The transcription activator–like effectors (TALEs) and the RNA-guided clustered regularly interspaced short palindromic repeat (CRISPR) associated protein (Cas9) utlilize distinct molecular mechanisms in targeting site recognition. The two proteins can be modified to carry additional functional domains to regulate expression of genomic loci in mammalian cells. In this study, we have compared the two systems in activation and suppression of the Oct4 and Nanog loci by targeting their enhancers. Although both are able to efficiently activate the luciferase reporters, the CRISPR/dCas9 system is much less potent in activating the endogenous loci and in the application of reprogramming somatic cells to iPS cells. Nevertheless, repression by CRISPR/dCas9 is comparable to or even better than TALE repressors. We demonstrated that dCas9 protein binding results in significant physical interference to binding of native transcription factors at enhancer, less efficient active histone markers induction or recruitment of activating complexes in gene activation. This study thus highlighted the merits and drawbacks of transcription regulation by each system. A combined approach of TALEs and CRISPR/dCas9 should provide an optimized solution to regulate genomic loci and to study genetic elements such as enhancers in biological processes including somatic cell reprogramming and guided differentiation.
Obesity is frequently accompanied with chronic inflammation over the whole body and is always associated with symptoms that include those arising from metabolic and vascular alterations. On the other hand, the chronic inflammatory status in the male genital tract may directly impair spermatogenesis and is even associated with male subfertility. However, it is still unclear if the chronic inflammation induced by obesity damages spermatogenesis in the male genital tract. To address this question, we used a high fat diet (HFD) induced obese mouse model and recruited obese patients from the clinic. We detected increased levels of tumor necrosis factor (TNF-α), interleukin-6 (IL-6), and NOD-like receptor family pyrin domain containing-3 (NLRP3) in genital tract tissues including testis, epididymis, seminal vesicle, prostate, and serum from obese mice. Meanwhile, the levels of immunoglobulin G (IgG) and corticosterone were significantly higher than those in the control group in serum. Moreover, signal factors regulated by TNF-α, i.e., p38, nuclear factor-κB (NF-κB), Jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK), and their phosphorylated status, and inflammasome protein NLRP3 were expressed at higher levels in the testis. For overweight and obese male patients, the increased levels of TNF-α and IL-6 were also observed in their seminal plasma. Furthermore, there was a positive correlation between the TNF-α and IL-6 levels and BMI whereas they were inversely correlated with the sperm concentration and motility. In conclusion, impairment of male fertility may stem from a chronic inflammatory status in the male genital tract of obese individuals.
Background: The mechanisms underlying the pathogenesis and progression of Parkinson’s disease (PD) remain elusive, but recent opinions and perspectives have focused on whether the inflammation process induced by microglia contributes to α-synuclein-mediated toxicity. Migration of microglia to the substantia nigra (SN) could precede neurodegeneration inA53Tmice. We hypothesized that CXCL12 could be a mediator in the α-synuclein-induced migration of microglia.Methods: After establishing appropriate animal and cell culture models, we explored the relationship between α-synuclein and CXCL12 inA53Tmice, primary microglia, and BV-2 cell lines. We also explored the mechanisms of these interactions and the signaling processes involved in neuroinflammation.Results: We confirmed the positive correlation between α-synuclein and CXCL12 in the postmortem brain tissue of PD patients and the upregulated CXCR4 expression in SN microglia ofA53Tmice. In addition, as expected, α-synuclein increased the production of CXCL12 in microglia via TLR4/IκB-α/NF-κB signaling. Importantly, CXCL12/CXCR4/FAK/Src/Rac1 signaling was shown to be involved in α-synuclein-induced microglial accumulation.Conclusions: Our study suggests that CXCL12 could be a novel target for the prevention of α-synuclein-triggered ongoing microglial responses. Blocking CXCL12/CXCR4 may be a potential therapeutic approach for PD progression.
Background: NLRP3 inflammasome is an inflammatory mediator. The expression of NLRP3 inflammasome is associated with the development of various tumors and is closely related to the prognosis of tumors. However, the role of NLRP3 inflammasome in laryngeal squamous cell carcinoma (LSCC) remains unclear. This study aim to investigate the influence of NLPR3 inflammasome expression in LSCC, and especially the NLRP3 inflammasome expression level and the prognosis of LSCC after surgery in a Chinese population. Methods: We used quantitative real-time PCR and immunohistochemical (IHC) staining to calculate the mRNA (20 patients, fresh tissue) and protein expression (104 patients, paraffin tissue microarray) levels of the NLRP3 inflammasome (NLRP3/IL-18/IL-1β/ASC/caspase-1), respectively. We also analyzed the relationship between NLRP3 inflammasome expression levels and LSCC cancer tissues compared with adjacent normal tissues and the clinical features of LSCC. Kaplan–Meier survival curves of overall survival (OS) and disease-free survival (DFS) in LSCC patients were compared and analyzed under different expression levels of the NLRP3 inflammasome. Results: Our results indicated that the mRNA expression of the NLRP3 inflammasome was higher in LSCC cancer tissues compared with adjacent normal tissues (p < 0.001). The IHC staining score also demonstrated that the expression of the NLRP3 inflammasome was higher than in the adjacent normal tissues (p < 0.001). The NLRP3 inflammasome expression also exhibited a close relationship with the clinicopathological characteristics (especially the stage of LSCC) of LSCC. Univariate Cox regression analysis and multivariate Cox regression analysis revealed that both NLRP3 and IL-1β had an increased risk of LSCC progression (p < 0.05). The Kaplan–Meier log rank test (OS and DFS) demonstrated that high expression of NLRP3/IL-18/IL-1β/ASC was statistically different than the low expression group (p < 0.05) of LSCC patients after surgery. Conclusion: The high expression group of the NLRP3 inflammasome (NLRP3/IL-18/IL-1β/ASC) had a poorer prognosis (OS and DFS) than the low expression group of LSCC patients 5 years after surgery. The NLRP3 inflammasome (NLRP3/IL-18/IL-1β/ASC) may be used as an auxiliary indicator to predict LSCC patient prognosis after surgery.