scholarly journals Ficolin B in Diabetic Kidney Disease in a Mouse Model of Type 1 Diabetes

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Charlotte Berg Holt ◽  
Jakob Appel Østergaard ◽  
Esben Axelgaard ◽  
Gitte Krogh Nielsen ◽  
Yuichi Endo ◽  
...  
Keyword(s):  
Knockout Mice ◽  
Diabetic Mice ◽  
Wild Type ◽  
Renal Hypertrophy ◽  
Kidney Weight ◽  
Diabetic Kidney ◽  
In The Wild ◽  
The Difference ◽  
Mannan Binding Lectin

Background.The innate immune system may have adverse effects in diabetes and cardiovascular disease. The complement system seems to play a key role through erroneous complement activation via hyperglycaemia-induced neoepitopes. Recently mannan-binding lectin (MBL) was shown to worsen diabetic kidney changes. We hypothesize that mouse ficolin B exerts detrimental effects in the diabetic kidney as seen for MBL.Methods.We induced diabetes with streptozotocin in female wild-type mice and ficolin B knockout mice and included two similar nondiabetic groups. Renal hypertrophy and excretion of urinary albumin and creatinine were quantified to assess diabetic kidney damage.Results.In the wild-type groups, the kidney weighed 24% more in the diabetic mice compared to the controls. The diabetes-induced increase in kidney weight was 29% in the ficolin B knockout mice, that is, equal to wild-type animals (two-way ANOVA,P=0.60). In the wild-type mice the albumin-to-creatinine ratio (ACR) was 32.5 mg/g higher in the diabetic mice compared to the controls. The difference was 62.5 mg/g in the ficolin B knockout mice, but this was not significantly different from the wild-type animals (two-way ANOVA,P=0.21).Conclusions.In conclusion, the diabetes-induced effects on kidney weight and ACR were not modified by the presence or absence of ficolin B.

scholarly journals Molecular and functional architecture of the mouse photoreceptor network

2020 ◽  
Vol 6 (28) ◽  
pp. eaba7232
Author(s):  
Nange Jin ◽  
Zhijing Zhang ◽  
Joyce Keung ◽  
Sean B. Youn ◽  
Munenori Ishibashi ◽  
...  
Keyword(s):  
Gap Junctions ◽  
Gap Junction ◽  
Knockout Mice ◽  
Conditional Knockout ◽  
Relative Importance ◽  
Wild Type ◽  
Functional Architecture ◽  
Rods And Cones ◽  
In The Wild

Mouse photoreceptors are electrically coupled via gap junctions, but the relative importance of rod/rod, cone/cone, or rod/cone coupling is unknown. Furthermore, while connexin36 (Cx36) is expressed by cones, the identity of the rod connexin has been controversial. We report that FACS-sorted rods and cones both express Cx36 but no other connexins. We created rod- and cone-specific Cx36 knockout mice to dissect the photoreceptor network. In the wild type, Cx36 plaques at rod/cone contacts accounted for more than 95% of photoreceptor labeling and paired recordings showed the transjunctional conductance between rods and cones was ~300 pS. When Cx36 was eliminated on one side of the gap junction, in either conditional knockout, Cx36 labeling and rod/cone coupling were almost abolished. We could not detect direct rod/rod coupling, and cone/cone coupling was minor. Rod/cone coupling is so prevalent that indirect rod/cone/rod coupling via the network may account for previous reports of rod coupling.

scholarly journals Therapy with antisense TGF-β1 oligodeoxynucleotides reduces kidney weight and matrix mRNAs in diabetic mice

2000 ◽  
Vol 278 (4) ◽  
pp. F628-F634 ◽  
Author(s):  
Dong Cheol Han ◽  
Brenda B. Hoffman ◽  
Soon Won Hong ◽  
Jia Guo ◽  
Fuad N. Ziyadeh
Keyword(s):  
Proximal Tubule ◽  
High Glucose ◽  
Leucine Incorporation ◽  
Diabetic Mice ◽  
Renal Hypertrophy ◽  
Kidney Weight ◽  
Cell Hypertrophy ◽  
Proximal Tubular ◽  
Tgf Β1

Inhibition of gene expression by antisense oligodeoxynucleotides (ODNs) relies on their ability to bind complementary mRNA sequences and prevent translation. The proximal tubule is a suitable target for ODN therapy in vivo because circulating ODNs accumulate in the proximal tubule in high concentrations. Because increased proximal tubular transforming growth factor- β1 (TGF-β1) expression may mediate diabetic renal hypertrophy, we investigated the effects of antisense TGF-β1 ODN on the high-glucose-induced proximal tubular epithelial cell hypertrophy in tissue culture and on diabetic renal hypertrophy in vivo. Mouse proximal tubular cells grown in 25 mM d-glucose and exposed to sense ODN as control (1 μM) exhibited increased3[H]leucine incorporation by 120% and total TGF-β1 protein by 50% vs. culture in 5.5 mM d-glucose. Antisense ODN significantly decreased the high-glucose-stimulated TGF-β1 secretion and leucine incorporation. Continuous infusion for 10 days of ODN (100 μg/day) was achieved via osmotic minipumps in diabetic and nondiabetic mice. Sense ODN-treated streptozotocin-diabetic mice had 15.3% increase in kidney weight, 70% increase in α1(IV) collagen and 46% increase in fibronectin mRNA levels compared with nondiabetic mice. Treatment of diabetic mice with antisense ODN partially but significantly decreased kidney TGF-β1 protein levels and attenuated the increase in kidney weight and the α1(IV) collagen and fibronectin mRNAs. In conclusion, therapy with antisense TGF-β1 ODN decreases TGF-β1 production and attenuates high-glucose-induced proximal tubular cell hypertrophy in vitro and partially prevents the increase in kidney weight and extracellular matrix expression in diabetic mice.

scholarly journals The Anabolic Response to Parathyroid Hormone Is Augmented in Rac2 Knockout Mice

Endocrinology ◽  
2008 ◽  
Vol 149 (8) ◽  
pp. 4009-4015 ◽  
Author(s):  
Tsutomu Kawano ◽  
Nancy Troiano ◽  
Douglas J. Adams ◽  
Jian Jun Wu ◽  
Ben-hua Sun ◽  
...  
Keyword(s):  
Knockout Mice ◽  
Serum Markers ◽  
Small Gtpase ◽  
Wild Type ◽  
Hematopoietic Tissue ◽  
Anabolic Response ◽  
Trabecular Thickness ◽  
Anabolic Therapy ◽  
Resorptive Activity

PTH is the only currently available anabolic therapy for osteoporosis. In clinical practice, the skeletal response to PTH varies and because therapy is limited to 2 yr, approaches to maximize the therapeutic response are desirable. Rac2 is a small GTPase that is expressed only in hematopoietic tissue. Rac2−/− mice have a slight increase in bone mass and osteoclasts isolated from these animals have reduced basal resorptive activity and reduced chemotaxis. To evaluate the anabolic response to PTH in Rac2−/− mice, we treated 18 Rac2−/− and 17 control, age-matched wild-type animals once daily for 28 d with 80 ng/g body weight of h(1–34)PTH. Treatment resulted in significantly greater increments in spinal, femur, and total bone density in the Rac2−/− as compared with wild-type animals. Microcomputed tomography analysis demonstrated greater increases in trabecular thickness and cortical thickness in the knockout mice. Interestingly, histomorphometric analysis showed an equivalent increase in osteoblast and osteoclast number in response to PTH treatment in both groups of animals. However, as judged by changes in serum markers, the resorptive response to PTH was impaired. Thus, telopeptide of type 1 collagen was 15.9 ± 6.9 ng/ml after PTH treatment in the knockout animals and 26.8 ± 11.1 ng/ml in the PTH-treated wild-type group. In contrast, serum aminoterminal propeptide of type 1 collagen and osteocalcin were equivalent in both groups. We conclude that, in the genetic absence of Rac2, the anabolic response to PTH is increased. This appears to be due to attenuated resorptive activity of osteoclasts.

Changes in angiotensin type 1 receptor binding and angiotensin-induced pressor responses in the rostral ventrolateral medulla of angiotensinogen knockout mice

2010 ◽  
Vol 298 (2) ◽  
pp. R411-R418 ◽  
Author(s):  
Daian Chen ◽  
Lisa Hazelwood ◽  
Lesley L. Walker ◽  
Brian J. Oldfield ◽  
Michael J. McKinley ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Receptor Binding ◽  
Knockout Mice ◽  
Pressor Response ◽  
Ventrolateral Medulla ◽  
Ang Ii ◽  
Wild Type ◽  
Intravenous Injections ◽  
Angiotensin Type

ANG II, the main circulating effector hormone of the renin-angiotensin system, is produced by enzymatic cleavage of angiotensinogen. The present study aimed to examine whether targeted deletion of the angiotensinogen gene ( Agt) altered brain ANG II receptor density or responsiveness to ANG II. In vitro autoradiography was used to examine the distribution and density of angiotensin type 1 (AT1) and type 2 receptors. In most brain regions, the distribution and density of angiotensin receptors were similar in brains of Agt knockout mice ( Agt −/− ) and wild-type mice. In Agt −/− mice, a small increase in AT1 receptor binding was observed in the rostral ventrolateral medulla (RVLM), a region that plays a critical role in blood pressure regulation. To examine whether Agt −/− mice showed altered responses to ANG II, blood pressure responses to intravenous injection (0.01–0.1 μg/kg) or RVLM microinjection (50 pmol in 50 nl) of ANG II were recorded in anesthetized Agt −/− and wild-type mice. Intravenous injections of phenylephrine (4 μg/kg and 2 μg/kg) were also made in both groups. The magnitude of the pressor response to intravenous injections of ANG II or phenylephrine was not different between Agt −/− and wild-type mice. Microinjection of ANG II into the RVLM induced a pressor response, which was significantly smaller in Agt −/− compared with wild-type mice (+10 ± 1 vs. +23 ± 4 mmHg, respectively, P = 0.004). Microinjection of glutamate into the RVLM (100 pmol in 10 nl) produced a robust pressor response, which was not different between Agt −/− and wild-type mice. A diminished response to ANG II microinjection in the RVLM of Agt −/− mice, despite an increased density of AT1 receptors suggests that signal transduction pathways may be altered in RVLM neurons of Agt −/− mice, resulting in attenuated cellular excitation.

scholarly journals Kynurenic Acid Protects Against Ischemia/Reperfusion-Induced Retinal Ganglion Cell Death in Mice

2020 ◽  
Vol 21 (5) ◽  
pp. 1795 ◽  
Author(s):  
Rooban B. Nahomi ◽  
Mi-Hyun Nam ◽  
Johanna Rankenberg ◽  
Stefan Rakete ◽  
Julie A. Houck ◽  
...  
Keyword(s):  
Knockout Mice ◽  
Kynurenic Acid ◽  
Ganglion Cells ◽  
Ischemia Reperfusion ◽  
Fasting Blood Glucose ◽  
Kynurenine Pathway ◽  
Retinal Ganglion ◽  
Diabetic Mice ◽  
Wild Type ◽  
Ganglion Cell Death

Background: Glaucoma is an optic neuropathy and involves the progressive degeneration of retinal ganglion cells (RGCs), which leads to blindness in patients. We investigated the role of the neuroprotective kynurenic acid (KYNA) in RGC death against retinal ischemia/reperfusion (I/R) injury. Methods: We injected KYNA intravenously or intravitreally to mice. We generated a knockout mouse strain of kynurenine 3-monooxygenase (KMO), an enzyme in the kynurenine pathway that produces neurotoxic 3-hydroxykynurenine. To test the effect of mild hyperglycemia on RGC protection, we used streptozotocin (STZ) induced diabetic mice. Retinal I/R injury was induced by increasing intraocular pressure for 60 min followed by reperfusion and RGC numbers were counted in the retinal flat mounts. Results: Intravenous or intravitreal administration of KYNA protected RGCs against I/R injury. The I/R injury caused a greater loss of RGCs in wild type than in KMO knockout mice. KMO knockout mice had mildly higher levels of fasting blood glucose than wild type mice. Diabetic mice showed significantly lower loss of RGCs when compared with non-diabetic mice subjected to I/R injury. Conclusion: Together, our study suggests that the absence of KMO protects RGCs against I/R injury, through mechanisms that likely involve higher levels of KYNA and glucose.

scholarly journals Renal effects of a neutralising RAGE-antibody in long-term streptozotocin-diabetic mice

2006 ◽  
Vol 188 (3) ◽  
pp. 493-501 ◽  
Author(s):  
Louise J N Jensen ◽  
Larry Denner ◽  
Bieke F Schrijvers ◽  
Ronald G Tilton ◽  
Ruth Rasch ◽  
...  
Keyword(s):  
Type 1 Diabetes ◽  
Tissue Growth ◽  
Membrane Thickness ◽  
Diabetic Mice ◽  
Kidney Weight ◽  
Basement Membrane Thickness ◽  
Renal Effects ◽  
Nmri Mice ◽  
Renal Changes

Advanced glycation endproducts (AGEs) have been implicated in the pathogenesis of diabetic kidney disease. The actions of AGEs are mediated both through a non-receptor mediated pathway and through specific receptors for AGEs (e.g. RAGE). To explore a potentially specific role for RAGE in renal changes in type 1 diabetes, we examined the renal effects of a neutralising murine RAGE-antibody (ab) in streptozotocin (STZ)-diabetic mice, a model of type 1 diabetes. One group of STZ-diabetic mice was treated for two months with the RAGE-ab, while another STZ-diabetic group was treated for the same period with an irrelevant immunoglobulin G (IgG). Two groups of non-diabetic NMRI mice were treated with either RAGE-ab or isotype-matched IgG for two months. Placebo-treated STZ-diabetic mice showed an increase in kidney weight, glomerular volume, basement membrane thickness (BMT), urinary albumin excretion (UAE) and creatinine clearance (CrCl), when compared with non-diabetic controls. In RAGE-ab-treated STZ-diabetic mice, the increase in kidney weight and UAE was reduced, while the increase in CrCl was abolished. RAGE-ab administration in NMRI mice caused a reduction in liver weight and an increase in BMT. Renal messenger RNA (mRNA) for connective tissue growth factor and collagen IVα1 was increased in placebo-treated diabetic animals. RAGE-ab treatment had no impact on the expression of these factors. The renal effects of RAGE-ab administration in STZ-diabetic mice were seen without impact on body weight, blood glucose or food consumption. In conclusion, the present data support the hypothesis that RAGE is an important pathogenic factor in the renal changes in an animal model of type 1 diabetes.

scholarly journals Angiotensin II stimulates superoxide production in the thick ascending limb by activating NOX4

2012 ◽  
Vol 303 (7) ◽  
pp. C781-C789 ◽  
Author(s):  
Katherine J. Massey ◽  
Nancy J. Hong ◽  
Jeffrey L. Garvin
Keyword(s):  
Angiotensin Ii ◽  
Nadph Oxidase ◽  
Knockout Mice ◽  
Thick Ascending Limb ◽  
Ang Ii ◽  
Wild Type ◽  
Outer Medulla ◽  
Catalytic Subunits ◽  
In The Wild

Angiotensin II (ANG II) stimulates production of superoxide (O2−) by NADPH oxidase (NOX) in medullary thick ascending limbs (TALs). There are three isoforms of the catalytic subunit (NOX1, 2, and 4) known to be expressed in the kidney. We hypothesized that NOX2 mediates ANG II-induced O2− production by TALs. To test this, we measured NOX1, 2, and 4 mRNA and protein by RT-PCR and Western blot in TAL suspensions from rats and found three catalytic subunits expressed in the TAL. We measured O2− production using a lucigenin-based assay. To assess the contribution of NOX2, we measured ANG II-induced O2− production in wild-type and NOX2 knockout mice (KO). ANG II increased O2− production by 346 relative light units (RLU)/mg protein in the wild-type mice ( n = 9; P < 0.0007 vs. control). In the knockout mice, ANG II increased O2− production by 290 RLU/mg protein ( n = 9; P < 0.007 vs. control). This suggests that NOX2 does not contribute to ANG II-induced O2− production ( P < 0.6 WT vs. KO). To test whether NOX4 mediates the effect of ANG II, we selectively decreased NOX4 expression in rats using an adenovirus that expresses NOX4 short hairpin (sh)RNA. Six to seven days after in vivo transduction of the kidney outer medulla, NOX4 mRNA was reduced by 77%, while NOX1 and NOX2 mRNA was unaffected. In control TALs, ANG II stimulated O2− production by 96%. In TALs transduced with NOX4 shRNA, ANG II-stimulated O2− production was not significantly different from the baseline. We concluded that NOX4 is the main catalytic isoform of NADPH oxidase that contributes to ANG II-stimulated O2− production by TALs.

scholarly journals Effect of Mutations in the Human Immunoglobulin A1 (IgA1) Hinge on Its Susceptibility to Cleavage by Diverse Bacterial IgA1 Proteases

2005 ◽  
Vol 73 (3) ◽  
pp. 1515-1522 ◽  
Author(s):  
Bernard W. Senior ◽  
Jenny M. Woof
Keyword(s):  
Peptide Bond ◽  
Human Immunoglobulin ◽  
Peptide Sequence ◽  
Wild Type ◽  
Peptide Bonds ◽  
Streptococcus Sanguis ◽  
In The Wild ◽  
Scissile Bond ◽  
Cleavable Peptide

ABSTRACT Components of the human immunoglobulin A1 (IgA1) hinge governing sensitivity to cleavage by bacterial IgA1 proteases were investigated. Recombinant antibodies with distinct hinge mutations were constructed from a hybrid comprised of human IgA2 bearing half of the human IgA1 hinge region. This hybrid antibody and all the mutant antibodies derived from it were resistant to cleavage by the IgA1 proteases from Streptococcus oralis and Streptococcus mitis biovar 1 strains but were cleaved to various degrees by those of Streptococcus pneumoniae, some Streptococcus sanguis strains, and the type 1 and 2 IgA1 proteases of Haemophilus influenzae, Neisseria meningitidis, and Neisseria gonorrhoeae. Remarkably, those proteases that cleave a Pro-Ser peptide bond in the wild-type IgA1 hinge were able to cleave mutant antibodies lacking a Pro-Ser peptide bond in the hinge, and those that cleave a Pro-Thr peptide bond in the wild-type IgA1 hinge were able to cleave mutant antibodies devoid of a Pro-Thr peptide bond in the hinge. Thus, the enzymes can cleave alternatives to their preferred postproline peptide bond when such a bond is unavailable. Peptide sequence analysis of a representative antibody digestion product confirmed this conclusion. The presence of a cleavable peptide bond near the CH2 end of the hinge appeared to result in greater cleavage than if the scissile bond was at the CH1 end of the hinge. Proline-to-serine substitution at residue 230 in a hinge containing potentially cleavable Pro-Ser and Pro-Thr peptide bonds increased the resistance of the antibody to cleavage by many IgA1 proteases.

Endothelial nitric oxide synthase-deficient mice exhibit increased susceptibility to endotoxin-induced acute renal failure

2004 ◽  
Vol 287 (5) ◽  
pp. F1044-F1048 ◽  
Author(s):  
Wei Wang ◽  
Amit Mitra ◽  
Brian Poole ◽  
Sandor Falk ◽  
M. Scott Lucia ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Renal Failure ◽  
Blood Flow ◽  
Acute Renal Failure ◽  
Knockout Mice ◽  
Endothelial Nitric Oxide Synthase ◽  
Wild Type ◽  
In The Wild ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide

Acute renal failure (ARF) in septic patients drastically increases the mortality to 50–80%. Nitric oxide (NO) has been shown to be increased in sepsis. Endothelial nitric oxide synthase (eNOS) is one of the major regulators of arterial blood pressure and regional blood flow; however, its in vivo role in septic ARF is still unclear. We hypothesized that eNOS affords a protective effect against the renal vasoconstriction during endotoxemia. Because there are no specific inhibitors for eNOS, the study was therefore undertaken in eNOS knockout mice. There was no significant difference in baseline glomerular filtration rate (GFR) between the wild-type mice and the eNOS knockout mice (140 ± 10 vs. 157 ± 18 μl/min, n = 9, P = not significant). However, renal blood flow (RBF) was significantly decreased in eNOS knockout mice compared with the wild-type controls (0.62 ± 0.05 ml/min, n = 6 vs. 0.98 ± 0.13 ml/min, n = 8, P < 0.05). Mean arterial pressure (MAP) was significantly higher in eNOS knockout mice than the wild-type controls (109 ± 5 vs. 80 ± 1 mmHg, n = 10, P < 0.01). Thus renal vascular resistance (RVR) was much higher in eNOS knockout mice than in the wild-type mice (176 ± 2, n = 6 vs. 82 ± 1 mmHg·ml−1·min−1, n = 8, P < 0.01). When 1.0 mg/kg LPS was injected, there was no change in MAP in either the wild-type (84 ± 3 mmHg, n = 10) or the eNOS knockout mice (105 ± 5 mmHg, n = 10). Although GFR (154 ± 22 μl/min, n = 8) and RBF (1.19 ± 0.05 ml/min, n = 9) remained unchanged with the 1.0-mg/kg dose of LPS in the wild-type mice, GFR (83 ± 18 vs. 140 ± 10 μl/min, n = 6, P < 0.01) and RBF (0.36 ± 0.04 vs. 0.62 ± 0.05 ml/min, n = 6, P < 0.01) decreased significantly in the eNOS knockout mice. Fractional excretion of sodium increased significantly in eNOS knockout mice during endotoxemia (3.61 ± 0.78, n = 7 vs. 0.95 ± 0.14, n = 6, P < 0.01), whereas it remained unchanged in the wild-type mice (0.59 ± 0.16, n = 9 vs. 0.42 ± 0.05, n = 6, P = not significant). In summary, eNOS knockout mice have increased RVR and are more susceptible to endotoxemic ARF than wild-type mice despite higher MAP.

scholarly journals Thrombospondin-1/CD36 pathway contributes to bone marrow-derived angiogenic cell dysfunction in type 1 diabetes via Sonic hedgehog pathway suppression

2013 ◽  
Vol 305 (12) ◽  
pp. E1464-E1472 ◽  
Author(s):  
Jie-Mei Wang ◽  
Jeffery S. Isenberg ◽  
Timothy R. Billiar ◽  
Alex F. Chen
Keyword(s):  
Bone Marrow ◽  
Sonic Hedgehog ◽  
Knockout Mice ◽  
Wound Repair ◽  
Tube Formation ◽  
Diabetic Patients ◽  
Diabetic Mice ◽  
Shh Signaling ◽  
Thrombospondin 1

Refractory wounds in diabetic patients present a significant clinical problem. Sonic hedgehog (SHH), a morphogenic protein central to wound repair, is deficient in diabetes. Regulation of SHH in wound healing is poorly understood. We hypothesize that thrombospondin-1 (TSP-1), through its receptor CD36, contributes to the SHH signaling defect in bone marrow-derived angiogenic cells (BMACs) in type 1 diabetic mice. Isolated BMACs from TSP-1-knockout mice demonstrated improved tube formation, migration, and adhesion in parallel with active SHH signaling. BMACs from STZ-induced type 1 diabetic mice showed significantly impaired Matrigel tube formation ( n = 5; P < 0.05 vs. control), which was rescued by TSP-1 depletion ( n = 5; P < 0.05 STZ-TSP-1−/−vs. STZ-WT) or exogenous SHH (20 mg/l, 24 h, n = 4; P < 0.05 vs. STZ-control). The expression of CD36 was elevated in BMACs from STZ mice ( n = 4; P < 0.05). SHH signaling was significantly higher in BMACs from TSP-1−/−mice and TSP-1 receptor CD36-knockout mice ( n = 6; P < 0.05 vs. WT) but not CD47-knockout mice ( n = 3; P > 0.05 vs. WT). The impairment of recombinant human TSP-1 (2.2 nM, 24 h) on BMAC Matrigel tube formation was delayed significantly by CD36 deletion ( n = 5; P < 0.05). CD36−/−BMACs demonstrated better tube formation under both normal and diabetic conditions with active SHH signaling ( n = 4; P < 0.05 vs. WT BMACs). In conclusion, The TSP-1/CD36 pathway contributes to the SHH signaling defect, resulting in BMAC dysfunction in type 1 diabetic mice.

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