NLRP3 inflammasome inhibitor cucurbitacin B suppresses gout arthritis in mice.

Gouty arthritis is a common inflammatory disease characterized by monosodium urate (MSU) crystal-induced nucleotide-binding oligomerization domain (NOD)-like receptor (NLR) family pyrin domain containing 3 (NLRP3) inflammasome activation with upregulated caspase 1 protease and IL-1ß in macrophages. Cucurbitacin B (CuB) is a tetracyclic triterpene that possesses a potential anti-inflammatory activity. However, the immunomodulatory and anti-inflammatory effects of CuB on gout have not been well characterized. Therefore, the purpose of the present study was to determine whether CuB exhibits anti-inflammatory effects on gout and to analyze the underlying molecular mechanism. We examined the effects of CuB on various stimuli-activated bone marrow-derived macrophages (BMDMs) and in a mouse model with MSU-induced acute gouty arthritis. Our results demonstrated that CuB effectively suppressed multiple stimuli-activated IL-1ß secretion by interrupting NLRP3 inflammasome complex formation, inhibiting NLRP3 inflammasome activation and suppressing key enzymes of glycolysis in macrophages. Consistent with this, CuB pretreatment also ameliorated MSU-induced arthritis in vivo models of gout arthritis, manifested by reduced foot swelling and inflammatory cell infiltration. Taken together, our data provide the evidence that CuB is an NLRP3 inflammasome inhibitor with therapeutic potential for treating NLRP3 inflammasome-mediated diseases, especially gouty arthritis.

Serum Calcium and Risk of Nonmedullary Thyroid Cancer in Patients with Primary Hyperparathyroidism.

BACKGROUND Clinical cases of nonmedullary thyroid carcinoma (NMTC) in combination with primary hyperparathyroidism (PHPT) have been reported occasionally. However, the clinical characteristics and risk factors of concomitant NMTC in PHPT patients remain unclear. This study aimed to assess the association between PHPT and NMTC, and evaluate the clinical characteristics and risk factors of NMTC in Chinese patients with PHPT. MATERIAL AND METHODS This was a retrospective cohort analysis. We reviewed the medical records of 155 patients who underwent surgery for PHPT in two large medical centers in China between 2009 and 2014. The clinical manifestations, biochemical abnormalities, and histological characteristics of PHPT patients were analyzed. RESULTS Of the 155 patients with PHPT, 58 patients (37.4%) had thyroid nodules and 12 patients (7.7%) were ill with concomitant NMTC. PHPT patients with NMTC demonstrated significantly lower preoperative serum calcium levels compared to PHPT patients with benign thyroid nodules (p<0.05). A significantly negative association between preoperative serum calcium levels and the presence of NMTC was found in PHPT patients (p<0.05). Furthermore, ROC analysis revealed that albumin-corrected serum calcium levels <2.67 mmol/L had good capacity to differentiate the PHPT patients with NMTC from those with benign thyroid nodules. CONCLUSIONS Compared with the reported much lower prevalence of thyroid carcinoma in the general population, our results suggest that PHPT might be a risk factor for the malignancy of thyroid nodules; a lower level of serum calcium may predict the existence of NMTC in PHPT patients with thyroid nodules.

A novel missense mutation, GGC(Arg454) --> TGC(Cys), of CYP11B1 gene identified in a Chinese family with steroid 11beta-hydroxylase deficiency.

BACKGROUND: Steroid 11beta-hydroxylase deficiency (11beta-OHD), an autosomal recessive inherited disease, accounts for 5% - 8% of congenital adrenal hyperplasia. It was scarcely reported in China. This article reports two Chinese girls with 11beta-OHD. METHODS: The two patients were sisters and presented with hypertrichosis, skin pigmentation, laryngeal prominence and virilization of external genitalia. The patients were followed up for their clinical symptoms and signs, hormone profile, and adrenal image. The genomic deoxyribonucleic acids of the patients and their parents were isolated. 11beta-hydroxylase gene (CYP11B1) was amplified by polymerase chain reaction and directly sequenced. RESULTS: Hormone tests showed that serum cortisol was in the low limit of normal range, whereas the concentrations of adrenocorticotropic hormone, testosterone and progesterone were much higher than those of normal adult females. There were obvious adrenal hyperplasia and advance of bone age. After 11 months of treatment with dexamethasone, the skin pigment became regressed; the breast, uterus and ovary gradually developed and normal menstrual cycle started while the manifestations of virilization did not change. A single point mutation of CYP11B1 (R454C, GGC --> TGC) in all the members of this family was detected. The sisters were homozygous and their parents were heterozygous. CONCLUSIONS: The clinical manifestation of 11beta-OHD is complicated. The manifestation of virilization could not regress after treatment with dexamethasone. The novel missense mutation of CYP11B1 (R454C, GGC --> TGC) is the pathogenesis of 11beta-OHD at least in some Chinese patients.

Expression of Rho GDIalpha in rat osteoblasts intermittently exposed to parathyroid hormone in vitro and in vivo.

AIM: To investigate the mechanism of the bone-forming effects of intermittent parathyroid hormone (PTH) administration and to search for novel molecules of bone anabolism via the PTH signaling pathway. METHODS: Primary cultures of rat osteoblasts (ROBs) were divided into an intermittent PTH-treated group (Itm) and a control group (Ctr). Imitating the pharmacokinetics of intermittent PTH administration in vivo, the ROBs in the Itm group were exposed to PTH for 6 h in a 24-h incubation cycle, and the ROBs in the Ctr group were exposed to vehicle for the entire incubation cycle. The cells were collected at 6 h and 24 h of the final cycle, and the proteins in the Itm and Ctr groups were analyzed by two-dimensional electrophoresis (2-DE) coupled with peptide mass fingerprinting and matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) to detect proteins that were differentially expressed. The proteins with the most significant changes in vitro were validated by immunohistochemistry (IHC) in a rat model. RESULTS: The proteomics analysis indicated that a total of 26 proteins were up- or down-regulated in the Itm group compared with the Ctr group at 6 h and 24 h; among these, 15 proteins were successfully identified. These proteins mainly belong to the cytoskeleton and molecular chaperone protein families, and most of these have anti-apoptotic effects in various cells. Rho GDP-dissociation inhibitor alpha (RhoGDIalpha) and vimentin were the most significantly changed proteins. Further studies by IHC showed that the expression of RhoGDIalpha in ROBs was significantly higher in PTH-treated sham-operated rats than in vehicle-treated sham-operated rats, but the difference was not significant between PTH-treated and vehicle-treated OVX rats. Vimentin expression was not changed in either PTH-treated sham-operated rats or PTH-treated OVX rats. CONCLUSION: Our research suggests that intermittent PTH treatment induces changes in expression of many proteins in ROBs in vitro, and it results in RhoGDIalpha up-regulation in ROBs both in vitro and in vivo when estrogen is present. This up-regulation of RhoGDIalpha may be one of the mechanisms underlying the synergistic bone-forming effect of PTH and estrogen.Acta Pharmacologica Sinica (2009) 30: 1001-1007; doi: 10.1038/aps.2009.60.