Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 67
Filter
Add more filters

Country/Region as subject
Publication year range
1.
Proc Natl Acad Sci U S A ; 121(20): e2320674121, 2024 May 14.
Article in English | MEDLINE | ID: mdl-38684007

ABSTRACT

Identifying and protecting hotspots of endemism and species richness is crucial for mitigating the global biodiversity crisis. However, our understanding of spatial diversity patterns is far from complete, which severely limits our ability to conserve biodiversity hotspots. Here, we report a comprehensive analysis of amphibian species diversity in China, one of the most species-rich countries on Earth. Our study combines 20 y of field surveys with new molecular analyses of 521 described species and also identifies 100 potential cryptic species. We identify 10 hotspots of amphibian diversity in China, each with exceptional species richness and endemism and with exceptional phylogenetic diversity and phylogenetic endemism (based on a new time-calibrated, species-level phylogeny for Chinese amphibians). These 10 hotspots encompass 59.6% of China's described amphibian species, 49.0% of cryptic species, and 55.6% of species endemic to China. Only four of these 10 hotspots correspond to previously recognized biodiversity hotspots. The six new hotspots include the Nanling Mountains and other mountain ranges in South China. Among the 186 species in the six new hotspots, only 9.7% are well covered by protected areas and most (88.2%) are exposed to high human impacts. Five of the six new hotspots are under very high human pressure and are in urgent need of protection. We also find that patterns of richness in cryptic species are significantly related to those in described species but are not identical.


Subject(s)
Amphibians , Biodiversity , Phylogeny , Animals , Amphibians/classification , China , Conservation of Natural Resources
2.
BMC Plant Biol ; 24(1): 516, 2024 Jun 08.
Article in English | MEDLINE | ID: mdl-38851686

ABSTRACT

BACKGROUND: The influence of native secondary succession associated with anthropogenic disturbance on the biodiversity of the forests in subtropical China remains uncertain. In particular, the evolutionary response of small understory shrubs, particularly pioneer species inhabiting continuously disturbed habitats, to topographic heterogeneity and climate change is poorly understood. This study aimed to address this knowledge gap by focusing on the Gaultheria crenulata group, a clade of small pioneer shrubs in subtropical China. RESULTS: We examined the genetic structure and demographic history of all five species of the G. crenulata group with two maternally inherited chloroplast DNA (cpDNA) fragments and two biparentally inherited low-copy nuclear genes (LCG) over 89 natural populations. We found that the genetic differentiation of this group was influenced by the geomorphological boundary between different regions of China in association with Quaternary climatic events. Despite low overall genetic diversity, we observed an isolation-by-distance (IBD) pattern at a regional scale, rather than isolation-by-environment (IBE), which was attributed to ongoing human disturbance in the region. CONCLUSION: Our findings suggest that the genetic structure of the G. crenulata group reflects the interplay of geological topography, historical climates, and anthropogenic disturbance during the Pliocene-Pleistocene-Holocene periods in subtropical China. The observed IBD pattern, particularly prominent in western China, highlights the role of limited dispersal and gene flow, possibly influenced by physical barriers or decreased connectivity over geographic distance. Furthermore, the east-to-west trend of gene flow, potentially facilitated by the East Asian monsoon system, underscores the complex interplay of biotic and abiotic factors shaping the genetic dynamics of pioneer species in subtropical China's secondary forests. These findings can be used to assess the impact of environmental changes on the adaptation and persistence of biodiversity in subtropical forest ecosystems.


Subject(s)
Forests , Genetic Variation , China , DNA, Chloroplast/genetics , Population Dynamics , Biodiversity , Gene Flow
3.
Bioorg Med Chem ; 99: 117595, 2024 Feb 01.
Article in English | MEDLINE | ID: mdl-38244254

ABSTRACT

Nicotinamide phosphoribosyltransferase (NAMPT) is a key rate-limiting enzyme in the nicotinamide adenine dinucleotide (NAD+) salvage pathway, primarily catalyzing the synthesis of nicotinamide mononucleotide (NMN) from nicotinamide (NAM), phosphoribosyl pyrophosphate (PRPP), and adenosine triphosphate (ATP). Metabolic diseases, aging-related diseases, inflammation, and cancers can lead to abnormal expression levels of NAMPT due to the pivotal role of NAD+ in redox metabolism, aging, the immune system, and DNA repair. In addition, NAMPT can be secreted by cells as a cytokine that binds to cell membrane receptors to regulate intracellular signaling pathways. Furthermore, NAMPT is able to reduce therapeutic efficacy by enhancing acquired resistance to chemotherapeutic agents. Recently, a few novel activators and inhibitors of NAMPT for neuroprotection and anti-tumor have been reported, respectively. However, NAMPT activators are still in preclinical studies, and only five NAMPT inhibitors have entered the clinical stage, unfortunately, three of which were terminated or withdrawn due to safety concerns. Novel drug design strategies such as proteolytic targeting chimera (PROTAC), antibody-drug conjugate (ADC), and dual-targeted inhibitors also provide new directions for the development of NAMPT inhibitors. In this perspective, we mainly discuss the structure, biological function, and role of NAMPT in diseases and the currently discovered activators and inhibitors. It is our hope that this work will provide some guidance for the future design and optimization of NAMPT activators and inhibitors.


Subject(s)
NAD , Neoplasms , Humans , NAD/metabolism , Nicotinamide Phosphoribosyltransferase , Cytokines/metabolism , Niacinamide , Drug Discovery , Neoplasms/drug therapy
4.
Molecules ; 28(22)2023 Nov 08.
Article in English | MEDLINE | ID: mdl-38005204

ABSTRACT

In this study, we not only optimized and improved the synthesis process of levobupivacaine hydrochloride (21) but also conducted a comprehensive exploration of critical industrial-scale production details, and a novel high-performance liquid chromatography (HPLC) analysis method was developed. Starting with the readily available and cost-effective (R,S)-N-(2,6-dimethylphenyl)piperidine-2-carboxamide (28) as the initial material and utilizing l-(-)-dibenzoyl tartaric acid (29) for chiral separation, and then through substitution and a salting reaction, levobupivacaine hydrochloride (21) was obtained with high purity (chemical purity of 99.90% and enantiomeric excess (ee) values of 99.30%). The total yield of the three steps was 45%. Structures of intermediates and the final product were confirmed using nuclear magnetic resonance (NMR) (1H NMR, 13C NMR), mass spectrometry (MS), and elemental analysis. The crystal structure of the final product was determined through differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and X-ray diffraction (XRD). Furthermore, we evaluated the risk of the substitution reaction using a reaction calorimeter and accelerating rate calorimetry (ARC). This process offers the advantages of simple operation, greenness, safety, controllable quality, and cost-effectiveness. It provides reliable technical support for the industrial-scale production of levobupivacaine hydrochloride (21), which is of significant importance in meeting clinical demands. Pilot-scale production has already been successfully completed by China National Medicines Guorui Pharmaceutical Co., Ltd., with a production scale of 20 kg.

5.
Int J Med Sci ; 18(12): 2493-2499, 2021.
Article in English | MEDLINE | ID: mdl-34104080

ABSTRACT

Purpose: The anatomical parameters of normal lacrimal puncta and vertical canaliculus using optical coherence tomography (OCT) and the OCT imaging features of punctal lesions were analyzed to provide a basis for clinical diagnosis and treatment. Methods: From June to September 2019, 40 volunteers (80 eyes) from Tongji Hospital were enrolled. The external punctal diameter (ELP) was measured using slit-lamp microscopy and OCT. The internal lacrimal punctal diameter (ILP) at 100 µm, vertical canalicular length (VCL), and tear meniscus depth were measured by OCT with open eyes. Twenty-eight volunteers (56 eyes) underwent the same examinations with their eyes closed. The OCT imaging features of 26 patients (27 eyes) with lacrimal lesions were examined. Results: The ELP of the right and left healthy eyes under slit-lamp microscopy were 564.40 and 555.40 µm respectively. Under OCT, the ELP, ILP, and VCL of the right and left eyes were 628.20 um and 616.85 µm, 343.40 µm and 346.95 µm, 731.95 um and 709.20 µm respectively. The ELP was larger when measured by OCT than slit-lamp microscopy (p<0.05). Twenty-eight volunteers (56 eyes) had measurements taken under different conditions. The ELP, ILP, and VCL of the open and closed right eyes were 667.54 and 567.21 µm, 369.18 and 303.18 µm, 715.00 and 417.14 µm, respectively. The ELP, ILP, and VCL of the open and closed left eyes were 655.86 um and 551.68 µm, 369.25 um and 313.54 µm, 719.96 um and 433.89 µm respectively. The anatomical parameters of the open eyes were greater than those of the closed eyes (p<0.05). Thus, we identified the imaging features of lacrimal stenosis, punctal obstruction, punctal tear, lacrimal atresia, and lacrimal mass using OCT. Conclusions: OCT can be used to measure the anatomical parameters of lacrimal puncta and vertical canaliculus in vivo. In addition, OCT can detect punctal lesions in vivo and provide an objective basis for the clinical diagnosis and treatment of punctal lesions.


Subject(s)
Lacrimal Apparatus/anatomy & histology , Tomography, Optical Coherence , Adult , Aged , Feasibility Studies , Female , Healthy Volunteers , Humans , Lacrimal Apparatus/diagnostic imaging , Male , Middle Aged , Prospective Studies , Slit Lamp Microscopy , Young Adult
6.
Cell Tissue Bank ; 20(3): 379-387, 2019 Sep.
Article in English | MEDLINE | ID: mdl-31240495

ABSTRACT

To evaluate the characteristics of microbiological contamination in donor corneas preserved for medium-term. A total of 82 donated corneas from June 1, 2014 to November 30, 2014 were retrospectively analyzed. The corneas were preserved in cornea chambers medium-term solution at 4-8 °C for keratoplasty. After removal of the central corneas for transplantation, the corneoscleral rims were put back into the medium for 1 month at room temperature (20-25 °C). The suspicious contaminated storage solutions indicated with transparency or color change were examined with bacteria and fungi cultivation for strain identification. The data collected included gender, age, procurement site and causes of death of donors, and follow-up of recipients. Statistical analysis was performed using Microsoft Excel and SPSS 24.0. Significance level was set at a P value < 0.05. The overall pathogen positive rate was 9.8% (n = 8), including 7 (87.5%) fungi and 1 (12.5%) bacteria. They were 2 (2.44%) Fusarium, 2 (2.44%) Chromomycosis, 1 (1.22%) Candida albicans, 1 (1.22%) Aspergillus versicolor, 1 (1.22%) Acremonium species, and 1 (1.22%) Enterococcus. 5 contaminated corneas were used for penetrating keratoplasty; although four out of five (80%) had not been given antifungal drugs during more than 6 months following-up period, none of the recipients was infected with a graft. Donor age (P = 0.839), gender (P = 0.062), procurement sites (P = 0.713) and cause of death (P = 0.711) had no statistically significant influence on the contamination rate. All donor corneas have a possibility of microbiological contamination. Strict tissue preservation protocol but not antifungal drugs following keratoplasty seems necessary to prevent graft infection.


Subject(s)
Cornea/microbiology , Corneal Transplantation/methods , Organ Preservation/adverse effects , Organ Preservation/methods , Specimen Handling/adverse effects , Adolescent , Adult , Aged , Aged, 80 and over , Bacteria , Child , Child, Preschool , Culture Media , Eye Banks , Female , Fungi , Humans , Infant , Male , Middle Aged , Retrospective Studies , Tissue Donors , Tissue Preservation/methods , Young Adult
7.
Int J Med Sci ; 15(12): 1260-1267, 2018.
Article in English | MEDLINE | ID: mdl-30275751

ABSTRACT

Purpose: To investigate whether lacrimal canaliculus epithelial stem cells (LCESC) could be isolated and expanded in vitro. Methods: The lacrimal canaliculus epithelium of 6 patients with limbal stem cell deficiency (LSCD) caused by alkali burn or Stevens Johnson Syndrome were examined by lacrimal endoscope. Cadaveric eyelids were fixed and prepared for cross section and stained with HE and antibodies against PCK, Vim, p63α, SCF and c-Kit. Canaliculus tissue was separated under an operating microscope using a lacrimal probe as an indicator and digested with collagenase A. The clusters of epithelial cells with closely associated stroma were further digested with Trypsin/EDTA to obtain single cells for culture on Matrigel-coated plastic plates in MESCM media. The expression of SCF, c-Kit and p63α was determined by immunostaining. The colony-forming efficiency on 3T3 feeder layers was also measured by calculating the percentage of the clone number divided by the total number cells seeded. Results: The epithelial layers of five out of six inferior lacrimal canaliculi and all the six superior lacrimal canaliculi were visually normal in appearance. Five to fifteen layers of the epithelium in the human lacrimal canaliculi were present with a small, tightly compacted basal layer of cells expressing PCK, p63α, SCF and c-Kit. LCESC were isolated by collagenase A and obtained clonal growth in MESCM. The colony-forming efficiency of LCESC holoclones on a 3T3 feeder layer was 3.2%, compared to 1.9% for those of limbal stem cells (LSC). Conclusions: Herein, we first report that LCESCs can be isolated and have stem cell characteristics, similar to those of LSCs. Such a discovery raises a promising substrate resource of stem cells for LSC reconstruction in LSCD patients.


Subject(s)
Cells, Cultured , Epithelial Cells , Epithelium, Corneal/cytology , Humans , Limbus Corneae , Stem Cells
8.
Mediators Inflamm ; 2017: 3059763, 2017.
Article in English | MEDLINE | ID: mdl-28638179

ABSTRACT

Danhong Huayu Koufuye (DHK), a traditional Chinese prescription, is used to treat central retinal vein occlusion clinically. We previously reported that DHK prevented diabetic retinopathy (DR) in rats. Moreover, we found that it protected endothelial cells from hyperglycemia-induced apoptosis through antioxidation and anti-inflammation. Here, we investigated whether antioxidative and anti-inflammatory activities of DHK contributed to its therapeutic effect on DR in streptozotocin- (STZ-) induced diabetic rats. DHK significantly blocked the breakdown of the blood-retinal barrier (BRB) and increased the thickness of the inner nuclear layer (INL), as well as suppressed the swelling of the ganglion cell layer (GCL) in diabetic retinas. DHK remarkably increased the activities of superoxide dismutase (SOD) and glutathione peroxidase (GPx) in plasma, and decreased serum level of nitric oxide (NO). Moreover, DHK markedly reduced the serum levels of vascular endothelial growth factor (VEGF) and intercellular adhesion molecule-1 (ICAM-1). Furthermore, DHK significantly downregulated protein expressions of VEGF and inducible NO synthase (iNOS) and mRNA expression of ICAM-1 in retinas. These results suggest that the antioxidative and anti-inflammatory activities of DHK may be important mechanisms involved in the protective effect of DHK on DR in STZ-induced diabetic rats.


Subject(s)
Anti-Inflammatory Agents/therapeutic use , Diabetes Mellitus, Experimental/drug therapy , Diabetes Mellitus, Experimental/metabolism , Diabetic Retinopathy/drug therapy , Diabetic Retinopathy/metabolism , Drugs, Chinese Herbal/therapeutic use , Animals , Antioxidants/metabolism , Blood-Retinal Barrier/drug effects , Blood-Retinal Barrier/metabolism , Glutathione Peroxidase/metabolism , Intercellular Adhesion Molecule-1/metabolism , Male , Rats , Rats, Sprague-Dawley , Retina/drug effects , Retina/metabolism , Superoxide Dismutase/metabolism , Vascular Endothelial Growth Factor A/metabolism
9.
J Surg Res ; 201(2): 340-7, 2016 Apr.
Article in English | MEDLINE | ID: mdl-27020817

ABSTRACT

BACKGROUND: Danhong huayu koufuye (DHK) has traditionally been used clinically for a long time in China. This study was to evaluate the effect of DHK in treating deep vein thrombosis (DVT) in rats and explore its possible mechanism. METHODS: Forty-eight Sprague-Dawley rats were divided into four groups, performed with incomplete inferior vena cava ligation to induce DVT, and orally administered with DHK (3.20 mg/kg/d), warfarin (2.00 mg/kg/d), or vehicle for 7 days. The involved inferior vena cava and thrombi were collected and measured in size. The tissue specimens were performed for routine histopathologic evaluation and immunohistochemical staining with tissue factor and matrix metalloproteinases-9. Blood samples were collected for detecting coagulation function, blood cell count, and the levels of interleukin-6 and tumor necrosis factor-α. RESULTS: The treatment of DHK markedly reduced the size of thrombi by 49.26%, and the vein wall thickness by 47.86%. The recanalization rate was significant higher in the DHK-treated group than the vehicle-treated group (26.34 ± 6.53% versus 15.91 ± 3.93%, P < 0.01). Comparing to vehicle control, DHK significantly reduced neutrophils (P < 0.05) and lymphocytes (P < 0.05), serum tumor necrosis factor-α level (4.90 ± 1.14 pg/mL versus 6.60 ± 1.62 pg/mL, P < 0.01), and the expression of matrix metalloproteinases-9 and tissue factor (P < 0.05) in thrombi. CONCLUSIONS: DHK effectively prevented DVT through anti-inflammatory action in rats.


Subject(s)
Drugs, Chinese Herbal/therapeutic use , Venous Thrombosis/prevention & control , Animals , Blood Cell Count , Blood Coagulation/drug effects , Drug Evaluation, Preclinical , Drugs, Chinese Herbal/pharmacology , Interleukin-6/blood , Male , Matrix Metalloproteinase 9/metabolism , Random Allocation , Rats, Sprague-Dawley , Thromboplastin/metabolism , Tumor Necrosis Factor-alpha/blood , Vena Cava, Inferior/drug effects , Vena Cava, Inferior/pathology , Venous Thrombosis/metabolism , Venous Thrombosis/pathology
10.
BMC Microbiol ; 15: 233, 2015 Oct 24.
Article in English | MEDLINE | ID: mdl-26498126

ABSTRACT

BACKGROUND: Bacterial plasmids have a major impact on metabolic function and adaptation of their hosts. An indigenous plasmid was identified in a Chinese isolate (GX01) of the invasive phytopathogen Xanthomonas oryzae pv. oryzicola (Xoc), the causal agent of rice bacterial leaf streak (BLS). To elucidate the biological functions of the plasmid, we have sequenced and comprehensively annotated the plasmid. METHODS: The plasmid DNA was extracted from Xoc strain GX01 by alkaline lysis and digested with restriction enzymes. The cloned and subcloned DNA fragments in pUC19 were sequenced by Sanger sequencing. Sequences were assembled by using Sequencher software. Gaps were closed by primer walking and sequencing, and multi-PCRs were conducted through the whole plasmid sequence for verification. BLAST, phylogenetic analysis and dinucleotide calculation were performed for gene annotation and DNA structure analysis. Transformation, transconjugation and stress tolerance tests were carried out for plasmid function assays. RESULTS: The indigenous plasmid from Xoc strain GX01, designated pXOCgx01, is 53,206-bp long and has been annotated to possess 64 open reading frames (ORFs), including genes encoding type IV secretion system, heavy metal exporter, plasmid stability factors, and DNA mobile factors, i.e., the Tn3-like transposon. Bioinformatics analysis showed that pXOCgx01 has a mosaic structure containing different genome contexts with distinct genomic heterogeneities. Phylogenetic analysis indicated that the closest relative of pXOCgx01 is pXAC64 from Xanthomonas axonopodis pv. citri str. 306. It was estimated that there are four copies of pXOCgx01 per cell of Xoc GX01 by PCR assay and the calculation of whole genome shotgun sequencing data. We demonstrate that pXOCgx01 is a self-transmissible plasmid and can replicate in some Xanthomonas spp. strains, but not in Escherichia coli DH5α. It could significantly enhance the tolerance of Xanthomonas oryzae pv. oryzae PXO99A to the stresses of heavy metal ions. The plasmid survey indicated that nine out of 257 Xoc Chinese isolates contain plasmids. CONCLUSIONS: pXOCgx01 is the first report of indigenous plasmid from Xanthomonas oryzae pv. oryzicola, and the first completely sequenced plasmid from Xanthomonas oryzae species. It is a self-transmissible plasmid and has a mosaic structure, containing genes for macromolecule secretion, heavy metal exportation, and DNA mobile factors, especially the Tn3-like transposon which may provide transposition function for mobile insertion cassette and play a major role in the spread of pathogenicity determinants. The results will be helpful to elucidate the biological significance of this cryptic plasmid and the adaptive evolution of Xoc.


Subject(s)
Plasmids/isolation & purification , Xanthomonas/genetics , China , Computational Biology , Conjugation, Genetic , DNA Replication , Drug Resistance, Bacterial , Escherichia coli/genetics , Gene Transfer, Horizontal , Metals, Heavy/toxicity , Molecular Sequence Annotation , Molecular Sequence Data , Open Reading Frames , Oryza/microbiology , Phylogeny , Plant Diseases/microbiology , Sequence Analysis, DNA , Sequence Homology , Xanthomonas/isolation & purification
11.
J Med Chem ; 67(11): 8667-8692, 2024 Jun 13.
Article in English | MEDLINE | ID: mdl-38651495

ABSTRACT

The targeting of cancer cell intrinsic metabolism has emerged as a promising strategy for antitumor intervention. In the study, we identified the first-in-class small molecules that effectively inhibit both mutant isocitrate dehydrogenase 1 (mIDH1) and nicotinamide phosphoribosyltransferase (NAMPT), two crucial targets in cancer metabolism, through structure-based drug design. Notably, compound 23h exhibits excellent and balanced inhibitory activities against both mIDH1 (IC50 = 14.93 nM) and NAMPT (IC50 = 12.56 nM), leading to significant suppression of IDH1-mutated glioma cell (U87 MG-IDH1R132H) proliferation. Significantly, compound 23h has the ability to cross the blood-brain barrier (B/P ratio, 0.76) and demonstrates remarkable in vivo antitumor efficacy (20 mg/kg) in the U87 MG-IDH1R132H orthotopic transplantation mouse models without any notable toxicity. This proof-of-concept investigation substantiates the viability of discovering small molecules that concurrently target mIDH1 and NAMPT, providing valuable leads for the treatment of glioma and an efficient approach for the discovery of multitarget antitumor drugs.


Subject(s)
Antineoplastic Agents , Cell Proliferation , Cytokines , Glioma , Isocitrate Dehydrogenase , Nicotinamide Phosphoribosyltransferase , Nicotinamide Phosphoribosyltransferase/antagonists & inhibitors , Nicotinamide Phosphoribosyltransferase/metabolism , Isocitrate Dehydrogenase/antagonists & inhibitors , Isocitrate Dehydrogenase/genetics , Isocitrate Dehydrogenase/metabolism , Glioma/drug therapy , Glioma/pathology , Animals , Humans , Antineoplastic Agents/pharmacology , Antineoplastic Agents/chemistry , Antineoplastic Agents/therapeutic use , Antineoplastic Agents/chemical synthesis , Mice , Cytokines/metabolism , Cell Proliferation/drug effects , Cell Line, Tumor , Mutation , Drug Discovery , Brain Neoplasms/drug therapy , Brain Neoplasms/pathology , Structure-Activity Relationship , Enzyme Inhibitors/pharmacology , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/therapeutic use , Enzyme Inhibitors/chemical synthesis , Mice, Nude
12.
World J Gastrointest Oncol ; 16(2): 414-435, 2024 Feb 15.
Article in English | MEDLINE | ID: mdl-38425399

ABSTRACT

BACKGROUND: Aberrant methylation is common during the initiation and progression of colorectal cancer (CRC), and detecting these changes that occur during early adenoma (ADE) formation and CRC progression has clinical value. AIM: To identify potential DNA methylation markers specific to ADE and CRC. METHODS: Here, we performed SeqCap targeted bisulfite sequencing and RNA-seq analysis of colorectal ADE and CRC samples to profile the epigenomic-transcriptomic landscape. RESULTS: Comparing 22 CRC and 25 ADE samples, global methylation was higher in the former, but both showed similar methylation patterns regarding differentially methylated gene positions, chromatin signatures, and repeated elements. High-grade CRC tended to exhibit elevated methylation levels in gene promoter regions compared to those in low-grade CRC. Combined with RNA-seq gene expression data, we identified 14 methylation-regulated differentially expressed genes, of which only AGTR1 and NECAB1 methylation had prognostic significance. CONCLUSION: Our results suggest that genome-wide alterations in DNA methylation occur during the early stages of CRC and demonstrate the methylation signatures associated with colorectal ADEs and CRC, suggesting prognostic biomarkers for CRC.

13.
Chemistry ; 19(45): 15396-403, 2013 Nov 04.
Article in English | MEDLINE | ID: mdl-24114981

ABSTRACT

A 3D organic-inorganic hybrid compound, (2-MepyH)3[{Fe(1,10-phen)3}3][{Pr4Sb12O18(OH)Cl(11.5)}(TDC)(4.5)({Pr4Sb12O18(OH)Cl(9.5)} Cl)]·3(2-Mepy)·28H2O (1; 2-Mepy=2-methylpyridine, 1,10-phen=1,10-phenanthroline, H2TDC=thiophene-2,5-dicarboxylic acid), was hydrothermally synthesized and structurally characterized. Unusually, two kinds of high-nuclearity clusters, namely [(Pr4Sb12O18(OH)Cl11)(COO)5](5-) and [(Pr4Sb12O18(OH)Cl9)Cl(COO)5](4-), coexist in the structure of compound 1; two of the latter clusters are doubly bridged by two µ2-Cl(-) moieties to form a new centrosymmetric dimeric cluster. An unprecedented spontaneous and reversible single-crystal-to-single-crystal transformation was observed, which simultaneously involved a notable organic-ligand movement between the metal ions and an alteration of the bridging ion in the dimeric cluster, induced by guest-release/re-adsorption, thereby giving rise to the interconversion between compound 1 and the compound (2-MepyH)3[{Fe(1,10-phen)3}3][{Pr4Sb12O18(OH)Cl(11.5)}(TDC)4({Pr4Sb12O18Cl(10.5)(TDC)(0.5)(H2O)(1.5)}O(0.5))]·25H2O (1'). The mechanism of this transformation has also been discussed in great detail. Photocatalytic H2-evolution activity was observed for compound 1' under UV light with Pt as a co-catalyst and MeOH as a sacrificial electron donor.

14.
Mol Ecol Resour ; 23(5): 1124-1141, 2023 Jul.
Article in English | MEDLINE | ID: mdl-36924341

ABSTRACT

DNA barcoding has greatly facilitated studies of taxonomy, biodiversity, biological conservation, and ecology. Here, we establish a reliable DNA barcoding library for Chinese snakes, unveiling hidden diversity with implications for taxonomy, and provide a standardized tool for conservation management. Our comprehensive study includes 1638 cytochrome c oxidase subunit I (COI) sequences from Chinese snakes that correspond to 17 families, 65 genera, 228 named species (80.6% of named species) and 36 candidate species. A barcode gap analysis reveals gaps, where all nearest neighbour distances exceed maximum intraspecific distances, in 217 named species and all candidate species. Three species-delimitation methods (ABGD, sGMYC, and sPTP) recover 320 operational taxonomic units (OTUs), of which 192 OTUs correspond to named and candidate species. Twenty-eight other named species share OTUs, such as Azemiops feae and A. kharini, Gloydius halys, G. shedaoensis, and G. intermedius, and Bungarus multicinctus and B. candidus, representing inconsistencies most probably caused by imperfect taxonomy, recent and rapid speciation, weak taxonomic signal, introgressive hybridization, and/or inadequate phylogenetic signal. In contrast, 43 species and candidate species assign to two or more OTUs due to having large intraspecific distances. If most OTUs detected in this study reflect valid species, including the 36 candidate species, then 30% more species would exist than are currently recognized. Several OTU divergences associate with known biogeographic barriers, such as the Taiwan Strait. In addition to facilitating future studies, this reliable and relatively comprehensive reference database will play an important role in the future monitoring, conservation, and management of Chinese snakes.


Subject(s)
Biodiversity , DNA Barcoding, Taxonomic , Humans , Animals , Phylogeny , DNA Barcoding, Taxonomic/methods , Snakes/genetics , Electron Transport Complex IV/genetics
15.
Stem Cells ; 29(11): 1874-85, 2011 Nov.
Article in English | MEDLINE | ID: mdl-21948620

ABSTRACT

Corneal epithelial stem cells (SCs) are an ideal model for investigating how adult lineage-committed epithelial SCs are regulated by an anatomically defined and accessible niche, that is, limbal palisades of Vogt, located between the cornea and the conjunctiva. We have used collagenase digestion to isolate the entire limbal epithelial SCs and subjacent mesenchymal cells, and we have demonstrated that their close association is crucial for promoting epithelial clonal growth, implying that the latter serves as niche cells (NCs). After their close association was disrupted by trypsin/EDTA, single SCs and NCs could reunite to generate sphere growth in three-dimensional Matrigel in the embryonic SC medium, and that such sphere growth initiated by SC-NC reunion was mediated by SDF-1 uniquely expressed by limbal epithelial progenitor cells and its receptor CXCR4, but not CXCR7, strongly expressed by limbal stromal NCs. Inhibition of CXCR4 by AMD3100 or a blocking antibody to CXCR4 but not CXCR7 disrupted their reunion and yielded separate spheres with a reduced size, while resultant epithelial spheres exhibited more corneal differentiation and a notable loss of holoclones. For the first time, these results provide strong evidence supporting that limbal SC function depends on close physical association with their native NCs via SDF-1/CXCR4 signaling. This novel in vitro model of sphere growth with NCs can be used for investigating how limbal SC self-renewal and fate decision might be regulated in the limbal niche.


Subject(s)
Cell Differentiation/physiology , Chemokine CXCL12/metabolism , Epithelium, Corneal/cytology , Limbus Corneae/cytology , Receptors, CXCR4/metabolism , Stem Cells/cytology , Stem Cells/metabolism , Stromal Cells/cytology , Stromal Cells/metabolism , Adolescent , Adult , Aged , Blotting, Western , Cell Differentiation/genetics , Cells, Cultured , Chemokine CXCL12/genetics , Collagenases/genetics , Collagenases/metabolism , Endopeptidases/genetics , Endopeptidases/metabolism , Fluorescent Antibody Technique , Humans , Middle Aged , Real-Time Polymerase Chain Reaction , Receptors, CXCR/genetics , Receptors, CXCR/metabolism , Receptors, CXCR4/genetics , Signal Transduction/genetics , Signal Transduction/physiology , Young Adult
16.
Zhonghua Yan Ke Za Zhi ; 48(8): 725-7, 2012 Aug.
Article in Zh | MEDLINE | ID: mdl-23141513

ABSTRACT

OBJECTIVE: To investigate the prevalence and anatomy features of iridociliary body cysts in patients with narrow anterior chamber angle. METHODS: Retrospective case series study. The prevalence and anatomy features of iridociliary body cysts in 223 patients (402 eyes) were analyzed retrospectively with ultrasound biomicroscopy (UBM). All of the patients were examined for susceptive narrow anterior chamber angle without complaint. The age of the patients, the site, diameter and number of cysts, the anterior chamber angle and the central anterior chamber depth were measured. RESULTS: Iridociliary body cysts were found in 19 patients (23 eyes) out of 223 patients (402 eyes), the prevalence is 5.7%. Fifteen patients were unilateral and four patients bilateral. Two cases originated from the ciliary process, eighteen cases from the iris root, and three from both the root and posterior surface of the iris. Twenty one cases were single cysts while two cases were multiple cysts. The diameter of the cysts ranged from 0.5 to 3.1 mm, averaged (0.71 ± 0.53) mm. The average age and the central anterior chamber depth of the eyes with iridociliary body cysts were (55.32 ± 10.74) years and (2.25 ± 0.39) mm, with no significant difference (t = 0.534, 0.783; P > 0.05) as compared to that of patients without cysts, which were (57.46 ± 10.52) years and (2.14 ± 0.34) mm. The anterior chamber angle in iridociliary body cysts group was 8.2° (21.0°, 0.0°), with no significant difference (Z = -0.062, P > 0.05) as compared to that of patients without cysts, which was 8.9° (21.4°, 0.0°). CONCLUSIONS: The prevalence rate of iridociliary body cysts in this study is 5.7%, central anterior chamber depth and anterior chamber angle in patients with cysts do not differ form patients without cysts.


Subject(s)
Ciliary Body/anatomy & histology , Cysts/pathology , Iris Diseases/pathology , Iris/anatomy & histology , Adult , Aged , Anterior Chamber/diagnostic imaging , Ciliary Body/diagnostic imaging , Cysts/diagnostic imaging , Female , Humans , Iris/diagnostic imaging , Iris Diseases/diagnostic imaging , Male , Microscopy, Acoustic , Middle Aged , Retrospective Studies
17.
J Med Chem ; 65(14): 9531-9547, 2022 07 28.
Article in English | MEDLINE | ID: mdl-35796517

ABSTRACT

Methionine adenosyltransferase 2A (MAT2A) is a rate-limiting enzyme in the methionine cycle that primarily catalyzes the synthesis of S-adenosylmethionine (SAM) from methionine and adenosine triphosphate (ATP). MAT2A has been recognized as a therapeutic target for the treatment of cancers. Recently, a few MAT2A inhibitors have been reported, and three entered clinical trials to treat solid tumorsor lymphoma with MTAP loss. This review aims to summarize the current understanding of the roles of MAT2A in cancer and the discovery of MAT2A inhibitors. Furthermore, a perspective on the use of MAT2A inhibitors for the treatment of cancer is also discussed. We hope to provide guidance for future drug design and optimization via analysis of the binding modes of known MAT2A inhibitors.


Subject(s)
Methionine Adenosyltransferase , Neoplasms , Humans , Methionine/metabolism , Methionine Adenosyltransferase/antagonists & inhibitors , Methionine Adenosyltransferase/metabolism , Neoplasms/drug therapy , Neoplasms/pathology , S-Adenosylmethionine/metabolism
18.
Biomed Pharmacother ; 147: 112659, 2022 Mar.
Article in English | MEDLINE | ID: mdl-35123232

ABSTRACT

BACKGROUND: Diabetes mellitus (DM)-related corneal epithelial dysfunction is a severe ocular disorder; however, the effects of nicotinamide mononucleotide (NMN) on high-glucose (HG)-treated human corneal epithelial cells (HCECs) remain unclear. METHODS: We conducted an in-vitro study to examine the effects of NMN treatment on HG-treated HCECs. Cell viability was measured using trypan blue stain, mitochondrial membrane potential was measured using JC-1 stain, and intracellular reactive oxygen species and apoptosis assays were conducted using flow cytometry. Transepithelial electrical resistance (TEER) and zonula occludens-1 (ZO-1) immunofluorescence for tight junction examinations were conducted. Immunoblot analyses were conducted to analyze the expression of silent information regulator-1 (SIRT1), nuclear factor erythroid 2-related factor 2 (Nrf2), and heme oxygenase-1 (HO-1) of the SIRT1/Nrf2/HO-1 pathway. RESULTS: NMN increased cell viability by reducing cell damage, reducing apoptosis, increasing cell migration, and restoring tight junctions in HG-treated HCECs. By analyzing the expressions of SIRT1, Nrf2, HO-1, NMN demonstrated protective effects via the SIRT1/Nrf2/HO-1 pathway. CONCLUSIONS: NMN increases cell viability by reversing cell damage, reducing apoptosis, increasing cell migration, and restoring tight junctions in HG-treated HCECs, and these effects may be mediated by the SIRT1/Nrf2/HO-1 pathway.


Subject(s)
Epithelium, Corneal/drug effects , Heme Oxygenase-1/drug effects , NF-E2-Related Factor 2/drug effects , Nicotinamide Mononucleotide/pharmacology , Sirtuin 1/drug effects , Tight Junctions/drug effects , Apoptosis/drug effects , Blood Glucose , Cell Survival/drug effects , Diabetic Retinopathy/pathology , Dose-Response Relationship, Drug , Humans , Membrane Potential, Mitochondrial/drug effects , Oxidative Stress/drug effects , Signal Transduction/drug effects
19.
Ophthalmic Res ; 45(2): 92-101, 2011.
Article in English | MEDLINE | ID: mdl-20720439

ABSTRACT

BACKGROUND: Current treatments for retinopathy of prematurity (ROP) targeting single vascular growth factors are ineffective in preventing neoangiogenesis. METHODS: We investigated the redundant/compensatory mechanisms between vascular growth factors in ROP. Cultured retinal vascular endothelial cells under CoCl2-induced hypoxia were transfected with recombinant adeno-associated virus type 2-vascular endothelial growth factor (VEGF) or pGIPZ-VEGF RNA interference to up- and downregulate VEGF expression, respectively. At 48 h after transfection, basic fibroblast growth factor (bFGF) and angiopoietin 1 (ANG1) gene expression as well as mitotic cycle changes were analyzed in the cells and correlated with the change in VEGF expression. RESULTS: Compared with the normal control group 1, at 30 min, 12 h and 24 h, the expressions of VEGF, bFGF and ANG1 in the hypoxia control group 2 were significantly higher. In the highly expressing VEGF group (group 3), the expressions of bFGF and ANG1 were downregulated, while in the low-expressing VEGF group 4, the expressions of bFGF and ANG1 were significantly upregulated. In the bevacizumab treatment group 5, the expressions of VEGF, bFGF and ANG1 were similar to those in group 2, and the difference was not significant. CONCLUSIONS: A compensatory mechanism (redundancy) exists between vascular growth factors in ROP. Such a phenomenon could partially explain why the inhibition of a single growth factor cannot effectively prevent the recurrence of neovascularization in ROP. A more effective strategy for treating ROP may be to inhibit VEGF and its redundant pathways.


Subject(s)
Angiopoietin-1/genetics , Endothelium, Vascular/metabolism , Fibroblast Growth Factor 2/genetics , Gene Expression Regulation/physiology , Retinopathy of Prematurity/genetics , Vascular Endothelial Growth Factor A/genetics , Adult , Blotting, Western , Cell Cycle/physiology , Cells, Cultured , Dependovirus/genetics , Endothelium, Vascular/cytology , Humans , Infant, Newborn , Plasmids , RNA Interference , RNA, Messenger/metabolism , Retinal Neovascularization/genetics , Retinal Vessels/cytology , Reverse Transcriptase Polymerase Chain Reaction , Transfection
20.
Zhong Xi Yi Jie He Xue Bao ; 9(11): 1199-205, 2011 Nov.
Article in Zh | MEDLINE | ID: mdl-22088585

ABSTRACT

BACKGROUND: As the main medicinal powder for drawing out pus and removing necrotic tissue in external therapies of traditional Chinese surgery, Sheng Powder has made great contributions to the treatment of inflammatory wounds and has the unique bactericidal and decay-discharging function that can not be replaced by antibiotics. However, Sheng Powder has toxicity because it contains mercury. So far, there is no clinical research on the standards of dose and usage of Sheng Powder and there is a lack of objective and quantitative criteria for operating standards and monitoring of toxicity and side effects. Therefore, the authors choose Jiuyi Powder, one of the most commonly used Sheng Powder, to evaluate the safety of its external use, and form a standardization program for clinical implementation. METHODS AND DESIGN: This study is a nonrandomized, nonblinded, self-controlled case study. There will be two key stages in the study. In stage one, 10 patients with plasma cell mastitis will be enrolled. The patients will receive continuous external application of Jiuyi Powder with a fixed dose (160 mg/d). Blood mercury and urine mercury levels will be dynamically tested at different time intervals, and the observation of pharmacokinetic parameters will be conducted after Jiuyi Powder has been absorbed by the surface of the wound. In stage two, 30 patients with each of the four conditions including postoperative wounds of head or facial surgeries, plasma cell mastitis, anal fistula and chronic absorption ulcer of the shank will be enrolled, respectively. According to the dose of 1.5 mg/cm(2), Jiuyi Powder will be externally applied to the wound surface for 14 d. On the basis of the first-phase study, the test time will be chosen and the toxicity outcome will be detected to evaluate the safety of external application of Jiuyi Powder and to establish recommendations for standardized clinical use. DISCUSSION: The purpose of this study is to evaluate the safety of the external application of Jiuyi Powder through a two-stage study. The pharmacokinetic parameters of external application of Jiuyi Powder at the clinical dose range, the changes in blood and urinary mercury levels and related safety indexes will be observed on different wounds located in different positions externally. The evaluation of whether Jiuyi Powder could be a routine medication for drawing out pus and removing necrotic tissue in inflammatory and refractory wounds will be stated. TRIAL REGISTRATION NUMBER: ChiCTR-TNC-11001366.


Subject(s)
Clinical Trials as Topic , Drugs, Chinese Herbal/administration & dosage , Drugs, Chinese Herbal/adverse effects , Phytotherapy/adverse effects , Phytotherapy/methods , Adult , Aged , Female , Humans , Male , Medicine, Chinese Traditional/methods , Mercury/blood , Mercury/urine , Middle Aged , Phytotherapy/standards , Research Design , Wound Healing/drug effects , Young Adult
SELECTION OF CITATIONS
SEARCH DETAIL