Harnessing non-Watson-Crick's base pairing to enhance CRISPR effectors cleavage activities and enable gene editing in mammalian cells.

Genomic DNA of the cyanophage S-2L virus is composed of 2-aminoadenine (Z), thymine (T), guanine (G), and cytosine (C), forming the genetic alphabet ZTGC, which violates Watson-Crick base pairing rules. The Z-base has an extra amino group on the two position that allows the formation of a third hydrogen bond with thymine in DNA strands. Here, we explored and expanded applications of this non-Watson-Crick base pairing in protein expression and gene editing. Both ZTGC-DNA (Z-DNA) and ZUGC-RNA (Z-RNA) produced in vitro show detectable compatibility and can be decoded in mammalian cells, including Homo sapiens cells. Z-crRNA can guide CRISPR-effectors SpCas9 and LbCas12a to cleave specific DNA through non-Watson-Crick base pairing and boost cleavage activities compared to A-crRNA. Z-crRNA can also allow for efficient gene and base editing in human cells. Together, our results help pave the way for potential strategies for optimizing DNA or RNA payloads for gene editing therapeutics and give insights to understanding the natural Z-DNA genome.

Comparative study of a modified double-lumen tube ventilation control connector and traditional connector in clinical use: a randomised-controlled trial.

BACKGROUND: A Y-shaped rotatable connector (YRC) for double-lumen tubes (DLT) is invented and compared with the traditional connector (Y-shaped connector, YC). METHODS: Sixty patients with ASA grade I-III, aged ≥ 18 years, who needed to insert a DLT for thoracic surgery were recruited and assigned into the YRC group (n = 30) and the YC group (n = 30) randomly. The primary endpoints included the inhaled air concentration (Fi) and the exhaled air concentration (Et) of sevoflurane before and after the switch between two-lung ventilation and one-lung ventilation at different times, positioning time, and switching time. The secondary endpoints were the internal gas volume of the two connectors, airway pressure, and the sputum suction time. RESULTS: The Et and Fi of the YRC group and the YC group were significantly different (all p < 0.05) at 5s, 10s, and 30s after the patient switched from two-lung ventilation to one-lung ventilation. The positioning time of the YRC group was less than YC group (89.75 ± 14.28 s vs 107.80 ± 14.96 s, p < 0.05), as well as the switching time (3.60 ± 1.20 s vs 9.05 ± 2.53 s, p < 0.05) and the internal gas volume (17.20 ml vs 24.12 ml). There was no difference in airway pressure and the sputum suction time in two groups. CONCLUSION: Compared with YC, YRC was beneficial for maintaining depth of anesthesia, improves efficiency for the switch between one-lung and two-lung ventilation, and shortens the tube positioning time.

Vitamin D Receptor Gene Polymorphisms and Risk of Atopic Dermatitis in Chinese Han Population.

BACKGROUND: Studies investigated the associations between four Vitamin D receptor (VDR) common variations and interactions of gene-environment factors and atopic dermatitis (AD) in Chinese population are few. METHODS: In this case-control study, 400 AD patients and 400 controls were genotyped for the FokI, TaqI, BsmI and ApalI variations of VDR genes by restriction fragment length polymorphism analysis. The associations between VDR genes and AD were assessed by univariate and multivariate logistic regression. The interactions between VDR genes and some risk factors were also explored using cross-over analysis. The corresponding odds ratio (ORs) and 95% confidence intervals (CI) were also calculated. RESULTS: The FoKI rs2228570 polymorphism was significantly associated with an increased risk of atopic dermatitis in the co-dominant model (OR=2.93, 95% CI: 1.78-4.82. P=0.000), recessive model (OR=2.67, 95% CI: 1.68-4.26, P=0.000) and dominant model (OR=1.38, 95% CI: 1.04-1.84, P=0.028), and allele model. No significant associations were found among TaqI, BsmI and ApalI polymorphism and AD. The C-A-T-C and C-G-T-T haplotypes significantly increased the risk of atopic dermatitis. For rs2228570, the increased effects were more evident in the subgroups of age ≤8-month, cow milk and mixed, and keeping pet. Interactions between rs2228570 gene polymorphism and family history, age >8, and keeping pet increased the AD risk. The rs2228570 C allele decreased the relative mRNA expression. CONCLUSION: The FokI rs2228570 C allele of VDR gene could be a risk candidate gene for AD. Interactions between FokI polymorphism and family history and some behaviors may increase the risk of AD.

Conditional inference trees in the assessment of tree mortality rates in the transitional mixed forests of Atlantic Canada.

Long-term predictions of forest dynamics, including forecasts of tree growth and mortality, are central to sustainable forest-management planning. Although often difficult to evaluate, tree mortality rates under different abiotic and biotic conditions are vital in defining the long-term dynamics of forest ecosystems. In this study, we have modeled tree mortality rates using conditional inference trees (CTREE) and multi-year permanent sample plot data sourced from an inventory with coverage of New Brunswick (NB), Canada. The final CTREE mortality model was based on four tree- and three stand-level terms together with two climatic terms. The correlation coefficient (R2) between observed and predicted mortality rates was 0.67. High cumulative annual growing degree-days (GDD) was found to lead to increased mortality in 18 tree species, including Betula papyrifera, Picea mariana, Acer saccharum, and Larix laricina. In another ten species, including Abies balsamea, Tsuga canadensis, Fraxinus americana, and Fagus grandifolia, mortality rates tended to be higher in areas with high incident solar radiation. High amounts of precipitation in NB's humid maritime climate were also found to contribute to heightened tree mortality. The relationship between high GDD, solar radiation, and high mortality rates was particularly strong when precipitation was also low. This would suggest that although excessive soil water can contribute to heightened tree mortality by reducing the supply of air to the roots, occasional drought in NB can also contribute to increased mortality events. These results would have significant implications when considered alongside regional climate projections which generally entail both components of warming and increased precipitation.

LncRNA MEG3 repressed malignant melanoma progression via inactivating Wnt signaling pathway.

Accumulating evidence has indicated that MEG3 can serve as a tumor suppressive lncRNA in various tumors. It is aberrantly expressed in multiple cancers. However, the biological roles of MEG3 in melanoma are poorly understood. Therefore, in our study, we concentrated on the biological mechanism of MEG3 in melanoma progression. First, we observed that MEG3 was obviously decreased in melanoma cells including A375, SK-MEL-1, B16, and A2058 cells compared to human epidermal melanocytes HEMa-LP. MEG3 was restored by transfecting LV-MEG3 in to A375 and A2058 cells. Subsequently, we found that overexpression of MEG3 was able to inhibit cell proliferation and colony formation capacity. Meanwhile, melanoma cell apoptosis was induced by up-regulation of MEG3. Overexpression of MEG3 greatly repressed melanoma cell migration and invasion ability. In addition, Wnt signaling pathway has been identified in the progression of various cancers. Here, in our study, it was indicated that Wnt signaling was highly activated in melanoma cells with ß-catenin expression significantly increased and GSK-3ß decreased. Interestingly, MEG restoration strongly inactivated Wnt signaling pathway by reducing ß-catenin and CyclinD1, elevating GSK-3ß levels in vitro. Finally, in vivo experiments were carried out to confirm the inhibitory roles of MEG3 in vivo. Taken these together, we suggested that MEG3 can inhibit melanoma development through blocking Wnt signaling pathway.

Erbium: YAG laser (2,940 nm) treatment stimulates hair growth through upregulating Wnt 10b and ß-catenin expression in C57BL/6 mice.

AIM: To evaluate the role of 2,940 nm erbium: YAG laser in hair growth in C57BL/6 mice. METHODS: Anagen was experimentally induced by depilation. Healthy C57BL/6 mice (n=22) were randomly divided into four groups, with treatment of laser or minoxidil, or with combined laser and minoxidil treatments. The skin color of each mouse was observed each day. The time from telogen (pink skin color) to anagen (black coloration) phase and from anagen (black coloration) to catagen (all hairs grew out of the depilated skin) have been recorded. Hematoxylin and eosin (H&E) assay was done at fifteen days after the first treatment for each group to observe hair follicles and hair cycle score. Western blot analysis was utilized to detect the expression levels of Wnt 10-b and ß-catenin. RESULTS: Black pigmentation started significantly earlier both in the laser and combination group than in the control group. Moreover, the time from anagen to catagen in the laser, minoxidil and combination groups were all significantly shorter from the control group. Histopathology with H&E staining showed an obvious increase in the number of hair follicles in the anagen phase caused by the treatment of 2,940 nm erbium: YAG laser and minoxidil. Similarly, the percentage of hair follicles in anagen VI accounted for 19.5%, 37.5%, 41.5% and 44% in control, laser, minoxidil, and combination group, respectively. Western blot analysis showed that both the levels of Wnt 10b and ß-catenin were significantly increased by the treatment of 2,940 nm erbium: YAG laser. CONCLUSION: Our findings showed that 2,940-nm Er: YAG laser could promote hair growth by inducing hair cycle transition from telogen to anagen phases in C57BL/6 mice through up regulating Wnt 10b and ß-catenin. These results suggest that 2,940-nm Er: YAG laser may be a potential therapy for hair loss.