scholarly journals Disruption of CXCR6 Ameliorates Kidney Inflammation and Fibrosis in Deoxycorticosterone Acetate/Salt Hypertension

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Yuanbo Wu ◽  
Changlong An ◽  
Xiaogao Jin ◽  
Zhaoyong Hu ◽  
Yanlin Wang
Keyword(s):  
Knockout Mice ◽  
Critical Role ◽  
Kidney Injury ◽  
Wild Type ◽  
Salt Treatment ◽  
Hypertensive Nephropathy ◽  
Deoxycorticosterone Acetate ◽  
Kidney Fibrosis ◽  
Salt Hypertension

AbstractCirculating cells have a pathogenic role in the development of hypertensive nephropathy. However, how these cells infiltrate into the kidney are not fully elucidated. In this study, we investigated the role of CXCR6 in deoxycorticosterone acetate (DOCA)/salt-induced inflammation and fibrosis of the kidney. Following uninephrectomy, wild-type and CXCR6 knockout mice were treated with DOCA/salt for 3 weeks. Blood pressure was similar between wild-type and CXCR6 knockout mice at baseline and after treatment with DOCA/salt. Wild-type mice develop significant kidney injury, proteinuria, and kidney fibrosis after three weeks of DOCA/salt treatment. CXCR6 deficiency ameliorated kidney injury, proteinuria, and kidney fibrosis following treatment with DOCA/salt. Moreover, CXCR6 deficiency inhibited accumulation of bone marrow–derived fibroblasts and myofibroblasts in the kidney following treatment with DOCA/salt. Furthermore, CXCR6 deficiency markedly reduced the number of macrophages and T cells in the kidney after DOCA/salt treatment. In summary, our results identify a critical role of CXCR6 in the development of inflammation and fibrosis of the kidney in salt-sensitive hypertension.

scholarly journals Regulation of the cognitive aging process by the transcriptional repressor RP58

2021 ◽  
Author(s):  
Tomoko Tanaka ◽  
Shinobu Hirai ◽  
Hiroyuki Manabe ◽  
Kentaro Endo ◽  
Hiroko Shimbo ◽  
...  
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Knockout Mice ◽  
Cognitive Aging ◽  
Critical Role ◽  
Harmful Effect ◽  
Transcriptional Repressor ◽  
Repair Pathway ◽  
Wild Type

Aging involves a decline in physiology which is a natural event in all living organisms. An accumulation of DNA damage contributes to the progression of aging. DNA is continually damaged by exogenous sources and endogenous sources. If the DNA repair pathway operates normally, DNA damage is not life threatening. However, impairments of the DNA repair pathway may result in an accumulation of DNA damage, which has a harmful effect on health and causes an onset of pathology. RP58, a zinc-finger transcriptional repressor, plays a critical role in cerebral cortex formation. Recently, it has been reported that the expression level of RP58 decreases in the aged human cortex. Furthermore, the role of RP58 in DNA damage is inferred by the involvement of DNMT3, which acts as a co-repressor for RP58, in DNA damage. Therefore, RP58 may play a crucial role in the DNA damage associated with aging. In the present study, we investigated the role of RP58 in aging. We used RP58 hetero-knockout and wild-type mice in adolescence, adulthood, or old age. We performed immunohistochemistry to determine whether microglia and DNA damage markers responded to the decline in RP58 levels. Furthermore, we performed an object location test to measure cognitive function, which decline with age. We found that the wild-type mice showed an increase in single-stranded DNA and gamma-H2AX foci. These results indicate an increase in DNA damage or dysfunction of DNA repair mechanisms in the hippocampus as age-related changes. Furthermore, we found that, with advancing age, both the wild-type and hetero-knockout mice showed an impairment of spatial memory for the object and increase in reactive microglia in the hippocampus. However, the RP58 hetero-knockout mice showed these symptoms earlier than the wild-type mice did. These results suggest that a decline in RP58 level may lead to the progression of aging.

Decreased renal NO excretion and reduced glomerular tuft area in mice lacking the bradykinin B2 receptor

2003 ◽  
Vol 284 (6) ◽  
pp. H1904-H1908 ◽  
Author(s):  
Joost P. Schanstra ◽  
Johan Duchene ◽  
Françoise Praddaude ◽  
Patrick Bruneval ◽  
Ivan Tack ◽  
...  
Keyword(s):  
Knockout Mice ◽  
Renal Hemodynamics ◽  
Wild Type ◽  
Kidney Fibrosis ◽  
Physiological Conditions ◽  
Pathological Conditions ◽  
Induced Hypertension ◽  
Free Environment ◽  
Glomerular Tuft

Bradykinin B2 receptor knockout mice (B2 −/−) have been useful to study the role of bradykinin under pathological conditions. With the use of these mice, it was shown that bradykinin plays an important role in angiogenesis, heart failure, salt-induced hypertension, and kidney fibrosis. Data on the role of the bradykinin B2 receptor under physiological conditions using these mice are controversial and scarce, because these mice have no typical phenotype. For this reason, we have studied, under physiological conditions, renal hemodynamics as well as a number of morphometric glomerular parameters of B2 −/− mice on a homogenized genetic background and on mice bred in a pathogen-free environment. Backcrossed B2 −/− mice had normal blood pressure and normal apparent renal hemodynamics and morphology. However, reduced renal nitrite excretion and glomerular cGMP content were found, which was associated with a reduced glomerular capillary surface area. These differences had, however, no detectable effects on renal hemodynamics. These differences between B2 −/− and wild-type mice might become important under pathological conditions as shown by a number of studies using these bradykinin B2 receptor knockout mice.

Abstract 175: The Role of Axl in Accumulation of Immune Cells in Kidney and the Onset of Hypertension

Hypertension ◽  
2012 ◽  
Vol 60 (suppl_1) ◽  
Author(s):  
Sri Nagarjun Batchu ◽  
Angie Hughson ◽  
Janice Gerloff ◽  
Deborah J Fowell ◽  
Vyacheslav A Korshunov
Keyword(s):  
Blood Pressure ◽  
Immune Cells ◽  
Immune Cell ◽  
Kidney Injury ◽  
Wild Type ◽  
Protein Levels ◽  
Immune Cell Subsets ◽  
Early Increase ◽  
Salt Hypertension

Introduction: Gas6/Axl pathway contributes to elevation of blood pressure. Immune cells are implicated in initiation and maintenance of hypertension. In this study we aimed to investigate the role of Axl in immune cells on kidney injury and initiation of hypertension. Methods and Results: Deoxycorticosterone-acetate (DOCA; 75mg, 60days release) and salt hypertension was induced for 1wk or 6wks in four groups of Axl chimeras (n=4-5) that were generated by bone marrow (BM) transplant. Multi parameter flow cytometry was used to quantify five major immune cell subsets in digested kidneys from Axl chimeras. Systolic blood pressure (SBP) increased by 30mmHg in Axl+/+ →Axl+/+, Axl-/- →Axl-/- and Axl+/+ →Axl-/- mice after 1wk of DOCA-salt. However, chimeras that lack Axl in the BM cells (Axl-/- →Axl+/+) showed reduction in early increase in SBP (16+2mmHg). We observed a significant decrease in urine protein levels in Axl-/- →Axl+/+ (0.3+0.1μg/μl) compared to other Axl chimeras (∼0.7μg/μl) after 1wk of DOCA-salt. Kidney glomeruli areas were reduced in Axl-/- →Axl+/+ (4,143+229μm 2 ) compared to other Axl chimeras (∼6,000μm 2 ) after 6wks of DOCA-salt. Kidneys from Axl-/- →Axl-/- showed an increase in total leukocytes (8 vs. 4%), B cells (29 vs. 12%) and decrease in monocytes/macrophages (16 vs. 22%) and dendritic cells (5 vs. 10%) compared to Axl+/+ →Axl+/+. Moreover, Axl-/- →Axl+/+ showed further increase in leukocytes (17%), B (39%) and dendritic (13%) cells in kidneys compared to other Axl chimeras. In addition a small percentage of wild type T cells was increased in the kidneys from Axl-/- →Axl+/+ chimeras. Conclusions: These findings suggest that Axl expression in BM-derived cells is critical for kidney injury in DOCA-salt hypertension. Axl-dependent pathways regulate immune cell populations in the kidneys during initiation of hypertension. This study was supported by HL105623 grant (VAK)

scholarly journals The Type 1 Insulin-Like Growth Factor Receptor (IGF-IR) Pathway Is Mandatory for the Follistatin-Induced Skeletal Muscle Hypertrophy

Endocrinology ◽  
2012 ◽  
Vol 153 (1) ◽  
pp. 241-253 ◽  
Author(s):  
S. Kalista ◽  
O. Schakman ◽  
H. Gilson ◽  
P. Lause ◽  
B. Demeulder ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Knockout Mice ◽  
Muscle Hypertrophy ◽  
Critical Role ◽  
Muscle Growth ◽  
Dominant Negative ◽  
Wild Type ◽  
Myostatin Inhibition

Myostatin inhibition by follistatin (FS) offers a new approach for muscle mass enhancement. The aim of the present study was to characterize the mediators responsible for the FS hypertrophic action on skeletal muscle in male mice. Because IGF-I and IGF-II, two crucial skeletal muscle growth factors, are induced by myostatin inhibition, we assessed their role in FS action. First, we tested whether type 1 IGF receptor (IGF-IR) is required for FS-induced hypertrophy. By using mice expressing a dominant-negative IGF-IR in skeletal muscle, we showed that IGF-IR inhibition blunted by 63% fiber hypertrophy caused by FS. Second, we showed that FS caused the same degree of fiber hypertrophy in wild-type and IGF-II knockout mice. We then tested the role of the signaling molecules stimulated by IGF-IR, in particular the Akt/mammalian target of rapamycin (mTOR)/70-kDa ribosomal protein S6 kinase (S6K) pathway. We investigated whether Akt phosphorylation is required for the FS action. By cotransfecting a dominant-negative form of Akt together with FS, we showed that Akt inhibition reduced by 65% fiber hypertrophy caused by FS. Second, we evaluated the role of mTOR in FS action. Fiber hypertrophy induced by FS was reduced by 36% in rapamycin-treated mice. Finally, because the activity of S6K is increased by FS, we tested its role in FS action. FS caused the same degree of fiber hypertrophy in wild-type and S6K1/2 knockout mice. In conclusion, the IGF-IR/Akt/mTOR pathway plays a critical role in FS-induced muscle hypertrophy. In contrast, induction of IGF-II expression and S6K activity by FS are not required for the hypertrophic action of FS.

scholarly journals Inhibition of Estrogen Sulfotransferase (SULT1E1/EST) Ameliorates Ischemic Acute Kidney Injury in Mice

2020 ◽  
Vol 31 (7) ◽  
pp. 1496-1508
Author(s):  
Anne C. Silva Barbosa ◽  
Dong Zhou ◽  
Yang Xie ◽  
You-Jin Choi ◽  
Hung-Chun Tung ◽  
...  
Keyword(s):  
Knockout Mice ◽  
Ischemia Reperfusion ◽  
Kidney Injury ◽  
Renal Ischemia ◽  
Male Mice ◽  
Wild Type ◽  
Estrogen Sulfotransferase ◽  
Female Mice ◽  
Pharmacologic Inhibition

BackgroundStudies have suggested that estrogens may protect mice from AKI. Estrogen sulfotransferase (SULT1E1, or EST) plays an important role in estrogen homeostasis by sulfonating and deactivating estrogens, but studies on the role of SULT1E1 in AKI are lacking.MethodsWe used the renal ischemia-reperfusion model to investigate the role of SULT1E1 in AKI. We subjected wild-type mice, Sult1e1 knockout mice, and Sult1e1 knockout mice with liver-specific reconstitution of SULT1E1 expression to bilateral renal ischemia-reperfusion or sham surgery, either in the absence or presence of gonadectomy. We assessed relevant biochemical, histologic, and gene expression markers of kidney injury. We also used wild-type mice treated with the SULT1E1 inhibitor triclosan to determine the effect of pharmacologic inhibition of SULT1E1 on AKI.ResultsAKI induced the expression of Sult1e1 in a tissue-specific and sex-specific manner. It induced expression of Sult1e1 in the liver in both male and female mice, but Sult1e1 induction in the kidney occurred only in male mice. Genetic knockout or pharmacologic inhibition of Sult1e1 protected mice of both sexes from AKI, independent of the presence of sex hormones. Instead, a gene profiling analysis indicated that the renoprotective effect was associated with increased vitamin D receptor signaling. Liver-specific transgenic reconstitution of SULT1E1 in Sult1e1 knockout mice abolished the protection in male mice but not in female mice, indicating that Sult1e1’s effect on AKI was also tissue-specific and sex-specific.ConclusionsSULT1E1 appears to have a novel function in the pathogenesis of AKI. Our findings suggest that inhibitors of SULT1E1 might have therapeutic utility in the clinical management of AKI.

scholarly journals Suppression of Chlamydial Pathogenicity by Nonspecific CD8+ T Lymphocytes

2020 ◽  
Vol 88 (10) ◽  
Author(s):  
Lingxiang Xie ◽  
Conghui He ◽  
Jianlin Chen ◽  
Lingli Tang ◽  
Zhiguang Zhou ◽  
...  
Keyword(s):  
T Cells ◽  
Knockout Mice ◽  
Critical Role ◽  
Wild Type ◽  
Tubal Infertility ◽  
Content Type ◽  
Chlamydia Muridarum ◽  
Chlamydial Antigen

ABSTRACT Chlamydia trachomatis, a leading infectious cause of tubal infertility, induces upper genital tract pathology, such as hydrosalpinx, which can be modeled with Chlamydia muridarum infection in mice. Following C. muridarum inoculation, wild-type mice develop robust hydrosalpinx, but OT1 mice fail to do so because their T cell receptors are engineered to recognize a single ovalbumin epitope (OVA457-462). These observations have demonstrated a critical role of Chlamydia-specific T cells in chlamydial pathogenicity. In the current study, we have also found that OT1 mice can actively inhibit chlamydial pathogenicity. First, depletion of CD8+ T cells from OT1 mice led to the induction of significant hydrosalpinx by Chlamydia, indicating that CD8+ T cells are necessary to inhibit chlamydial pathogenicity. Second, adoptive transfer of CD8+ T cells from OT1 mice to CD8 knockout mice significantly reduced chlamydial induction of hydrosalpinx, demonstrating that OT1 CD8+ T cells are sufficient for attenuating chlamydial pathogenicity in CD8 knockout mice. Finally, CD8+ T cells from OT1 mice also significantly inhibited hydrosalpinx development in wild-type mice following an intravaginal inoculation with Chlamydia. Since T cells in OT1 mice are engineered to recognize only the OVA457-462 epitope, the above observations have demonstrated a chlamydial antigen-independent immune mechanism for regulating chlamydial pathogenicity. Further characterization of this mechanism may provide information for developing strategies to reduce infertility-causing pathology induced by infections.

scholarly journals The critical role of FXR is associated with the regulation of autophagy and apoptosis in the progression of AKI to CKD

2021 ◽  
Vol 12 (4) ◽  
Author(s):  
Dong-Hyun Kim ◽  
Jung Sun Park ◽  
Hoon-In Choi ◽  
Chang Seong Kim ◽  
Eun Hui Bae ◽  
...  
Keyword(s):  
Critical Role ◽  
Kidney Injury ◽  
Farnesoid X Receptor ◽  
Wild Type ◽  
Expression Levels ◽  
Related Proteins ◽  
Hk2 Cells ◽  
Oxidative Species ◽  
Feeding And Fasting

AbstractAutophagy is important for cells to break down and recycle cellular proteins, remove damaged organelles, and especially, for recovery from acute kidney injury (AKI). Despite research on the role and cellular mechanism of autophagy in AKI, the role of autophagy in the progression to chronic kidney disease (CKD) remains poorly understood. Here, using farnesoid X receptor (FXR) knockout (KO) mice, we determined whether FXR prevents the progression of AKI to CKD after renal ischemic-reperfusion (such as I/R) injury through the regulation of renal autophagy and apoptosis. FXR regulated genes that participate in renal autophagy under feeding and fasting conditions, such as hepatic autophagy, and the activation of FXR by agonists, such as GW4064 and INT-747, attenuated the increased autophagy and apoptosis of hypoxia-induced human renal proximal tubule epithelial (HK2) cells. The expression levels of autophagy-related and apoptosis-related proteins in FXR KO mice were increased compared with those in wild-type (WT) mice. We also showed that the increase in reactive oxidative species (ROS) in hypoxia-treated HK2 cells was attenuated by treatment with FXR agonist or by FXR overexpression, and that the level of ROS was elevated in FXR-deficient cells and mice. At 28 days after I/R injury, the autophagy levels were still elevated in FXR KO mice, and the expression levels of fibrosis-related proteins and ROS deposits were higher than those in WT mice. In conclusion, the regulation of renal autophagy and apoptosis by FXR may be a therapeutic target for the early stages of kidney damage, and the progression of AKI to CKD.

scholarly journals The critical role of T cells in glucocorticoid-induced osteoporosis

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Lin Song ◽  
Lijuan Cao ◽  
Rui Liu ◽  
Hui Ma ◽  
Yanan Li ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
Steady State ◽  
Side Effects ◽  
Critical Role ◽  
Wild Type ◽  
Receptor Activator ◽  
Steady State Levels ◽  
Induced Apoptosis

AbstractGlucocorticoids (GC) are widely used clinically, despite the presence of significant side effects, including glucocorticoid-induced osteoporosis (GIOP). While GC are believed to act directly on osteoblasts and osteoclasts to promote osteoporosis, the detailed underlying molecular mechanism of GC-induced osteoporosis is still not fully elucidated. Here, we show that lymphocytes play a pivotal role in regulating GC-induced osteoporosis. We show that GIOP could not be induced in SCID mice that lack T cells, but it could be re-established by adoptive transfer of splenic T cells from wild-type mice. As expected, T cells in the periphery are greatly reduced by GC; instead, they accumulate in the bone marrow where they are protected from GC-induced apoptosis. These bone marrow T cells in GC-treated mice express high steady-state levels of NF-κB receptor activator ligand (RANKL), which promotes the formation and maturation of osteoclasts and induces osteoporosis. Taken together, these findings reveal a critical role for T cells in GIOP.

Heparan sulfate side chains have a critical role in the inhibitory effects of perlecan on vascular smooth muscle cell response to arterial injury

2014 ◽  
Vol 307 (3) ◽  
pp. H337-H345 ◽  
Author(s):  
Lara Gotha ◽  
Sang Yup Lim ◽  
Azriel B. Osherov ◽  
Rafael Wolff ◽  
Beiping Qiang ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Critical Role ◽  
Arterial Injury ◽  
Side Chains ◽  
Wild Type ◽  
Injury Response ◽  
Migratory Response

Perlecan is a proteoglycan composed of a 470-kDa core protein linked to three heparan sulfate (HS) glycosaminoglycan chains. The intact proteoglycan inhibits the smooth muscle cell (SMC) response to vascular injury. Hspg2Δ3/Δ3 (MΔ3/Δ3) mice produce a mutant perlecan lacking the HS side chains. The objective of this study was to determine differences between these two types of perlecan in modifying SMC activities to the arterial injury response, in order to define the specific role of the HS side chains. In vitro proliferative and migratory activities were compared in SMC isolated from MΔ3/Δ3 and wild-type mice. Proliferation of MΔ3/Δ3 SMC was 1.5× greater than in wild type ( P < 0.001), increased by addition of growth factors, and showed a 42% greater migratory response than wild-type cells to PDGF-BB ( P < 0.001). In MΔ3/Δ3 SMC adhesion to fibronectin, and collagen types I and IV was significantly greater than wild type. Addition of DRL-12582, an inducer of perlecan expression, decreased proliferation and migratory response to PDGF-BB stimulation in wild-type SMC compared with MΔ3/Δ3. In an in vivo carotid artery wire injury model, the medial thickness, medial area/lumen ratio, and macrophage infiltration were significantly increased in the MΔ3/Δ3 mice, indicating a prominent role of the HS side chain in limiting vascular injury response. Mutant perlecan that lacks HS side chains had a marked reduction in the inhibition of in vitro SMC function and the in vivo arterial response to injury, indicating the critical role of HS side chains in perlecan function in the vessel wall.

scholarly journals Cytosolic Phospholipase A2α–deficient Mice Are Resistant to Collagen-induced Arthritis

2003 ◽  
Vol 197 (10) ◽  
pp. 1297-1302 ◽  
Author(s):  
Martin Hegen ◽  
Linhong Sun ◽  
Naonori Uozumi ◽  
Kazuhiko Kume ◽  
Mary E. Goad ◽  
...  
Keyword(s):  
Critical Role ◽  
Wild Type ◽  
Collagen Induced Arthritis ◽  
Cytosolic Phospholipase ◽  
Severity Scores ◽  
In The Wild ◽  
Cytosolic Phospholipase A2α ◽  
Antibody Levels ◽  
Deficient Mice

Pathogenic mechanisms relevant to rheumatoid arthritis occur in the mouse model of collagen-induced arthritis (CIA). Cytosolic phospholipase A2α (cPLA2α) releases arachidonic acid from cell membranes to initiate the production of prostaglandins and leukotrienes. These inflammatory mediators have been implicated in the development of CIA. To test the hypothesis that cPLA2α plays a key role in the development of CIA, we backcrossed cPLA2α-deficient mice on the DBA/1LacJ background that is susceptible to CIA. The disease severity scores and the incidence of disease were markedly reduced in cPLA2α-deficient mice compared with wild-type littermates. At completion of the study, &gt;90% of the wild-type mice had developed disease whereas none of the cPLA2α-deficient mice had more than one digit inflamed. Furthermore, visual disease scores correlated with severity of disease determined histologically. Pannus formation, articular fibrillation, and ankylosis were all dramatically reduced in the cPLA2α-deficient mice. Although the disease scores differed significantly between cPLA2α mutant and wild-type mice, anti-collagen antibody levels were similar in the wild-type mice and mutant littermates. These data demonstrate the critical role of cPLA2α in the pathogenesis of CIA.

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