Apoptosis and proliferation of cultured mesangial cells isolated from kidneys of rosiglitazone-treated pregnant diabetic rats.
BACKGROUND
The peroxisome proliferator activating nuclear receptors (PPAR) are activated in the context of inflammation, diabetes or normal pregnancy. Renal mesangial cells express PPAR-gamma which upon activation are capable of exerting anti-inflammatory effects. We investigated the effect of in vivo treatment by rosiglitazone on angiotensin II (A-II) stimulated manifestations of inflammation in cultured renal mesangial cells, such as proliferation, apoptosis, TGF-beta1 production and nuclear factor kappaB (NF-kappaB) activation, in the situation of pregnancies, complicated or not with diabetes.


METHODS
Mesangial cells were isolated from the following groups, receiving or not 5 mg/kg rosiglitazone for 20 days: normal controls, normal pregnant rats, those with streptozotocine induced diabetes and pregnant diabetic rats. Proliferation was assessed by 3H-thymidine incorporation. Apoptosis was evaluated by TUNEL assay. AT-1/AT-2 receptor density was assessed by 125I-AT-2 labelling, TGF-beta and NF-kappaB by specific ELISAs.


RESULTS
Rosiglitazone pretreatment resulted in significantly decreased proliferation, apoptosis and reduced responsiveness to A-II stimulation in cultures from controls, pregnant rats and non-pregnant diabetic animals. In the pregnant diabetic group which received rosiglitazone prior to sacrifice, responsiveness to A-II was completely blunted. Moderate attenuation of TGF-beta synthesis and significant decrease in the levels of NF-kappaB in mesangial cell nuclei were observed in all rosiglitazone treated groups.


CONCLUSIONS
PPAR-gamma activation by rosiglitazone resulted in decreased manifestation of inflammatory hallmarks, including inhibition of mesangial cell proliferation, downregulation of apoptosis and blunted responsiveness to A-II. These anti-inflammatory renoprotective effects were maximally expressed in cultures from pregnant diabetic animals. The therapeutic relevance of these observations is a matter of further investigations.
Weissgarten
Joshua
J
Nephrology Division, Assaf Harofeh Medical Center, Zerifin 70300, Israel. Weissgarten@asaf.health.gov.il
Berman
Sylvia
S
Efrati
Shai
S
Rapoport
Micha
M
Averbukh
Zhan
Z
Feldman
Leonid
L
D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D049109:Cell Proliferation / Q000187:drug effects*; D002478:Cells, Cultured; D003920:Diabetes Mellitus / Q000378:metabolism*; D004195:Disease Models, Animal; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005920:Glomerular Mesangium / Q000166:cytology / Q000187:drug effects; D020287:In Situ Nick-End Labeling; D047495:PPAR gamma / Q000187:drug effects* / Q000378:metabolism; D011247:Pregnancy; D011270:Pregnancy, Animal; D011336:Probability; D051381:Rats; D017207:Rats, Sprague-Dawley; D012016:Reference Values; D012307:Risk Factors; D000077154:Rosiglitazone; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric; D013311:Streptozocin; D045162:Thiazolidinediones / Q000494:pharmacology*; D016212:Transforming Growth Factor beta / Q000378:metabolism
D047495:PPAR gamma; D045162:Thiazolidinediones; D016212:Transforming Growth Factor beta; D000077154:Rosiglitazone; D013311:Streptozocin