Recent studies indicate that human induced pluripotent stem cells (hiPSCs) contain genomic structural variations and point mutations in coding regions. However, these studies have focused on fibroblast-derived hiPSCs, and it is currently unknown whether the use of alternative somatic cell sources with varying reprogramming efficiencies would result in different levels of genetic alterations. Here we characterize the genomic integrity of eight hiPSC lines derived from five different non-fibroblast somatic cell types. We show that protein-coding mutations are a general feature of the hiPSC state and are independent of somatic cell source. Furthermore, we analyze a total of 17 point mutations found in hiPSCs and demonstrate that they do not generally facilitate the acquisition of pluripotency and thus are not likely to provide a selective advantage for reprogramming.
Molecular control of the pluripotent state is thought to reside in a core circuitry of master transcription factors including the homeodomain-containing protein Nanog1–2, which plays an essential role in establishing ground state pluripotency during somatic cell reprogramming3–4. While the genomic occupancy of Nanog has been extensively investigated, comparatively little is known about Nanog-associated proteins5 and their contribution to the Nanog-mediated reprogramming process. Using enhanced purification techniques and a stringent computational algorithm, we identified 27 high-confidence protein interaction partners of Nanog in mouse ES cells. These consist of 19 novel partners of Nanog that have not been reported before including the Ten eleven translocation (Tet) family methylcytosine hydroxylase Tet1. We confirmed physical association of Nanog with Tet1, and demonstrated that Tet1, in synergy with Nanog, enhances the efficiency of reprogramming. We also found physical association and reprogramming synergy of Tet2 with Nanog, and demonstrated that knockdown of Tet2 abolishes the reprogramming synergy of Nanog with a catalytically deficient mutant of Tet1 (Tet1Mut). These results indicate that the physical interaction between Nanog and Tet1/2 proteins facilitates reprogramming in a manner that is dependent on Tet1/2's catalytic activity. Tet1 and Nanog co-occupy genomic loci of genes associated with both maintenance of pluripotency and lineage commitment in ES cells, and Tet1 binding is reduced upon Nanog depletion. Co-expression of Nanog and Tet1 results in expression priming of and increased 5hmC levels at top ranked common targets Esrrb and Oct4 before reprogramming to naïve pluripotency. We propose that Tet1 is recruited by Nanog to enhance the expression of a subset of key reprogramming target genes. These results provide an insight into the reprogramming mechanism of Nanog and uncover a novel role for 5mC hydroxylases in the establishment of naïve pluripotency.
Nanog; Tet1; Tet2; pluripotency; reprogramming; self-renewal; epigenetics
Itch-specific neurons have been sought for decades. The existence of such neurons is in doubt recently due to the observation that itch-mediating neurons also respond to painful stimuli. Here, we genetically labeled and manipulated MrgprA3+ neurons in dorsal root ganglion (DRG) and found that they exclusively innervate the epidermis of the skin and respond to multiple pruritogens. Ablation of MrgprA3+ neurons led to significant reductions in scratching evoked by multiple pruritogens and occurring spontaneously under chronic itch conditions whereas pain sensitivity remained intact. Importantly, mice with TRPV1 exclusively expressed in MrgprA3+ neurons exhibited only itch- and not pain behavior in response to capsaicin. Although MrgprA3+ neurons are sensitive to noxious heat, activation of TRPV1 in these neurons by noxious heat did not alter pain behavior. These data suggest that MrgprA3 defines a specific subpopulation of DRG neurons mediating itch. Our study opens new avenues for studying itch and developing anti-pruritic therapies.
A similar immune response is implicated in the pathogenesis of pulmonary fibrosis and allergic disorders. We investigated the potential therapeutic efficacy and mechanism of rupatadine, a dual antagonist of histamine and platelet-activation factor (PAF), in bleomycin- (BLM-) and silica-induced pulmonary fibrosis. The indicated dosages of rupatadine were administered in rodents with bleomycin or silica-induced pulmonary fibrosis. The tissue injury, fibrosis, inflammatory cells and cytokines, and lung function were examined to evaluate the therapeutic efficacy of rupatadine. The anti-fibrosis effect of rupatadine was compared with an H1 or PAF receptor antagonist, and efforts were made to reveal rupatadine’s anti-fibrotic mechanism. Rupatadine promoted the resolution of pulmonary inflammation and fibrosis in a dose-dependent manner, as indicated by the reductions in inflammation score, collagen deposition and epithelial-mesenchymal transformation, and infiltration or expression of inflammatory cells or cytokines in the fibrotic lung tissue. Thus, rupatadine treatment improved the declined lung function and significantly decreased animal death. Moreover, rupatadine was able not only to attenuate silica-induced silicosis but also to produce a superior therapeutic efficacy compared to pirfenidone, histamine H1 antagonist loratadine, or PAF antagonist CV-3988. The anti-fibrotic action of rupatadine might relate to its attenuation of BLM- or PAF-induced premature senescence because rupatadine treatment protected against the in vivo and in vitro activation of the p53/p21-dependent senescence pathway. Our studies indicate that rupatadine promotes the resolution of pulmonary inflammation and fibrosis by attenuating the PAF-mediated senescence response. Rupatadine holds promise as a novel drug to treat the devastating disease of pulmonary fibrosis.
Glutamate scanning mutagenesis was used to assess the role of the calcicludine binding segment in regulating channel permeation and gating using both Ca2+ and Ba2+ as charge carriers. As expected, wild-type L-type calcium channels had a Ba2+ conductance ~2× that in Ca2+ (GBa/GCa = 2) and activation was ~10 mV more positive in Ca2+ vs. Ba2+. Of the eleven mutants tested, F1126E was the only one mutant that showed unique permeation and gating properties compared to wild-type. F1126E equalized the L-channel conductance (GBa/GCa = 1) and activation voltage-dependence between Ca2+ and Ba2+. Ba2+ permeation was reduced because the interactions among multiple Ba2+ ions and the pore were specifically altered for F1126E, which resulted in Ca2+-like ionic conductance and unitary current. However, high affinity block of monovalent cation flux was not altered for either Ca+2 or Ba2+. The half activation voltage of F1126E in Ba2+ was depolarized to match that in Ca2+, which was unchanged from wild-type. As a result, the voltages for half activation and half inactivation of F1126E in Ba2+ and Ca+2 were similar to those of wild-type in Ca+2. This effect was specific to F1126E since F1126A did not affect the half activation voltage in either Ca+2 or Ba2+. These results indicate that residues in the outer vestibule of the L-channel pore are major determinants of channel gating, selectivity and permeation.
mutation; voltage-dependent; surface charge; outer vestibule; selectivity filter; pore; electrophysiology
Recent studies have suggested that lipopolysaccharides (LPS) induce nitric oxide (NO) production and defense gene expression in plants. Our current work investigated the signaling mechanism of NO and the role of NONEXPRESSOR OF PATHOGENESIS-RELATED GENES1 (NPR1) in LPS-induced innate immunity of Arabidopsis (Arabidopsis thaliana). We have provided evidence that LPS-elicited NO generation as well as increased antioxidant enzyme activities capable of maintaining the redox state could be important to protect plants against oxidative damage from pathogen attack. In addition, LPS-activated defense responses, including callose deposition and defense-related gene expression, are regulated through an NPR1-dependent signaling pathway. Our results contribute to elucidation of the signaling mechanism of NO and highlight an important role of NPR1 in modulating LPS-triggered innate immunity in plants. However, further research is necessary to clarify the cross-talk between mitochondria and NO on activating LPS-induced defense responses, and the regulatory mechanism of NO in LPS-induced innate immunity needs further improvement.
nitric oxide; lipopolysaccharides; NPR1; nitric oxide synthase; plant innate immunity; priming
Metabolic risk factors and abnormalities such as obesity and hypertension are rapidly rising among the Chinese population following China’s tremendous economic growth and widespread westernization of lifestyle in recent decades. Limited information is available about the current burden of metabolic syndrome (MetS) in China.
We analyzed data on metabolic risk factors among 22,457 adults aged ≥ 32 years participating in the “Zhabei Health 2020” survey (2009–2010), a cross-sectional study of a representative sample of community residents in Zhabei District. We defined MetS using Chinese-specific cut-off points for central obesity according to consensus criteria recently endorsed by several international and national organizations in defining MetS in different populations worldwide. We used a multiple logistic regression model to assess the associations of potential risk factors with MetS.
The unadjusted prevalence of the MetS was 35.1% for men and 32.5% for women according to the consensus criteria for Chinese. The prevalence increased progressively from 12.1% among participants aged 32–45 years to 45.4% among those aged ≥ 75 years. Age, smoking, family history of diabetes, and education are significantly associated with risk of MetS.
The MetS is highly prevalent and has reached epidemic proportion in Chinese urban adult community residents.
Metabolic syndrome; Prevalence; Population-based survey; China
Group I metabotropic glutamate receptors (mGluRs), including mGluR1 and mGluR5, are G protein–coupled receptors (GPCRs) that are expressed at excitatory synapses in brain and spinal cord. GPCRs are often negatively regulated by specific G protein–coupled receptor kinases and subsequent binding of arrestin-like molecules. Here we demonstrate an alternative mechanism in which group I mGluRs are negatively regulated by proline-directed kinases that phosphorylate the binding site for the adaptor protein Homer, and thereby enhance mGluR–Homer binding to reduce signaling. This mechanism is dependent on a multidomain scaffolding protein, Preso1, that binds mGluR, Homer and proline-directed kinases and that is required for their phosphorylation of mGluR at the Homer binding site. Genetic ablation of Preso1 prevents dynamic phosphorylation of mGluR5, and Preso1−/− mice exhibit sustained, mGluR5-dependent inflammatory pain that is linked to enhanced mGluR signaling. Preso1 creates a microdomain for proline-directed kinases with broad substrate specificity to phosphorylate mGluR and to mediate negative regulation.
Identifying peptides from the fragmentation spectra is a fundamental step in mass spectrometry (MS) data processing. The significance (discriminability) of every peak varies, providing additional information for potentially enhancing the identification sensitivity and the correct match rate. However this important information was not considered in previous algorithms. Here we presented a novel method based on Peptide Matching Discriminability (PMD), in which the PMD information of every peak reflects the discriminability of candidate peptides. In addition, we developed a novel peptide scoring algorithm Dispec based on PMD, by taking three aspects of discriminability into consideration: PMD, intensity discriminability and m/z error discriminability. Compared with Mascot and Sequest, Dispec identified remarkably more peptides from three experimental datasets with the same confidence at 1% PSM-level FDR. Dispec is also robust and versatile for various datasets obtained on different instruments. The concept of discriminability enhances the peptide identification and thus may contribute largely to the proteome studies. As an open-source program, Dispec is freely available at http://bioinformatics.jnu.edu.cn/software/dispec/.
Previous studies have reported that methyl jasmonate (MeJA) can promote plant senescence. Arabidopsis thaliana BI1 (AtBI1) participates in leaf senescence and JA signal pathway. Our recent report has suggested that AtBI1 plays a crucial role in MeJA-induced leaf senescence. Concomitantly, cytosolic calcium ([Ca2+]cyt) and MPK6, a mitogen-activated protein kinase (MAPK), participate in the process of MeJA-induced leaf senescence. And AtBI1 might play its roles in delaying MeJA-induced leaf senescence by suppressing the [Ca2+]cyt-dependent activation of MPK6. Our study contributes to the understanding of the function and mechanism of AtBI1 in plant senescence. Though some of signaling molecules have been elucidated in this type of plant senescence, the mechanism of AtBI-1 functions in reducing the [Ca2+]cyt during MeJA-induced leaf senescence needs further improvement, and the source and location of Ca2+ are still not clear enough. By using the Arabidopsis and MeJA as the research model, the subsequent researches have been performed to investigate the upstream regulation and downstream function of Ca2+ in this type of plant senescence.
Arabidopsis Bax inhibitor-1; calcium; leaf senescence; methyl jasmonate; mitogen-activated protein kinase 6
As a vital cell-signaling molecule, nitric oxide (NO) has been reported to regulate toxic metal responses in plants. Our recent report has suggested that caspase-3-like protease activation was detected in Arabidopsis (Arabidopsis thaliana) after Cd2+ treatment. NO contributed caspase-3-like protease activation in Cd2+ induced Arabidopsis thaliana programmed cell death (PCD), which was mediated by MPK6. It was first shown that NO promotes Cd2+-induced Arabidopsis PCD by promoting MPK6-mediated caspase-3-like activation. Our study contributed to the understanding of NO signaling pathway in Cd2+-induced Arabidopsis thaliana PCD. Although several studies have revealed that NO regulates plant PCD, compared with the study of signaling pathways involved in animal cell apoptosis, the mechanism of NO function still remains elusive and the molecular mechanisms of MAPK are far from clear in Cd2+-induced PCD. By using the fluorescence techniques and the Arabidopsis seedlings as the reference model, the subsequent researches have been performed to obtain comprehensive understanding of Cd2+-induced plant PCD.
Arabidopsis PCD; caspase-3-like protease; Cd2+ stress; MAPK pathway; nitric oxide signal
AIM: To investigate the significance of Twist2 for colorectal cancer (CRC).
METHODS: In this study, 93 CRC patients were included who received curative surgery in Eastern Hepatobiliary Surgery Hospital from January 1999 to December 2010. Records of patients’ clinicopathological characteristics and follow up data were reviewed. Formalin-fixed, paraffin-embedded tissue blocks were used to observe the protein expression of Twist2 and E-cadherin by immunohistochemistry. Two independent pathologists who were blinded to the clinical information performed semiquantitative scoring of immunostaining. A total score of 3-6 (sum of extent + intensity) was considered as Twist2-positive expression. The expression of E-cadherin was divided into two levels (preserved and reduced). An exploratory statistical analysis was conducted to determine the association between Twist2 expression and clinicopathological parameters, as well as E-cadherin expression. Furthermore, the variables associated with prognosis were analyzed by Cox’s proportional hazards model. Kaplan-Meier analysis was used to plot survival curves according to different expression levels of Twist2.
RESULTS: Twist2-positive expression was observed in 66 (71.0%) samples and mainly located in the cytoplasm. Forty-three (46.2%) samples showed reduced expression of E-cadherin. There were no significant correlations between Twist2 expression and any of the clinicopathological parameters. However, Twist2-positive expression was significantly associated with reduced expression of E-cadherin (P = 0.040). Multivariate analysis revealed that bad M-stage [hazard ratio (HR) = 7.694, 95%CI: 2.927-20.224, P < 0.001] and Twist2-positive (HR = 5.744, 95%CI: 1.347-24.298, P = 0.018) were the independent risk factors for poor overall survival (OS), while Twist2-positive (HR = 3.264, 95%CI: 1.455-7.375, P = 0.004), bad N-stage (HR = 2.149, 95%CI: 1.226-3.767, P = 0.008) and bad M-stage (HR = 10.907, 95%CI: 4.937-24.096, P < 0.001) were independently associated with poor disease-free survival (DFS). Survival curves showed a definite trend for Twist2-negative patients to have longer OS and DFS than Twist2-negative patients, not only overall, but also for patients in different stages, especially for DFS of patients in stage III (P = 0.033) and IV (P = 0.026).
CONCLUSION: Our data suggests, for the first time, that Twist2 is a valuable prognostic biomarker for CRC, particularly for patients in stage III and IV.
Colorectal cancer; Prognostic biomarker; Twist2; Epithelial-mesenchymal transition; Immunohistochemstry
β-alanine, a popular supplement for muscle building, induces itch and tingling after consumption, but the underlying molecular and neural mechanisms are obscure. Here we show that, in mice, β-alanine elicited itch-associated behavior that requires MrgprD, a G protein-coupled receptor expressed by a subpopulation of primary sensory neurons. These neurons exclusively innervate the skin, respond to β-alanine, heat and mechanical noxious stimuli but do not respond to histamine. In humans, intradermally injected β-alanine induced itch but neither wheal nor flare suggesting that the itch was not mediated by histamine. Thus, the primary sensory neurons responsive to β-alanine are likely part of a histamine-independent itch neural circuit and a target for treating clinical itch that is unrelieved by anti-histamines.
The Southeast Asian deletion (--SEA) is the most commonly observed mutation among diverse α-thalassemia alleles in Southeast Asia and South China. It is generally argued that mutation --SEA, like other variants causing hemoglobin disorders, is associated with protection against malaria that is endemic in these regions. However, little evidence has been provided to support this claim.
We first examined the genetic imprint of recent positive selection on the --SEA allele and flanking sequences in the human α-globin cluster, covering a genomic region spanning ~410 kb, by genotyping 28 SNPs in a Chinese population consisting of 76 --SEA heterozygotes and 138 normal individuals. The pattern of linkage disequilibrium (LD) and the long-range haplotype test revealed a signature of positive selection. The network of inferred haplotypes suggested a single origin of the --SEA allele.
Thus, our data support the hypothesis that the --SEA allele has been subjected to recent balancing selection, triggered by malaria.
ATP-binding cassette sub-family G member 2 (ABCG2) is a protein that in humans is encoded by the ABCG2 gene. ABCG2 participates in efflux of many chemotherapeutic agents. ABCG2 is often expressed in hematopoietic progenitor or stem cells. Vacuolar-H + −ATPase (V-ATPase) plays a key role in adjusting and maintaining intracellular pH and in regulating the drug tolerance of cells. The TNM Classification of Malignant Tumours (TNM) is a cancer staging system that describes the extent of cancer in a patient’s body. In this study, the expression of ABCG2 and V-ATPase in esophageal squamous cancer cells was detected.
Immunohistochemistry staining and Immunofluorescence double staining were used to detect the expression of ABCG2 and V-ATPase in in 66 cases of esophageal squamous cancer cells. Associations and differences in expression of ABCG2 with that of V-ATPase were analyzed.
Positive staining patterns for both ABCG2 (66.67%) and V-ATPase (68.18%) were located mainly in the plasma membrane and cytoplasm. Marked differences in expression were also shown (P < 0.001) among 3 groups of pathological grades and TNM stages in these carcinomas. Marked differences were also found for ABCG2 expression between the two groups in the pathological grades and in the TNM staging groups (P < 0.01), but not between the αb and βgroups. V-ATPase expression was statistically significant between the 2 groups in the pathological grades and TNM stages (P < 0.05). This was not evident between α and β groups of pathological grades or between αb and βof the TNM stages. Marked differences in expression of ABCG2 and V-ATPase were found between metastatic and non-metastatic groups in the same carcinomas (P < 0.0001). There was also a clear correlation between the expression of ABCG2 and V-ATPase (P ≤ 0.001) in the various groups of pathological grades and TNM stages.
Both ABCG2 and V-ATPase were over-expressed in esophageal squamous cancer cells. Their expression was associated with pathological grade, TNM stage and tumor metastasis in esophageal squamous cancer cells, suggesting interaction relationship between them. ABCG2 and V-ATPase expression may be strongly associated with drug resistance and tumor metastasis.
The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/3823783918433897
Esophageal carcinoma; Squamous cell carcinoma; ABCG2; V-ATPase; Drug resistance
A new series of phosphodiesterase-9 (PDE9) inhibitors that contain a scaffold of 6-amino-pyrazolopyrimidinone have been discovered by a combination of structure-based design and computational docking. This procedure significantly saved load of chemical synthesis and is an effective method for the discovery of inhibitors. The best compound 28 has an IC50 of 21 nM and 3.3 µM respectively for PDE9 and PDE5, and about three orders of magnitude of selectivity against other PDE families. The crystal structure of the PDE9 catalytic domain in complex with 28 has been determined and shows a hydrogen bond between 28 and Tyr424. This hydrogen bond may account for the 860-fold selectivity of 28 against PDE1B, in comparison with about 30-fold selectivity of BAY73-6691. Thus, our studies suggest that Tyr424, a unique residue of PDE8 and PDE9, is a potential target for improvement of selectivity of PDE9 inhibitors.
Epidermal growth factor receptor (EGFR) gene mutation and copy number are useful predictive markers that guide the selection of non-small cell lung cancer (NSCLC) patients for EGFR-targeting therapy. This study aimed to investigate the correlation between EGFR gene mutation and copy number and clinicopathologic characteristics of Chinese patients with NSCLC. NSCLC specimens collected from 205 patients between November 2009 and January 2011 were selected to detect EGFR gene mutations with real-time polymerase chain reaction (RT-PCR) and to detect EGFR gene copy number with fluorescence in situ hybridization (FISH). EGFR mutations primarily occurred in females, non-smokers, and patients with adenocarinomas (all P < 0.001). Tissues from 128 (62%) patients were FISH-positive for EGFR, including 37 (18%) with gene amplification and 91 (44%) with high polysomy. EGFR gene mutation was correlated with FISH-positive status (R = 0.340, P < 0.001). Multivariate analysis showed that not smoking (OR = 5.910, 95% CI = 2.363–14.779, P < 0.001) and having adenocarcinoma (OR = 0.122, 95% CI = 0.026–0.581, P = 0.008) were favorable factors for EGFR gene mutation. These results show a high frequency of EGFR FISH positivity in NSCLC tissues from Chinese patients and a significant relevance between EGFR gene mutations and FISH-positive status. Among the FISH-positive samples, EGFR gene mutation occurred more frequently in samples with gene amplification compared to those with high polysomy, suggesting that EGFR mutation and gene amplification should be used as clinical decision parameters to predict response to EGFR-targeting therapy.
Epidermal growth factor receptor; gene mutation; gene copy number; non-small cell lung cancer; correlation
Response criteria remain controversial in therapeutic evaluation for locally advanced esophageal carcinoma treated with neoadjuvant chemotherapy. We aimed to identify the predictive value of tumor regression grading (TRG) in tumor response and prognosis. Fifty-two patients who underwent neoadjuvant chemotherapy followed by esophagectomy and radical 2-field lymphadenectomy between June 2007 and June 2011 were included in this study. All tissue specimens were reassessed according to the TRG scale. Potential prognostic factors, including clinicopathologic factors, were evaluated. Survival curves were generated by using the Kaplan-Meier method and compared with the log-rank test. Prognostic factors were determined with multivariate analysis by using the Cox regression model. Our results showed that of 52 cases, 43 (83%) were squamous cell carcinoma and 9 (17%) were adenocarcinoma. TRG was correlated with pathologic T (P = 0.006) and N (P < 0.001) categories. Median overall survival for the entire cohort was 33 months. The 1- and 2-year overall survival rates were 71% and 44%, respectively. Univariate survival analysis results showed that favorable prognostic factors were histological subtype (P = 0.003), pathologic T category (P = 0.026), pathologic N category (P < 0.001), and TRG G0 (P = 0.041). Multivariate analyses identified pathologic N category (P < 0.001) as a significant independent prognostic parameter. Our results indicate that histomorphologic TRG can be considered as an alternative option to predict the therapeutic efficacy and prognostic factor for patients with locally advanced esophageal carcinoma treated by neoadjuvant chemotherapy.
Tumor regression grading; esophageal cancer; neoadjuvant chemotherapy; efficacy assessment
The development of scaffolded DNA origami, a technique in which a long single-stranded viral genome is folded into arbitrary shapes by hundreds of short synthetic oligonucleotides, represents an important milestone in DNA nanotechnology. Recent findings have revealed that two-dimensional (2D)DNA origami structures based on the original design parameters adopt a global twist with respect to the tile plane, which may be because the conformation of the constituent DNA (10.67 bp/turn) deviates from the natural B-type helical twist (10.4 bp/turn). Here we aim to characterize the effects of DNA hairpin loops on the overall curvature of the tile and explore their ability to control, and ultimately eliminate any unwanted curvature. A series of dumbbell-shaped DNA loops were selectively displayed on the surface of DNA origami tiles with the expectation that repulsive interactions among the neighboring dumbbell loops and between the loops and the DNA origami tile would influence the structural features of the underlying tiles. A systematic, atomic force microscopy (AFM) study of how the number and position of the DNA loops influenced the global twist of the structure was performed, and several structural models to explain the results were proposed. The observations unambiguously revealed that the first generation of rectangular shaped origami tiles adopt a conformation in which the upper right (corner 2) and bottom left (corner 4) corners bend upward out of the plane, causing linear superstructures attached by these corners to form twisted ribbons. Our experimental observations are consistent with the twist model predicted by the DNA mechanical property simulation software CanDo. Through the systematic design and organization of various numbers of dumbbell loops on both surfaces of the tile, a nearly planar rectangular origami tile was achieved.
Tea is widely consumed all over the world. Studies have demonstrated the role of tea in prevention and treatment of various chronic diseases including diabetes and obesity, but the underlying mechanism is unclear. PTP1B is a widely expressed tyrosine phosphatase which has been defined as a target for therapeutic drug development to treat diabetes and obesity. In screening for inhibitors of PTP1B, we found that aqueous extracts of teas exhibited potent PTP1B inhibitory effects with an IC50 value of 0.4 to 4 g dry tea leaves per liter of water. Black tea shows the strongest inhibition activities, followed by oolong and then by green tea. Biochemical fractionations demonstrated that the major effective components in tea corresponded to oxidized polyphenolic compounds. This was further verified by the fact that tea catechins became potent inhibitors of PTP1B upon oxidation catalyzed by tyrosinases. When applied to cultured cells, tea extracts induced tyrosine phosphorylation of cellular proteins. Our study suggests that some beneficial effects of tea may be attributed to the inhibition of PTP1B.
Tyrosine phosphatase; inhibitor; polyphenol; tea; diabetes; obesity
The crystal structure of the title compound, C17H15BrO3, a chalcone derivative, exhibits two crystallographically independent molecules per asymmetric unit showing an E conformation about the ethylene double bond. In each molecule, the two phenyl rings are almost coplanar: the mean planes make dihedral angles of 9.3 (2) and 19.4 (2)°. In the crystal, molecules are linked through weak intermolecular C—H⋯O hydrogen bonds.
Early detection and subsequent complete surgical resection are among the most efficient methods for treating cancer. However, low detection sensitivity and incomplete tumor resection are two challenging issues. Nanoparticle-based imaging-guided surgery has proven promising for cancer-targeted imaging and subsequent debulking surgery. Particularly, the use of near infrared (NIR) fluorescent probes such as NIR quantum dots (QDs) allows deep penetration and high sensitivity for tumor detection. In this study, NIR-emitting CdTe QDs (maximum fluorescence emission peak at 728 nm) were synthesized with a high quantum yield (QY) of 38%. The tumor-specific QD bioconjugates were obtained by attaching cyclic Arg-Gly-Asp peptide (cRGD) to the surface of synthesized QDs, and then injected into U87 MG tumor-bearing mice via tail veins for tumor-targeted imaging. The tumor and its margins were visualized and distinguished by NIR QD bioconjugates, and tumor resection was successfully accomplished via NIR guidance using a Fluobeam-700 NIR imaging system. Our work indicates that the synthesized tumor-specific NIR QDs hold great promise as a potential fluorescent indicator for intraoperative tumor imaging.
Imaging-guided surgery; NIR quantum dots; cancer treatment; cancer-targeted imaging; RGD
The aim of this study was to observe the effects of autologous nerve implantation into the denervated finger flap on the regression and regeneration of sensory nerve endings and Meissner’s corpuscles.
Bilateral nerves of fingers were separated: one was removed and the other was implanted into the denervated finger in the implantation group. In the non-implantation group, both nerves were removed. The ventral skin of fingers was collected for immunohistochemistry and electron microscopy 3, 6, 9 and 12 months after surgery.
The nerve endings in the Meissner’s corpuscles began to degenerate 3 months after denervation. The elementary structure of Meissner’s corpuscles was not significantly altered. Nerve fibers were present around the Meissner’s corpuscles, accompanied by growing into its inward. The axons in the denervated nerve disappeared and the Meissner’s corpuscles began to atrophy at month 6. More regenerated nerve fibers were observed after nerve implantation, including intensive and thick fibers, accompanied by reinnervation of Meissner’s corpuscles. More nerve fibers and a higher proportion of myelinated nerve fibers were noted at month 9 in the implantation group, and the reinnervation was present in the majority of Meissner’s corpuscles. Naive myelinated nerve fibers appeared at the caudal end of Meissner’s corpuscles. The nerve fibers in the Meissner’s corpuscles increased to the normal level at 12 months after nerve implantation.
The implanted nerve regenerated a large amount of free nerve endings, which helped to regenerate simple Meissner’s corpuscles via governing previously degenerated corpuscles.
neurotization; denervated skin; Meissner’s corpuscle; nerve fiber; regeneration
Defined transcription factors can induce epigenetic reprogramming of adult mammalian cells into induced pluripotent stem cells. Although DNA factors are integrated during some reprogramming methods, it is unknown whether the genome remains unchanged at the single nucleotide level. Here we show that 22 human induced pluripotent stem (hiPS) cell lines reprogrammed using five different methods each contained an average of five protein-coding point mutations in the regions sampled (an estimated six protein coding point mutations per exome). The majority of these mutations were non-synonymous, nonsense, or splice variants, and were enriched in genes mutated or having causative effects in cancers. At least half of these reprogramming-associated mutations pre-existed in fibroblast progenitors at low frequencies, while the rest were newly occurring during or after reprogramming. Thus, hiPS cells acquire genetic modifications in addition to epigenetic modifications. Extensive genetic screening should become a standard procedure to ensure hiPS safety before clinical use.