| 1. |
- Ling, Charlotte, et al.
(författare)
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Identification of Functional Prolactin (PRL) Receptor Gene Expression: PRL Inhibits Lipoprotein Lipase Activity in Human White Adipose Tissue
- 2003
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Ingår i: The Journal of Clinical Endocrinology & Metabolism. - : The Endocrine Society. - 0013-7227 .- 1945-7197 .- 0021-972X. ; 88:4, s. 1804-1808
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Tidskriftsartikel (refereegranskat)abstract
- During lactation serum levels of prolactin (PRL) are elevated, and the activity of lipoprotein lipase (LPL) is decreased in the adipose tissue and increased in the mammary gland. However, PRL has been suggested to affect the adipose tissue in an indirect fashion during lactation. In the present study, we demonstrated expression of four PRL receptor (PRLR)mRNA isoforms (L, I, S1a, and S1b) in human sc abdominal adipose tissue and breast adipose tissue using RT-PCR/Southern blot analysis. In addition, L-PRLR [relative molecular mass (Mr) 90,000] and I-PRLR (Mr 50,000) protein expression was detected in human sc abdominal adipose tissue and breast adipose tissue using immunoblot analysis. Two additional protein bands with the molecular weight Mr 40–35,000 were also detected. The direct effect of PRL on the regulation of LPL activity in human abdominal adipose tissue cultured in vitro was investigated. PRL (500 ng/ml) reduced the LPL activity in human adipose tissue to 31 +/- 7.7%, compared with control.GH (100 ng/ml) also reduced the LPL activity, to 45 +/- 8.6%, compared with control. In agreement with previous studies, cortisol increased the LPL activity and GH inhibited cortisolinduced LPL activity. Furthermore, we found that PRL also inhibited the cortisol-induced LPL activity. Taken together, these results demonstrate a direct effect of PRL, via functional PRLRs, in reducing the LPL activity in human adipose tissue, and these results suggest that LPL might also be regulated in this fashion during lactation.
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| 2. |
- Feng, Yi, et al.
(författare)
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Effects of androgen and leptin on behavioral and cellular responses in female rats.
- 2011
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Ingår i: Hormones and behavior. - : Elsevier BV. - 1095-6867 .- 0018-506X. ; 60:4, s. 427-38
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Tidskriftsartikel (refereegranskat)abstract
- The causes of anxiety and depression in women with polycystic ovary syndrome (PCOS) remain elusive. To identify steps linking androgen signaling to the regulation of affective symptoms in vivo, we compared behavioral responses in female rats continuously exposed to DHT from puberty (a model of DHT-induced PCOS) and in rats exposed to DHT for 1week. Continuous and 1week of DHT exposure resulted in a general decrease in locomotor activity and time spent on the open arms in the elevated plus maze, indicating anxiety-like behavior. Rats with DHT-induced PCOS have increases in adiposity and circulating leptin levels accompanied by leptin resistance. One week of DHT exposure decreased androgen receptor (AR) expression in the hypothalamus and leptin synthesis and function in adipocytes; it also inhibited signal transducer and activator of transcription 3 (STAT3) and attenuated leptin activity by increasing levels of soluble leptin receptor, a leptin-binding protein, in the hypothalamus. This may affect the androgen-induced anxiety-related behavior in female rats. In conclusion, our results highlight the central role of androgens in behavioral function in female rats and suggest that androgens directly regulate the AR by decreasing its hypothalamic expression. Androgens also increase leptin synthesis in adipocytes, which drives central leptin signaling, and may regulate anxiety-related behaviors. Elucidating mechanisms by which androgens modulate female anxiety-like behavior may uncover useful approaches for treating women with PCOS who have symptoms of anxiety.
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| 3. |
- Feng, Yi, et al.
(författare)
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Spatiotemporal expression of androgen receptors in the female rat brain during the oestrous cycle and the impact of exogenous androgen administration: a comparison with gonadally intact males.
- 2010
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Ingår i: Molecular and cellular endocrinology. - : Elsevier BV. - 1872-8057 .- 0303-7207. ; 321:2, s. 161-74
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Tidskriftsartikel (refereegranskat)abstract
- Little is known about the regulation and cellular distribution of androgen receptors (ARs) in female rodent brains at various stages of the oestrous cycle. This information is critical for further studies of androgen signalling in the regulation of brain function under physiological and pathophysiological conditions. In this report, we show that the distribution of AR immunoreactivity in the female rat brain is consistent with reported AR mRNA hybridisation signals in the male brain, except for the dentate gyrus of the hippocampus. Immunohistochemical and Western blot analyses performed herein revealed that the onset of region-specific changes in AR proteins was strongly correlated with circulating and ovarian levels of estradiol and testosterone across the oestrous cycle. During the metestrus and diestrus stages, however, the highest levels of AR expression were abolished by chronic dihydrotestosterone (DHT) treatment. This demonstrates that fluctuations in endogenous androgens are required for the regulation of AR expression in the female rat brain. Colocalisation studies revealed that: (1) anatomical variations in AR protein localisation existed between female and male brains, (2) AR immunoreactivity was both neuronal and non-neuronal, and (3) AR protein expression was lower in female rat brains at all stages of the oestrous cycle compared to age-matched males. Our results indicate the presence of regional sex differences in AR expression and changes in the proportion of AR between different subcellular compartments. Furthermore, DHT was found to down-regulate the level of AR in the subcellular compartment in females in a region-specific manner. As a whole, the present study provides the first step toward understanding the dynamics of AR expression and regulation in the brain during normal physiological conditions and for differences in neuronal androgen effects based on sex.
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| 4. |
- Feng, Yi, et al.
(författare)
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The onset of human ectopic pregnancy demonstrates a differential expression of miRNAs and their cognate targets in the Fallopian tube
- 2014
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Ingår i: International Journal of Clinical and Experimental Pathology. - 1936-2625. ; 7:1, s. 64-79
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Tidskriftsartikel (refereegranskat)abstract
- Human ectopic pregnancy (EP) is a leading cause of pregnancy-related death, but the molecular basis underlying the onset of tubal EP is largely unknown. Female Dicer1 conditional knockout mice are infertile with dysfunctional Fallopian tube and have a different miRNA expression profile compared to wild-type mice, and we speculated that Dicer-mediated regulation of miRNA expression and specific miRNA-controlled targets might contribute to the onset of tubal EP. In the present study, we used microarray analysis and quantitative RT-PCR to examine the expression of miRNAs and core miRNA regulatory components in Fallopian tube tissues from women with EP. We found that the levels of DICER1, four miRNAs (let-7i, miR-149, miR-182, and miR-424), and estrogen receptor α distinguished the tubal implantation site from the non-implantation site. Computational algorithms and screening for interactions with the estrogen and progesterone receptor signaling pathways showed that the four miRNAs were predicted to target ten genes, including NEDD4, TAF15, and SPEN. Subsequent experiments showed differences in NEDD4 mRNA and protein levels between the implantation and non-implantation sites. Finally, we revealed that increases in smooth muscle cell NEDD4 and stromal cell TAF15, in parallel with a decrease in epithelial cell SPEN, were associated with tubal implantation. Our study suggests that changes in miRNA levels by the DICER-mediated miRNA-processing machinery result in aberrant expression of cell type-specific proteins that are potentially involved in the onset of tubal EP.
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| 5. |
- Hu, Junting, et al.
(författare)
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The regulation of nitric oxide synthase isoform expression in mouse and human fallopian tubes: Potential insights for ectopic pregnancy
- 2015
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Ingår i: International Journal of Molecular Sciences. - : MDPI AG. - 1422-0067. ; 16:1, s. 49-67
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Tidskriftsartikel (refereegranskat)abstract
- Nitric oxide (NO) is highly unstable and has a half-life of seconds in buffer solutions. It is synthesized by NO-synthase (NOS), which has been found to exist in the following three isoforms: neuro nitric oxide synthase (nNOS), inducible nitric oxide synthase (iNOS), and endothelial nitric oxide synthase (eNOS). NOS activity is localized in the reproductive tracts of many species, although direct evidence for NOS isoforms in the Fallopian tubes of mice is still lacking. In the present study, we investigated the expression and regulation of NOS isoforms in the mouse and human Fallopian tubes during the estrous and menstrual cycles, respectively. We also measured isoform expression in humans with ectopic pregnancy and in mice treated with lipopolysaccharide (LPS). Our results confirmed the presence of different NOS isoforms in the mouse and human Fallopian tubes during different stages of the estrous and menstrual cycles and showed that iNOS expression increased in the Fallopian tubes of women with ectopic pregnancy and in LPS-treated mice. Elevated iNOS activity might influence ovulation, cilia beats, contractility, and embryo transportation in such a manner as to increase the risk of ectopic pregnancy. This study has provided morphological and molecular evidence that NOS isoforms are present and active in the human and mouse Fallopian tubes and suggests that iNOS might play an important role in both the reproductive cycle and infection-induced ectopic pregnancies.
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| 6. |
- Ivarsson, Karin, 1970, et al.
(författare)
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Evaluation of the effects of DNase treatment on signal specificity in RT-PCR and in situ RT-PCR.
- 1998
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Ingår i: BioTechniques. - : Future Science Ltd. - 0736-6205 .- 1940-9818. ; 25:4
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- In this study, the effects of DNase treatment on the specificity of reverse transcription (RT)-PCR have been investigated on different samples, containing RNA, DNA, DNA/RNA and DNA/cDNA. This was to evaluate the possibilities of getting specific results in a direct in situ RT-PCR. All DNA targets in the samples were eliminated after 1 h of DNase treatment. However, some DNA fragments still remained after both 1 h and overnight DNase treatment. When these fragments served as primers for amplification, nonspecific smears resulted. In samples containing small amounts of RNA, the RNA was affected by overnight treatment with DNase. Our conclusion is that the direct in situ RT-PCR is an unreliable method because the necessary DNase treatment induces nonspecific amplification, and no size-separation is possible. We conclude that the best way to perform an in situ RT-PCR is to hybridize with a labeled specific probe after amplification is completed.
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| 7. |
- Johnning, Anna, 1985, et al.
(författare)
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Resistance Mutations in gyrA and parC are Common in Escherichia Communities of both Fluoroquinolone-Polluted and Uncontaminated Aquatic Environments
- 2015
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Ingår i: Frontiers in Microbiology. - : Frontiers Media SA. - 1664-302X. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- Alterations in the target proteins of fluoroquinolones, especially in GyrA and ParC, are known to cause resistance. Here, we investigated environmental Escherichia communities to explore the possible link between the abundance of mutations, and the exposure to fluoroquinolones. Sediment samples were collected from a relatively pristine lake, up and downstream from a sewage treatment plant, and from several industrially polluted sites. The quinolone resistance-determining regions of gyrA and parC were analyzed using amplicon sequencing of metagenomic DNA. Five non-synonymous substitutions were present in all samples, and all of these mutations have been previously linked to fluoroquinolone resistance in Escherichia coli. In GyrA, substitutions S83L and D87N were on average detected at frequencies of 86 and 32%, respectively, and 31% of all amplicons encoded both substitutions. In ParC, substitutions S80I, E84G, and E84V were detected in 42, 0.9, and 6.0% of the amplicons, respectively, and 6.5% encoded double substitutions. There was no significant correlation between the level of fluoroquinolone pollution and the relative abundance of resistance mutations, with the exception of the most polluted site, which showed the highest abundance of said substitutions in both genes. Our results demonstrate that resistance mutations can be common in environmental Escherichia, even in the absence of a fluoroquinolone selective pressure.
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| 8. |
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| 9. |
- Kristiansson, Erik, 1978, et al.
(författare)
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Pyrosequencing of Antibiotic-Contaminated River Sediments Reveals High Levels of Resistance and Gene Transfer Elements
- 2011
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Ingår i: Plos One. - : Public Library of Science (PLoS). - 1932-6203. ; 6:2
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Tidskriftsartikel (refereegranskat)abstract
- The high and sometimes inappropriate use of antibiotics has accelerated the development of antibiotic resistance, creating a major challenge for the sustainable treatment of infections world-wide. Bacterial communities often respond to antibiotic selection pressure by acquiring resistance genes, i.e. mobile genetic elements that can be shared horizontally between species. Environmental microbial communities maintain diverse collections of resistance genes, which can be mobilized into pathogenic bacteria. Recently, exceptional environmental releases of antibiotics have been documented, but the effects on the promotion of resistance genes and the potential for horizontal gene transfer have yet received limited attention. In this study, we have used culture-independent shotgun metagenomics to investigate microbial communities in river sediments exposed to waste water from the production of antibiotics in India. Our analysis identified very high levels of several classes of resistance genes as well as elements for horizontal gene transfer, including integrons, transposons and plasmids. In addition, two abundant previously uncharacterized resistance plasmids were identified. The results suggest that antibiotic contamination plays a role in the promotion of resistance genes and their mobilization from environmental microbes to other species and eventually to human pathogens. The entire life-cycle of antibiotic substances, both before, under and after usage, should therefore be considered to fully evaluate their role in the promotion of resistance.
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| 10. |
- Lagali, Neil, et al.
(författare)
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Donor and recipient endothelial cell population of the transplanted human cornea: a two-dimensional imaging study.
- 2010
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Ingår i: Investigative ophthalmology & visual science. - : Association for Research in Vision and Ophthalmology (ARVO). - 1552-5783 .- 0146-0404. ; 51:4, s. 1898-904
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Tidskriftsartikel (refereegranskat)abstract
- Purpose. To elucidate the pattern of donor and recipient endothelial cell populations in transplanted human corneas and determine the degree to which donor endothelial cells survive in the graft. Methods. Thirty-six corneal grafts were collected from recipients of opposite sex to the donor, at the time of retransplantation for various indications. Cells from the endothelial side of the grafts were harvested, preserving their relative location on the endothelium. Fluorescence in situ hybridization of the sex chromosomes enabled each cell to be identified as donor- or recipient-derived. Images of the graft endothelium were assembled, to depict the pattern of cell population of the graft, and the proportion of donor cells present was estimated. Results. Endothelial cells of donor origin were found in 26 of 36 grafts (72.2%)-in one case, up to 26 years after transplantation. The proportion of donor endothelium ranged from 2% to 99%; however, there was no significant correlation of this proportion with postoperative time (P = 0.19). The mean annual rate of donor cell loss correlated negatively with the time to graft failure by endothelial decompensation (P = 0.002). Endothelial images indicated a highly variable pattern of recipient cell repopulation of the graft. A tendency toward donor cell retention in transparent, successful grafts was noted; however, this feature alone was not a reliable indicator of long-term graft transparency. Conclusions. Two-dimensional imaging of the corneal graft endothelium revealed a variable pattern and extent of donor and recipient cell population, indicating the highly dynamic nature of the corneal endothelium after transplantation.
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