The physiologic complexity of beat-to-beat blood pressure is associated with age-related alterations in blood pressure regulation.

The fluctuations in resting-state beat-to-beat blood pressure (BP) are physiologically complex, and the degree of such BP complexity is believed to reflect the multiscale regulation of this critical physiologic process. Hypertension (HTN), one common age-related condition, is associated with altered BP regulation and diminished system responsiveness to perturbations such as orthostatic change. We thus aimed to characterize the impact of HTN on resting-state BP complexity, as well as the relationship between BP complexity and both adaptive capacity and underlying vascular characteristics. We recruited 392 participants (age: 60-91 years), including 144 that were normotensive and 248 with HTN (140 controlled- and 108 uncontrolled-HTN). Participants completed a 10-min continuous finger BP recording during supine rest, then underwent measures of lying-to-standing BP change, arterial stiffness (i.e., brachial-ankle pulse wave velocity), and endothelial function (i.e., flow-mediated vasodilation). The complexity of supine beat-to-beat systolic (SBP) and diastolic (DBP) BP was quantified using multiscale entropy. Thirty participants with HTN (16 controlled-HTN and 14 uncontrolled-HTN) exhibited orthostatic hypotension. SBP and DBP complexity was greatest in normotensive participants, lower in those with controlled-HTN, and lowest in those in uncontrolled-HTN (p < 0.0005). Lower SBP and DBP complexity correlated with greater lying-to-standing decrease in SBP and DBP level (ß = -0.33 to -0.19, p < 0.01), greater arterial stiffness (ß = -0.35 to -0.18, p < 0.01), and worse endothelial function (ß = 0.17-0.22, p < 0.01), both across all participants and within the control- and uncontrolled-HTN groups. These results suggest that in older adults, BP complexity may capture the integrity of multiple interacting physiologic mechanisms that regulate BP and are important to cardiovascular health.

Characterizing Tensile Strength of Building Sandstone via Uniaxial Tensile, Compressive, and Flexural Bending Tests.

Sandstone is widely used a construction and building material. However, its uniaxial tensile strength (UTS) is not adequately understood. To characterize the uniaxial tensile strength of natural sandstone, three groups of specimens were fabricated for four-point bending, uniaxial compressive, and tensile tests. To characterize the evolution of the stress-strain profiles obtained via these tests, representative expressions were developed in terms of normalized strain and strength. The magnitude of the uniaxial tensile strength exceeded that of the four-point bending strength, indicating that the uniaxial tensile strength cannot be represented by the four-point bending strength. The experimental ratio of uniaxial tensile and compression strength (33-41) was underestimated by the empirical expressions reported in the literature. The suggested correction coefficient for the FBS is 0.25. The compressive modulus (Ec) was generally identical to the experimental results published in the literature, whereas the tensile modulus (Et) was overestimated. The experimental modular ratio, Et/Ec, ranged from 0.12 to 0.14; it was not sensitive to Poisson's ratio, but it increased slightly with the compressive modulus. This work can serve as a reference for computing the load-bearing capacity of sandstone components under tension.

The alterations in multiple neurophysiological procedures are associated with frailty phenotype in older adults.

Background: Older adults oftentimes suffer from the conditions in multiple physiologic systems, interfering with their daily function and thus contributing to physical frailty. The contributions of such multisystem conditions to physical frailty have not been well characterized. Methods: In this study, 442 (mean age = 71.4 ± 8.1 years, 235 women) participants completed the assessment of frailty syndromes, including unintentional weight loss, exhaustion, slowness, low activity, and weakness, and were categorized into frail (≥3 conditions), pre-frail (1 or 2 conditions), and robust (no condition) status. Multisystem conditions including cardiovascular diseases, vascular function, hypertension, diabetes, sleep disorders, sarcopenia, cognitive impairment, and chronic pain were assessed. Structural equation modeling examined the interrelationships between these conditions and their associations with frailty syndromes. Results: Fifty (11.3%) participants were frail, 212 (48.0%) were pre-frail, and 180 (40.7%) were robust. We observed that worse vascular function was directly associated with higher risk of slowness [standardized coefficient (SC) = -0.419, p < 0.001], weakness (SC = -0.367, p < 0.001), and exhaustion (SC = -0.347, p < 0.001). Sarcopenia was associated with both slowness (SC = 0.132, p = 0.011) and weakness (SC = 0.217, p = 0.001). Chronic pain, poor sleep quality, and cognitive impairment were associated with exhaustion (SC = 0.263, p < 0.001; SC = 0.143, p = 0.016; SC = 0.178, p = 0.004, respectively). The multinomial logistic regression showed that greater number of these conditions were associated with increased probability of being frail (odds ratio>1.23, p < 0.032). Conclusion: These findings in this pilot study provide novel insights into how multisystem conditions are associated with each other and with frailty in older adults. Future longitudinal studies are warranted to explore how the changes in these health conditions alter frailty status.

The Multiscale Dynamics of Beat-to-Beat Blood Pressure Fluctuation Links to Functions in Older Adults.

Background: The blood pressure (BP) is regulated by multiple neurophysiologic elements over multiple temporal scales. The multiscale dynamics of continuous beat-to-beat BP series, which can be characterized by "BP complexity", may, thus, capture the subtle changes of those elements, and be associated with the level of functional status in older adults. We aimed to characterize the relationships between BP complexity and several important functions in older adults and to understand the underlying factors contributing to BP complexity. Method: A total of 400 older adults completed a series of clinical and functional assessments, a finger BP assessment of at least 10 min, and blood sample and vessel function tests. Their hypertensive characteristics, cognitive function, mobility, functional independence, blood composition, arterial stiffness, and endothelial function were assessed. The complexity of systolic (SBP) and diastolic (DBP) BP series was measured using multiscale entropy. Results: We observed that lower SBP and DBP complexity was significantly associated with poorer functional independence (ß > 0.17, p < 0.005), cognitive function (ß > 0.45, p = 0.01), and diminished mobility (ß < -0.57, p < 0.003). Greater arterial stiffness (ß < -0.48, p = 0.02), decreased endothelial function (ß > 0.42, p < 0.03), and excessed level of blood lipids (p < 0.03) were the main contributors to BP complexity. Conclusion: Blood pressure complexity is closely associated with the level of multiple functional statuses and cardiovascular health in older adults with and without hypertension, providing novel insights into the physiology underlying BP regulation. The findings suggest that this BP complexity metric would serve as a novel marker to help characterize and manage the functionalities in older adults.

The Multiscale Dynamics of Beat-to-Beat Blood Pressure Fluctuation Mediated the Relationship Between Frailty and Arterial Stiffness in Older Adults.

BACKGROUND: Beat-to-beat blood pressure (BP) is an important cardiovascular output and regulated by neurophysiological elements over multiple temporal scales. The multiscale dynamics of beat-to-beat BP fluctuation can be characterized by "BP complexity" and has been linked to age-related adverse health outcomes. We here aimed to examine whether BP complexity mediates the association between arterial stiffness and frailty. METHOD: This cross-sectional study was completed between January and October 2021. A total of 350 older adults completed assessments for frailty, arterial stiffness (ie, average brachial-ankle pulse wave velocity), and beat-to-beat finger BP. The complexity of beat-to-beat systolic blood pressure (SBP) and diastolic blood pressure (DBP) BP series was measured using multiscale entropy. The relationships between frailty, BP complexity, and arterial stiffness were examined using analysis of variance and linear regression models. The effects of BP complexity on the association between arterial stiffness and frailty were examined using mediation analyses. RESULTS: Compared with non-frail, prefrail, and frail groups had significantly elevated lower SBP and DBP complexity (F > 11, p < .001) and greater arterial stiffness (F = 16, p < .001). Greater arterial stiffness was associated with lower BP complexity (ß < -0.42, p < .001). Beat-to-beat SBP and DBP complexity mediated the association between arterial stiffness and frailty (indirect effects >0.28), accounting for at least 47% of its total effects on frailty (mediated proportion: SBP: 50%, DBP: 47%). CONCLUSION: This study demonstrates the association between BP complexity and frailty in older adults, and BP complexity mediates the association between arterial stiffness and frailty, suggesting that this metric would serve as a marker to help characterize important functions in the older adults.

Identification of HSC/MPP expansion units in fetal liver by single-cell spatiotemporal transcriptomics.

Limited knowledge of cellular and molecular mechanisms underlying hematopoietic stem cell and multipotent progenitor (HSC/MPP) expansion within their native niche has impeded the application of stem cell-based therapies for hematological malignancies. Here, we constructed a spatiotemporal transcriptome map of mouse fetal liver (FL) as a platform for hypothesis generation and subsequent experimental validation of novel regulatory mechanisms. Single-cell transcriptomics revealed three transcriptionally heterogeneous HSC/MPP subsets, among which a CD93-enriched subset exhibited enhanced stem cell properties. Moreover, by employing integrative analysis of single-cell and spatial transcriptomics, we identified novel HSC/MPP 'pocket-like' units (HSC PLUS), composed of niche cells (hepatoblasts, stromal cells, endothelial cells, and macrophages) and enriched with growth factors. Unexpectedly, macrophages showed an 11-fold enrichment in the HSC PLUS. Functionally, macrophage-HSC/MPP co-culture assay and candidate molecule testing, respectively, validated the supportive role of macrophages and growth factors (MDK, PTN, and IGFBP5) in HSC/MPP expansion. Finally, cross-species analysis and functional validation showed conserved cell-cell interactions and expansion mechanisms but divergent transcriptome signatures between mouse and human FL HSCs/MPPs. Taken together, these results provide an essential resource for understanding HSC/MPP development in FL, and novel insight into functional HSC/MPP expansion ex vivo.

A Comparative Study on the Electrical and Piezoresistive Sensing Characteristics of GFRP and CFRP Composites with Hybridized Incorporation of Carbon Nanotubes, Graphenes, Carbon Nanofibers, and Graphite Nanoplatelets.

In this study, hybridized carbon nanomaterials (CNMs), such as carbon nanotubes (CNTs)-graphene, CNT-carbon nanofibers (CNFs), or CNT-graphite nanoplatelet (GNP) materials were embedded in glass-fiber-reinforced plastic (GFRP) or carbon-fiber-reinforced plastic (CFRP) composites to obtain electrical/piezoresistive sensing characteristics that surpass those of composites with only one type of CNM. In addition, to quantitatively assess their sensing characteristics, the materials were evaluated in terms of gauge factor, peak shift, and R-squared values. The electrical property results showed that the GFRP samples containing only CNTs or both CNTs and graphene exhibited higher electrical conductivity values than those of other composite samples. By evaluating piezoresistive sensing characteristics, the CNT-CNF GFRP composites showed the highest gauge factor values, followed by the CNT-graphene GFRP and CNT-only GFRP composites. These results are explained by the excluded volume theory. The peak shift and R-squared value results signified that the CNT-graphene GFRP composites exhibited the best sensing characteristics. Thus, the CNT-graphene GFRP composites would be the most feasible for use as FRP composite sensors.

Protocols for isolation and characterization of mouse placental hemogenic endothelial cells.

The murine mid-gestational placenta has been identified as a hematopoietic site during embryonic development. Here, we describe a protocol for isolation and characterization of the hemogenic endothelial (HE) cells from mouse placenta. We also describe techniques for dissection of placental tissues and for the optimization of tissue digestion and antibody conjugation conditions to identify HE cells via fluorescence-activated cell sorting. For details on the usage and application of this protocol, please refer to Liang et al. (2021).

IL-39 increases ROS production and promotes the phosphorylation of p38 MAPK in the apoptotic cardiomyocytes.

INTRODUCTION: The cytokine interleukin (IL)-39 is a novel member of the IL-12 family. Our previous study found that the serum level of IL-39 significantly increased in patients with acute myocardial infarction. However, the role of IL-39 in cardiomyocyte apoptosis remains unclear. MATERIAL AND METHODS: In this study, the cultured mouse HL-1 cardiomyocytes were incubated with PBS, 0-100 ng/mL IL-39, 200 µM H2O2 or 20 µM Trolox. RESULTS: IL-39 promoted the production of intracellular reactive oxygen species (ROS) in a concentration dependent manner in HL-1 cardiomyocytes. IL-39 and H2O2 both significantly promoted the production of intracellular ROS, increased the level of intracellular CCL2, stimulated the apoptotic progress of cardiomyocytes, increased the mRNA and protein expression levels of Bax, caspase-3, and p-p38 MAPK, and decreased the mRNA and protein expression levels of Bcl-2. ROS production, CCL2 level, cardiomyocyte apoptosis, and expression of Bax, caspase-3, and p-p38 MAPK were significantly amplified by the administration of IL-39 combined with H2O2, and these processes were significantly alleviated by an antioxidant Trolox. CONCLUSION: This study was novel in revealing that IL-39 promoted apoptosis by stimulating the phosphorylation of p38 MAPK in mouse HL-1 cardiomyocytes.

De novo generation of macrophage from placenta-derived hemogenic endothelium.

Macrophages play pivotal roles in immunity, hematopoiesis, and tissue homeostasis. In mammals, macrophages have been shown to originate from yolk-sac-derived erythro-myeloid progenitors and aorta-gonad-mesonephros (AGM)-derived hematopoietic stem cells. However, whether macrophages can arise from other embryonic sites remains unclear. Here, using single-cell RNA sequencing, we profile the transcriptional landscape of mouse fetal placental hematopoiesis. We uncover and experimentally validate that a CD44+ subpopulation of placental endothelial cells (ECs) exhibits hemogenic potential. Importantly, lineage tracing using the newly generated Hoxa13 reporter line shows that Hoxa13-labeled ECs can produce placental macrophages, named Hofbauer cell (HBC)-like cells. Furthermore, we identify two subtypes of HBC-like cells, and cell-cell interaction analysis identifies their potential roles in angiogenesis and antigen presentation, separately. Our study provides a comprehensive understanding of placental hematopoiesis and highlights the placenta as a source of macrophages, which has important implications for both basic and translational research.

Genome-wide identification, phylogeny, and gonadal expression of fox genes in Nile tilapia, Oreochromis niloticus.

The fox genes play important roles in various biological processes, including sexual development. In the present study, we isolated 65 fox genes, belonging to 18 subfamilies named A-R, from Nile tilapia through genome-wide screening. Twenty-four of them have two or three (foxm1) copies. Furthermore, 16, 25, 68, and 45 fox members were isolated from nematodes, protochordates, teleosts, and tetrapods, respectively. Phylogenetic analyses indicated fox gene family had undergone three expansions parallel to the three rounds of genome duplication during evolution. We also analyzed the clustered fox genes and found that apparent linkage duplication existed in teleosts, which further supported fish-specific genome duplication hypothesis. In addition, species- and lineage-specific duplication is another reason for fox gene family expansion. Based on the four pairs of XX and XY gonadal transcriptome data from four critical developmental stages, we analyzed the expression profile of all fox genes and identified sexually dimorphic fox genes at each stage. All fox genes were detected in gonads, with 15 of them at the background expression level (total read per kb per million reads, RPKM < 10), 29 at moderate expression level (10 < total RPKM < 100), and 21 at high expression level (total RPKM > 100). There are 27, 24, 28, and 9 sexually dimorphic fox genes at 5, 30, 90, and 180 days after hatching (dah), respectively. foxq1a, foxf1, foxr1, and foxr1 were identified as the most differentially expressed genes at each stage. foxl2 was characterized as XX-dominant gene, while foxd5, foxi3, foxn3, foxj1a, foxj3b, and foxo6b were characterized as XY-dominant genes. qPCR and in situ hybridization of foxh1 and foxj1a were performed to confirm the expression profiles and to validate the transcriptome data. Our results suggest that fox genes might play important roles in sex determination and gonadal development in teleosts.

Transdifferentiation of differentiated ovary into functional testis by long-term treatment of aromatase inhibitor in Nile tilapia.

Females with differentiated ovary of a gonochoristic fish, Nile tilapia, were masculinized by long-term treatment with an aromatase inhibitor (Fadrozole) in the present study. The reversed gonads developed into functional testes with fertile sperm. The longer the fish experienced sex differentiation, the longer treatment time was needed for successful sex reversal. Furthermore, Fadrozole-induced sex reversal, designated as secondary sex reversal (SSR), was successfully rescued by supplement of exogenous 17ß-estradiol. Gonadal histology, immunohistochemistry, transcriptome, and serum steroid level were analyzed during SSR. The results indicated that spermatogonia were transformed from oogonia or germline stem cell-like cells distributed in germinal epithelium, whereas Leydig and Sertoli cells probably came from the interstitial cells and granulosa cells of the ovarian tissue, respectively. The transdifferentiation of somatic cells, as indicated by the appearance of doublesex- and Mab-3-related transcription factor 1 (pre-Sertoli cells) and cytochrome P450, family 11, subfamily B, polypeptide 2 (pre-Leydig cells)-positive cells in the ovary, provided microniche for the transdifferentiation of germ cells. Decrease of serum 17ß-estradiol was detected earlier than increase of serum 11-ketotestosterone, indicating that decrease of estrogen was the cause, whereas increase of androgen was the consequence of SSR. The sex-reversed gonad displayed more similarity in morphology and histology with a testis, whereas the global gene expression profiles remained closer to the female control. Detailed analysis indicated that transdifferentiation was driven by suppression of female pathway genes and activation of male pathway genes. In short, SSR provides a good model for study of sex reversal in teleosts and for understanding of sex determination and differentiation in nonmammalian vertebrates.

Characterization of gonadal transcriptomes from Nile tilapia (Oreochromis niloticus) reveals differentially expressed genes.

Four pairs of XX and XY gonads from Nile tilapia were sequenced at four developmental stages, 5, 30, 90, and 180 days after hatching (dah) using Illumina Hiseq(TM) technology. This produced 28 Gb sequences, which were mapped to 21,334 genes. Of these, 259 genes were found to be specifically expressed in XY gonads, and 69 were found to be specific to XX gonads. Totally, 187 XX- and 1,358 XY-enhanced genes were identified, and 2,978 genes were found to be co-expressed in XX and XY gonads. Almost all steroidogenic enzymes, including cyp19a1a, were up-regulated in XX gonads at 5 dah; but in XY gonads these enzymes, including cyp11b2, were significantly up-regulated at 90 dah, indicating that, at a time critical to sex determination, the XX fish produced estrogen and the XY fish did not produce androgens. The most pronounced expression of steroidogenic enzyme genes was observed at 30 and 90 dah for XX and XY gonads, corresponding to the initiation of germ cell meiosis in the female and male gonads, respectively. Both estrogen and androgen receptors were found to be expressed in XX gonads, but only estrogen receptors were expressed in XY gonads at 5 dah. This could explain why exogenous steroid treatment induced XX and XY sex reversal. The XX-enhanced expression of cyp19a1a and cyp19a1b at all stages suggests an important role for estrogen in female sex determination and maintenance of phenotypic sex. This work is the largest collection of gonadal transcriptome data in tilapia and lays the foundation for future studies into the molecular mechanisms of sex determination and maintenance of phenotypic sex in non-model teleosts.

Involvement of FGF9/16/20 subfamily in female germ cell development of the Nile tilapia, Oreochromis niloticus.

Fibroblast growth factors (FGFs) have been proved to participate in a wide variety of processes, including growth, differentiation, cell proliferation, migration, sex determination and sex differentiation. The roles of FGF9/16/20 subfamily members in the gonadal development of teleost fish have not yet been reported. Three FGFs (16, 20a and 20b) of the FGF9/16/20 subfamily were cloned from the Nile tilapia by RT-PCR and RACE. Phylogenetic, bioinformatic and syntenic analyses demonstrated that these cloned FGFs are genuine FGF16, 20a and 20b. Our analyses further supported the non-existence of FGF9 ortholog and the existence of two FGF20 paralogs in teleost genomes. Tissue distribution analysis by RT-PCR demonstrated that FGF16 was expressed in a wide range of tissues including the testis and ovary, FGF20b in the brain, pituitary, intestine and ovary, but not in the testis, while FGF20a in the brain, pituitary and spleen, but not in the gonad. These results were consistent with the Northern blot analysis. The expression profiles of FGF16 and FGF20b during normal and sex reversed gonadal development were investigated by real-time PCR. Both showed much higher expression in the XX ovary and 17 beta-estradiol induced XY ovary compared with the XY testis and fadrozole and tamoxifen induced XX testis, with the highest in both sexes at 120 dah. Strong signals of FGF16 and FGF20b were detected in phase II oocytes by in situ hybridization. These data suggest that FGF9/16/20 subfamily is involved in the early oocyte development of the female.

MtsB, a hydrophobic membrane protein of Streptococcus iniae, is an effective subunit vaccine candidate.

Streptococcus iniae is a major bacterium that causes invasive disease in cultured fish worldwide. The protection relies mainly on anti-microbial compounds and vaccines, and there is much interest in developing S. iniae vaccine based on conserved protein immunogens. Subcellular localization of protein has important influence on its immunogenicity. The surface and extracellular proteins of pathogenic bacteria can be easily recognized by the infected host compare to intracellular proteins, which are the feasible vaccine development targets. However, a putative hydrophobic membrane protein (designated MtsB) of the ATP-binding cassette (ABC) transporter system was found to be protective against S. iniae HD-1 infection when used as an injection vaccine administered intraperitoneally into tilapia. The MtsB protein is present on the cytoplasmic membrane and is expressed in vivo during Kunming mice infection by S. iniae HD-1. This is believed to be the first report on the use of a hydrophobic membrane protein of the ABC system as an S. iniae subunit vaccine.

Characterization, phylogeny, alternative splicing and expression of Sox30 gene.

BACKGROUND: Members of the Sox gene family isolated from both vertebrates and invertebrates have been proved to participate in a wide variety of developmental processes, including sex determination and differentiation. Among these members, Sox30 had been considered to exist only in mammals since its discovery, and its exact function remains unclear. RESULTS: Sox30 cDNA was cloned from the Nile tilapia by RT-PCR and RACE. Screening of available genome and EST databases and phylogenetic analysis showed that Sox30 also exists in non-mammalian vertebrates and invertebrates, which was further supported by synteny analyses. Tissue expression in human, mouse and tilapia suggested that Sox30 was probably a gonad-specific gene, which was also supported by the fact that Sox30 EST sequences were obtained from gonads of the animal species. In addition, four alternatively spliced isoforms were isolated from tilapia gonad. Their temporal and spatial expression patterns during normal and sex reversed gonadal development were investigated by RT-PCR and in situ hybridization. Our data suggest that expressions of Sox30 isoforms are related to stage and phenotypic-sex, observed in the germ cells of male gonad and in somatic cells of the female gonad. CONCLUSIONS: Sox30 is not a gene only existed in mammals, but exists widely throughout the animal kingdom as supported by our bioinformatic, phylogenetic and syntenic analyses. It is very likely that Sox30 is expressed exclusively in gonads. Expression analyses revealed that Sox30 may be involved in female and male gonadal development at different stages by alternative splicing.

A solute-binding protein for iron transport in Streptococcus iniae.

BACKGROUND: Streptococcus iniae (S. iniae) is a major pathogen that causes considerable morbidity and mortality in cultured fish worldwide. The pathogen's ability to adapt to the host affects the extent of infection, hence understanding the mechanisms by which S. iniae overcomes physiological stresses during infection will help to identify potential virulence determinants of streptococcal infection. Grow S. iniae under iron-restricted conditions is one approach for identifying host-specific protein expression. Iron plays an important role in many biological processes but it has low solubility under physiological condition. Many microorganisms have been shown to be able to circumvent this nutritional limitation by forming direct contacts with iron-containing proteins through ATP-binding cassette (ABC) transporters. The ABC transporter superfamilies constitute many different systems that are widespread among living organisms with different functions, such as ligands translocation, mRNA translation, and DNA repair. RESULTS: An ABC transporter system, named as mtsABC (metal transport system) was cloned from S. iniae HD-1, and was found to be involved in heme utilization. mtsABC is cotranscribed by three downstream genes, i.e., mtsA, mtsB, and mtsC. In this study, we cloned the first gene of the mtsABC transporter system (mtsA), and purified the corresponding recombinant protein MtsA. The analysis indicated that MtsA is a putative lipoprotein which binds to heme that can serve as an iron source for the microorganism, and is expressed in vivo during Kunming mice infection by S. iniae HD-1. CONCLUSIONS: This is believed to be the first report on the cloning the ABC transporter lipoprotein from S. iniae genomic DNA. Together, our data suggested that MtsA is associated with heme, and is expressed in vivo during Kunming mice infection by S. iniae HD-1 which indicated that it can be a potential candidate for S. iniae subunit vaccine.

Molecular cloning of two isoforms of 11beta-hydroxylase and their expressions in the Nile tilapia, Oreochromis niloticus.

P450 11beta-hydroxylase, encoded by P450(11beta) gene, is a key mitochondrial enzyme to produce 11beta-hydroxy testosterone, substrate for the production of 11-ketotestosterone (11-KT), which has been shown to be potent androgen in several fish species. In the present work, two alternative splicing isoforms i.e. P450(11beta)-1 and P450(11beta)-2 cDNAs were cloned from the Nile tilapia, Oreochromis niloticus. They were 1614 and 1227bp in length with open reading frames encoding proteins of 537 and 408 amino acids, respectively. In contrast to P450(11beta)-1, which derived from 9 exons of the P450(11beta) gene, the 7th and 8th exons were absent in P450(11beta)-2. Tilapia P450(11beta)-1 shares the highest homology with that of medaka, Oryzias latipes. Expressions of P450(11beta)-1 and -2 were detected in the kidney and head kidney of both sexes, and in the testis but not in the ovary, with P450(11beta)-2 lower than P450(11beta)-1. Ontogenic expressions of both isoforms were detected in testis from 50dah onwards. P450(11beta)-1 and -2 were strongly expressed in sex reversed XX testis after fadrozole and tamoxifen treatment, but completely inhibited in 17beta-estradiol induced XY ovary. The existence of two alternatively spliced isoforms and the sexual dimorphic expression of P450(11beta)s were further confirmed by Northern blot. Strong expression signals in Leydig cells and weak signals in spermatogonia were detected by in situ hybridization and immunohistochemistry. Taken together, our data suggest a role for P450(11beta) in the spermatogenesis of tilapia through the production of 11-KT in testis, in addition to cortisol production in head kidney.

The effect of quercetin on neointima formation in a rat artery balloon injury model.

This study aimed at investigating the effect of quercetin on neointima hyperplasia in the abdominal aorta of rats after balloon injury and expressions of related growth factors. Fifty-four healthy male Sprague-Dawley rats were randomly divided into five groups: a sham-operation group (sham, n=6), a control group (control, n=12), and three quercetin-treated groups: Q50 group (50mg/kg body weight/day, n=12), Q100 group (100mg/kg body weight/day, n=12), and Q200 group (200mg/kg body weight/day, n=12) 3 days before balloon injury until the end of the experiment. Fourteen days after injury, rats were killed, and the abdominal aortas were harvested. Hematoxylin-eosin staining showed that quercetin significantly reduced the neointimal areas and the intimal to medial ratio in the Q100 and Q200 groups 14 days after injury. Immunohistochemical analysis showed that quercetin significantly inhibited PCNA, PDGF-BB, b-FGF, and TGF-beta1 expressions in the neointima. Masson's trichrome showed that quercetin significantly reduced collagen deposition in the neointima. We concluded that quercetin significantly inhibited neointimal hyperplasia in rat abdominal aorta 14 days after injury in relatively high doses. This effect of quercetin might be partially attributed to the suppression of PDGF-BB, b-FGF, and TGF-beta1 expressions.

Expression of three gonadotropin subunits in Southern catfish gonad and their possible roles during early gonadal development.

The three gonadotropin (GtH) subunit cDNAs, GtHalpha, FSHbeta and LHbeta, which contain complete open reading frames were isolated from Southern catfish (Silurus meridionalis Chen) ovary. RT-PCR revealed that GtHalpha, FSHbeta and LHbeta mRNA were expressed in ovary, female and male pituitaries, but not in testis. Ontogeny study showed that GtHalpha and FSHbeta expressed in ovary from 25 dah (days after hatching) and LHbeta expressed from 40 dah onwards. The expression levels of these genes in all-female Southern catfish gonad were down-regulated after treatment with tamoxifen from 5 to 25 dah when measured at 65 dah. These results indicated the involvement of the three subunits in gonadal development and sexual differentiation.