Sorafenib, an orally available kinase inhibitor, is the standard first-line systemic drug for advanced hepatocellular carcinoma (HCC), and it exerts potent inhibitory activity against epithelial–mesenchymal transition (EMT) and multidrug resistance (MDR) by inhibiting mitogen-activated protein kinase (MAPK) signaling in HCC. However, after long-term exposure to sorafenib, HCC cells exhibit EMT and resistance to sorafenib. The activation of AKT by sorafenib is thought to be responsible for the development of these characteristics. The present study aims to examine the underlying mechanism and seek potential strategies to reverse this resistance and the progression to EMT. Sorafenib-resistant cells showed increased metastatic and invasive ability, with a higher expression of P-glycoprotein (P-gp), compared with the parental cells. This phenomenon was at least partially due to EMT and the appearance of MDR in sorafenib-resistant HCC cells. Moreover, MDR was a downstream molecular event of EMT. Silencing Snail with siRNA blocked EMT and partially reversed the MDR, thereby markedly abolishing invasion and metastasis in sorafenib-resistant HCC cells, but silencing of MDR1 had no effect on the EMT phenotype. Additionally, HCC parental cells that were stably transfected with pCDNA3.1-Snail exhibited EMT and MDR. Two sorafenib-resistant HCC cell lines, established from human HCC HepG2 and Huh7 cells, were refractory to sorafenib-induced growth inhibition but were sensitive to MK-2206, a novel allosteric AKT inhibitor. Thus, the combination of sorafenib and MK-2206 led to significant reversion of the EMT phenotype and P-gp-mediated MDR by downregulating phosphorylated AKT. These findings underscore the significance of EMT, MDR and enhanced PI3K/AKT signaling in sorafenib-resistant HCC cells.
For tamoxifen-dependent Cre recombinase, also known as CreER recombinase, tamoxifen (TAM) is used to activate the Cre to generate time- and tissue-specific mouse mutants. TAM is a potent CreER system inducer; however, TAM is also an active selective estrogen receptor modulator (SERM) that can influence bone homeostasis. The purpose of this study was to optimize the TAM dose for Cre recombinase activation while minimizing the effects of TAM on bone turnover in young growing mice. Methods To evaluate the effects of TAM on bone turnover and bone mass, 1-month-old male wild-type mice were intraperitoneally injected with TAM at 0, 1, 10 or 100 mg/kg/day for four consecutive days. The distal femurs were analyzed one month after the last TAM injection by microCT, mechanical test, and surface-based bone histomorphometry. Similar doses of TAM were used in Col1 (2.3 kb)-CreERT2; mT/mG reporter mice to evaluate the dose-dependent efficacy of Cre-ER activation in bone tissue. Results A TAM dose of 100 mg/kg × 4 days significantly increased trabecular bone volume/total volume (BV/TV) of the distal femur, femur length, bone strength, and serum bone turnover markers compared to the 0 mg control group. In contrast, TAM doses ≤ 10 mg/kg did not significantly change any of these parameters compared to the 0 mg group, although a higher bone strength was observed in the 10 mg group. Surface-based histomorphometry revealed that the 100 mg/kg dose of TAM dose significantly increased trabecular bone formation and decreased periosteal bone formation at 1-week post-TAM treatment. Using the reporter mouse model Col1-CreERT2; mT/mG, we found that 10 mg/kg TAM induced Col1-CreERT2 activity in bone at a comparable level to the 100 mg/kg dose. Conclusions TAM treatment at 100 mg/kg/day × 4 days significantly affects bone homeostasis, resulting in an anabolic bone effect on trabecular bone in 1-month-old male mice. However, a lower dose of TAM at 10 mg/kg/day × 4 days can yield similar Col1-CreERT2 induction efficacy with minimum effects on bone turnover in young male mice.
Objective Anti-DFS70 antibodies correlating with the nuclear dense fine speckled (DFS) pattern in the HEp-2 indirect immunofluorescence assay (IFA) are less common in patients with systemic autoimmune rheumatic disease (SARD) than in healthy subjects and their clinical associations remain elusive. We hosted a multi-center HEp-2 IFA training program to improve the ability of clinical laboratories to recognize the DFS pattern and to investigate the prevalence and relevance of anti-DFS70 antibodies. Methods DFS pattern sera identified by HEp-2 IFA in 29 centers in China were redirected to a central laboratory for anti-DFS70 testing by line immunoblot assay (LIA), enzyme-linked immunosorbent assay (ELISA), and IFA with HEp-2 ELITE/DFS70-KO substrate. Anti-extractable nuclear antigen antibodies were measured by LIA and the clinical relevance was examined in adult and pediatric patients. Results HEp-2 IFA positive rate and DFS pattern in positive sera were 36.2% (34,417/95,131) and 1.7% (582/34,417) in the patient cohort, and 10.0% (423/4,234) and 7.8% (33/423) in a healthy population, respectively. Anti-DFS70 prevalence among sera presenting the DFS pattern was 96.0, 93.7, and 49.6% by ELISA, LIA, and HEp-2 ELITE, respectively. 15.5% (52/336) of adult and 50.0% (20/40) of pediatric anti-DFS70 positive patients were diagnosed with SARD. Diseases most common in anti-DFS70 positive patients were spontaneous abortion (28.0%) in adults and juvenile idiopathic arthritis (22.5%) in pediatric patients. Conclusion Accurate DFS pattern identification increased the detection rate of anti-DFS70 antibodies by ELISA and LIA. Anti-DFS70 antibodies are remarkably high in cases of spontaneous abortion and in pediatric SARD patients, but not prevalent in adult SARD patients.
Renal pathology was a commonly seen complication in patients with diabetes. Geniposide (GPO) was previously demonstrated to modulate glucose metabolism in diabetes. This study was to investigate effects of GPO in streptozotocin-induced diabetic rats and its underlying mechanism. Renal function in diabetic rats was evaluated by levels of serum creatinine (Scr), blood urea nitrogen (BUN), and urinary albumin. Renal inflammation was appraised by inflammatory cells infiltration and pro-inflammatory cytokines production. Renal monocytes, T lymphocytes infiltration, and intercellular adhesion molecule-1 (ICAM-1) expression were quantitated by immunohistochemistry. Moreover, renal nuclear factor-kappa B (NF-κB) was assayed by Western blotting. Diabetic rats showed renal dysfunction as evidenced by increased levels of Scr, BUN, urinary albumin, and elevator renal index. Histological examination revealed significant glomerular basement membrane (GBM) thickening. However, GPO notably improved renal function and diabetes-induced GBM changes. Additionally, diabetic rats showed noteworthy renal inflammation,as reflected by enhancement of monocytes and T lymphocytes infiltration, increased expression of ICAM-1, tumor necrosis factor-α, interleukin-1 (IL-1), and IL-6. Interestingly, the level of monocytes infiltration positively correlated with the severity of GBM. Further study indicated diabetic rats displayed increased activation of NF-κB, indicated by increased expression of NF-κB p65, IKKα, and p-IκBα in renal tissue. However, all the changes in renal inflammation and NF-κB pathway were obviously reversed in GPO-treated diabetic rats. Our works indicate GPO ameliorates structural and functional abnormalities of kidney in diabetic rats, which is associated with its suppression of NF-κB-mediated inflammatory response.
Background: Ubiquitin-fold modifier-1 (Ufm1) is a recently identified ubiquitin-like protein. We previously confirmed that Ufm1 expression was increased in diabetic mice. However, its role in the development of diabetes remains undefined. Methods: Lentivirus-mediated gene knockdown and overexpression techniques were used to observe the effect of Ufm1 on the expression of inflammatory factors, adhesion molecules and chemokines, as well as the transcriptional activity of nuclear factor kappa-B (NF-κB) in macrophages. Western blot and immunofluorescence analyses were used to analyse the mechanism by which Ufm1 affects the transcriptional activity of NF-κB. Finally, the effects of Ufm1 on inflammation and pancreatic, renal and myocardial damage were observed in db/db mice. Results: Knockdown of Ufm1 by lentivirus shRNA targeting Ufm1 (Lv-shUfm1) led to decreased secretion of IL-6, IL-1β, ICAM-1, VCAM-1, MCP-1 and CXCL2 in RAW264.7 cells that were exposed to LPS and TNF-α, while lentiviral overexpression of Ufm1 (Lv-Ufm1) caused the opposite effect. Interestingly, further investigation indicated that Ufm1 induced NF-κB p65 nuclear translocation in RAW264.7 cells via increasing the ubiquitination and degradation of IκBα. In an in vivo experiment, pretreatment of db/db mice with Lv-shUfm1 reduced the mRNA levels of TNF-α, IL-6, IL-1β, ICAM-1, VCAM-1, MCP-1 and CXCL2 in resident peritoneal macrophages (RPMs) and decreased the plasma levels of TNF-α, IL-6, IL-1β, ICAM-1, VCAM-1, MCP-1 and CXCL2. Additionally, in Lv-Ufm1-treated mice, the inverse results were observed. Following treatment with Lv-shUfm1 and Lv-Ufm1, NF-κB p65 nuclear translocation in RPMs was decreased and increased, respectively. Importantly, we observed that Lv-shUfm1 injection led to a decrease in plasma glycaemia, a reduction in urinary albuminuria and cardiomyocyte hypertrophy and an improvement in the histopathological appearance of pancreatic, kidney and myocardial tissue. Pretreatment of the mice with Lv-shUfm1 inhibited macrophage infiltration in the pancreas, kidney and myocardial tissue. Conclusion: Our data elucidate a new biological function of Ufm1 that mediates inflammatory responses. Ufm1-mediated p65 nuclear translocation occurs by modulating the ubiquitination and degradation of IκBα. Moreover, downregulating Ufm1 is an effective strategy to prevent the development of type 2 diabetes and its complications.
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