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Mitochondrial PKC, NAD(P)H oxidase and superoxide anion in the renal medullary thick ascending limb during type 1 diabetes
Author(s) -
Yang Jing,
Lane Pascale H.,
Pollock Jennifer S.,
Carmines Pamela K.
Publication year - 2011
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.25.1_supplement.664.12
Subject(s) - medicine , endocrinology , superoxide , mitochondrion , protein kinase c , nadph oxidase , nox4 , streptozotocin , chemistry , nad(p)h oxidase , biology , diabetes mellitus , oxidative stress , biochemistry , kinase , enzyme
Type 1 diabetes (T1D) increases superoxide (O2 •− ) production by the rat renal medullary thick ascending limb (mTAL) via a PKC‐ and NAD(P)H oxidase (NOX)‐dependent process. Mitochondria are a source of O2 •− during ATP generation by the respiratory chain, and the NOX catalytic subunit Nox4 has been detected in renal mitochondria. We hypothesized that T1D alters PKC and NOX levels in mTAL mitochondria, in association with increased mitochondrial O2 •− production. mTAL suspensions were prepared from rats with streptozotocin‐induced T1D (STZ mTALs) and Sham rats (Sham mTALs). Confocal immunofluorescence of mTAL suspensions revealed that Nox2, Nox4 and p47phox co‐localized with mitochondrial markers, as did PKCα, PKCβ and PKCδ. In mitochondrial fractions prepared from mTAL suspensions, O2 •− production (lucigenin chemiluminescence) was higher in STZ mTALs (851±105 RLU/sec/mg protein) than Sham mTALs (357±33 RLU/sec/mg protein; P <0.05). PKCα protein levels were elevated in mitochondria from STZ mTALs (138±15% of Sham; P <0.05), but PKCδ and PKCβ levels did not differ between Sham and STZ. Mitochondria from STZ mTALs also had significantly increased levels of Nox2 (169±18% of Sham) and Nox4 (140±13% of Sham), but no change in p47phox. Thus, mTALs from STZ rats exhibit upregulation of mitochondrial PKCα, Nox2 and Nox4, which may contribute to increased mitochondrial O2 •− production by the mTAL during T1D.