Podocyte‐specific overexpression of metallothionein mitigates diabetic complications in the glomerular filtration barrier and glomerular histoarchitecture: a transmission electron microscopy stereometric analysis

Carlson, Edward C.; Chhoun, Jennifer; Laturnus, Donna I.; Bikash, KC; Berg, Brittany; Zheng, Shirong; Epstein, Paul N.

doi:10.1002/dmrr.2342

Cited by 12 publications

(28 citation statements)

References 51 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This strongly supports our working hypothesis that oxidative insult to glomerular cells is a primary cause of DN chronic complications. Furthermore, data in the current study demonstrate that OVE-JTMT mitigation of DN features is remarkably similar to the renoprotection provided by the Nmt transgene in podocytes of OVENmt mice (Carlson et al, 2013). It seems possible, therefore, that the development of a future tri-transgenic (OVE-Nmt-JTMT) mouse could be an even more powerful new tool in the renoprotective armamentarium of future diabetes researchers.…”

Section: Introductionsupporting

confidence: 69%

“…By this method, mice were perfused with a 0.9% saline washout solution until the effluent was clear. This was followed by infusion of 20 ml of warm, then 40 ml of cold PIPES fixative (1% paraformaldehyde with 1% gluteraldehyde and 5% dextran in 0.1 M piperazine- N - N , bis 2-ethane sulphonic acid) buffered with NaOH (pH 7.6) as previously described (Carlson et al, 2013). Animals destined for qualitative TEM only (e.g.…”

Section: Methodsmentioning

confidence: 99%

“…(Carlson et al, 2003). In an effort to retain only scrupulously unbiased samples at each experimental step, rigid sampling procedures as established in our prequel studies (Carlson et al, 2013) were rigorously enforced.…”

Section: Methodsmentioning

confidence: 99%

“…These experiments formed a basis for those carried out by us in a subsequent unbiased TEM stereometric investigation (Carlson et al, 2013) in which we sought to clarify the quantitative aspects of the OVENmt analysis. Our TEM investigation affirmed the results of the study by Zheng and co-workers (Zheng et al, 2008) and provided rigorous numerical evidence that oxidative damage to podocytes induces a number of primary DN features, complications of which were significantly mitigated by targeted MT overexpression in podocytes.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Renoprotection From Diabetic Complications in OVE Transgenic Mice by Endothelial Cell Specific Overexpression of Metallothionein: A TEM Stereological Analysis

Carlson

Chhoun

Grove

et al. 2017

The Anatomical Record

Self Cite

View full text Add to dashboard Cite

We previously demonstrated that OVE transgenic diabetic mice are susceptible to chronic complications of diabetic nephropathy (DN) including substantial oxidative damage to the renal glomerular filtration barrier (GFB). Importantly, the damage was mitigated significantly by overexpression of the powerful antioxidant, metallothionein (MT) in podocytes. To test our hypothesis that GFB damage in OVE mice is the result of endothelial oxidative insult, a new JTMT transgenic mouse was designed in which MT overexpression was targeted specifically to endothelial cells. At 60 days of age, JTMT mice were crossed with age‐matched OVE diabetic mice to produce bi‐transgenic OVE‐JTMT diabetic progeny that carried the endothelial targeted JTMT transgene. Renal tissues from the OVE‐JTMT progeny were examined by unbiased TEM stereometry for possible GFB damage and other alterations from chronic complications of DN. In 150 day‐old OVE‐JTMT mice, blood glucose and HbA1c were indistinguishable from age‐matched OVE mice. However, endothelial‐specific MT overexpression in OVE‐JTMT mice mitigated several DN complications including significantly increased non‐fenestrated glomerular endothelial area, and elimination of glomerular basement membrane thickening. Significant renoprotection was also observed outside of endothelial cells, including reduced podocyte effacement, and increased podocyte and total glomerular cell densities. Moreover, when compared to OVE diabetic animals, OVE‐JTMT mice showed significant mitigation of nephromegaly, glomerular hypertrophy, increased mesangial cell numbers and increased total glomerular cell numbers. These results confirm the importance of oxidative stress to glomerular damage in DN, and show the central role of endothelial cell injury to the pathogenesis of chronic complications of diabetes. Anat Rec, 2017. © 2017 Wiley Periodicals, Inc. Anat Rec, 300:560–576, 2017. © 2016 The Authors. The Anatomical Record published by Wiley Periodicals, Inc. on behalf of American Association of Anatomists.

show abstract

Section: Introductionsupporting

confidence: 69%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Renoprotection From Diabetic Complications in OVE Transgenic Mice by Endothelial Cell Specific Overexpression of Metallothionein: A TEM Stereological Analysis

Carlson

Chhoun

Grove

et al. 2017

The Anatomical Record

Self Cite

View full text Add to dashboard Cite

show abstract

“…The most likely cause of too much proximal tubule cell uptake is very high concentrations of albumin in the tubule lumen from leaking glomeruli. We previously described structural abnormalities in the OVE glomerular filtration barrier [12, 13, 21–25] and functional results showing that a subset of OVE glomeruli have severe leakage of albumin [15]. Supplemental Figure 3 shows that OVE glomeruli still filter TR-albumin, despite possessing obviously abnormal podocyte organization, as revealed by a podocyte GFP transgene [26].…”

Section: Discussionmentioning

confidence: 99%

Impaired Albumin Uptake and Processing Promote Albuminuria in OVE26 Diabetic Mice

Long

Zheng

Kralik

et al. 2016

Journal of Diabetes Research

View full text Add to dashboard Cite

The importance of proximal tubules dysfunction to diabetic albuminuria is uncertain. OVE26 mice have the most severe albuminuria of all diabetic mouse models but it is not known if impaired tubule uptake and processing are contributing factors. In the current study fluorescent albumin was used to follow the fate of albumin in OVE26 and normal mice. Compared to normal urine, OVE26 urine contained at least 23 times more intact fluorescent albumin but only 3-fold more 70 kD fluorescent dextran. This indicated that a function other than size selective glomerular sieving contributed to OVE26 albuminuria. Imaging of albumin was similar in normal and diabetic tubules for 3 hrs after injection. However 3 days after injection a subset of OVE26 tubules retained strong albumin fluorescence, which was never observed in normal mice. OVE26 tubules with prolonged retention of injected albumin lost the capacity to take up albumin and there was a significant correlation between tubules unable to eliminate fluorescent albumin and total albuminuria. TUNEL staining revealed a 76-fold increase in cell death in OVE26 tubules that retained fluorescent albumin. These results indicate that failure to process and dispose of internalized albumin leads to impaired albumin uptake, increased albuminuria, and tubule cell apoptosis.

show abstract

Diabetic Basement Membrane Thickening Does Not Occur in Myocardial Capillaries of Transgenic Mice When Metallothionein is Overexpressed in Cardiac Myocytes

Velić

Laturnus

Chhoun

et al. 2013

The Anatomical Record

Self Cite

View full text Add to dashboard Cite

Diabetic cardiomyopathy is a clinically distinct disease characterized by impaired cardiac function as a result of reduced contractility and hypertension-induced athero-or arteriosclerosis. This may be due either to generalized vascular disease, tissue-based injury such as focal cardiomyocyte dysmorphia, or microvascular damage manifested by myocardial capillary basement membrane (CBM) thickening. Hyperglycemia-driven increases in reactive oxygen species (ROS) have been proposed to contribute to such damage. To address this hypothesis, we utilized light (LM) and transmission electron microscopy (TEM) to demonstrate cardiomyocyte morphology and myocardial CBM thickness in the left ventricles of four mouse genotypes: FVB (background Friend virus B controls), OVE (transgenic diabetics), Mt [transgenics with targeted overexpression of the antioxidant protein metallothionein (MT) in cardiomyocytes], and OVEMt (bi-transgenic cross of OVE and Mt) animals. Mice were prepared for morphometric analysis by vascular perfusion. Focal myocardial disorganization was identified in OVE mice but not in the remaining genotypes. Not unexpectedly, myocardial CBM thickness was increased significantly in OVE relative to FVB (P < 0.05) and Mt (P < 0.05) animals (128% and 139.5%, respectively). Remarkably, however, OVEMt myocardial CBMs showed no increase in width; rather they were 3% thinner than FVB controls. Although the molecular mechanisms regulating CBM width remain elusive, it seems possible that despite a significant hyperglycemic environment, MT antioxidant activity may mitigate local oxidative stress and reduce downstream excess microvascular extracellular matrix (ECM) formation. In addition, the reduction of intraand perivascular ROS may protect against incipient endothelial damage and the CBM thickening that results from such injury. Anat Rec,

show abstract

Podocyte‐specific overexpression of metallothionein mitigates diabetic complications in the glomerular filtration barrier and glomerular histoarchitecture: a transmission electron microscopy stereometric analysis

Cited by 12 publications

References 51 publications

Renoprotection From Diabetic Complications in OVE Transgenic Mice by Endothelial Cell Specific Overexpression of Metallothionein: A TEM Stereological Analysis

Renoprotection From Diabetic Complications in OVE Transgenic Mice by Endothelial Cell Specific Overexpression of Metallothionein: A TEM Stereological Analysis

Impaired Albumin Uptake and Processing Promote Albuminuria in OVE26 Diabetic Mice

Diabetic Basement Membrane Thickening Does Not Occur in Myocardial Capillaries of Transgenic Mice When Metallothionein is Overexpressed in Cardiac Myocytes

Contact Info

Product

Resources

About