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1.
Effects of TGF-betas and a specific antagonist on apoptosis of immature rat male germ cells in vitro 总被引:1,自引:0,他引:1
Konrad L Keilani MM Laible L Nottelmann U Hofmann R 《Apoptosis : an international journal on programmed cell death》2006,11(5):739-748
Massive apoptosis of pubertal male germ cells is important for the development of functional spermatogenesis in the adult
testis. Although the trigger(s) for male germ cell loss at puberty remain undefined, we have hypothesized that transforming
growth factor-betas (TGF-βs) play an active role. Here we demonstrate that the three mammalian TGF-β isoforms, TGF-β1, TGF-β2
and TGF-β3, induce distinct apoptosis of pubertal spermatogonia and spermatocytes in a dose-dependent manner. Induction of
male germ cell death by activation of caspase-3 was most pronounced with TGF-β2 compared to TGF-β1 and TGF-β3. Furthermore,
we found colocalization of activated caspase-3 with apoptotic protease-activating factor-1 (Apaf-1) in apoptotic germ cells,
thus indicating the importance of the intrinsic mitochondrial pathway in TGF-β-induced apoptosis. The specificity of the TGF-β
effects was proven by addition of recombinant latency-associated peptide against TGF-β1 (rLAP-TGF-β1) which completely abolished
TGF-β1-induced and TGF-β3-induced germ cell apoptosis. Although TGF-β2-triggered germ cell death also was significantly reduced
by rLAP-TGF-β1, inhibition was not maximal. Our results suggest that the three TGF-β isoforms induce apoptosis of pubertal
male germ cells via the mitochondrial pathway in vitro and are thus likely candidates involved in the excessive first wave of apoptosis of male germ cells during puberty.
Lutz Konrad and Marcel Munir Keilani contributed equally to this work. 相似文献
2.
NAG-1 up-regulation mediated by EGR-1 and p53 is critical for quercetin-induced apoptosis in HCT116 colon carcinoma cells 总被引:4,自引:0,他引:4
Lim JH Park JW Min DS Chang JS Lee YH Park YB Choi KS Kwon TK 《Apoptosis : an international journal on programmed cell death》2007,12(2):411-421
Quercetin, a flavonoid molecule ubiquitously present in nature, has multiple effects on cancer cells, including the inhibition
of cell proliferation and migration. However, the responsible molecular mechanisms are not fully understood. We found that
quercetin induces the expression of NAG-1 (Non-steroidal anti-inflammatory drug activated gene-1), a TGF-β superfamily protein,
during quercetin-induced apoptosis of HCT116 human colon carcinoma cells. Reporter assays using the luciferase constructs
containing NAG-1 promoter region demonstrate that early growth response-1 (EGR-1) and p53 are required for quercetin-mediated
activation of the NAG-1 promoter. Overexpression of NAG-1 enhanced the apoptotic effect of quercetin, but suppression of quercetin-induced
NAG-1 expression by NAG-1 siRNA attenuated quercetin-induced apoptosis in HCT116 cells. Taken together, the present study
demonstrates for the first time that quercetin induces apoptosis via NAG-1, providing a mechanistic basis for the apoptotic
effect of quercetin in colon carcinoma cells. 相似文献
3.
The in vitro occurrence of apoptosis in hepatic cells has not been well characterized because it depends on apoptosis inducing-agents
and culture conditions. Furthermore, for a given hepatic cell and the same agent, discrepant results have been reported depending
on the technique used to evaluate the proportion of apoptotic cells. In this study, we compared the effects of several apoptosis-inducing
agents – transforming growth factor β1 (TGF-β1), retinoic acid (RA), okadaic acid (OA), and cycloheximide (CY) – on two types of hepatic cells, the human hepatoma cell
line Hep3B and normal rat hepatocytes, maintained either plated for 24 to 48 h or in suspension for 20 h. Chromatin condensation
and/or nucleus fragmentation were investigated morphologically by DAPI staining. DNA fragmentation was investigated biochemically
by agarose gel electrophoresis and poly(ADP-ribose) polymerase (PARP) cleavage was studied by western blot. Apoptotic cells
were quantified either by counting cells on UV microscopy after DAPI staining or by flow cytometry. Nuclear changes, the ladder
pattern on DNA electrophoresis and PARP cleavage were observed in plated cells, hepatoma cells and normal rat hepatocytes,
with all inducers but especially with OA. Semiquantification confirmed that OA was a strong inducer in plated cells under
the present conditions, since about 14% and 30% of Hep3B cells (with DAPI staining and flow cytometry, respectively) were
apoptotic after 48 h treatment, while, with the other inducers, apoptosis was weaker and discrepancies were also observed
between the two counting methods (TGF-β1; 4% and 12%; RA, 7% and 12%; CY, 4% and 16%, with DAPI staining and flow cytometry, respectively). OA induced a moderate
apoptosis in cultured hepatocytes (13% with DAPI staining), while TGF-β1, RA and CY were found to be weakly apoptotic (respectively 4% for the first two and 6% for the last ) after 48 h. In contrast,
in suspension cells, apoptosis was observed neither in Hep3B cells nor in normal hepatocytes, whatever the apoptotic inducer
and whatever the techniques used to detect apoptosis. In conclusion, our results show that induction of apoptosis in hepatic
cells depends not only on the apoptosis-inducing agent but also on the culture conditions.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
4.
Activation of extracellular signal-regulated kinase by TGF-β1 via TβRII and Smad7 dependent mechanisms in human bronchial epithelial BEP2D cells 总被引:1,自引:0,他引:1
Huo YY Hu YC He XR Wang Y Song BQ Zhou PK Zhu MX Li G Wu DC 《Cell biology and toxicology》2007,23(2):113-128
Transforming growth factor-β1 (TGF-β1) can activate mitogen-activated protein kinases (MAPKs) in many types of cells. The
mechanism of this activation is not well elucidated. Here, we explore the role of TGF-β/Smads signaling compounds in TGF-β1-mediated
activation of extracellular signal-regulated kinase (ERK) MAPK in human papillomavirus (HPV)-18 immortalized human bronchial
epithelial cell line BEP2D and the role of TGF-β1-induced phosphorylation of ERK in proliferation and apoptosis of BEP2D.
The cell models of siRNA-mediated silencing of TGF-β receptor type II (TβRII), Smad2, Smad3, Smad4, and Smad7 were employed
in this study. Our results demonstrate that TGF-β1 activates ERK in a time-dependent manner with a maximum effect at 60 min;
overexpression of Smad7 increased this TGF-β1-mediated phosphorylation of the ERK; and siRNA-mediated silencing of TβRII,
Smad3, Smad4, and Smad7 abrogated this effect. Moreover, we observed that overexpression of Smad7 restored TGF-β1-mediated
ERK phosphorylation in Smad4 knockdown cells but not in TβRII knockdown cells. In BEP2D cells, TGF-β1 treatment effectively
inhibited cells’ proliferation and induced their apoptosis. Pretreatment with U0126, an inhibitor of ERK1/2, significantly
enhanced the TGF-β1-mediated antiproliferative and apoptosis induction effects in BEP2D cells. These data revealed that TβRII
and Smad7 play the critical roles in TGF-β1-mediated activation of ERK; Smad3 and Smad4 can play an indirect role through
up-regulating Smad7 expression; and TGF-β1-induced phosphorylation of ERK may participate in BEP2D cell proliferation and
apoptosis regulation. 相似文献
5.
Huang EJ Wu CC Lee SD Chen JH Liu JY Ko JL Lin JA Lu MC Chen LM Huang CY Kuo WW 《Molecular and cellular biochemistry》2006,287(1-2):137-145
Hepatocellular carcinoma (HCC), the major manifestation of primary liver cancer, is one of the most frequent and malignant cancers worldwide, especially in Taiwan. Estrogen receptors (ERs) have been reported to play either a proliferation- or apoptosis-enhancing role in the differentiation of cancers, including HCC. In a previous experiment, we showed that transient overexpressed estrogen receptor-α induced early stage HCC cell line Hep 3B cell apoptosis by increasing the hTNF-α gene expression in a ligand-independent manner. To further clarify if the apoptotic effect occurs in poorly differentiated HCC cell line, HA22T, and elucidate the roles of ERs and TNF-α, DNA fragmentation and caspase activity were measured in late stage HCC cell line, HA22T, by measuring the expression of hER-α and hER-β using a Tetracycline-induciable system (Tet-on). Increased DNA fragmentation and caspase-3 activity were found in hERβ-overexpressed HA22T cells treated with estrogen (10−8 M) but not in hERα-overexpressed HA22T cells. Using RT-PCR/PCR and western blotting in HA22T cells, overexpressed hER-β was also found to increase the expression of hTNF-α mRNA and induce hTNF-α-dependent luciferase activity in a ligand-dependent manner. Additionally, LPS treatment and hER-β overexpression both enhance caspase-8 activities, whereas neither hER-β nor E2 treatment affected caspase-9 activities. In addition, the overexpressed hER-β plus E2 enhanced DNA fragmentation and caspase-8 activities were only partially reduced by anti-hTNF-α (0.1ng/ml), which was possibly due to the involvement of P53 and TGF-β. Taken together, our data indicates that overexpressed hER-β but not hER-α may induce caspase-8-mediated apoptosis by increasing the hTNF-α gene expression in a ligand-dependent manner in poorly differentiated HA22T cells. (Mol Cell Biochem xxx: 1–9, 2005)Shares equally contribution Contract grant sponsor: National Science Council; Contract grant number: NSC 91-2314-B-075A-006, NSC 92-2314-B-075A-014. 相似文献
6.
7.
Zhiguo Zhang Lin Wu Julei Wang Gang Li Dayun Feng Bin Zhang Lihong Li Jiandong Yang Lianting Ma Huaizhou Qin 《PloS one》2014,9(4)
Nonsteroidal anti-inflammatory drug (NSAID) activated gene-1 (NAG-1) is a divergent member of the transforming growth factor-beta (TGF-β) superfamily. NAG-1 plays remarkable multifunctional roles in controlling diverse physiological and pathological processes including cancer. Like other TGF-β family members, NAG-1 can play dual roles during cancer development and progression by negatively or positively modulating cancer cell behaviors. In glioblastoma brain tumors, NAG-1 appears to act as a tumor suppressor gene; however, the precise underlying mechanisms have not been well elucidated. In the present study, we discovered that overexpression of NAG-1 induced apoptosis in U87 MG, U118 MG, U251 MG, and T98G cell lines via the intrinsic mitochondrial pathway, but not in A172 and LN-229 cell lines. NAG-1 could induce the phosphorylation of PI3K/Akt and Smad2/3 in all six tested glioblastoma cell lines, except Smad3 phosphorylation in A172 and LN-229 cell lines. In fact, Smad3 expression and its phosphorylation were almost undetectable in A172 and LN-229 cells. The PI3K inhibitors promoted NAG-1-induced glioblastoma cell apoptosis, while siRNAs to Smad2 and Smad3 decreased the apoptosis rate. NAG-1 also stimulated the direct interaction between Akt and Smad3 in glioblastoma cells. Elevating the level of Smad3 restored the sensitivity to NAG-1-induced apoptosis in A172 and LN-229 cells. In conclusion, our results suggest that PI3K/Akt and Smad-dependent signaling pathways display opposing effects in NAG-1-induced glioblastoma cell apoptosis. 相似文献
8.
Liagre B Vergne-Salle P Corbiere C Charissoux JL Beneytout JL 《Arthritis research & therapy》2004,6(4):R373-R383
In the present study, we have shown for the first time that a plant steroid, diosgenin, causes an inhibition of the growth
of fibroblast-like synoviocytes from human rheumatoid arthritis, with apoptosis induction associated with cyclooxygenase-2
(COX-2) up-regulation. Celecoxib, a selective COX-2 inhibitor, provoked a large decrease in diosgenin-induced apoptosis even
in the presence of exogenous prostaglandin E2, whereas interleukin-1β, a COX-2 inducer, strongly increased diosgenin-induced apoptosis of these synoviocytes. These findings
suggest that the proapoptotic effect of diosgenin is associated with overexpression of COX-2 correlated with overproduction
of endogenous prostaglandin E2. We also observed a loss of mitochondrial membrane potential, caspase-3 activation, and DNA fragmentation after diosgenin
treatment. 相似文献
9.
Background
Functional antagonism between transforming growth factor beta (TGF-β) and hyaluronidase has been demonstrated. For example, testicular hyaluronidase PH-20 counteracts TGF-β1-mediated growth inhibition of epithelial cells. PH-20 sensitizes various cancer cells to tumor necrosis factor (TNF) cytotoxicity by upregulating proapoptotic p53 and WW domain-containing oxidoreductase (WOX1). TGF-β1 blocks PH-20-increased TNF cytotoxicity. In the present study, the functional antagonism between TGF-β1 and lysosomal hyaluronidases Hyal-1 and Hyal-2 was examined. 相似文献10.
Effects of representative members of the transforming growth factor-β (TGF-β) family, TGF-β1, activin A and BMP-2, on melanin
content and expression of pigment-producing enzymes were examined in B16 melanoma cells. Treatment with TGF-β1 or activin
A but not with BMP-2 significantly decreased melanin content and expression of Tyrosinase and Tyrp-1, suggesting an inhibitory effect of TGF-β1 and activin A on melanin synthesis. TGF-β1 completely inhibited melanin synthesis
induced by α-melanin stimulating hormone (α-MSH), whereas activin A only slightly did. As compared with parental B16 cells,
the inhibitory effects of TGF-β1 and activin A on melanin content were relative smaller in B16 F10 cells, a subline of B16
cells that contain more pigment. The present study indicates that in addition to TGF-β, activin negatively regulates melanogenesis
in the absence of α-MSH, but that the activity in the presence of α-MSH was slightly different between TGF-β and activin. 相似文献
11.
12.
The transforming growth factor-beta (TGF-β) 1 is a mediator of extracellular matrix (ECM) gene expression in mesangial cells
and the development of diabetic glomerulopathy. Here, we investigate the effects of TGF-β1 on laminin γ1 and fibronectin polypeptide
expression and cell survival in mouse mesangial cells (MES-13). TGF-β1 (10 ng/ml) stimulates laminin-γ1 and fibronectin expression
~two-fold in a time-dependent manner (0–48 h). TGF-β1 treatment also retards laminin-γ1 mobility on SDS-gels, and tunicamycin,
an inhibitor of the N-linked glycosylation, blocks the mobility shift. TGF-β1 increases the binding of laminin γ1 to WGA-agarose
and the binding is abolished by tunicamycin suggesting that laminin γ1 is modified by N-linked glycosylation. TGF-β1 also
elevates fibronectin glycosylation but its mobility is not altered. The degradation of laminin γ1 and fibronectin proteins
is reduced by their glycosylation. In addition, TGF-β1 enhances mesangial cell viability and metabolic activities initially
(0–24 h); however, eventually leads to cell death (24–48 h). TGF-β1 elevates pro-apoptotic caspase-3 activity and decrease
cell cycle progression factor cyclin D1 expression, which parallels cell death. These results indicate that TGF-β1 plays an
important role in ECM expression, protein glycosylation and demise of mesangial cells in the diabetic glomerular mesangium.
(Mol Cell Biochem 278: 165–175, 2005) 相似文献
13.
Méndez C Alcántara L Escalona R López-Casillas F Pedernera E 《Cell and tissue research》2006,325(1):143-149
The gonadal development of chicken embryo is regulated by hormones and growth factors. Transforming growth factor beta (TGF-β) isoforms may play a critical role in the regulation of growth in chicken gonads. We have investigated the effect of the TGF-β isoforms on the number of germ and somatic cells in the ovary of the chicken embryo. Ovaries were obtained from chicken embryos at 9 days of incubation. They were organ-cultured for 72 h in groups treated with TGF-β1, TGF-β2, soluble betaglycan, TGF-β1 plus soluble betaglycan, or TGF-β2 plus soluble betaglycan, and untreated (control). TGF-β1 and TGF-β2 diminished the somatic cell number in the ovary of the chicken embryo at this age by inhibiting the proliferation of the somatic cells without increasing apoptosis. On the other hand, TGF-β1 and TGF-β2 did not affect the number of germ cells in the cultured ovary. The capacity of TGF-β1 and TGF-β2 to diminish the number of somatic cells in the ovary was blocked with soluble betaglycan, a natural TGF-β antagonist. However, changes in the location of germ cells within the ovary suggested that TGF-β promoted the migration of the germ cells from the ovarian cortex to the medulla. Thus, TGF-β affects germ and somatic cells in the ovary of the 9-day-old chicken embryo and inhibits the proliferation of somatic cells.This work was supported by DGAPA-UNAM (IN214403) and CONACYT (45030). 相似文献
14.
Nonsteroidal anti-inflammatory drug-activated gene-1 (NAG-1) is induced by nonsteroidal anti-inflammatory drugs and possesses proapoptotic and antitumorigenic activities. Although tolfenamic acid (TA) induces apoptosis in head and neck cancer cells, the relationship between NAG-1 and TA has not been determined. This study investigated the induction of apoptosis in head and neck cancer cells treated by TA and the role of NAG-1 expression in this induction. TA reduced head and neck cancer cell viability in a dose-dependent manner and induced apoptosis. The induced apoptosis was coincident with the expression of NAG-1. Overexpression of NAG-1 enhanced the apoptotic effect of TA, whereas suppression of NAG-1 expression by small interfering RNA attenuated TA-induced apoptosis. TA significantly inhibited tumor formation as assessed by xenograft models, and this result accompanied the induction of apoptotic cells and NAG-1 expression in tumor tissue samples. Taken together, these results demonstrate that TA induces apoptosis via NAG-1 expression in head and neck squamous cell carcinoma, providing an additional mechanistic explanation for the apoptotic activity of TA. 相似文献
15.
16.
Caspase-3 antisense oligodeoxynucleotides inhibit apoptosis in γ-irradiated human leukemia HL-60 cells 总被引:1,自引:0,他引:1
Zhang XT Song TB Du BL Li DM Li XM 《Apoptosis : an international journal on programmed cell death》2007,12(4):743-751
To study the inhibitory effects of caspase-3 mRNA antisense oligodeoxynucleotides (ASODNs) on apoptosis, we designed four
ASODNs targeting different regions of caspase-3 mRNA and transfected them into human leukemia HL-60 cells. The transfected
cells were given 10 Gy γ-irradiation followed by incubation for 18 h and measurement of apoptosis and caspase-3 expression.
Our results showed that ASODN-2 targeting the 5′ non-coding region of sites –62 to –46, and ASODN-3 targeting the 5′ coding
region of sites –1 to 16, both reduced apoptosis measured by gel electrophoresis and flow cytometry. Hoechst 33258 staining
and TUNEL assay revealed that apoptotic indexes in the ASODN-2 and ASODN-3 groups were significantly lower than those in the
untransfected and mismatched oligodeoxynucleotide (MODN) groups. Immunocytochemistry, Western blotting and RT-PCR showed that
expression levels of caspase-3 protein and mRNA in both ASODN-2 and ASODN-3 groups were decreased compared with those in the
untransfected and MODN groups. In conclusion, caspase-3 mRNA ASODNs can inhibit γ-radiation-induced apoptosis of HL-60 cells
and reduce expression of caspase-3 protein and mRNA. The results suggest that antisense approach may be useful for therapeutic
treatment of certain neurodegenerative diseases in which apoptosis is involved.
The work was supported by a grant from the National Natural Science Foundation of China (No. 39880008). 相似文献
17.
Liver fibrosis occurs in most types of chronic liver diseases and is characterized by excessive accumulation of extracellular
matrix proteins, leading to disruption of tissue function and eventually organ failure. Transforming growth factor (TGF)-β
represents an important pro-fibrogenic factor and aberrant TGF-β action has been implicated in many disease processes of the
liver. Endoglin is a TGF-β co-receptor expressed mainly in endothelial cells that has been shown to differentially regulates
TGF-β signal transduction by inhibiting ALK5-Smad2/3 signalling and augmenting ALK1-Smad1/5 signalling. Recent reports demonstrating
upregulation of endoglin expression in pro-fibrogenic cell types such as scleroderma fibroblasts and hepatic stellate cells
have led to studies exploring the potential involvement of this TGF-β co-receptor in organ fibrosis. A recent article by Meurer
and colleagues now shows that endoglin expression is increased in transdifferentiating hepatic stellate cells in vitro and
in two different models (carbon tetrachloride intoxication and bile duct ligation) of liver fibrosis in vivo. Moreover, they
show that endoglin overexpression in hepatic stellate cells is associated with enhanced TGF-β-driven Smad1/5 phosphorylation
and α-smooth muscle actin production without altering Smad2/3 signaling. These findings suggest that endoglin may play an
important role in hepatic fibrosis by altering the balance of TGF-β signaling via the ALK1-Smad1/5 and ALK-Smad2/3 pathways
and raise the possibility that targeting endoglin expression in transdifferentiating hepatic stellate cells may represent
a novel therapeutic strategy for the treatment of liver fibrosis. 相似文献
18.
目的:探讨重组干扰质粒pshRNA-COX-2对人肝癌细胞Hep3B裸鼠皮下移植瘤生长和肿瘤血管生成的抑制作用。方法:重组干扰质粒pshRNA-COX-2转染Hep3B细胞并筛选后,RT-PCR和Western blot检测COX-2mRNA和蛋白表达,RT-PCR检测VEGFmRNA表达。将被成功转染的Hep3B细胞种植于裸鼠皮下,测量肿瘤大小,4周后处死裸鼠,免疫组织化学法检测肿瘤组织中COX-2蛋白表达和肿瘤微血管密度(MVD)。结果:与未转染细胞相比,干扰组COX-2mRNA和蛋白表达抑制率分别为65.3%和52.8%(P<0.05),干扰组VEGFmRNA表达抑制率为56.5%(P<0.05)。干扰组瘤体大小明显小于阴性组和空白组(P<0.01)。干扰组COX-2得分和MVD均明显低于阴性组和空白组(P<0.01)。结论:pshRNA-COX-2通过抑制COX-2表达明显抑制人肝癌细胞Hep3B裸鼠皮下移植瘤生长和肿瘤血管生成。 相似文献
19.
20.
Transforming growth factor-β (TGF-β) and glial-cell-line-derived neurotrophic factor (GDNF) have been shown to synergize in
several paradigms of neuronal survival. We have previously shown that cerebellar granule neurons (CGN) degenerate in low potassium
via ERK1/2 (extra-cellular-regulated kinase)-dependent plasma membrane (PM) damage and caspase-3-dependent DNA fragmentation.
Here, we have investigated the putative synergistic function of GDNF and TGF-β in CGN degeneration. GDNF alone prevents low-potassium-induced
caspase-3 activation and DNA fragmentation but does not affect either low-potassium-induced ERK activation or PM damage. TGF-β
alone does not affect low-potassium-induced DNA fragmentation but potentiates low-potassium-induced PM damage. This effect
of TGF-β is independent of ERK1/2 activation but dependent on p38-MAPK (mitogen-activated protein kinase) activation. When
co-applied with TGF-β, GDNF paradoxically antagonizes TGF-β-induced potentiation of PM damage by inhibiting TGF-β-induced
p38-MAPK activation. In addition, PI3K (phosphatidylinositol 3-kinase) inhibitors abolish the GDNF effect. This study thus
demonstrates a differential mechanism of action of GDNF and TGF-β on CGN degeneration. GDNF inhibits caspase-3-dependent DNA
fragmentation but does not affect ERK-dependent PM damage. However, GDNF can attenuate TGF-β-induced p38-MAPK-dependent PM
damage via the PI3K pathway.
This work was supported by the Deutsche Forschungsgemeinschaft (STR 616/1–2) and by a fellowship (Young Investigator Award)
from the Medical Faculty, University of Heidelberg, Germany to S. Subramaniam. 相似文献