Fekete, Andrea, Á dám Vannay, Á gota Vér, Krisztina Rusai, Veronika Mü ller, György Reusz, Tivadar Tulassay, and Attila J. Szabó. Sex differences in heat shock protein 72 expression and localization in rats following renal ischemia-reperfusion injury. Am J Physiol Renal Physiol 291: F806 -F811, 2006. First published April 11, 2006 doi:10.1152/ajprenal.00080.2006.-Previously, we demonstrated gender differences in Na-K-ATPase (NKA) expression and function after renal ischemia-reperfusion (I/R) injury (Sex differences in the alterations of Na ϩ , K ϩ -ATPase following ischemia-reperfusion injury in the rat kidney. J Physiol 555: [471][472][473][474][475][476][477][478][479][480] 2004). Postischemic membrane destruction causes inhibition of NKA, whereas heat shock protein (HSP) 72 helps to preserve it. We tested the sex differences in postischemic expression of HSP72 and colocalization with NKA. The left renal pedicle of uninephrectomized female (F) and male (M) Wistar rats was clamped for 55 min followed by 2 (T2), 16 (T16), and 24 h (T24) of reperfusion. Uninephrectomized, sham-operated F and M rats served as controls. Postischemic blood urea nitrogen (BUN), serum creatinine, and renal histology were analyzed. HSP72 mRNA expression was detected by RT-PCR, protein levels by Western blot analysis. Fluorescent immunohistochemistry was performed to evaluate the localization of HSP72 and NKA ␣ 1-subunit. Postischemic BUN and creatinine were higher, and renal histology showed more rapid progression in M vs. F (P Ͻ 0.05). HSP72 mRNA expression was higher in F vs. M in control and in all I/R groups (P Ͻ 0.05). Similar changes were observed in HSP72 protein levels (F vs. M, P Ͻ 0.05, control, T2, T16, T24, respectively). Immunohistochemical localization of HSP72 and NKA ␣ 1 was similar in control F and M. In postischemic F kidneys, the majority of NKA ␣ 1 and HSP72 was colocalized on the basolateral membrane of tubular cells, whereas in M prominent staining was observed in the cytosol and apical domain. This study indicates that in female kidneys the higher basal and postischemic levels of HSP72 and different colocalization with NKA might contribute to the gender differences in renal I/R injury.

Postischaemic acute renal failure (ARF) is influenced by sex. Na + ,K + -ATPase (NKA) plays a crucial role in the pathogenesis of postischaemic ARF. We tested the impact of sex on mRNA, protein expression, cellular distribution and enzyme activity of NKA following renal ischaemia-reperfusion (I-R) injury. The left renal pedicle of uninephrectomized female (F) and male (M) Wistar rats was clamped for 55 min followed by 2 h (T2) and 16 h (T16) of reperfusion. Uninephrectomized, sham-operated F and M rats served as controls (n = 6 per group). Blood urea nitrogen, serum creatinine and renal histology were evaluated to detect the severity of postischaemic ARF. mRNA expression of NKA α1 and β1 subunits were detected by RT-PCR. The effect of I-R on cellular distribution was compared by Triton X-100 extraction. Cellular proteins were divided into Triton-insoluble and Triton-soluble fractions and assessed by Western blot. NKA enzyme activity was also determined. After the ischaemic insult blood urea nitrogen and serum creatinine were higher and renal histology showed more rapid progression in M versus F (P < 0.05). mRNA expression of the NKA α1 subunit decreased in I-R groups versus controls, but was higher in F versus M both in control and I-R groups (P < 0.05). However, protein levels of the NKA α1 subunit in total tissue homogenate did not differ in controls, but were higher in F versus M in I-R groups (P < 0.05). Triton X-100 extractability was lower in F versus M at T16 (P < 0.05). NKA enzyme activity was the same in controls, but was higher in F versus M in I-R groups (T2: 14.9 ± 2.3 versus 9.15 ± 2.21 U) (T16: 11.7 ± 4.1 versus 5.65 ± 2.3 U; P < 0.05). mRNA and protein expression of the NKA β1 subunit did not differ between F and M in any of the protocol. We concluded that NKA is more protected from the detrimental effects of postischaemic injury in females. Higher mRNA and protein expression of the NKA α1 subunit and higher enzyme activity might be additional contributing factors to the improved postischaemic renal function of female rats.

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Variants of the leptin receptor gene (LEPR) may modulate the effect of elevated serum leptin levels in pre-eclampsia. The aim of our study was to evaluate the LEPR gene polymorphisms Lys109Arg (A109G) and Gln223Arg (A223G) in severely pre-eclamptic women. In a case-control study, we analyzed blood samples from 124 severely pre-eclamptic patients and 107 healthy control women by the polymerase chain reaction-restriction fragment length polymorphism method. The Pearson chi2 test was used to estimate odds ratios (OR) and 95% confidence intervals (CI). The association was adjusted for maternal age, pre-pregnancy body mass index and primiparity with logistic regression analysis. Pregnant women with the LEPR 223G allele (223A/G or 223G/G genotype) had almost double the risk of developing severe pre-eclampsia compared with patients with the 223A/A genotype (adjusted OR = 1.92, 95% CI: 1.07-3.41). Genotype variants of LEPR A109G alone did not affect the risk of severe pre-eclampsia. Haplotype estimation of A109G and A223G polymorphisms of the LEPR gene revealed that the G-A haplotype versus other pooled haplotypes was significantly less common in the pre-eclamptic group (p < 0.01), while the G-G haplotype versus others was overrepresented among severely pre-eclamptic patients (p < 0.01), compared with controls. In conclusion, our data indicate that LEPR A223G polymorphism may individually modify the risk of severe pre-eclampsia.

BackgroundThere has been an increasing body of epidemiologic and biochemical evidence implying the role of cerebral insulin resistance in Alzheimer-type dementia. For a better understanding of the insulin effect on the central nervous system, we performed microarray-based global gene expression profiling in the hippocampus, striatum and prefrontal cortex of streptozotocin-induced and spontaneously diabetic Goto-Kakizaki rats as model animals for type 1 and type 2 diabetes, respectively.ResultsFollowing pathway analysis and validation of gene lists by real-time polymerase chain reaction, 30 genes from the hippocampus, such as the inhibitory neuropeptide galanin, synuclein gamma and uncoupling protein 2, and 22 genes from the prefrontal cortex, e.g. galanin receptor 2, protein kinase C gamma and epsilon, ABCA1 (ATP-Binding Cassette A1), CD47 (Cluster of Differentiation 47) and the RET (Rearranged During Transfection) protooncogene, were found to exhibit altered expression levels in type 2 diabetic model animals in comparison to non-diabetic control animals. These gene lists proved to be partly overlapping and encompassed genes related to neurotransmission, lipid metabolism, neuronal development, insulin secretion, oxidative damage and DNA repair. On the other hand, no significant alterations were found in the transcriptomes of the corpus striatum in the same animals. Changes in the cerebral gene expression profiles seemed to be specific for the type 2 diabetic model, as no such alterations were found in streptozotocin-treated animals.ConclusionsAccording to our knowledge this is the first characterization of the whole-genome expression changes of specific brain regions in a diabetic model. Our findings shed light on the complex role of insulin signaling in fine-tuning brain functions, and provide further experimental evidence in support of the recently elaborated theory of type 3 diabetes.