Study on the therapeutic effect of glucocorticoids on acute kidney injury in rats exposed to diquat

AIMS

To preliminarily explore, whether glucocorticoids have a therapeutic effect on diquat-induced acute kidney injury in rats.

METHOD

150 Wistar rats were randomly divided into six groups: exposure model group (DQ group), dexamethasone control group (GC group), blank control group (Ctrl group), dexamethasone 2.1 mg/kg dose group (DQ+L-GC group), dexamethasone 4.2 mg/kg dose group (DQ+M-GC group), and dexamethasone 8.4 mg/kg dose group (DQ+H-GC group), with 25 rats in each group. Each group was further divided into five subgroups, 24 h, 3 d, 7 d, 14 d, and 21 d after exposure, according to the feeding time and the course of treatment, with five animals in each subgroup. The rats in DQ, DQ+L-GC, DQ+M-GC, and DQ+H-GC groups were administered 115.5 mg/kg diquat by gavage, respectively. Moreover, 30 min after gavage, rats in DQ+L-GC group, DQ+M-GC group, DQ+H-GC group and GC group were intragastric administered dexamethasone 2.1 mg/kg, 4.2 mg/kg, 8.4 mg/kg and 8.4 mg/kg, respectively. After 7 days, the intraperitoneal injection of dexamethasone was changed to 6.3 mg/kg prednisone by intragastric administration. Subsequently, 7 days later, it was changed to 3.15 mg/kg prednisone by intragastric administration until the end of the experiment on 21 days. After the start of the experiment, changes in the conditions of the rats in each group were observed at a fixed time every day, changes in the body weight of the rats were monitored at the same time, and the death of the rats was recorded at 24 h, 3 d, 7 d, 14 d, and 21 d after exposure. The rats were sacrificed by an intraperitoneal injection of 100 mg/kg sodium pentobarbital overdose. Blood was collected by puncture of the inferior vena cava, used to determine Cr and BUN. The upper segment of the left kidney was collected for histopathological examination. Elisa was used to detect neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 (KIM-1) in the lower segment of left kidney. TLR4, Myd88, and NF-κB were detected in the right kidney.

RESULTS

(1) After exposure, most rats in DQ group, DQ+L-GC group, DQ+M-GC group and DQ+H-GC group showed shortness of breath, oliguria, diarrhea, yellow hair and other symptoms. No symptoms and related signs were observed in Ctrl group and GC group. (2) The weight of rats in the Ctrl group and the GC group increased slowly during the test. the body weight of the rats in the DQ, DQ+L-GC, DQ+M-GC, and DQ+H-GC groups continued to decrease after self-infection. Body weight dropped to the lowest point at approximately 7 d, and gradually increased from 7 d to 21 d. (3) A small amount of capillary congestion in the medulla was observed after 7 days in the GC group. The DQ group showed tubular atrophy, edema of the epithelial cells, and over time, the tubules were seen dilated and became irregular in shape; large amount of capillary congestion was also observed in the renal cortex and medulla. The renal injury in the DQ+L-GC group was less than that in the DQ group. DQ+H-GC group had no obvious injury before 7 d, but more renal tubules were seen in the DQ+H-GC group from 7 d to 14 d. (4) Compared with the DQ group, there was no difference before 14 d, and at 14 d-21 d, DQ+L-GC group, DQ+M-GC group, DQ+H-GC group all had different degrees of decline. NGAL content: Compared with the DQ group, the content of NGAL and KIM-1 in kidney tissue of the DQ+L-GC, DQ+M-GC, and DQ+H-GC groups decreased compared with the DQ group at each time node. (5) Compared with the Ctrl group, the expression of TNF-α, TLR4, MyD88, NF-κB in the DQ, DQ+L-GC, DQ+M-GC, and DQ+H-GC groups at each time node increased in the renal tissue. The content of TNF-α, TLR4, MyD88, NF-κB in kidney tissue of the DQ+L-GC, DQ+M-GC, and DQ+H-GC groups at each time node was lower than that in the DQ group.

CONCLUSION

(1) Diquat can cause kidney damage in rats, mainly manifested as renal tubular atrophy, epithelial cell edema, capillary congestion and dilation, and the renal function damage indicators have been improved to varying degrees. (2) Glucocorticoids have therapeutic effects on acute kidney injury in rats exposed to diquat. During the treatment, the efficacy of glucocorticoids did not increase with increasing doses after reaching a dose of 4.2 mg/kg. (3) TLR4 receptor-mediated TLR4/Myd88/NF-κB signaling pathway is involved in the inflammatory response of acute kidney injury in diquat poisoning rats. Glucocorticoids can inhibit the inflammatory response, thereby affecting the expression of TLR4/Myd88/NF-κB signaling pathway-related proteins.

Gender differences in UV-induced skin inflammation, skin carcinogenesis and systemic damage

Ultraviolet (UV) radiation-induced chronic inflammation contributes to all stages of skin tumor development. In addition, gender plays an important role in inflammatory diseases or cancer. In this study, histopathology changes, hematology, oxidative stress and inflammatory response were used to evaluate sex differences in UV-induced chronic inflammation-associated cancer development. The results showed that the male and female mice had photoaging damage at the 9th week. However, skin tumors only appeared in male mice at 31st week. Furthermore, UV increased ROS production, p65, p-p65, IL-6 and TNF-α protein expressions in skin, and these factors elevated more in male mouse model. Hematology results showed that the parameters of blood systemic inflammation were changed in different degrees in model groups, while the pathological results showed inflammatory cell infiltration in the internal organs of both model groups in varying degrees. These results indicate that there are gender differences in UV-induced skin inflammation, carcinogenesis and systemic damage. Moreover, male mice are more sensitive to UV irradiation, which may be responsible to greater oxidative stress and inflammatory damage.

[Electroacupuncture improves locomotor function by regulating expression of inflammation and oxidative stress-related proteins in mice with spinal cord injury]

OBJECTIVE

To observe the effect of electroacupuncture (EA) on the expression of apolipoprotein E (ApoE) and related proteins of inflammation and anti-oxidative stress in spinal cord in mice with spinal cord injury (SCI), so as to explore its mechanisms underlying function repair.

METHODS

Thirty-six female C57BL/6 mice were equally randomized into 3 groups: sham operation, model and EA. The SCI model was established by clamping the spinal cord for 25 s with a serrefine after laminectomy of the 1^st lumbar vertebra (L1). EA (1.5 Hz/7.5 Hz, 1.0 mA) was applied to bila-teral "Zusanli" (ST36) and "Sanyinjiao" (SP6) for 10 min, once a day for 7 days. The hindlimb locomotor function was assessed according to the state of the range of motion, coordination, claw gesture of the hind leg ankle-joint, trunk stabi-lity and the tail posture by using Basso Mouse Scale(BMS). The histopathological changes of the injured area of the spinal cord were determined by H.E. staining. The expression levels of ApoE, phosphorylated nuclear transcription factor-κB(p-NF-κB), interleukin 1 beta(IL-1β), phosphorylated extracellular regulatory protein kinase(p-ERK1/2), extracellular regulatory protein kinase(ERK1/2), nuclear factor erythroid 2-related factor 2(Nrf2) and heme oxidase-1(HO-1) in the spinal cord were detected by Western blot, and the glial fibrillary acidic protein (GFAP)-positive astrocytes were displayed by immunofluorescence staining.

RESULTS

After modeling, the BMS scores were significantly decreased in the model group compared with the sham operation group (P<0.05). Following EA, the BMS scores were markedly increased in the EA group relevant to the model group (P<0.05), suggesting an improvement of the hindlimb locomotor function. H.E. stain showed structural disorder with lots of cavities, severe inflammatory infiltration with large quantity of inflammatory cells, and apparent reduction of normal neurons in the injured spinal cord tissue of model group, which was milder in the EA group. The expression levels of ApoE, p-NF-κB, IL-1β, p-ERK1/2 (not ERK1/2), Nrf2 and HO-1 were significantly increased in the model group than those in the sham operation group (P<0.05). Compared with the model group, the expression levels of ApoE, p-ERK1/2, Nrf2 and HO-1 were further notably up-regulated (P<0.05), and those of p-NF-κB and IL-1β proteins obviously down-regulated in the EA group (P<0.05). Immunoflorescence staining showed that the number of GFAP-positive cells was apparently increased in the model group compared with the sham operation group and observably decreased in the EA group relevant to the model group (P<0.05).

CONCLUSION

EA can significantly improve locomotor function in SCI mice, which is associated with its effects in reducing inflammation, oxi-dative stress reactions and reactive astrocyte proliferation via up-regulating expression of ApoE, p-ERK1/2, and Nrf2/HO-1 (antioxidant pathway) and inhibiting IL-1β and NF-κB expression.

[The role and mechanism of TRAF2 in the biological behavior of gastric cancer]

Objective: To clarify the effect of TRAF2 in the biological behavior of gastric cancer and explore the mechanism. Methods: TRAF2 stably depleted AGS cell was established. Cell growth was monitored by x-CELLigence system. Cell proliferation was detected using cell viability assay. The apoptosis and cell cycle were detected by flow cytometry. The difference of migration and invasion abilities were measured by real-time xCELLigence system and Transwell. The expression and activity of NF-κB signaling pathway were measured by western blot and TransAM assay. The expression of TRAF2 in gastric cancer tissue and its clinical significance were detected by immunohistochemistry. Results: The cell index of AGS-siTRAF2 cells was significantly lower than that of AGS-sictrl cells at 8 h. In the cell viability assay, the A values of AGS-siTRAF2 cells were 51 296.00±2 631.06, 68 389.25±6 703.21 and 65 559.50±6 339.22 at 24 h, 48 h and 72 h. The values of the viability of AGS-siTRAF2 cells were significantly lower than those of AGS-sictrl cells (P<0.001). The results of flow cytometry showed that the apoptosis rates of AGS-siTRAF2 cells were (1.42±0.07)%, (2.98±0.11)% and (1.56±0.03)% at 24 h, 48 h and 72 h, respectively, which were significantly higher than those of AGS-sictrl cells (all P<0.05). The distribution of S phase in AGS-siTRAF2 cells was (23.57±1.12)%, while that in the AGS-sictrl cells was (19.49±1.19)%. The difference was statistically significant (P=0.012). AGS-siTRAF2 cells migrated much slower than AGS-sictrl cells from 3 h and the number of migrated AGS-sictrl cells was 121.7±6.7 while that of AGS-siTRAF2 cells was 84.0±6.6 (P=0.002). The cell index of AGS-siTRAF2 cells was less than that of AGS-sictrl cells from 3 h. In Transwell assay, the number of invaded AGS-sictrl cells was 109.3±3.1 after 24 h of culture, significantly higher than 79.0±6.2 of AGS-siTRAF2 cells (P=0.002). Western blot analysis showed that the expression levels of RelA, RelB, p50 and p52 in AGS-siTRAF2 cells were significantly lower than those in AGS-sictrl cells. The activities of RelA, RelB, p50 and p52 in AGS-siTRAF2 cells were 0.01±0.00, 0.01±0.01, 0.92±0.01 and 0.53±0.03, respectively, significantly lower than those of AGS-sictrl cells (all P<0.001). High TRAF2 expression (TRAF2-high) was found in 53.0% of GC samples, while TRAF2-high was only observed in 38.0% of the paired adjacent tissues (P=0.033). The expression of TRAF2 was significantly higher in the tubular adenocarcinoma, poor differentiation advanced T, advanced N, and clinical staging (P<0.05). The median survival time were 17 months and 78 months in the TRAF2 high-expression and low-expression groups, respectively, and the difference was statistically significant (P=0.010). Conclusions: Depletion of TRAF2 inhibits the AGS cell growth, migration and invasion. The expression of TRAF2 is increased in gastric tumor tissue. The expression of TRAF2 is associated with the prognosis of gastric cancer.

Relationship between expression of CXCR7 and NF-κB in breast cancer tissue and occurrence of breast cancer and lymphatic metastasis

It is designed to discuss the relationship between the expression of chemokine receptor 7 (chemokine receptor 7, CXCR7) and nuclear transcription factor-κB (nuclear factor kappa B, NF-κB) and the occurrence of the breast cancer and lymphatic metastasis. Method: 80 samples were excised and confirmed as breast cancer through our hospital pathology from January 2014 to December 2016 and tumor tissues and normal mammary tissues 2 cm from the tumor edges were taken as an experimental group and a control group, respectively. The method of immunohistochemical is utilized to test the expression of CXCR7 and NF-κB in the breast cancer tissue, compared with the para-carcinoma tissue, and analyze its relevance with the clinicopathologic features of the breast cancer tissue, such as tumor size, TNM staging, lymphatic metastasis and other conditions. Results: both CXCR7 and NF-κB were highly expressed in the breast cancer tissue, the positive rate was significantly higher that that of paracancerous normal tissues, and the difference was statistically significant. And the expressions of CXCR7 and NF-κB were related to TNM staging of the breast cancer and lymphatic metastasis and unrelated to the tumor size, age, and expressions of ER, PR and HER2. Conclusion: both CXCR7 and NF-κB are related to the malignant grade of the breast cancer and lymphatic metastasis, which may be regarded as in important indicator to judge the prognosis of the breast cancer and be expected to be the new target of curing part of the breast cancer.

Cold-inducible RNA-binding protein mediates cold air inducible airway mucin production through TLR4/NF-κB signaling pathway

Mucus overproduction is an important feature in patients with chronic inflammatory airway diseases and cold air stimulation has been shown to be associated with the severity of these diseases. However, the regulatory mechanisms that mediate excessive mucin production under cold stress remain elusive. Recently, the cold-inducible RNA-binding protein (CIRP) has been shown to be markedly induced after exposure to cold air. In this study, we sought to explore the expression of CIRP within bronchial biopsy specimens, the effect on mucin5AC (MUC5AC) production in chronic inflammatory airway diseases and the potential signaling pathways involved in cold air stimulation process. We found that CIRP protein expression was significantly increased in patients with COPD and in mice treated with cold air. Moreover, cold air stimulation induced MUC5AC expression in wild-type mice but not in CIRP(-/-) mice. In vitro, cold air stress significantly elevated the transcriptional and protein expression levels of MUC5AC in human bronchial epithelial cells. CIRP, toll-like receptor 4 (TLR4) and phosphorylated NF-κB p65 (p-p65) increased significantly in response to cold stress and CIRP siRNA, TLR4 - neutralizing Ab and a specific inhibitor of NF-κB could attenuated cold stress inducible MUC5AC expression. In addition, CIRP siRNA could hindered the expression levels of TLR4 and p-p65 both induced by cold stress. Taken together, these results suggest that airway epithelial cells constitutively express CIRP in vitro and in vivo. CIRP is responsible for cold-inducible MUC5AC expression by activating TLR4/NF-κB signaling pathway.

Regulating effect of activated NF-κB on edema induced by traumatic brain injury of rats

OBJECTIVE

To observe the effect of nuclear transcription factor-κB (NF-κB) on cerebral edema in rats with traumatic brain injury (TBI).

METHODS

Male SD rats with fluid percussion injury (FPI) were selected. After separation and culture, rats' astrocytes all suffered FPI. The expression of NF-κB and the water content were detected at the animal and cellular levels, while the activity of NOX was evaluated at the cellular level.

RESULTS

According to the results, the positive expression of NF-κB and expression of mRNA were significantly increased and the water content was increased for rats after TBI, while NF-κB inhibitor BAY11-7082 could significantly reduce the effect of TBI. 1 and 3 h after FPI of astrocytes, the activation of NF-κB was increased and BAY 11-7082 could significantly improve the injury-induced swelling of astrocytes. After the injury of astrocytes, the activity of NOX was also increased, while BAY 11-7082 could reduce the activity of NOX.

CONCLUSIONS

The results show that the activation of NF-κB in astrocytes is a key factor in the process of cerebral edema after TBI of rats.

Diethylcarbamazine inhibits NF-κB activation in acute lung injury induced by carrageenan in mice

Diethylcarbamazine citrate (DEC) is widely used to treat lymphatic filariasis and Tropical Pulmonary Eosinophilia. A number of studies have reported a possible role in the host immune system, but exactly how DEC exerts this effect is still unknown. The present study reports the effects of DEC pretreatment on NF-κB regulation using the pleurisy model induced by carrageenan. Swiss male mice (Mus musculus) were divided into four experimental groups: control (SAL); carrageenan (CAR); diethylcarbamazine (DEC) and curcumin (CUR). The animals were pretreated with DEC (50mg/kg, v.o), CUR (50mg/kg, i.p) or distilled water for three consecutive days before pleurisy. One way analysis of variance (ANOVA) was performed by Tukey post-hoc test, and values were considered statistically significant when p<0.05. DEC pretreatment reduced tissue damage and the production of inflammatory markers, such as NO, iNOS, PGE2, COX-2, and PARP induced by carrageenan. Similarly, a known inhibitor of NF-κB pathway (curcumin) was also able to reduce these parameters. Like curcumin, DEC prevents NF-κB activation by reducing NF-κB p65 phosphorylation and IκBα degradation. DEC prevented NF-κB activation via p38 MAPK, but did not interfere in the ERK pathway in this experimental model. However, further studies should be developed to confirm this hypothesis. These findings suggest that DEC could be a promising drug for inflammatory disorders, especially in pulmonary diseases such as Acute Lung Inflammation, due its high anti-inflammatory potential which prevents NF-κB activation.

Antiinflammatory Activity of Gynura bicolor ( Hóng Fèng Cài) Ether Extract Through Inhibits Nuclear Factor Kappa B Activation

This study investigated effects of the Gynura bicolor (Roxb. and Willd.) DC. ether extract (GBEE) on nitric oxide (NO) and prostaglandin (PG)E2 production on the lipopolysaccharide (LPS)-induced inflammatory response in RAW 264.7 cells. A composition analysis of GBEE showed that the major compounds were b-carotene, chlorophyll, and quercetin, respectively. Furthermore, NO and PGE2 levels of 120 μg/ml GBEE-treated cells were 70% and 9.8%, respectively, than those of cells treated with LPS alone. Immunoblots assays showed that the GBEE dose-dependently suppressed LPS-induced inducible NO synthase (iNOS) and cyclooxygenase (COX)-2 protein levels. The GBEE significantly decreased cytosolic phosphorylated (p)-IκBa and nuclear p65 protein expressions. Electrophoresis mobility shift assays indicated that the GBEE effectively inhibited nuclear factor kappa B (NF-κB) activation induced by LPS. These results support a role of the GBEE in suppressing activation of NF-κB to inhibit NO and PGE2 production in the LPS-induced inflammatory response by RAW 264.7 cells.

Combination use of ferulic acid, ligustrazine and tetrahydropalmatine inhibits the growth of ectopic endometrial tissue: a multi-target therapy for endometriosis rats

ETHNOPHARMACOLOGICAL RELEVANCE

Ferulic acid (FA), ligustrazine (LZ) and tetrahydropalmatine (THP) are separately isolated from Chinese Angelica, Szechwan Lovage Rhizome and Rhizoma in the Jiawei-Foshou-San formula, a popular traditional Chinese medicine for irregular menses. It has been reported that the combination use of FA+LZ+THP has similar effect on endometriosis, but the underlying mechanisms are unclear. This study was to investigate the combination effects and mechanisms of FA+LZ+THP on endometriosis rats.

MATERIALS AND METHODS

Fifty endometriosis rats were intragastricly treated with FA+LZ+THP for 4 wk. The volume of ectopic endometrial tissue was measured to evaluate the effects. Then the changes in hypothalamic-pituitary-ovarian axis and ERE pathway were indicated by the levels of E2, GnRH, FSH and LH, and the expressions of ER, HSP90 and COX-2, respectively. In addition, peritoneal macrophages of each rat were cultured in vitro and treated with (FA+LZ+THP)-medicated serum for 24h. The proliferation and phagocytosis abilities, the levels of IL-1β and TNF-α, and the expression of IκBα were then measured for the changes of peritoneal macrophage activities.

RESULTS

Combination use of FA+LZ+THP diminished the volume of the ectopic endometrial tissues (P<0.05 or P<0.01). It also decreased the E2 level, suppressed the expression of GnRH, FSH and LH, and decreased the protein expression of ER, HSP90 and COX-2 (all P<0.05 or P<0.01). The phagocytosis ability of peritoneal macrophage was enhanced by (FA+LZ+THP)-medicated serum (P<0.05) with no change of proliferation (P>0.05). Moreover, IL-1β and TNF-α were downregulated (both P<0.05 or P<0.01) and IκBα was upregulated by the (FA+LZ+THP)-medicated serum (P<0.01).

CONCLUSIONS

The combination use of FA, LZ and THP could inhibit the growth of ectopic endometrial tissue in endometriosis rats. It might be related to the down-regulation of hypothalamic-pituitary-ovarian axis, the amelioration in ERE pathway and the improvement of peritoneal macrophage activities.