Effects of the Glucocorticoid-Mediated Mitochondrial Translocation of Glucocorticoid Receptors on Oxidative Stress and Pyroptosis in BV-2 Microglia.

Microglia are resident macrophages within the central nervous system, serving as the first responders to neuroinflammation. Glucocorticoids (GCs) may cause damage to brain tissue, but the specific mechanism remains unclear. This study was divided into two parts: a glucocorticoid receptor (GR) mitochondrial translocation intervention experiment and a mitochondrial oxidative stress inhibition experiment. BV-2 microglia were stimulated with dexamethasone (DEX) and treated with either tubastatin-A or mitoquinone (MitoQ) for 24 h. Our results showed that DEX increased the translocation of GRs to mitochondria, and this effect was accompanied by decreases in the expression of mitochondrially encoded cytochrome c oxidase 1 (MT-CO1) and mitochondrially encoded cytochrome c oxidase 3 (MT-CO3) and increases in the expression of NOD-like receptor thermal protein domain-associated protein 3 (NLRP3), caspase-1, and Gasdermin D (GSDMD). The level of mitochondrial respiratory chain complex IV (MRCC IV) and adenosine triphosphate (ATP) was decreased. An elevation in the level of mitochondrial oxidative stress and the opening of the mitochondrial permeability transition pore (mPTP) was also observed. Mechanistically, tubastatin-A significantly suppressed the mitochondrial translocation of GRs, improved the expression of mitochondrial genes, promoted the restoration of mitochondrial function, and inhibited pyroptosis. MitoQ significantly prevented mitochondrial oxidative stress, improved mitochondrial function, and reduced apoptosis and pyroptosis. Both tubastatin-A and MitoQ suppressed DEX-induced pyroptosis. This study substantiates that the increase in the mitochondrial translocation of GRs mediated by GCs exacerbates oxidative stress and pyroptosis in microglia, which indicates that the regulation of mitochondrial pathways by GCs is pathogenic to microglia.

MT-CO1 expression in nine organs and tissues of different-aged MRL/lpr mice: Investigation of mitochondrial respiratory chain dysfunction at organ level in systemic lupus erythematosus pathogenesis.

Objectives: This study aims to investigate the expression patterns of mitochondrially encoded cytochrome c oxidase 1 (MT-CO1) in different organs and tissues of MRL/lpr mice aged six and 18 weeks. Materials and methods: Six-week-old female MRL/lpr mice (n=10) were considered young lupus model mice, and 18-week-old MRL/lpr mice (n=10) were considered old lupus model mice. Additionally, six-week-old (n=10) and 39-week-old (n=10) female Balb/c mice were used as the young and old controls, respectively. The messenger ribonucleic acid (mRNA) and protein expression levels of MT-CO1 in nine organs/tissues were detected via quantitative polymerase chain reaction (qPCR) and Western blot. Malondialdehyde (MDA) levels were determined with thiobarbituric acid colorimetry. The correlation coefficient of MT-CO1 mRNA levels and MDA levels in each organ/tissue at different ages was analyzed by Pearson correlation analysis. Results: The results showed that most non-immune organs/tissues (heart, lung, liver, kidneys, and intestines) showed increased MT-CO1 expression levels in younger MRL/lpr mice (p<0.05) and decreased MT-CO1 expression in older mice (p<0.05). Expression of MT-CO1 in the lymph nodes was low in younger mice but high in older mice. In other immune organs (spleen and thymus), MT-CO1 expression was low in older MRL/lpr mice. Lower mRNA expression and higher MDA levels were observed in the brains of MRL/lpr mice. However, all MRL/lpr mice showed higher MDA levels than Balb/c mice in every organ no matter younger or older MRL/lpr mice. Conclusion: Our study results suggest that lymphoid mitochondrial hyperfunction at organ level may be an important intrinsic pathogenesis in systemic lupus erythematosus activity, which may affect mitochondrial dysfunction in non-immune organs.

The expression characteristics of cytochrome C oxidase subunit I in mitochondrial of MRL/lpr lupus mice.

OBJECTIVES: We sought to analyse the expression characteristics of cytochrome C oxidase subunit I in mitochondrial of MRL/lpr lupus mice. METHODS: The whole blood of MRL/lpr lupus mice was detected for whole mitochondrial genome sequencing performed by Illumina HiSeq PE150 instrument, compared with house mouse (NC_005089.1) and screened for the maximum difference gene, MT-CO1. Quantitative real-time polymerase chain reaction (qRT-PCR) and western blot were used to detect the mRNA and protein expression of MT-CO1 in lupus mice and control mice. The total antioxidant capacities of lupus mice and control mice were measured using the rapid 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS) method. RESULTS: The mitochondrial genome sequencing showed that five mitochondrial genes had base differences and MT-CO1 was the maximum difference gene, 31 in total. Among the 31 base difference sites, 2 were missense mutations and 29 were synonymous_variant. qRT-PCR test results showed that the MT-CO1 expression in lupus mouse blood was statistically lower than that in control mice blood (t=4.333; p=0.0003). Western blot test results revealed that the expression of MT-CO1 was lower in the lupus mice compared with the control mice at the protein level. Serum total antioxidant capacity testing showed that: the serum total antioxidant capacity of lupus mice was statistically lower than that of the control mice (t=9.957; p<0.0001). CONCLUSIONS: High mutation rate and decreased expression of MT-CO1 in MRL/lpr lupus mice accompanied the decrease of antioxidant capacity, which indicated that abnormal MT-CO1 might be involved in the pathogenesis of SLE and the production of anti-dsDNA antibodies.

Gastrointestinal involvement in Henoch-Schönlein purpura.

OBJECTIVE: To analyse the gastrointestinal manifestation of Henoch-Schonlein purpura (HSP) in adult patients, including clinical and endoscopic features. MATERIAL AND METHODS: Patients with a final diagnosis of HSP admitted from January 1995 to January 2006 were included. Their medical records, including clinical presentation, laboratory data, endoscopy and pathology reports, were reviewed retrospectively. RESULTS: One-hundred-and-fifteen patients were included. Gastrointestinal symptoms occurred in 90 patients (78.2%), with abdominal pain the most common symptom. Fifty-four patients underwent gastroscopy, while 24 underwent colonoscopy. The endoscopic lesions included mucosal erythema, oedema, multiple irregular ulcers and nodular changes. In the upper GI tract, the second portion of the duodenum was the most frequently involved area and is where the most severe lesions occur. In the lower GI tract, the rectum was the most frequently involved area, but the most severe lesions were found in the terminal ileum. CONCLUSIONS: HSP may present with acute abdomen without typical skin manifestations, and gastroscopy and colonoscopy can be helpful in the early diagnosis of HSP in these patients. Typical endoscopic findings include diffuse mucosal oedema, erythema, petechia or multiple irregular ulcers, especially in the second portion of the duodenum or in the terminal ileum.

[Study on the mechanism by which Rhubarb protects the mucosal barrier of intestine of mouse].

OBJECTIVE: To observe the influence of Rhubarb on the the excretion of Type II PLA2 and lysozyme of small intestine of mouse. METHODS: Forty ICR mice were randomized to two groups. In the experiment group, the mice were gavaged with 0.3 ml 10% Rhubarb decoction every 8 hours; in the control group, the mice were given normal saline instead of Rhubarb decoction. After 24 hours, the mice were subjected to cervical dislocation, and their jejunum and ileum were taken out. The lumen of each resected intestine was rinsed with 100 g/L acetic acid, and the washed intestines from each mouse were cut into pieces 1-2 mm in length. Then the perfusate and homogenate were prepared, lyophilized, sealed, and stored at -20 degrees C. The Type II PLA2 activity and lysozyme were assayed respectively. RESULTS: The Type II PLA2 activities and lysozyme of homogenate in Rhubarb group were lower than those in Saline group (P<0.01). The type II PLA2 activities and lysozyme of perfusate in Rhubarb group were higher than those in Saline group (P<0.01). CONCLUSION: Rhubarb can stimulate the small intestine of mice to excrete Type II PLA2 and lysozyme, thus resulting in the increase of Type II PLA2 and lysozyme contents in the intestinal tract and enhancing the function of mucosal barrier of intestine.

[Effect of somatostatin on modulation of IL-10 and TGF-beta 1 during acute pancreatitis].

OBJECTIVE: To observe the effect of somatostatin on modulation of IL-10 and TGF-beta 1 in acute pancreatitis and investigate the mechanism. METHODS: SD male rats were divided into 3 groups: Group 1, the normal rats as control (n = 6); Group 2, the rats with acute pancreatitis induced by ductual injection with 5% sodium cholate sulfur at the volume of 0.6 ml/kg without any other treatment (n = 8); Group 3, after pancreatitis were induced, the rats were injected hypodermically with somatostatin 3 micrograms/(kg.hr)(n = 6). The animals were killed at 2, 6 and 24 hours after operation (each period n = 7). The blood samples were taken for measurement of IL-10 and TGF-beta 1 (by ELISA). The weight of pancreatic tissue and amylopsin was also observed. RESULTS: Both IL-10 and TGF-beta 1 in blood of acute pancreatitis increased significantly (P < 0.05). After the injection of somatostatin, IL-10 and TGF-beta 1 were found remarkably decreased at 24 hours postoperation (P < 0.05). No changes of the weight of pancreatic tissue and amylopsin were observed after the injection of somatostatin. CONCLUSION: Somatostatin can depress the increase of inflammatory-associated cytokines (IL-10 and TGF-beta 1) that increased remarkably in acute pancreatitis, which is one of the most important reasons why somatostatin cannot relieve pancreatitis.

[The alteration of inflammatory cytokine during acute pancreatitis].

OBJECTIVE: To observe the alteration of both inflammatory and anti-inflammatory cytokines during acute pancreatitis, and to investigate the effect of somatostatin on modulation of inflammatory and anti-inflammatory cytokines in experimental acute pancreatitis. METHODS: SD male rats were divided into 3 groups: group 1. the normal rats as control (n = 6); group 2, the rats with acute pancreatitis induced by transabdominal injection of 5% sodium cholate sulfur (at the volume of 1.0 ml/kg) into the parcreatic duct and not given drug treatment; group 3, the rats injected with stilamin 20 micrograms/kg, intravenously, 30 minutes after the successful induction of acute pancreatitis. The animals in groups 2 and 3 were killed at 2, 6 and 24 hours after operation. The blood samples were taken for measurement of IL-1, TNF alpha, IL-6 (by Bioassay) and IL-10, TNF-beta (by ELISA). The wet weight of pancreatic tissue and amylase were also determined. RESULTS: Serum IL-1, TNF alpha, IL-6, IL-10 and TGF-beta in control group were 0.56 +/- 0.06 ng/ml, 23.50 +/- 1.87 IU/ml, 69.0 +/- 6.40 IU/ml, 32.05 +/- 14.87 pg/ml and 66.4 +/- 13.20 pg/ml, respectively. After acute pancreatitis was induced, the serum level of these inflammation-concerned cytokines increased significantly in group 2 (P < 0.05). Serum IL-1, TNF alpha, IL-6, IL-10 and TGF-beta in group 2 at 24 hours after pancreatitis were 1.15 +/- 0.13 ng/ml, 55.33 +/- 12.79 IU/ml. 127.17 +/- 13.91 IU/ml, 68.13 +/- 19.90 pg/ml, and 103.77 +/- 28.95 pg/ml, respectively. After administration of somatostatin, the inflammation-concerned cytokines in group 3 were remarkably decreased (P < 0.05). Serum IL-1, TNF alpha, IL-6, IL-10 and TGF-beta in group 3 were 0.83 +/- 0.12 ng/ml, 33.00 +/- 7.40 IU/ml. 71.83 +/- 6.34 IU/ml, 42.2 +/- 14.55 pg/ml, and 45.98 +/- 18.10 pg/ml, respectively. The indeies of the severity of pancreatitis, such as amylase and the weight of pancreas alse improved in group 3. CONCLUSION: Both inflammatory and antiinflammatory cytokines increased remarkably in the rats with acute pancreatitis. This result indicates that there is a potential tendency of inflammatory response syndrome and compensatory anti-inflammatory response syndrome in the course of acute pancreatitis. Somatostatin can modulate the derangement of these cytokines in acute pancreatitis.