (P<0.01). Compared with the asthma group, inflammatory cell infiltration and secretions in the trachea were reduced in the two intervention groups, and the levels of HIF-1α and VEGF in BALF and p-mTOR and p-4EBP1 expression in lung tissues were also reduced (P<0.01). There were no significant differences in the above changes between the two intervention groups and control group (P>0.05). In the asthma group, there was a pairwise positive correlation between lung p-mTOR and p-4EBP1 expression and HIF-1α and VEGF levels in BALF (P<0.05). However, there were no correlations in the above indexes in the intervention groups and control group.

CONCLUSIONS

p-mTOR, p-4EBP1, HIF-1α and VEGF together are involved in the pathogenesis of asthma. Rapamycin treatment can block this signaling pathway, suggesting that this pathway can be used as a novel target for asthma treatment.

[Effect of montelukast sodium intervention on airway remodeling and percentage of Th17 cells/CD4+CD25+ regulatory T cells in asthmatic mice]

OBJECTIVE

To study the dynamic changes in the percentage of Th17 cells/CD4⁺CD25⁺ regulatory T cells after intervention with montelukast sodium, a leukotriene receptor antagonist, in asthmatic mice and the association between them.

METHODS

Balb/c mice were randomly divided into blank group, asthma group, and montelukast sodium group. The asthmatic mouse model of airway remodeling was established by sensitization with intraperitoneal injection of chicken ovalbumin (OVA) and aluminum hydroxide suspension and aerosol inhalation of OVA. The mice in the blank group were given normal saline, and those in the montelukast sodium group were given montelukast sodium by gavage before aerosol inhalation. Eight mice were randomly sacrificed within 24 hours after 2, 4, and 8 weeks of aerosol inhalation. The pathological sections of lung tissue were used to observe the degree of airway remodeling. Flow cytometry was used to measure the percentages of Th17 cells and CD4⁺CD25⁺ regulatory T cells in CD4⁺ T cells.

RESULTS

The asthma group and the montelukast sodium group had significantly higher bronchial wall thickness and smooth muscle thickness at all time points compared with the blank group (P<0.05). At 8 weeks of intervention, the montelukast sodium group had significantly greater improvements in the above changes compared with the asthma group (P<0.05). Compared with the blank group, the asthma group and the montelukast sodium group had significant increases in Th17 cells (positively correlated with airway remodeling) and significant reductions in CD4⁺CD25⁺ regulatory T cells (negatively correlated to airway remodeling) at all time points (P<0.05). At 8 weeks of intervention, the montelukast sodium group had a significant reduction in the number of Th17 cells and a significant increase in the number of CD4⁺CD25⁺ regulatory T cells compared with the asthma group (P<0.05).

CONCLUSIONS

Montelukast sodium intervention can alleviate airway remodeling and achieve better improvements over the time of intervention. The possible mechanism may be related to the improvement of immunologic derangement of CD4⁺CD25⁺ regulatory T cells and inhibition of airway inflammation.

[Effect of respiratory syncytial virus-related pulmonary infection on endogenous metabolites in large intestinal mucosa in mice]

OBJECTIVE

To investigate the effect of respiratory syncytial virus (RSV)-related pulmonary infection on endogenous metabolites in large intestinal mucosa in BALB/c mice using metabolomics technology based on gas chromatography-mass spectrometry (GC-MS).

METHODS

Mice were randomly divided into a control group and a RSV pneumonia model group (n=16 each). The mouse model of RSV pneumonia was established using intranasal RSV infection (100×TCID₅₀, 50 μL/mouse, once a day). After 7 days of intranasal RSV infection, the mice were sacrificed and GC-MS was used to identify endogenous metabolites and measure the changes in their relative content in colon tissue. SMCA-P12.0 software was used to perform principal component analysis (PCA) and orthogonal partial least squares-discriminant analysis (OPLS-DA) for endogenous metabolites in colon tissue. The differentially expressed metabolites in colon tissue were imported into the metabolic pathway platform Metaboanalyst to analyze related metabolic pathways.

RESULTS

PCA and OPLS-DA showed significant differences between the control and RSV pneumonia model groups. A total of 32 metabolites were identified in the colon tissue of the mice with RSV pneumonia. The RSV pneumonia model group had significant increases in the content of leucine, isoleucine, glycine, alanine, arachidonic acid, and lactic acid, which were related to the valine, leucine, isoleucine, arachidonic acid, and pyruvic acid metabolic pathways.

CONCLUSIONS

RSV pneumonia might cause metabolic disorders in the large intestinal tissue in mice.

[Role of transient receptor potential vanilloid 1 in airway inflammation in asthmatic mice]

OBJECTIVE

To study the effects of the change in transient receptor potential vanilloid 1 (TRPV1) channel activity on the degree of airway inflammation in asthmatic mice.

METHODS

BALB/c mice were randomly divided into control, asthma, capsaicin (TRPV1 agonist), capsazepine (TRPV1 antagonist), and dexamethasone groups. The asthmatic mouse model was established by intraperitoneal injection of mixed ovalbumin-aluminium hydroxide solution and ultrasonic atomization with OVA for sensitization and challenge. The capsaicin, capsazepine, and dexamethasone groups were given intraperitoneal injection of capsaicin (30 μg/kg), capsazepine (10 μmol/kg), and dexamethasone (2 mg/kg) respectively, at 30 minutes before challenge. Hematoxylin and eosin staining was used to observe the degree of pulmonary inflammation. ELISA was used to measure the content of interleukin-8 (IL-8) and interleukin-13 (IL-13) in bronchoalveolar lavage fluid (BALF). Real-Time PCR was used to measure the relative content of TRPV1 mRNA in lung tissue.

RESULTS

Compared with the asthma group, the capsazepine and dexamethasone groups showed reduced pulmonary inflammation, while the capsaicin group showed aggravated pulmonary inflammation. Compared with the control group, the asthma and capsaicin groups showed increases in the content of IL-13 and IL-8 in BALF and the mRNA expression of TRPV1 in lung tissue (P<0.05). Compared with the asthma group, the capsazepine and dexamethasone groups showed reductions in the content of IL-13 and IL-8 in BALF and the mRNA expression of TRPV1 in lung tissue (P<0.05). The capsaicin group showed increases in the content of IL-13 and IL-8 in BALF (P<0.05).

CONCLUSIONS

TRPV1 channel agonist and antagonist can influence the degree of airway inflammation in asthmatic mice. Dexamethasone may reduce airway inflammation through regulating TRPV1 level.

[Inhibitory effect of KyoT2 overexpression on proliferation and migration of airway smooth muscle cells in mice with asthma]

OBJECTIVE

To investigate the effect of KyoT2 on the proliferation and migration of airway smooth muscle cells (ASMCs) in mice with asthma.

METHODS

Ovalbumin (OVA) was used to establish the asthmatic model of airway remodeling in BALB/c mice. ASMCs were isolated and cultured, and primarily cultured ASMCs were used as the control group. The expression of KyoT2 in ASMCs was measured in the control and asthma groups. After the ASMCs from asthmatic mice were transfected with pCMV-Myc (empty vector group) or pCMV-Myc-KyoT2 plasmid with overexpressed KyoT2 (KyoT2 expression group) for 48 hours, RT-PCR and Western blot were used to measure the mRNA and protein expression of KyoT2, the MTT assay and BrdU assay were used to measure the proliferation of ASMCs, and Transwell assay was used to measure the migration of ASMCs. Western blot was used to determine the effect of KyoT2 overexpression on the protein expression of RBP-Jκ, PTEN, and AKT.

RESULTS

Compared with the control group, the asthma group had significantly downregulated expression of KyoT2 in ASMCs, and the KyoT2 expression group had significantly upregulated expression of KyoT2 in ASMCs (P<0.05). Compared with the empty vector group, overexpressed KyoT2 significantly inhibited cell proliferation and migration, downregulated the expression of RBP-Jκ and AKT, and upregulated the expression of PTEN.

CONCLUSIONS

Overexpressed KyoT2 can inhibit the proliferation and migration of ASMCs through the negative regulation of RBP-Jκ/PTEN/AKT signaling pathway.

[Role of transient receptor potential vanilloid 1 in airway inflammation in asthmatic mice]

OBJECTIVE

To study the effects of the change in transient receptor potential vanilloid 1 (TRPV1) channel activity on the degree of airway inflammation in asthmatic mice.

METHODS

BALB/c mice were randomly divided into control, asthma, capsaicin (TRPV1 agonist), capsazepine (TRPV1 antagonist), and dexamethasone groups. The asthmatic mouse model was established by intraperitoneal injection of mixed ovalbumin-aluminium hydroxide solution and ultrasonic atomization with OVA for sensitization and challenge. The capsaicin, capsazepine, and dexamethasone groups were given intraperitoneal injection of capsaicin (30 μg/kg), capsazepine (10 μmol/kg), and dexamethasone (2 mg/kg) respectively, at 30 minutes before challenge. Hematoxylin and eosin staining was used to observe the degree of pulmonary inflammation. ELISA was used to measure the content of interleukin-8 (IL-8) and interleukin-13 (IL-13) in bronchoalveolar lavage fluid (BALF). Real-Time PCR was used to measure the relative content of TRPV1 mRNA in lung tissue.

RESULTS

Compared with the asthma group, the capsazepine and dexamethasone groups showed reduced pulmonary inflammation, while the capsaicin group showed aggravated pulmonary inflammation. Compared with the control group, the asthma and capsaicin groups showed increases in the content of IL-13 and IL-8 in BALF and the mRNA expression of TRPV1 in lung tissue (P<0.05). Compared with the asthma group, the capsazepine and dexamethasone groups showed reductions in the content of IL-13 and IL-8 in BALF and the mRNA expression of TRPV1 in lung tissue (P<0.05). The capsaicin group showed increases in the content of IL-13 and IL-8 in BALF (P<0.05).

CONCLUSIONS

TRPV1 channel agonist and antagonist can influence the degree of airway inflammation in asthmatic mice. Dexamethasone may reduce airway inflammation through regulating TRPV1 level.

[Effect of triggering receptor expressed on myeloid cells 2 overexpression on airway inflammation and remodeling in mice with allergic asthma]

OBJECTIVE

To investigate the effect of triggering receptor expressed on myeloid cells 2 (TREM-2) overexpression on airway inflammation and remodeling in mice with asthma.

METHODS

A total of 40 BALB/c mice were randomly divided into normal control, asthma, empty vector, and TREM-2 overexpression groups (n=10 each). Ovalbumin (OVA) sensitization and challenge were performed to establish the model of asthma. The mice in the control group were given normal saline, and those in the empty vector and TREM-2 overexpression groups were transfected with adenovirus vector and TREM-2 adenovirus, respectively. RT-PCR and Western blot were used to measure the expression of TREM-2, MMP-2, MMP-9, ADAM33, and ADAM8. Bronchoalveolar lavage fluid (BALF) was collected to perform cell counting and classification. ELISA was used to measure the total serum level of IgE and the levels of cytokines in BALF.

RESULTS

Compared with the control group, the asthma group showed significant reductions in the mRNA and protein expression of TREM-2 (P<0.05), a significantly increased level of Th2 cytokine (P<0.05), and significantly increased numbers of total cells and classified cells. Compared with the asthma group, the TREM-2 overexpression group showed a significantly reduced level of Th2 cytokine (P<0.05), a significantly reduced level of IgE (P<0.05), and significantly reduced numbers of total cells and classified cells (P<0.05), as well as significantly downregulated expression of the inflammatory factors and growth factors MMP-2, MMP-9, TGF-β1, ADAM8, and ADAM33 (P<0.05).

CONCLUSIONS

TREM-2 overexpression significantly alleviates airway inflammation and airway remodeling in mice with asthma and may become a potential target for the prevention and treatment of childhood asthma.

脂肪间充质干细胞移植对食物过敏小鼠免疫干预作用

OBJECTIVE

To investigate the immunoregulatory effect of adipose-derived stem cell (ADSC) transplantation by intraperitoneal injection in food-allergic young mice before and after ovalbumin (OVA) sensitization.

METHODS

Thirty-two 3-week-old female Balb/c mice were randomly divided into control, allergic model, ADSC treatment, and ADSC prevention groups (n=8 each). A young mouse model of food allergy was established by OVA sensitization via intraperitoneal injection. Each mouse from the prevention and treatment groups was transplanted with 1×10(6) ADSCs on days 1 and 15 post-sensitization, respectively. The allergic symptoms of all groups were observed and scored. The jejunal villi and inflammatory cell infiltration were observed by hematoxylin-eosin staining. Serum levels of allergy-related inflammatory cytokines were measured by Luminex.

RESULTS

Compared with the allergic model group, the ADSC prevention and ADSC treatment groups had significantly reduced allergic symptom scores (P<0.05). The two groups also showed significantly alleviated allergic pathological damage of the jejunal mucosa. Serum levels of interleukin (IL)-4, IL-5, IL-6, IL-17A, IL-22 and IL-23 were significantly lower in the ADSC prevention and treatment groups than in the allergic model group (P<0.05). However, the ADSC treatment group had a significantly increased serum interferon-γ level and a significantly reduced serum monocyte chemotactic protein-1 level compared with the allergic model and ADSC prevention groups (P<0.05).

CONCLUSIONS

ADSC transplantation, performed before or after sensitization, has an immunoregulatory effect on food allergy in young Balb/c mice, but this effect is better if transplantation is performed after sensitization.

呼吸道合胞病毒感染后期Poly(I:C)诱发小鼠气道炎症及其机制研究

OBJECTIVE

To investigate the pathogenic mechanisms of airway inflammation and recurrent wheezing induced by recurrent respiratory virus infection after respiratory syncytial virus (RSV) infection.

METHODS

Sixty-four female BALB/c mice (aged 6-8 weeks) were randomly divided into four groups: control, RSV, Poly(I:C), and RSV+Poly(I:C) (n=16 each). The bronchoalveolar lavage fluid (BALF) was collected on the 3rd day after Poly(I:C) administration, and the total cell number and differential counts in BALF were determined. Hematoxylin-eosin staining was used to observe pulmonary pathological changes. The airway responsiveness was detected. ELISA was used to measure the levels of interferon-γ (IFN-γ), interleukin-4 (IL-4), interleukin-13 (IL-13), matrix metallopeptidase-9 (MMP-9), and tissue inhibitor of metalloproteinase-1 (TIMP-1) in BALF.

RESULTS

Compared with the other three groups, the RSV+Poly(I:C) group had significant increases in the total number of inflammatory infiltrating cells in the airway, airway responsiveness, and MMP-9 level in BALF (P<0.05). The RSV+Poly(I:C) group showed more severe pulmonary tissue injuries compared with the control and RSV groups (P<0.01). Compared with the RSV group, the RSV+Poly(I:C) group showed significant reductions in the levels of IL-4 and TIMP-1 in BALF (P<0.01).

CONCLUSIONS

Viral re-infection in the late stage of RSV infection may cause an imbalance of MMP-9/TIMP-1 expression and thus contribute to aggravated airway inflammation.

Effect of hepatic insulin expression on lipid metabolism in diabetic mice

BACKGROUND

Hypertriglyceridemia is a common lipid disorder that is characterized by elevated plasma levels of triglyceride (TG)-rich particles, such as very low-density lipoprotein (VLDL), in poorly controlled diabetes. The aim of the present study was to determine the potential therapeutic effect of hepatic insulin production on hypertriglyceridemia in mice.

METHODS

Mice were induced diabetic and hypertriglyceridemic by streptozotocin (STZ) treatment. Using an adenovirus-mediated gene transfer approach, we delivered rat preproinsulin cDNA into the liver of diabetic mice and then determined plasma TG metabolism. To investigate the mechanism by which hepatic insulin improves TG metabolism, we determined hepatic expression of apolipoprotein C-III (ApoC-III), a structural moiety and functional inhibitor of VLDL-TG catabolism.

RESULTS

Plasma VLDL-TG levels were markedly elevated in STZ-treated mice, and were accompanied by hyperglycemia and hypertriglyceridemia. These metabolic abnormalities were restored to near normal following hepatic insulin production in insulin vector-treated diabetic mice. In contrast, hypertriglyceridemia and hyperglycemia persisted in control vector-treated diabetic animals. Hepatic ApoC-III expression became deregulated secondary to insulin deficiency, contributing to impaired TG metabolism in diabetic mice. Hepatic insulin production suppressed excessive hepatic ApoC-III production to basal levels.

CONCLUSION

Hepatic insulin production is efficacious in correcting hypertriglyceridemia associated with insulin deficiency in diabetic mice.

[Tranilast inhibits myocardial fibrosis in mice with viral myocarditis]

OBJECTIVE

To investigate the effect of tranilast on myocardial fibrosis in mice with viral myocarditis (VMC).

METHODS

Male balb/c mice (n=72) were randomly divided into control, VMC and tranilast groups (n=24 each). In the VMC and tranilast groups, the mice were infected with Coxsackie virus B3 (CVB3) to prepare VMC model, while the control group was treated with Eagle's medium. After modeling, the tranilast group was administrated with tranilast [200 mg/(kg.d)] until the day before sampling. On days 7, 14 and 28 after CVB3 or Eagle's medium infection, heart specimens (n=8) were taken and examined after Toluidine blue staining and Nissl staining for counts of mast cells (MC), hematoxylin-eosin staining for myocardial pathological changes, and Masson staining for myocardial fibrosis. The expression of CTGF and type I collagen (Col I) in the myocardial tissue was measured by RT-PCR and Western blot. The correlations of CTGF mRNA expression with MC counts and Col I expression were analyzed.

RESULTS

The myocardial pathological changes and collagen volume fraction in the VMC group were significantly higher than in the control group at all three time points (P<0.05). Tranilast treatment significantly decreased the myocardial pathological changes and collagen volume fraction compared with the VMC group (P<0.05). The mRNA and protein expression of CTGF and Col I increased in the VMC group compared with the control group, and the increases were reduced with tranilast treatment (P<0.05). The number of MC was positively correlated to CTGF mRNA expression on the 7th day and 14th day (r=0.439, P=0.049) in the VMC group. There were positive correlations between the mRNA expression of Col I and CTGF on the 7th day and 14th day (r=0.646, P=0.007) and the 28th day (r=0.326, P=0.031).

CONCLUSIONS

Tranilast may inhibit the aggregation of MC and down-regulate the expression of CTGF, relieving myocardial fibrosis of mice with VMC.

[Tranilast inhibits myocardial fibrosis in mice with viral myocarditis]

OBJECTIVE

To investigate the effect of tranilast on myocardial fibrosis in mice with viral myocarditis (VMC).

METHODS

Male balb/c mice (n=72) were randomly divided into control, VMC and tranilast groups (n=24 each). In the VMC and tranilast groups, the mice were infected with Coxsackie virus B3 (CVB3) to prepare VMC model, while the control group was treated with Eagle's medium. After modeling, the tranilast group was administrated with tranilast [200 mg/(kg.d)] until the day before sampling. On days 7, 14 and 28 after CVB3 or Eagle's medium infection, heart specimens (n=8) were taken and examined after Toluidine blue staining and Nissl staining for counts of mast cells (MC), hematoxylin-eosin staining for myocardial pathological changes, and Masson staining for myocardial fibrosis. The expression of CTGF and type I collagen (Col I) in the myocardial tissue was measured by RT-PCR and Western blot. The correlations of CTGF mRNA expression with MC counts and Col I expression were analyzed.

RESULTS

The myocardial pathological changes and collagen volume fraction in the VMC group were significantly higher than in the control group at all three time points (P<0.05). Tranilast treatment significantly decreased the myocardial pathological changes and collagen volume fraction compared with the VMC group (P<0.05). The mRNA and protein expression of CTGF and Col I increased in the VMC group compared with the control group, and the increases were reduced with tranilast treatment (P<0.05). The number of MC was positively correlated to CTGF mRNA expression on the 7th day and 14th day (r=0.439, P=0.049) in the VMC group. There were positive correlations between the mRNA expression of Col I and CTGF on the 7th day and 14th day (r=0.646, P=0.007) and the 28th day (r=0.326, P=0.031).

CONCLUSIONS

Tranilast may inhibit the aggregation of MC and down-regulate the expression of CTGF, relieving myocardial fibrosis of mice with VMC.

[Screening and validation of long non-coding RNAs in brain tissue of inflammation-induced preterm mice]

OBJECTIVE

To investigate the association between long non-coding RNAs (lncRNAs) and brain injury in inflammation-induced preterm mice, and to provide a reference for the prevention and treatment of brain injury.

METHODS

An intraperitoneal injection of lipopolysaccharide in pregnant mice was performed to establish a model of inflammation-induced preterm mice with brain injury (preterm group). The full-term mice delivered by normal pregnant mice were used as controls (full-term group). The lncRNA chip assay was used to screen out the lncRNAs associated with brain injury in preterm mice. Quantitative real-time PCR was used to validate the lncRNAs identified by the above method.

RESULTS

The preterm and full-term groups showed significant differences in the expression of 1 978 lncRNAs (P<0.05), consisting of 786 up-regulated lncRNAs and 1 192 down-regulated lncRNAs, and 29 lncRNAs were 1.5 or more times differentially expressed between the two groups. A further analysis was performed for the 10 most differentially expressed lncRNAs, and the results showed that these lncRNAs were involved in the biological processes including transcription, signal transduction, apoptosis, cell cycle, and inflammatory response, as well as G protein-coupled receptor signaling pathway and neuropeptide signaling pathway. Real-time PCR was performed to validate the expression of two lncRNAs in brain tissue in the preterm and full-term groups, and the results were consistent with those of the chip assay.

CONCLUSIONS

The expression profiles of lncRNAs in brain tissue change significantly in inflammation-induced preterm mice, and the G protein-coupled receptor signaling pathway may be involved in the pathogenesis of preterm brain injury.

[Expression and role of Tc17 cells in mice with neutrophilic asthma]

OBJECTIVE

To determine the proportion of Tc17 cells in the lungs of mice with neutrophilic(NEU) asthma, and to investigate the role of Tc17 cells in the pathogenesis of NEU asthma.

METHODS

Thirty-two C57/B6 mice of clean grade were randomly divided into two groups: NEU asthma and control. The mice in the NEU asthma group were sensitized by airway instillation of ovalbumin (OVA) and lipopolysaccharide (LPS), and challenged with an aerosol of OVA, while those in the control group were sensitized and challenged with normal saline. At 24 hours after the final challenge, bronchoalveolar lavage fluid (BALF) was collected, and the total number and differential counts of nucleated cells and percentage of each type were determined. The lung tissues were separated and hematoxylin-eosin staining was performed to observe the pathological changes of lungs; flow cytometry was applied to determine the percentages of Tc17 and Th17 cells in the lung tissues. Enzyme-linked immunosorbent assay was applied to determine the levels of interleukin-6 (IL-6), transforming growth factor &beta; (TGF-&beta;), and interleukin-17 (IL-17) in BALF.

RESULTS

The NEU asthma group had a significantly higher total number of nucleated cells, a significantly higher percentage of eosinophils, and a significantly higher percentage of neutrophils in BALF than the control group (P<0.01). The NEU asthma group also had significantly higher percentages of Tc17 and Th17 cells than the control group (P<0.01). In the NEU asthma group, the percentage of Tc17 cells was positively correlated with that of Th17 cells (P<0.05). The NEU asthma group had significantly higher concentrations of IL-6, TGF-&beta;, and IL-17 in BALF than the control group (P<0.05).

CONCLUSIONS

The expression of Tc17 cells in the lung tissues increases in mice with NEU asthma, and the increased number of Tc17 cells may be involved in the pathogenesis of NEU asthma. Tc17 cells may play an important role in NEU asthma through IL-17.