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1.
PLoS Pathog ; 17(8): e1009758, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-34379705

RESUMEN

Since the pandemic of COVID-19 has intensely struck human society, small animal model for this infectious disease is in urgent need for basic and pharmaceutical research. Although several COVID-19 animal models have been identified, many of them show either minimal or inadequate pathophysiology after SARS-CoV-2 challenge. Here, we describe a new and versatile strategy to rapidly establish a mouse model for emerging infectious diseases in one month by multi-route, multi-serotype transduction with recombinant adeno-associated virus (AAV) vectors expressing viral receptor. In this study, the proposed approach enables profound and enduring systemic expression of SARS-CoV-2-receptor hACE2 in wild-type mice and renders them vulnerable to SARS-CoV-2 infection. Upon virus challenge, generated AAV/hACE2 mice showed pathophysiology closely mimicking the patients with severe COVID-19. The efficacy of a novel therapeutic antibody cocktail RBD-chAbs for COVID-19 was tested and confirmed by using this AAV/hACE2 mouse model, further demonstrating its successful application in drug development.


Asunto(s)
COVID-19 , Enfermedades Transmisibles Emergentes , Modelos Animales de Enfermedad , Células 3T3 , Enzima Convertidora de Angiotensina 2/genética , Animales , Anticuerpos Antivirales/inmunología , Anticuerpos Antivirales/uso terapéutico , COVID-19/inmunología , COVID-19/patología , COVID-19/fisiopatología , Chlorocebus aethiops , Dependovirus/genética , Humanos , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Transducción Genética , Células Vero
2.
J Org Chem ; 88(14): 10252-10256, 2023 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-37406152

RESUMEN

The skeletal editing of dibenzolactones to fluorenes by Ni- or Pd-catalyzed decarboxylation is reported. In contrast to previously reported intramolecular decarboxylative couplings, inductively electron-withdrawing ortho substituents on the aryl carboxylate moiety and metal additives are not required. The decarboxylation reaction proceeds cleanly and can be applied to the skeletal editing of a natural product analogue. Mechanistic observations are consistent with stabilization of the carboxylate-ligated Ni complex over the Ni-carboxylate ion pair, which is the key factor in promoting the challenging decarboxylation step in the catalytic cycle.

3.
J Biomed Sci ; 29(1): 49, 2022 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-35799178

RESUMEN

BACKGROUND: With the continuous emergence of new SARS-CoV-2 variants that feature increased transmission and immune escape, there is an urgent demand for a better vaccine design that will provide broader neutralizing efficacy. METHODS: We report an mRNA-based vaccine using an engineered "hybrid" receptor binding domain (RBD) that contains all 16 point-mutations shown in the currently prevailing Omicron and Delta variants. RESULTS: A booster dose of hybrid vaccine in mice previously immunized with wild-type RBD vaccine induced high titers of broadly neutralizing antibodies against all tested SARS-CoV-2 variants of concern (VOCs). In naïve mice, hybrid vaccine generated strong Omicron-specific neutralizing antibodies as well as low but significant titers against other VOCs. Hybrid vaccine also elicited CD8+/IFN-γ+ T cell responses against a conserved T cell epitope present in wild type and all VOCs. CONCLUSIONS: These results demonstrate that inclusion of different antigenic mutations from various SARS-CoV-2 variants is a feasible approach to develop cross-protective vaccines.


Asunto(s)
COVID-19 , SARS-CoV-2 , Animales , Anticuerpos Neutralizantes , Anticuerpos Antivirales , Anticuerpos ampliamente neutralizantes , COVID-19/prevención & control , Humanos , Ratones , SARS-CoV-2/genética , Vacunas Sintéticas , Vacunas de ARNm
4.
J Asian Nat Prod Res ; 24(7): 679-684, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-34292113

RESUMEN

A new isocoumarin, penicimarin N (1), along with five known compounds (2-6), were isolated from the mangrove-derived fungus Penicillium sp. TGM112. The structure of 1 was elucidated on the basis of extensive spectroscopic data analysis, and the absolute configuration of 1 was determined by comparison of their circular dichroism (CD) spectra with the literature. The structures of known compounds were determined by comparison with the literature data. All the isolated compounds were examined for their antioxidant and α-glucosidase activities. Compound 1 showed strong antioxidant activity with the IC50 value of 1.0 mM, and 1 also exhibited moderate inhibitory activity against α-glucosidase with the IC50 value of 620 µM.


Asunto(s)
Isocumarinas , Penicillium , Hongos/metabolismo , Estructura Molecular , Penicillium/química , alfa-Glucosidasas/metabolismo
5.
Immun Ageing ; 18(1): 21, 2021 May 04.
Artículo en Inglés | MEDLINE | ID: mdl-33947427

RESUMEN

BACKGROUND: Chronic infections played a detrimental role on health outcomes in the aged population, and had complex associations with lymphocyte subsets distribution. Our study aimed to explore the predictive roles of chronic infections, lymphopenia, and lymphocyte subsets on unexpected admission and mortality in the institutionalized oldest-old during 3 year follow-up period. RESULTS: There were 163 participants enrolled prospectively with median age of 87.3 years (IQR: 83.1-90.2), male of 88.3%, and being followed for 156.4 weeks (IQR: 136.9-156.4 weeks). The unexpected admission and mortality rates were 55.2 and 24.5% respectively. The Cox proportional hazards models demonstrated the 3rd quartile of cytomegalovirus IgG (OR: 3.26, 95% CI: 1.55-6.84), lymphopenia (OR: 2.85, 95% CI: 1.2-6.74), and 1st quartile of CD19+ B cell count (OR: 2.84, 95% CI: 1.29-6.25) predicted elevated risks of unexpected admission after adjusting for potential confounders; while the 3rd quartile of CD3+ T cell indicated a reduced risk of mortality (OR: 0.19, 95% CI: 0.05-0.71). Negative association between CMV IgG and CD19+ B cell count suggested that CMV infection might lead to B cell depletion via decreasing memory B cells repertoire. CONCLUSIONS: CMV infection, lymphopenia, and CD19+ B cell depletion might predict greater risk of unexpected admission, while more CD3+ T cell would suggest a reduced risk of mortality among the oldest-old population. A non-linear or U-shaped relationship was supposed between health outcomes and CMV infection, CD3+ T cell, or CD19+ B cell counts. Further prospective studies with more participants included would be needed to elucidate above findings.

6.
BMC Geriatr ; 21(1): 726, 2021 12 18.
Artículo en Inglés | MEDLINE | ID: mdl-34922488

RESUMEN

BACKGROUND: Few studies have made longitudinal comparisons between frailty phenotype (FP) and frailty index (FI) changes. We aimed to investigate frailty status changes defined by FP and FI concurrently, and to compare the associated factors and incident disability among different combination of FI and FP trajectory groups. METHODS: Data on respondents aged over 50 who completed the 1999, 2003 and 2007 Taiwan Longitudinal Study on Aging (TLSA) surveys (n = 2807) were excerpted. Changes of FI, FP and major time-dependent variables were constructed by group-based trajectory modeling. Logistic regression was used to investigate the associated factors and relationships with incident disability among different frailty trajectories. RESULTS: We identified four FP trajectories - stably robust, worsened frailty, improved frailty, and stably frail and three FI trajectories - stable FI, moderate increase FI and rapid increase FI. Lower self-rated health, mobility impairment, and depressed mood were associated with unfavorable FP and FI changes (all p < 0.001). Regardless of FP trajectory groups, the moderate and rapid increase FI group had significantly more comorbidities than the stable FI group, and more visual, hearing, oral intake impairment, more difficulty in meeting living expenses, and poorer cognitive function in ≥65-year-olds (all p < 0.05). In addition, the worsened frailty, improved frailty, and stably frail groups had ORs for incident disability of 10.5, 3.0, and 13.4, respectively, compared with the stably robust group (all p < 0.01); the moderate and rapid increase FI groups had 8.4-fold and 77.5-fold higher risk than the stable FI group (both p < 0.001). When combining FI and FP trajectories, risk increased with FI trajectory steepness, independent of FP change (all p < 0.01 in rapid increase FI vs stable FI). CONCLUSIONS: Four FP trajectories (stably robust, worsened frailty, improved frailty, and stably frail) and three FI trajectories (stable FI, moderate increase FI and rapid increase FI) were identified. Lower self-rated health, mobility impairment, and depressed mood were associated with both unfavorable FP and FI trajectories. Nevertheless, even for individuals in stably robust or improved frailty FP groups, moderate or rapid increase in FI, either due to comorbidities, sensory impairment, cognitive deficits, or financial challenges, may still increase the risk of incident disability.


Asunto(s)
Fragilidad , Anciano , Envejecimiento , Anciano Frágil , Fragilidad/diagnóstico , Fragilidad/epidemiología , Evaluación Geriátrica , Humanos , Estudios Longitudinales
7.
Int J Mol Sci ; 22(3)2021 Jan 29.
Artículo en Inglés | MEDLINE | ID: mdl-33572787

RESUMEN

Age-related macular degeneration (AMD) is the progressive degeneration of the retinal pigment epithelium (RPE), retina, and choriocapillaris among elderly individuals and is the leading cause of blindness worldwide. Thus, a better understanding of the underlying mechanisms in retinal tissue activated by blue light exposure is important for developing novel treatment and intervention strategies. In this study, blue-light-emitting diodes with a wavelength of 440 nm were applied to RPE cells at a dose of 3.7 ± 0.75 mW/cm2 for 24 h. ARPE-19 cells were used to investigate the underlying mechanism induced by blue light exposure. A trypan blue exclusion assay was used for the cell viability determination. Flow cytometry was used for apoptosis rate detection and autophagy analysis. An immunofluorescence microscopy analysis was used to investigate cellular oxidative stress and DNA damage using DCFDA fluorescence staining and an anti-γH2AX antibody. Blue light exposure of zebrafish larvae was established to investigate the effect on retinal tissue development in vivo. To further demonstrate the comprehensive effect of blue light on ARPE-19 cells, next-generation sequencing (NGS) was performed for an ingenuity pathway analysis (IPA) to reveal additional related mechanisms. The results showed that blue light exposure caused a decrease in cell proliferation and an increase in apoptosis in ARPE-19 cells in a time-dependent manner. Oxidative stress increased during the early stage of 2 h of exposure and activated DNA damage in ARPE-19 cells after 8 h. Furthermore, autophagy was activated in response to blue light exposure at 24-48 h. The zebrafish larvae model showed the unfavorable effect of blue light in prohibiting retinal tissue development. The RNA-Seq results confirmed that blue light induced cell death and participated in tissue growth inhibition and maturation. The current study reveals the mechanisms by which blue light induces cell death in a time-dependent manner. Moreover, both the in vivo and NGS data uncovered blue light's effect on retinal tissue development, suggesting that exposing children to blue light could be relatively dangerous. These results could benefit the development of preventive strategies utilizing herbal medicine-based treatments for eye diseases or degeneration in the future.


Asunto(s)
Autofagia/efectos de la radiación , Daño del ADN/efectos de la radiación , Luz/efectos adversos , Degeneración Macular/etiología , Estrés Oxidativo/efectos de la radiación , Epitelio Pigmentado de la Retina/efectos de la radiación , Animales , Línea Celular , Modelos Animales de Enfermedad , Humanos , Degeneración Macular/genética , Degeneración Macular/metabolismo , Degeneración Macular/patología , Epitelio Pigmentado de la Retina/metabolismo , Epitelio Pigmentado de la Retina/patología , Pez Cebra
8.
Molecules ; 25(17)2020 Sep 02.
Artículo en Inglés | MEDLINE | ID: mdl-32887242

RESUMEN

The effects of microbial transglutaminase (MTGase) cross-linking on the physicochemical characteristics of individual caseins were investigated. MTGase was used to modify three major individual caseins, namely, κ-casein (κ-CN), αS-casein (αS-CN) and ß-casein (ß-CN). The SDS-PAGE analysis revealed that MTGase-induced cross-linking occurred during the reaction and that some components with high molecular weights (>130 kDa) were formed from the individual proteins κ-CN, αS-CN and ß-CN. Scanning electron microscopy (SEM) and particle size analysis respectively demonstrated that the κ-CN, αS-CN and ß-CN particle diameters and protein microstructures were larger and polymerized after MTGase cross-linking. The polymerized κ-CN (~749.9 nm) was smaller than that of ß-CN (~7909.3 nm) and αS-CN (~7909.3 nm). The enzyme kinetics results showed KM values of 3.04 × 10-6, 2.37 × 10-4 and 8.90 × 10-3 M for κ-CN, αS-CN and ß-CN, respectively, and, furthermore, kcat values of 5.17 × 10-4, 1.92 × 10-3 and 4.76 × 10-2 1/s, for κ-CN, αS-CN and ß-CN, respectively. Our results revealed that the cross-linking of ß-CN catalyzed by MTGase was faster than that of αS-CN or κ-CN. Overall, the polymers that formed in the individual caseins in the presence of MTGase presented a higher molecular weight and larger particles.


Asunto(s)
Bacterias/enzimología , Caseínas/química , Fenómenos Químicos , Reactivos de Enlaces Cruzados/química , Transglutaminasas/metabolismo , Caseínas/ultraestructura , Cinética , Tamaño de la Partícula , Polimerizacion
9.
J Biol Chem ; 293(31): 12259-12270, 2018 08 03.
Artículo en Inglés | MEDLINE | ID: mdl-29929979

RESUMEN

Certain dysregulated chondrocyte metabolic adaptive responses such as decreased activity of the master regulator of energy metabolism AMP-activated protein kinase (AMPK) promote osteoarthritis (OA). Metabolism intersects with epigenetic and transcriptional responses. Hence, we studied chondrocyte ATP-citrate lyase (ACLY), which generates acetyl-CoA from mitochondrial-derived citrate, and modulates acetylation of histones and transcription factors. We assessed ACLY in normal and OA human knee chondrocytes and cartilages by Western blotting and immunohistochemistry, and quantified acetyl-CoA fluorometrically. We examined histone and transcription factor lysine acetylation by Western blotting, and assessed histone H3K9 and H3K27 occupancy of iNOS, MMP3, and MMP13 promoters by chromatin immunoprecipitation (ChIP) and quantitative PCR (qPCR). We analyzed iNOS, MMP3, MMP13, aggrecan (ACAN), and Col2a1 gene expression by RT-qPCR. Glucose availability regulated ACLY expression and function, nucleocytosolic acetyl-CoA, and histone acetylation. Human knee OA chondrocytes exhibited increased ACLY activation (assessed by Ser-455 phosphorylation), associated with increased H3K9 and H3K27 acetylation. Inhibition of ACLY attenuated IL-1ß-induced transcription of iNOS, MMP3, and MMP13 by suppressing acetylation of p65 NF-κB, H3K9, and H3K27, blunted release of NO, MMP3, and MMP13, and also reduced SOX9 acetylation that promoted SOX9 nuclear translocation, leading to increased aggrecan and Col2a1 mRNA expression. ACLY is a novel player involved in regulation of cartilage matrix metabolism. Increased ACLY activity in OA chondrocytes increased nucleocytosolic acetyl-CoA, leading to increased matrix catabolism via dysregulated histone and transcription factor acetylation. Pharmacologic ACLY inhibition in OA chondrocytes globally reverses these changes and stimulates matrix gene expression and AMPK activation, supporting translational investigation in OA.


Asunto(s)
ATP Citrato (pro-S)-Liasa/metabolismo , Cartílago Articular/enzimología , Condrocitos/enzimología , Matriz Extracelular/enzimología , Osteoartritis de la Rodilla/enzimología , ATP Citrato (pro-S)-Liasa/genética , Acetilcoenzima A/metabolismo , Acetilación , Agrecanos/genética , Agrecanos/metabolismo , Cartílago Articular/metabolismo , Células Cultivadas , Condrocitos/metabolismo , Matriz Extracelular/genética , Matriz Extracelular/metabolismo , Histonas/metabolismo , Humanos , Interleucina-1beta/genética , Interleucina-1beta/metabolismo , Metaloproteinasa 13 de la Matriz/genética , Metaloproteinasa 13 de la Matriz/metabolismo , Metaloproteinasa 3 de la Matriz/genética , Metaloproteinasa 3 de la Matriz/metabolismo , Osteoartritis de la Rodilla/genética , Osteoartritis de la Rodilla/metabolismo
10.
J Am Chem Soc ; 141(7): 3153-3159, 2019 02 20.
Artículo en Inglés | MEDLINE | ID: mdl-30678456

RESUMEN

Carbon-carbon bond-forming reductive elimination from elusive organocopper(III) complexes has been considered the key step in many copper-catalyzed and organocuprate reactions. However, organocopper(III) complexes with well-defined structures that can undergo reductive elimination are extremely rare, especially for the formation of Csp3-Csp3 bonds. We report herein a general method for the synthesis of a series of [alkyl-CuIII-(CF3)3]- complexes, the structures of which have been unequivocally characterized by NMR spectroscopy, mass spectrometry, and X-ray crystal diffraction. At elevated temperature, these complexes undergo reductive elimination following first-order kinetics, forming alkyl-CF3 products with good yields (up to 91%). Both kinetic studies and DFT calculations indicate that the reductive elimination to form Csp3-CF3 bonds proceeds through a concerted transition state, with a Δ H⧧ = 20 kcal/mol barrier.

11.
FASEB J ; 32(7): 3870-3877, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-29475396

RESUMEN

Appropriate sexual selection or individual sexual attractiveness is closely associated with the reproductive success of a species. Here, we report that young male flies exhibit innate courtship preference for female flies that are raised on higher-yeast diets and that have greater body weight and fecundity, but reduced locomotor activity and shortened lifespan. Male flies discriminate among females that have been fed diets that contain 3 different yeast concentrations-1, 5, and 20% yeast- via gustatory, but not visual or olfactory, perception. Female flies that are raised on higher-yeast diets exhibit elevated expression levels of Drosophila insulin-like peptides (di lps), and we demonstrate that hypomorphic mutations of di lp2, 3, 5 or foxo, as well as oenocyte-specific gene disruption of the insulin receptor, all abolish this male courtship preference for high yeast-fed females. Moreover, our data demonstrate that disrupted di lp signaling can alter the expression profile of some cuticular hydrocarbons (CHCs) in female flies, and that genetic inhibition of an enzyme involved in the biosynthesis of CHCs in oenocytes, elongase F, also eliminates the male courtship preference. Together, our findings provide mechanistic insights that link female reproductive potential to sexual attractiveness, thereby encouraging adaptive mating and optimal reproductive success.-Lin, W.-S., Yeh, S.-R., Fan, S.-Z., Chen, L.-Y., Yen, J.-H., Fu, T.-F., Wu, M.-S., Wang, P.-Y. Insulin signaling in female Drosophila links diet and sexual attractiveness.


Asunto(s)
Dieta , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Péptidos y Proteínas de Señalización Intercelular/metabolismo , Preferencia en el Apareamiento Animal , Animales , Proteínas de Drosophila/genética , Drosophila melanogaster/fisiología , Femenino , Péptidos y Proteínas de Señalización Intercelular/genética , Masculino , Transducción de Señal
12.
Phys Chem Chem Phys ; 21(32): 17605-17612, 2019 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-31384855

RESUMEN

The conversion of N2(g) to NH3(g) is an important industrial process that plays a vital role in sustaining the current human population. This chemical transformation relies heavily on the Haber-Bosch process (N2 thermal reduction, N2TR), which requires enormous quantities of energy (2% of the world supply) and extreme conditions (200 atm and 500 °C). Alternatively, N2(g) can be reduced to NH3(g) through electrochemical means (N2ER), which may be a less energy intensive and lower-capital approach since the H atoms come from H2O not H2. However, N2ER efficiency is far from satisfactory. In order to provide the basis for developing a new generation of energy efficient processes, we report the detailed atomistic mechanism and kinetics for N2ER on Ru(0001) along with a comparison to N2TR. We obtained these results using a new electrochemical model for quantum mechanics (QM) calculations to obtain free energy surfaces for all plausible reaction pathways for N2ER under a constant electrode potential of 0.0 VSHE. For both processes, the elementary steps involve several steps of breaking of the NN bonds, hydrogenation of surface N2HX or NHX, and NH3 release. We find similar energetics for the NN cleavage steps for both systems. However, the hydrogenation steps are very different, leading to much lower free energy barriers for N2ER compared to N2TR. Thus, N2ER favors an associative route where successive hydrogen atoms are added to N2 prior to breaking the NN bonds rather than the dissociative route preferred by N2TR, where the NN bonds are broken first followed by the addition of Hs. Our QM results provide the detailed free energy surfaces for N2ER and N2TR, suggesting a strategy for improving the efficiency of N2ER.

13.
Proc Natl Acad Sci U S A ; 113(7): 1829-34, 2016 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-26831079

RESUMEN

Spermatogonial stem cells (SSCs) are a subpopulation of undifferentiated spermatogonia located in a niche at the base of the seminiferous epithelium delimited by Sertoli cells and peritubular myoid (PM) cells. SSCs self-renew or differentiate into spermatogonia that proliferate to give rise to spermatocytes and maintain spermatogenesis. Glial cell line-derived neurotrophic factor (GDNF) is essential for this process. Sertoli cells produce GDNF and other growth factors and are commonly thought to be responsible for regulating SSC development, but limited attention has been paid to the role of PM cells in this process. A conditional knockout (cKO) of the androgen receptor gene in PM cells resulted in male infertility. We found that testosterone (T) induces GDNF expression in mouse PM cells in vitro and neonatal spermatogonia (including SSCs) co-cultured with T-treated PM cells were able to colonize testes of germ cell-depleted mice after transplantation. This strongly suggested that T-regulated production of GDNF by PM cells is required for spermatogonial development, but PM cells might produce other factors in vitro that are responsible. In this study, we tested the hypothesis that production of GDNF by PM cells is essential for spermatogonial development by generating mice with a cKO of the Gdnf gene in PM cells. The cKO males sired up to two litters but became infertile due to collapse of spermatogenesis and loss of undifferentiated spermatogonia. These studies show for the first time, to our knowledge, that the production of GDNF by PM cells is essential for undifferentiated spermatogonial cell development in vivo.


Asunto(s)
Factor Neurotrófico Derivado de la Línea Celular Glial/genética , Espermatogonias/citología , Testículo/citología , Animales , Diferenciación Celular , Masculino , Ratones , Ratones Noqueados , ARN Mensajero/genética
14.
J Am Chem Soc ; 140(43): 14357-14366, 2018 10 31.
Artículo en Inglés | MEDLINE | ID: mdl-30346739

RESUMEN

5,14-Diaryldiindeno[2,1- f:1',2' -j]picene (DDP, 1), a thermally and chemically stable helical arene, can be prepared from 1,4-bis[2-(arylethynyl)phenyl]benzene in four synthetic steps. Its helical backbone, which incorporates an o-quinodimethane moiety, was verified by X-ray crystallography, and this structural feature results in a very high barrier to racemization (exceeding 50 kcal/mol). DDP possesses versatile and promising properties, including a small HOMO-LUMO energy gap (1.31 eV for the dimesityl-substituted derivative 1ab), an electron spin resonance (ESR)-active character, a small triplet-singlet energy gap (4.75 kcal/mol), broad photoabsorption covering the ultraviolet, visible, and near-infrared (NIR) regions, two-photon absorption in the NIR range, and respectable ambipolar charge-transport behavior in a solution-processed organic field-effect transistor.

15.
Appl Microbiol Biotechnol ; 102(22): 9549-9562, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30232534

RESUMEN

Marine actinobacterium Streptomyces xinghaiensis NRRL B-24674T has been characterized as a novel species, but thus far, its biosynthetic potential remains unexplored. In this study, the high-quality genome sequence of S. xinghaiensis NRRL B-24674T was obtained, and the production of anticomplement agents, xiamycin analogs, and siderophores was investigated by genome mining. Anticomplement compounds are valuable for combating numerous diseases caused by the abnormal activation of the human complement system. The biosynthetic gene cluster (BGC) nrps1 resembles that of complestatins, which are potent microbial-derived anticomplement agents. The identification of the nrps1 BGC revealed a core peptide that differed from that in complestatin; thus, we studied the anticomplement activity of this strain. The culture broth of S. xinghaiensis NRRL B-24674T displayed good anticomplement activity. Subsequently, the disruption of the genes in the nrps1 BGC resulted in the loss of anticomplement activity, confirming the involvement of this BGC in the biosynthesis of anticomplement agents. In addition, the mining of the BGC tep5, which resembles that of the antiviral pentacyclic indolosesquiterpene xiamycin, resulted in the discovery of nine xiamycin analogs, including three novel compounds. In addition to the BGCs responsible for desferrioxamine B, neomycin, ectoine, and carotenoid, 18 BGCs present in the genome are predicted to be novel. The results of this study unveil the potential of S. xinghaiensis as a producer of novel anticomplement agents and provide a basis for further exploration of the biosynthetic potential of S. xinghaiensis NRRL B-24674T for the discovery of novel bioactive compounds by genome mining.


Asunto(s)
Proteínas Bacterianas/genética , Proteínas Inactivadoras de Complemento/biosíntesis , Genoma Bacteriano , Familia de Multigenes , Sesquiterpenos/metabolismo , Streptomyces/genética , Secuencia de Aminoácidos , Proteínas Bacterianas/metabolismo , Proteínas Inactivadoras de Complemento/química , Datos de Secuencia Molecular , Estructura Molecular , Filogenia , Alineación de Secuencia , Sesquiterpenos/química , Streptomyces/química , Streptomyces/clasificación , Streptomyces/metabolismo
16.
J Am Chem Soc ; 139(47): 17015-17021, 2017 11 29.
Artículo en Inglés | MEDLINE | ID: mdl-29088912

RESUMEN

An Fe(III)-promoted oxidative annulation reaction was developed for the synthesis of 1,2-naphthoquinones. A variety of substituted arylglyoxals and internal alkynes undergo the transformation in the presence of FeCl3 at room temperature to afford the 1,2-naphthoquinone products in good yields in a short reaction time. Interestingly, the products show unusual pseudomigration of the substituent on the arene ring of arylglyoxals. A possible mechanism involving Fe(III)-promoted formation of a vinyl cation from arylglyoxal and alkyne, electrophilic addition of the vinyl cation to the ipso carbon of the aryl group to give a spiral intermediate, and then migration of the keto carbon to the ortho carbon was proposed as key steps and verified using quantum mechanics.

17.
Stem Cells ; 34(11): 2772-2783, 2016 11.
Artículo en Inglés | MEDLINE | ID: mdl-27350140

RESUMEN

In this study, we identify a novel and essential role for the Krüppel-like zinc finger transcription factor GLI-similar 3 (GLIS3) in the regulation of postnatal spermatogenesis. We show that GLIS3 is expressed in gonocytes, spermatogonial stem cells (SSCs) and spermatogonial progenitors (SPCs), but not in differentiated spermatogonia and later stages of spermatogenesis or in somatic cells. Spermatogenesis is greatly impaired in GLIS3 knockout mice. Loss of GLIS3 function causes a moderate reduction in the number of gonocytes, but greatly affects the generation of SSCs/SPCs, and as a consequence the development of spermatocytes. Gene expression profiling demonstrated that the expression of genes associated with undifferentiated spermatogonia was dramatically decreased in GLIS3-deficient mice and that the cytoplasmic-to-nuclear translocation of FOXO1, which marks the gonocyte-to-SSC transition and is necessary for SSC self-renewal, is inhibited. These observations suggest that GLIS3 promotes the gonocyte-to-SSC transition and is a critical regulator of the dynamics of early postnatal spermatogenesis. Stem Cells 2016;34:2772-2783.


Asunto(s)
Proteínas Represoras/genética , Espermatocitos/metabolismo , Espermatogénesis/genética , Espermatogonias/metabolismo , Células Madre/metabolismo , Testículo/metabolismo , Transactivadores/genética , Animales , Diferenciación Celular , Proteínas de Unión al ADN , Proteína Forkhead Box O1/genética , Proteína Forkhead Box O1/metabolismo , Perfilación de la Expresión Génica , Regulación del Desarrollo de la Expresión Génica , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Transporte de Proteínas , Proteínas Represoras/deficiencia , Espermatocitos/citología , Espermatogonias/citología , Células Madre/citología , Testículo/citología , Transactivadores/deficiencia
18.
BMC Infect Dis ; 17(1): 213, 2017 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-28298208

RESUMEN

BACKGROUND: Herpes zoster (HZ) is a prevalent viral disease that inflicts substantial morbidity and associated healthcare and socioeconomic burdens. Current treatments are not fully effective, especially among the most vulnerable patients. Although widely recommended, vaccination against HZ is not routine; barriers in Asia-Pacific include long-standing neglect of adult immunisation and sparse local data. To address knowledge gaps, raise awareness, and disseminate best practice, we reviewed recent data and guidelines on HZ from the Asia-Pacific region. METHODS: We searched PubMed, Scopus, and World Health Organization databases for articles about HZ published from 1994 to 2014 by authors from Australia, China, Hong Kong, India, Indonesia, Japan, Korea, Malaysia, New Zealand, the Philippines, Singapore, Taiwan, Thailand, and Vietnam. We selected articles about epidemiology, burden, complications, comorbidities, management, prevention, and recommendations/guidelines. Internet searches retrieved additional HZ immunisation guidelines. RESULTS: From 4007 retrieved articles, we screened-out 1501 duplicates and excluded 1264 extraneous articles, leaving 1242 unique articles. We found guidelines on adult immunisation from Australia, India, Indonesia, Malaysia, New Zealand, the Philippines, South Korea, and Thailand. HZ epidemiology in Asia-Pacific is similar to elsewhere; incidence rises with age and peaks at around 70 years - lifetime risk is approximately one-third. Average incidence of 3-10/1000 person-years is rising at around 5% per year. The principal risk factors are immunosenescence and immunosuppression. HZ almost always causes pain, and post-herpetic neuralgia is its most common complication. Half or more of hospitalised HZ patients have post-herpetic neuralgia, secondary infections, or inflammatory sequelae that are occasionally fatal. These disease burdens severely diminish patients' quality of life and incur heavy healthcare utilisation. CONCLUSIONS: Several countries have abundant data on HZ, but others, especially in South-East Asia, very few. However, Asia-Pacific countries generally lack data on HZ vaccine safety, efficacy and cost-effectiveness. Physicians treating HZ and its complications in Asia-Pacific face familiar challenges but, with a vast aged population, Asia bears a unique and growing burden of disease. Given the strong rationale for prevention, most adult immunisation guidelines include HZ vaccine, yet it remains underused. We urge all stakeholders to give higher priority to adult immunisation in general and HZ in particular.


Asunto(s)
Vacuna contra el Herpes Zóster/uso terapéutico , Herpes Zóster/epidemiología , Neuralgia Posherpética/prevención & control , Vacunación/estadística & datos numéricos , Asia/epidemiología , Auditoría Clínica , Análisis Costo-Beneficio , Conocimientos, Actitudes y Práctica en Salud , Encuestas Epidemiológicas , Herpes Zóster/prevención & control , Vacuna contra el Herpes Zóster/inmunología , Humanos , Neuralgia Posherpética/epidemiología , Islas del Pacífico/epidemiología , Guías de Práctica Clínica como Asunto
20.
Appl Opt ; 55(21): 5729-37, 2016 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-27463930

RESUMEN

For employing optimized wavelengths, a near-infrared (NIR) tomographic imaging system with multiwavelengths in a continuous wave (CW) enables us to provide accurate information of chromophores. In this paper, we discuss wavelength optimization with a selection from commercial laser diodes. Through theoretical analysis, the residual norm (R) and the condition number (κ) represent the uniqueness of a matrix problem and the smooth singular-value distribution of each chromophore, respectively. The optimum wavelengths take place for large R and small κ. We considered a total of 38 wavelengths of laser diodes in the range of 633-980 nm commercially available to discover optimum sets for a broad range of chromophore combinations. In the 38 wavelengths, there exists 501,942 (C538), 2,760,681 (C638), and 12,620,256 (C738) combinations of five, six, and seven wavelength sets, respectively, for accurately estimating chromophores (HbO2, HbR, H2O, and lipids), water, lipids, and the scattering prefactor A. With the numerical calculation, the top 10 wavelength sets were selected based on the principle of large R and small κ. In the study, the chromophore concentration for young and elderly women are investigated; finally, choosing the laser diodes with a wavelength of 650, 690, 705, 730, 870/880, 915, and 937 nm is recommended either for young or elderly women to construct a spectral NIR tomographic imaging system in the CW domain. Simulated data were used to validate the claims.

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