| 1. |
- Bondestam, Jonas, et al.
(författare)
-
Engagement of activin and bone morphogenetic protein signaling pathway Smad proteins in the induction of inhibin B production in ovarian granulosa cells
- 2002
-
Ingår i: Molecular and Cellular Endocrinology. - 0303-7207 .- 1872-8057. ; 195:1-2, s. 79-88
-
Tidskriftsartikel (refereegranskat)abstract
- In the mammalian ovary cell growth and differentiation is regulated by several members of the transforming growth factor beta (TGF beta) superfamily including activins, inhibins, growth differentiation factors and bone morphogenetic proteins (BMPs). The effects of TGF beta family members are mediated to the target cells via heteromeric complexes of type I and II serine/threonine kinase receptors which activate Smad signaling protein pathways in various cell types. We have previously shown that inhibin B, a hormonally important product from human granulosa cells, is up regulated by activin and BMPs. Here, we report the use of adenoviral gene transfer methodology to manipulate the TGF beta growth factor signaling system in primary cultures of human granulosa cells. These cells are exceedingly difficult to transfect by conventional transfection methods, but were virtually 100% infected with recombinant adenoviruses expressing green fluorescent protein (GFP). Adenoviruses expressing constitutively active forms of the seven known mammalian type I activin receptor-like kinase receptors (Ad-caALK1 through Ad-caALK7) cause activation of endogenous and adenovirally transferred Smad signaling proteins so that Ad-caALK1/2/3/6 and Ad-caALK4/5/7 induced phosphorylation of the Smad1 and Smad2 pathways, respectively. Activin A and BMP-2 activated the Smad1 and Smad2 pathways as well as inhibin B production as did all the Ad-caALKs. Furthermore, overexpression of adenoviral Smad1 and Smad2 proteins without exogenously added ligands induced inhibin B production. The inhibitory Smad7 protein suppressed BMP-2 and activin induced inhibin B production. Collectively, the present data demonstrate that adenoviral gene transfer provides an effective approach for dissecting the TGF beta signaling pathways in primary ovarian cells in vitro and more specifically indicate that the Smad1 and Smad2 pathways are involved in the regulation of inhibin B production by TGF beta family ligands in the ovary.
|
|
| 2. |
- Liu, Kui, et al.
(författare)
-
Expression pattern and functional studies of matrix degrading proteases and their inhibitors in the mouse corpus luteum
- 2003
-
Ingår i: Molecular and Cellular Endocrinology. - 0303-7207 .- 1872-8057. ; 205:1-2, s. 131-140
-
Tidskriftsartikel (refereegranskat)abstract
- The formation of the corpus luteum (CL) is accompanied with angiogenesis and tissue remodeling and its regression involves tissue degradation. Matrix degrading proteases such as plasminogen activators (PAs) and matrix metalloproteinases (MMPs) are thought to play important roles in such controlled proteolytic processes. In this study, in situ hybridization has been used to examine the regulation and expression pattern of mRNAs coding for proteases and protease inhibitors belonging to the PA- and MMP-systems during the life cycle of the CL in an adult pseudopregnant mouse model. Of the nine proteases and five protease inhibitors that were studied, the majority were found to be temporally expressed during the formation and/or the regression of the CL. However, the mRNAs coding for urokinase type PA (uPA), membrane-type 1 MMP (MT1-MMP), and tissue inhibitor of metalloproteinases type-3 (TIMP-3) were constantly expressed in the mouse CL throughout its whole life span. To study the functional role of uPA in the CL, we analyzed luteal formation and function in uPA deficient mice. Our results revealed no significant difference in ovarian weight, serum progesterone levels, and blood vessel density in the functional CL between uPA deficient and wild type control mice. The temporal and spatial expression pattern of proteases and protease inhibitors during the CL life span suggests that members of the PA- and MMP-systems may play important roles in the angiogenesis and tissue remodeling processes during CL formation, as well as in the tissue degradation during luteal regression. However, the absence of reproductive phenotypes in mice lacking uPA and several other matrix degrading proteases indicates that there are redundancies among different matrix degrading proteases or that tissue remodeling in the ovary may involve other additional unique elements.
|
|
| 3. |
- Vaskivuo, Tommi E, et al.
(författare)
-
Role of apoptosis, apoptosis-related factors and 17beta-hydroxysteroid dehydrogenases in human corpus luteum regression
- 2002
-
Ingår i: Molecular and Cellular Endocrinology. - 0303-7207 .- 1872-8057. ; 194:1-2, s. 191-200
-
Tidskriftsartikel (refereegranskat)abstract
- The human corpus luteum (CL) is a transient endocrine organ with a life span of 14-16 days. Apoptosis has been suggested to be the mechanism of CL regression and the possible regulatory role of the bcl-2 family in this process has been studied in animals and, to some extent, in humans. In the present study, apoptosis was studied in the human CL and in luteinised granulosa cells by in situ 3'-end labelling and gel electrophoretic DNA fragmentation analysis. The apoptosis-regulating factors Bcl-2, Bax and TNF-alpha, transcription factor NF-kappaB and Caspase-3, a key executioner protein in apoptotic cell death, were studied by immunohistochemistry and in situ hybridisation. Furthermore, we analysed expression of 17beta hydroxysteroid dehydrogenase (17HSD) type 1 and 2, key enzymes in the estrogen metabolism. Apoptosis was found in the CL throughout the luteal phase, but a marked increase of apoptotic luteal cells was observed during the late luteal phase (CL day 11-14). This was preceded by a clear increase of 17HSD type 1 expression. The apoptosis-regulating proteins Bcl-2 and Bax were expressed constantly in the CL throughout the luteal phase. TNF-alpha expression was constant during the early and mid-luteal phases, but in the late luteal phase, some specimens showed increased immunostaining. NF-kappaB and Caspase-3 were present in the CL throughout the luteal phase and in individual specimens, the expression of Caspase-3 was associated with a high rate of apoptosis in the late luteal phase. In conclusion, apoptosis is involved in human luteal regression and estradiol (E(2)) may function as a trigger for this process. The expression of the pro- and anti-apoptotic factors studied in the CL suggest their part in this process, but the conclusive evidence for the exact molecular mechanisms remains open.
|
|
| 4. |
- Andersson, Annika K., et al.
(författare)
-
Cytokine-induced PGE2 formation is reduced from iNOS deficient murine islets
- 2004
-
Ingår i: Molecular and Cellular Endocrinology. - : Elsevier BV. - 0303-7207 .- 1872-8057. ; 220:1-2, s. 21-29
-
Tidskriftsartikel (refereegranskat)abstract
- Cytokines may be involved in islet destruction during Type 1 diabetes. Exposure to interleukin-1beta (IL-1beta) or IL-1beta plus interferon-gamma (IFN-gamma) of rodent islets induces expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Subsequent formation of nitric oxide (NO) and prostaglandin E(2) (PGE(2)) may impair beta-cell function. Using iNOS deficient (iNOS -/-) islets, we have further investigated the relation between NO formation and PGE(2) induction. We found that iNOS -/- islets responded with a reduced PGE(2) formation following IL-1beta or (IL-1beta + IFN-gamma) treatment compared to wild-type (wt) islets, while COX-2 mRNA or protein content were unchanged. By the addition of an NO donor together with IL-1beta, PGE(2) formation could be stimulated from iNOS -/- islets. We conclude that the lowered capacity of PGE(2) formation observed from cytokine exposed iNOS -/- islets is due to a decreased stimulation of PGE(2) formation by the COX-2 enzyme in the absence of NO, rather then differences in expressed COX-2 protein.
|
|
| 5. |
- Liang, Min, et al.
(författare)
-
Proteasome-dependent degradation of ERalpha but not ERbeta in cultured mouse aorta smooth muscle cells.
- 2004
-
Ingår i: Molecular and Cellular Endocrinology. - : Elsevier BV. - 1872-8057 .- 0303-7207. ; 224:1-2, s. 65-71
-
Tidskriftsartikel (refereegranskat)abstract
- Here we investigate ERα and ERβ expression and regulation in vascular smooth muscle cells from mouse aorta. Immunocytochemistry showed nuclear staining for both ERα and ERβ. Double stainings revealed co-expression of ERα and ERβ in vascular smooth muscle cells. ERα (66 kDa) and ERβ (54 kDa) expression determined by Western blotting was unchanged within 7 h after inhibition of protein synthesis with cycloheximide in the absence of 17β-estradiol (E2), showing that both proteins are stable without ligand-binding. Treatment with 10 nM E2 for 7 h in the presence of cycloheximide increased ERα, suggesting that E2 causes a conformational change in the ERα protein. The ERβ was not affected by E2. Treatment with the proteasome inhibitor epoxomicin (100 nM) for 3 days caused a prominent upregulation of ERα both in the absence and in the presence of E2, while ERβ was unaffected, suggesting that ERα but not ERβ is degraded by ubiquitin–proteasome system in vascular smooth muscle cells. In summary, we disclose a short-term regulation of ERα protein by estrogen and that ERα but not ERβ is degraded via the ubiquitin–proteasome pathway in vascular smooth muscle cells.
|
|
| 6. |
- Ny, Tor, et al.
(författare)
-
Matrix remodeling in the ovary : regulation and functional role of the plasminogen activator and matrix metalloproteinase systems.
- 2002
-
Ingår i: Molecular and Cellular Endocrinology. - 0303-7207 .- 1872-8057. ; 187:1-2, s. 29-38
-
Tidskriftsartikel (refereegranskat)abstract
- In each reproductive cycle, extensive tissue remodeling takes place in the ovary during follicular development, ovulation, formation and regression of corpus luteum (CL) and follicular atresia. Several lines of indirect evidence suggest that these changes are mediated, in part, by proteases belonging to the plasminogen activator (PA) and the matrix metalloproteinase (MMP) systems. These two enzyme systems include both proteinases and associated inhibitors, that are thought to act in concert via a cascade of proteolytic events, the end result of which is the generation of a broad spectrum proteolytic activity, that can mediate physiological tissue remodeling throughout the body. The current review highlights the key features of these two enzyme systems and focuses on their regulation and functional role during the dynamic remodeling processes that takes place in the ovary during each reproductive cycle.
|
|
| 7. |
|
|
| 8. |
|
|
| 9. |
|
|
| 10. |
|
|
