Low concentrations of TNF-α in vitro transform the phenotype of vascular smooth muscle cells and enhance their survival in a three-dimensional culture system.

BACKGROUND: Vascular smooth muscle cells (VSMCs) are commonly used as seed cells in tissue-engineered vascular constructions. However, their variable phenotypes and difficult to control functions pose challenges. This study aimed to overcome these obstacles using a three-dimensional culture system. METHODS: Calf VSMCs were administered tumor necrosis factor-alpha (TNF-α) before culturing in two- and three-dimensional well plates and polyglycolic acid (PGA) scaffolds, respectively. The phenotypic markers of VSMCs were detected by immunofluorescence staining and western blotting, and the proliferation and migration abilities of VSMCs were detected by CCK-8, EDU, cell counting, scratch, and Transwell assays. RESULTS: TNF-α rapidly decreased the contractile phenotypic markers and elevated the synthetic phenotypic markers of VSMCs, as well as markedly increasing the proliferation and migration ability of VSMCs under two- and three-dimensional culture conditions. CONCLUSIONS: TNF-α can rapidly induce a phenotypic shift in VSMCs and change their viability on PGA scaffolds.

Prognostic factors and treatment responses among patients with gross residual disease in differentiated thyroid cancer.

BACKGROUND: Various postoperative staging systems were developed to assess the outcome of differentiated thyroid cancer (DTC) from initial risk after surgery to dynamic changing prognosis during follow-up. The objective of our retrospective cohort study was to identify risk factors contributing to macroscopic positive surgical margin (R2 resection) and parameters in discriminating the treatment responses and prognosis among R2 patients. METHODS: In total, 242 DTC patients with extrathyroidal extension who underwent a thyroidectomy at Kaohsiung Chang Gung Memorial Hospital between January 2013 and July 2018, were included. The patients were grouped according to the presence or absence of gross residual disease (R2). The R2 patients were further classified into two categories according to their treatment response into excellent and non-excellent groups. The parameters and treatment outcomes were compared between these groups. RESULTS: The mean follow-up time was 45.3 months. 207 (85.5%) patients had either surgery-free or microscopic margins (R0/R1), while 35 (14.5%) had R2 resection. In the R2 group (n = 35), 15 (42.9%) patients achieved an excellent response, while 20 (57.1%) achieved a non-excellent response. Statistically significant differences were observed in the extent of neck dissection, TSH-Tg level, post-RAI Tg level, nodal status, and recurrence between the two groups. The Kaplan-Meier curves for 5-year local and distant recurrence-free survival (LRFS and DRFS) of R0/R1 vs. R2 patients were 90.0% vs. 66.3%, and 98.4% vs.90.7% respectively, (p <0.001). Among the R2 patients, the excellent responders had a higher LRFS than non-excellent responders (93.3% vs. 45.1%, p=0.008). CONCLUSION: There are significant disparities in RFS among R2 patients with different treatment responses. The nodal status of PTC and thyroglobulin level after thyroidectomy and RAI were factors contributing to difference in their treatment responses.

Potential of dental pulp stem cells and their products in promoting peripheral nerve regeneration and their future applications.

Peripheral nerve injury (PNI) seriously affects people's quality of life. Stem cell therapy is considered a promising new option for the clinical treatment of PNI. Dental stem cells, particularly dental pulp stem cells (DPSCs), are adult pluripotent stem cells derived from the neuroectoderm. DPSCs have significant potential in the field of neural tissue engineering due to their numerous advantages, such as easy isolation, multidifferentiation potential, low immunogenicity, and low transplant rejection rate. DPSCs are extensively used in tissue engineering and regenerative medicine, including for the treatment of sciatic nerve injury, facial nerve injury, spinal cord injury, and other neurodegenerative diseases. This article reviews research related to DPSCs and their advantages in treating PNI, aiming to summarize the therapeutic potential of DPSCs for PNI and the underlying mechanisms and providing valuable guidance and a foundation for future research.

mTORC2 acts as a gatekeeper for mTORC1 deficiency-mediated impairments in ILC3 development.

Group 3 innate lymphoid cells (ILC3s) are mediators of intestinal immunity and barrier function. Recent studies have investigated the role of the mammalian target of rapamycin complex (mTOR) in ILC3s, whereas the mTORC1-related mechanisms and crosstalk between mTORC1 and mTORC2 involved in regulating ILC3 homeostasis remain unknown. In this study, we found that mTORC1 but not mTORC2 was critical in ILC3 development, IL-22 production, and ILC3-mediated intestinal homeostasis. Single-cell RNA sequencing revealed that mTORC1 deficiency led to disruption of ILC3 heterogeneity, showing an increase in differentiation into ILC1-like phenotypes. Mechanistically, mTORC1 deficiency decreased the expression of NFIL3, which is a critical transcription factor responsible for ILC3 development. The activities of both mTORC1 and mTORC2 were increased in wild-type ILC3s after activation by IL-23, whereas inhibition of mTORC1 by Raptor deletion or rapamycin treatment resulted in increased mTORC2 activity. Previous studies have demonstrated that S6K, the main downstream target of mTORC1, can directly phosphorylate Rictor to dampen mTORC2 activity. Our data found that inhibition of mTORC1 activity by rapamycin reduced Rictor phosphorylation in ILC3s. Reversing the increased mTORC2 activity via heterozygous or homozygous knockout of Rictor in Raptor-deleted ILC3s resulted in severe ILC3 loss and complete susceptibility to intestinal infection in mice with mTORC1 deficiency (100% mortality). Thus, mTORC1 acts as a rheostat of ILC3 heterogeneity, and mTORC2 protects ILC3s from severe loss of cells and immune activity against intestinal infection when mTORC1 activity is diminished.

Recombinant human thyrotropin versus thyroid hormone withdrawal preparation for radioiodine ablation in differentiated thyroid cancer: Experience in a South Taiwanese medical center.

This retrospective study was designed to compare the treatment response of patients with differentiated thyroid cancer (DTC) prepared for radioiodine ablation (RIA) with thyroid hormone withdrawal (THW) or recombinant human thyrotropin (rhTSH) stimulation. Patients with DTC were followed-up retrospectively between 2013 and 2018 in Kaohsiung Chang Gung Memorial Hospital, Taiwan. We compared the excellent response ratios between THW (49.9%) and rhTSH (50.1%) stimulation. Patients were then divided into subgroups, on the basis of age, sex, extrathyroidal extension, lymph node metastasis, and tumor-node-metastasis stage, for analysis. In all, 647 patients were followed-up after RIA. The ratios of THW or rhTSH use in the different subgroups were not statistically significant. In all the patients, the excellent response rate with THW and rhTSH was 80% and 76.5%, respectively, which was not statistically significant. The subgroup analysis, including age, sex, extrathyroidal extension, lymph node metastasis, and tumor-node-metastasis stage (low and high risk), showed similar results. Furthermore, the logistic regression analysis revealed no statistically significant differences among the subgroups. The multivariate analysis showed extrathyroidal extension, lymph node metastasis, and high I131 dose were the prognostic factors affecting the excellent response rate. In conclusion, the THW and rhTSH preparations for RIA were similar in terms of the excellent response rates and subgroup clinical outcomes.

Magnetic Resonance Imaging of Transplanted Porcine Neonatal Pancreatic Cell Clusters Labeled with Exendin-4-Conjugated Manganese Magnetism-Engineered Iron Oxide Nanoparticles.

Recently, we have shown that manganese magnetism-engineered iron oxide nanoparticles (MnMEIO NPs) conjugated with exendin-4 (Ex4) act as a contrast agent that directly trace implanted mouse islet ß-cells by magnetic resonance imaging (MRI). Here we further advanced this technology to track implanted porcine neonatal pancreatic cell clusters (NPCCs) containing ducts, endocrine, and exocrine cells. NPCCs from one-day-old neonatal pigs were isolated, cultured for three days, and then incubated overnight with MnMEIO-Ex4 NPs. Binding of NPCCs and MnMEIO-Ex4 NPs was confirmed with Prussian blue staining in vitro prior to the transplantation of 2000 MnMEIO-Ex4 NP-labeled NPCCs beneath the left renal capsule of six nondiabetic nude mice. The 7.0 T MRI on recipients revealed persistent hypointense areas at implantation sites for up to 54 days. The MR signal intensity of the graft on left kidney reduced 62-88% compared to the mirror areas on the contralateral kidney. Histological studies showed colocalization of insulin/iron and SOX9/iron staining in NPCC grafts, indicating that MnMEIO-Ex4 NPs were taken up by mature ß-cells and pancreatic progenitors. We conclude that MnMEIO-Ex4 NPs are excellent contrast agents for detecting and long-term monitoring implanted NPCCs by MRI.

Exendin-4-Conjugated Manganese Magnetism-Engineered Iron Oxide Nanoparticles as a Potential Magnetic Resonance Imaging Contrast Agent for Tracking Transplanted ß-Cells.

To specifically detect and trace transplanted islet ß-cells by magnetic resonance imaging (MRI), we conjugated manganese magnetism-engineered iron oxide nanoparticles (MnMEIO NPs) with exendin-4 (Ex4) which specifically binds glucagon-like peptide-1 receptors on the surface of ß-cells. The size distribution of MnMEIO and MnMEIO-Ex4 NPs were 67.8 ± 1.3 and 70.2 ± 2.3 nm and zeta potential 33.3 ± 0.5 and 0.6 ± 0.1 mV, respectively. MnMEIO and MnMEIO-Ex4 NPs with iron content ≤ 40 µg/mL did not affect MIN6 ß-cell viability and insulin secretion. Positive iron staining was found in MIN6 ß-cells loaded with MnMEIO-Ex4 NPs but not in those with MnMEIO NPs. A transmission electron microscope confirmed MnMEIO-Ex4 NPs were distributed in the cytoplasm of MIN6. In vitro MR images revealed a loss of signal intensity in MIN6 ß-cells labeled with MnMEIO-Ex4 NPs but not with MnMEIO NPs. After transplantation of islets labeled with MnMEIO-Ex4, the graft under kidney capsule could be visualized on MRI as persistent hypointense areas up to 17 weeks. Moreover, histology of the islet graft showed positive staining for insulin, glucagon and iron. Our results indicate MnMEIO-Ex4 NPs are safe and effective for the detection and long-term monitoring of transplanted ß-cells by MRI.

Static Retention of Dynamic Chiral Arrangements for Achiral Shear Thinning Metal-Organic Colloids.

Chiral compounds are known to be important not only because they are the fundamental components of living organisms, but also for their unique chiroptical properties. In recent years, scientists have fabricated several chiral organic supramolecular aggregates by using chiral physical fields, such as vortex flow. Herein, the relationship between dynamic chiroptical properties and rheological nature is discussed, suggesting the shear thinning properties of non-Newtonian fluids might help colloidal particles adopt a chiral arrangement in vortices. Furthermore, the storage modulus of colloids could be increased by adding a linking agent, which successfully kept the dynamic chiroptical properties in the static state. Moreover, the salt effect on the host-guest interaction involved in the colloids was studied, the results suggested a significant enhancement of the transferred dynamic circular dichroism for the achiral guest molecule.

Noninvasive Tracking of mPEG-poly(Ala) Hydrogel-Embedded MIN6 Cells after Subcutaneous Transplantation in Mice.

Recently, we demonstrated the feasibility of subcutaneous transplantation of MIN6 cells embedded in a scaffold with poly(ethylene glycol) methyl ether (mPEG)-poly(Ala) hydrogels. In this study, we further tracked these grafts using magnetic resonance (MR) and bioluminescence imaging. After being incubated overnight with chitosan-coated superparamagnetic iron oxide (CSPIO) nanoparticles and then mixed with mPEG-poly(Ala) hydrogels, MIN6 cells appeared as dark spots on MR scans. For in vivo experiments, we transfected MIN6 cells with luciferase and/or incubated them overnight with CSPIO overnight; 5 × 106 MIN6 cells embedded in mPEG-poly(Ala) hydrogels were transplanted into the subcutaneous space of each nude mouse. The graft of CSPIO-labeled MIN6 cells was visualized as a distinct hypointense area on MR images located at the implantation site before day 21. However, this area became hyperintense on MR scans for up to 64 days. In addition, positive bioluminescence images were also observed for up to 64 days after transplantation. The histology of removed grafts showed positive insulin and iron staining. These results indicate mPEG-poly(Ala) is a suitable scaffold for ß-cell encapsulation and transplantation. Moreover, MR and bioluminescence imaging are useful noninvasive tools for detecting and monitoring mPEG-poly(Ala) hydrogel-embedded MIN6 cells at a subcutaneous site.

Magnetic Resonance Imaging of Transplanted Porcine Neonatal Pancreatic Cell Clusters Labeled with Chitosan-Coated Superparamagnetic Iron Oxide Nanoparticles in Mice.

Neonatal pancreatic cell clusters (NPCCs) are potential tissues for the treatment of diabetes. Different from adult cells, they continuously proliferate and differentiate after transplantation. In this study, we utilized magnetic resonance imaging (MRI) to detect and monitor implanted NPCCs. NPCCs were isolated from one-day-old neonatal pigs, cultured for three days, and then incubated overnight with the contrast agent chitosan-coated superparamagnetic iron oxide (CSPIO) nanoparticles. In vitro, Prussian blue staining and MR scans of CSPIO-labeled NPCCs were performed. In vivo, we transplanted 2000 CSPIO-labeled NPCCs under the kidney capsule of nondiabetic nude mice. Recipients were scanned with 7.0T MRI. Grafts were removed for histology with insulin and Prussian blue staining. After being incubated overnight with CSPIO, NPCCs showed positive iron staining and appeared as dark spots on MR scans. After transplantation of CSPIO-labeled NPCCs, persistent hypointense areas were observed at recipients' implant sites for up to 54 days. Moreover, histology showed colocalization of the insulin and iron staining in 15-, 51- and 55-day NPCC grafts. Our results indicate that transplanted NPCCs survived and differentiated to ß cells after transplantation, and that MRI is a useful tool for the detection and monitoring of CSPIO-labeled NPCC grafts.

Circularly Polarized Luminescence of Achiral Metal-Organic Colloids and Guest Molecules in a Vortex Field.

Recently, scientists have reported a range of chiral fluorescence materials or chiral composites that can emit circularly polarized luminescence. Herein, two achiral metal-organic colloidal solutions were studied, showing active circularly polarized luminescence, which is observed in vortex stirring. The absolute values for glum are 0.05 and 0.03 and the plus or minus sign of glum depends on the colloidal structure and stirring direction, which make the property easy to manipulate. Further, the host-guest interaction study suggests both electrostatic interactions and coordination bonding may influence the chiroptical property from the colloidal solution to the guest molecule. Rhodamine 6G and its carboxylic acid derivative exhibit good quantum yields and acceptable glum values in the colloidal solution.

Analysis of overall survival in differentiated thyroid cancer patients with double primary malignancy.

Differentiated thyroid cancer (DTC) survivors are at increased risk of developing double primary malignancy (DPM). The aim of this study was to investigate clinicopathological characteristics and survival in DTC patients diagnosed with DPM. A total of 975 patients with DTC diagnosed between 2013 and 2017, treated, and followed at a medical center in Taiwan were retrospectively reviewed. Data from enrolled patients were analyzed for differences in prognosis dependent on the presence of DPM, and which clinicopathological variables affected their prognosis. Among 975 thyroid cancer patients, 94 (9.6%) were diagnosed with DPMs and 16 (1.6%) patients died of any cause. DPM patients had a greater proportion of males, had a higher mean age, more commonly presented with a thyroid mass incidentally by imaging and cervical lymph node metastases, showed a more advanced thyroid cancer stage, and had a higher proportion of lymph node metastases. Overall survival (OS) was significantly lower in patients diagnosed with DPM. Male gender (hazard ratio [HR] = 4.597), two or more DPMs (HR = 8.071), and shorter time interval between two cancers occurrences (HR = 7.101) were significantly risk factors for DPM-related death. In conclusion, the risk of developing DPM in DTC patients was elevated in older, male patients with an advanced tumor-node-metastasis stage. DPM adversely affected the OS of thyroid cancer patients. Male gender, two or more DPMs, and shorter time interval between occurrences were significant risk factors for OS in DPM patients.

The impact of bisphosphonates on mortality and cardiovascular risk among osteoporosis patients after cardiovascular disease.

BACKGROUND/PURPOSE: Bisphosphonates (BPs) impact on the survival and cardiovascular safety of osteoporosis patients after acute coronary syndrome (ACS) or acute ischemic stroke (AIS) was evaluated. METHODS: A nationwide epidemiological study was conducted using the Taiwan National Health Insurance Research Database from 2000 to 2010. From the 1456 osteoporosis patients with previous ACS or AIS, mortality and cardiovascular safety was compared between 464 patients who used BPs and 464 patients who did not. Primary outcomes included all-cause mortality, and major adverse cardiovascular events. RESULTS: The BPs group had a lower risk of all-cause mortality than the control group after the 8-year follow-up (HR, 0.64; 95% CI, 0.46-0.88; P = 0.006). The risks of myocardial infarction, ischemic stroke, cardiovascular death, hospitalization for heart failure or other causes of mortality were similar across groups. However, there was a higher risk of hospitalization for atrial fibrillation in the BPs group than the control group (HR, 1.76; 95% CI, 1.26-2.46; P = 0.001). CONCLUSION: Among osteoporosis patients after ACS or AIS, BPs use was associated with a reduced risk of all-cause mortality. However, patients with previous cardiovascular disease who received BP treatment should be careful about the risk of atrial fibrillation.

Solvent-assisted planar structure of a stilbene-based salicylhydrazone compound: crystal structure, solvent- and aggregation-induced emission, and switchable luminescence colouration.

A novel stilbene-based salicylhydrazone compound {systematic name: (E)-4,4'-(ethene-1,2-diyl)bis[(N'E)-N'-(2-hydroxybenzylidene)benzohydrazide] dimethyl sulfoxide disolvate, C30H24N4O4·2C2H6OS or L·2DMSO} was synthesized and characterized by single-crystal X-ray diffraction, powder X-ray diffraction and luminescence spectroscopy. The title compound crystallizes in the monoclinic space group P21/c, with half a symmetry-independent L molecule and one dimethyl sulfoxide (DMSO) solvent molecule in the asymmetric unit. The L molecule adopts an almost planar structure, with a small dihedral angle between the planes of the stilbene and salicylhydrazone groups. There are multiple π-π stacking interactions between adjacent L molecules. The DMSO solvent molecules act as proton donors and acceptors, forming hydrogen bonds of various strengths with the L molecules. In addition, the geometry optimization of a single molecule of L and its luminescence properties either in solution, as a solvated solid or as a desolvated solid were studied. The compound shows an aggregation-induced emission (AIE) effect and exhibits switchable luminescence colouration in the solid state by the simple removal or re-addition of the DMSO solvent.

Effect of high-fat diet on the pharmacokinetics and safety of flumatinib in healthy Chinese subjects.

PURPOSE: To evaluate the effect of a high-fat diet on the pharmacokinetics and safety of flumatinib mesylate tablets in healthy Chinese subjects. METHODS: This study was a randomized, open-label, single-dose, two-period crossover trial in which subjects were randomly assigned to take 400 mg of flumatinib mesylate after a high-fat diet or a fasted state. After a 14-day washout period, the two groups were administered flumatinib mesylate under opposite conditions. Blood samples were collected at baseline 0 and 0.5, 1, 1.5, 2, 2.5, 3, 4, 5, 6, 8, 10, 12, 24, 48, 72, and 96 h, respectively. Plasma concentrations of flumatinib and its metabolites (M1 and M3) were analyzed using liquid chromatography-mass spectrometry. Pharmacokinetic parameters were calculated using the non-compartmental module of the Phoenix WinNonlin Version 7.0 software. BE module of WinNonLin was used for statistical analysis of AUC0-t, AUC0-∞ and Cmax in plasma. RESULTS: Twelve healthy subjects, half male and half female, were enrolled. One subject withdrew due to a treatment-emergent adverse event. Eleven subjects were administered drugs on fasting and 12 were administered drugs after a high-fat diet. On high-fat diet/fasting, the least square geometric mean (LSGM) ratios of flumatinib, M1, M3, and their 90% confidence interval (CI) were as follows: for flumatinib, Cmax, AUC0-t and AUC0-∞ were 281.65% (225.80-351.31%), 167.43% (143.92-194.79%), and 166.87% (143.47-194.09%); for M1, Cmax, AUC0-t, and AUC0-∞ were 188.59% (145.29-244.79), 163.94% (149.11-180.24%), and 164.48% (150.36-179.94%); for M3, Cmax, AUC0-t, and AUC0-∞ were 63.47% (54.02-74.57%), 85.23% (74.72-97.22%), and 96.73% (86.63-108.02%). CONCLUSION: Among the subjects, oral administration of 400 mg of flumatinib was safe and well tolerated. High-fat diet significantly increases the exposure to flumatinib, therefore, fasting may be recommended. CLINICAL TRIAL REGISTRATION: The study was registered at chictr.org Identifier: ChiCTR-IIR-17013179.

A randomized, double-blind, single-dose study to evaluate the biosimilarity of QL1101 with bevacizumab in healthy male subjects.

PURPOSE: This is the first study to compare the pharmacokinetics of QL1101, a proposed bevacizumab biosimilar, with Avastin® sourced from Roche Diagnostics GmbH. METHODS: In this double-blind, single-dose, parallel-group study, healthy male subjects were randomized 1:1 to receive QL1101 or Avastin® 3 mg/kg intravenously. Pharmacokinetic assessments were conducted for 85 days, with additional safety and immunogenicity assessments until day 90. Primary study endpoints were area under the concentration-time curve (AUC) from time zero to infinity (AUC0-∞), AUC from time zero to the last quantifiable concentration (AUC0-last), and maximum serum concentration (Cmax). Pharmacokinetic equivalence was shown if the 90% confidence intervals (CIs) of the geometric mean ratios (GMRs) of the C0-max, AUC0-last, and AUC0-∞ were within the predefined bioequivalence margin of 80-125.00%. RESULTS: A total of 82 subjects were randomized to the following groups: 42 to QL1101 and 40 to Avastin®. The 90% CIs of the GMRs of AUC0-∞, AUC0-last, and Cmax of QL1101 and Avastin® were (97.8%, 107.0%), (94.5%, 106.9%), and (94.1%, 107.3%), respectively, which were all within the bioequivalence margin. The incidence of adverse events was 90.5% and 95.0% in the QL1101 and Avastin® groups, respectively. Mean serum concentration-time profiles, secondary pharmacokinetic parameters, and safety and immunogenicity profiles were comparable across the two treatment groups. CONCLUSIONS: The study demonstrated the pharmacokinetic equivalence of QL1101 to Avastin®. QL1101 (3 mg/kg, iv) is safe and tolerable in healthy Chinese subjects. These data support the further clinical evaluation of QL1101 as a bevacizumab biosimilar.

A series of pure-blue-light emitting Cu(i) complexes with thermally activated delayed fluorescence: structural, photophysical, and computational studies.

Four mononuclear Cu(i)-halide complexes containing phosphines and pyridine ligands with strong electron donor substituents, [CuCl(PPh3)2(4-NMe2py)] (1), [CuI(PPh3)2(4-NH2py)] (2), [CuI(POP)(4-NH2py)] (3), and [CuI(POP)(4-NMe2py)]·0.5(Et2O) (4), (PPh3 = triphenylphosphine, 4-NMe2py = 4-(dimethylamino)pyridine, POP = bis[(2-diphenyl-phosphino)phenyl]ether, 4-NH2py = 4-aminopyridine, Et2O = diethyl ether) were synthesized and studied with regard to their structural, photophysical properties and theoretical calculations. The complexes exhibit pure blue thermally activated delayed fluorescence (λmax = 442 (1), 436 (2), 464 (3), and 448 nm (4)) in crystalline at room temperature. Emission lifetime analyses and density functional theory (DFT) calculations show that the blue-light emission at room temperature is the singlet (metal + halide)-to-ligand charge transfer state, (1(M + X)LCT), while that at 77 K is the state of 3(M + X)LCT transition character, owing to the small singlet-triplet energy gaps (ΔE = 660-1680 cm-1). X-ray diffraction structure analysis, photophysical studies and theoretical calculations suggest that the much larger torsion angle between the N-heterocyclic rings and N-Cu-X planes of complex 3 than that of 1, 2 and 4 might causes the bathochromic shift of luminescence, although these complexes containing similar heterocycle ligands.

Effects of light-dark cycle on hippocampal iNOS expression and CREB activation in rats.

Nitric oxide (NO) is one of the most important interneural signaling molecules mediating hippocampal functions for learning and memory. The diurnal expression of neuronal NO synthase (nNOS) has been well studied. However, the temporal profile and underlying mechanisms of inducible NOS (iNOS) expression in a normal photoperiod or in altered light-dark cycles remain unclear. We examined the temporal profile of iNOS expression in adult male Sprague-Dawley rats maintained in a 12h-light/ 12h-dark photoperiod (12L/12D), which were pre-synchronized for 7 days before the experiment. The protein and mRNA levels of iNOS in the cortex and hippocampus were measured to examine the photic influences on iNOS expression. The results showed rhythmically changes of the levels of iNOS mRNA and protein in the hippocampus, but not in the cerebral cortex. The iNOS mRNA levels peaked at Zeitgeber time (ZT) 6 and ZT22, and the protein levels peaked at ZT8 and ZT18. Notably, the peaks in iNOS mRNA and protein levels in the 12L/12D group were 10 to 12 h apart, and the rhythmic pattern was absent in the 24-h period of the darkness group. In addition, the level of the phosphorylated cAMP response element binding protein (phospho-CREB) was the highest at ZT18, prior to a peak in iNOS mRNA expression at ZT22. A phospho-CREB-iNOS signaling pathway was further confirmed by the interaction of phospho-CREB and the iNOS DNA in histone complexes isolated by chromatin immunoprecipitation at ZT18. In conclusion, the photoperiod affects the diurnal expression of iNOS and activation of CREB in the hippocampus, which provide clues for the possible impact of circadian changes in hippocampal functions.

Enantioselective synthesis of a chiral coordination polymer with circularly polarized visible laser.

Circular dichroism is known to be the feature of a chiral agent which has inspired scientist to study the interesting phenomena of circularly polarized light (CPL) modulated molecular chirality. Although several organic molecules or assemblies have been found to be CPL-responsive, the influence of CPL on the assembly of chiral coordination compounds remains unknown. Herein, a chiral coordination polymer, which is constructed from achiral agents, was used to study the CPL-induced enantioselective synthesis. By irradiation with either left-handed or right-handed CPL during the reaction and crystallization, enantiomeric excesses of the crystalline product were obtained. Left-handed CPL resulted in crystals with a left-handed helical structure, and right-handed CPL led to crystals with a right-handed helical structure. It is exciting that the absolute asymmetric synthesis of a chiral coordination polymer could be enantioselective when using CPL, and provides a strategy for the control of the chirality of chiral coordination polymers.