53 research outputs found

    Differential effects of taurine treatment and taurine deficiency on the outcome of renal ischemia reperfusion injury

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    Taurine possesses membrane stabilization, osmoregulatory and antioxidant properties, aspects of relevance to ischemic injury. We tested the hypothesis that body taurine status is a determinant of renal ischemic injury. Accordingly, renal function and structure were examined in control (C), taurine-treated (TT) and taurine deficient (TD) rats that were subjected to bilateral renal ischemia (60 min) followed by reperfusion (IR); sham operated rats served as controls. Baseline urine osmolality was greater in the TD group than in the control and the TT groups, an effect associated with increased renal aquaporin 2 level. The IR insult reduced urine osmolality (i.e., day-1 post insult); the TD/IR group displayed a more marked recovery in urine osmolality by day-6 post insult than the other two groups. Fluid and sodium excretions were lower in the TD/IR group, suggesting propensity to retention. Histopathological examination revealed the presence of tubular necrotic foci in the C/IR group than sham controls. While renal architecture of the TD/IR group showed features resembling sham controls, the TT/IR group showed dilated tubules, which lacked immunostaining for aquaporin 2, but not 1, suggestive of proximal tubule origin. Finally, assessment of cell proliferation and apoptosis revealed lower proliferation but higher apoptotic foci in the TT/IR group than other IR groups. Collectively, the results indicate that body taurine status is a major determinant of renal IR injury

    Effects of chromium picolinate on glycemic control and kidney of the obese Zucker rat

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    <p>Abstract</p> <p>Background</p> <p>Chromium picolinate (Cr(pic)3) is advocated as adjuvant therapy for impaired glycemic control, despite concerns for DNA damage. Potential toxicity of Cr(pic)3 should be greater for the kidney that accumulates chromium. Therefore, we tested the hypothesis that Cr(pic)3 treatment of obese Zucker rats (OZR) exacerbates renal abnormalities associated with dysglycemia.</p> <p>Methods</p> <p>Male OZR were treated with diets lacking or containing 5 and 10 mg/kg of chromium, as Cr(pic)3, for 20 weeks; lean Zucker rats (LZR) served as controls. Glycemic and renal effects of Cr(pic)3 were determined in the context of indices of oxidative stress and inflammation.</p> <p>Results</p> <p>The OZR displayed increased fasting plasma glucose and insulin in association with enlarged pancreatic islets exhibiting collagen and periodic acid Schiff-positive deposits compared to LZR; Cr(pic)3 treatment did not affect these parameters. The OZR, irrespective of Cr(pic)3, excreted more albumin than LZR. Also, other indices of renal function or histopathology were not affected by Cr(pic)3 treatment. Urinary excretion of 8-hydroxydeoxyguanosine (8-OHdG), an index of oxidative DNA damage, was greater in the OZR than LZR; dietary Cr(pic)3 treatment attenuated 8-OHdG excretion. However, immunostaining of kidney for 8-OHdG revealed similar staining pattern and intensity, despite significant renal accumulation of chromium in Cr(pic)3-treated groups. Finally, increased renal nitrotyrosine and cyclooxygenase-2 levels and urinary excretion of monocyte chemoattractant protein-1 of OZR were partially reversed by Cr(pic)3 treatment.</p> <p>Conclusion</p> <p>Dietary Cr(pic)3 treatment of OZR does not beneficially influence glycemic status or increase the risk for oxidative DNA damage; rather, the treatment attenuates indices of oxidative stress and inflammation.</p

    Increased Innate Lymphoid Cells in Periodontal Tissue of the Murine Model of Periodontitis: The Role of AMP-Activated Protein Kinase and Relevance for the Human Condition

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    Innate lymphoid cells (ILCs) are master regulators of immune and inflammatory responses, but their own regulatory mechanisms and functional roles of their subtypes (i.e., ILC1s–ILC3s) remain largely unresolved. Interestingly, AMP-activated protein kinase (AMPK), influences inflammatory responses, but its role in modulation of ILCs is not known. Periodontitis is a prevalent disorder with impairment of immune and inflammatory responses contributing importantly to its pathogenesis; however, neither the role of ILCs nor AMPK has been explored in this condition. We tested the hypotheses that (a) periodontitis increases ILCs and expression of relevant cytokines thereby contributing to inflammation and (b) knockdown of AMPK worsens indices of periodontitis in association with further increases in subtypes of ILCs and cytokine expression. The studies utilized wild-type (WT) and AMPK knockout (KO) mice, subjected to ligature-induced periodontitis or sham operation, in association with the use of micro-CT for assessment of bone loss, immunogold electron microscopy to show presence of ILCs in periodontal tissues, flow cytometry for quantitative assessment of subtypes of ILCs and RT-polymerase chain reaction analyses to measure mRNA expression of several relevant cytokines. The results for the first time show (a) presence of each subtype of ILCs in periodontal tissues of sham control and periodontitis animals, (b) that periodontitis is associated with increased frequencies of ILC1s–ILC3s with the effect more marked for ILC2s and differential phenotypic marker expression for ILC3s, (c) that AMPK KO mice display exacerbation of indices of periodontitis in association with further increases in the frequency of subtypes of ILCs with persistence of ILC2s effect, and (d) that periodontitis increased mRNA for interleukin (IL)-33, but not IL-5 or IL-13, in WT mice but expression of these cytokines was markedly increased in AMPK KO mice with periodontitis. Subsequently, we showed that human periodontitis is associated with increases in each ILCs subtype with the effect more marked for ILC2s and that mRNA expressions for IL-33 and IL-5 are markedly greater for sites affected by periodontitis than healthy sites. Collectively, these novel observations indicate a pivotal role for ILCs in pathogenesis of periodontitis and that AMPK is a regulator of their phenotype expression in this condition

    Expression Profiles of GILZ and Annexin A1 in Human Oral Candidiasis and Lichen Planus

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    Adrenal glands are the major source of glucocorticoids, but recent studies indicate tissue-specific production of cortisol, including that in the oral mucosa. Both endogenous and exogenous glucocorticoids regulate the production of several proteins, including the glucocorticoid-induced leucine zipper (GILZ) and Annexin A1, which play important roles in the regulation of immune and inflammatory responses. Common inflammation-associated oral conditions include lichen planus and candidiasis, but the status of GILZ and Annexin A1 in these human conditions remains to be established. Accordingly, archived paraffin-embedded biopsy samples were subjected to immunohistochemistry to establish tissue localization and profile of GILZ and Annexin A1 coupled with the use of hematoxylin–eosin stain for histopathological assessment; for comparison, fibroma specimens served as controls. Histopathological examination confirmed the presence of spores and pseudohyphae for oral candidiasis (OC) specimens and marked inflammatory cell infiltrates for both OC and oral lichen planus (OLP) specimens compared to control specimens. All specimens displayed consistent and prominent nuclear staining for GILZ throughout the full thickness of the epithelium and, to varying extent, for inflammatory infiltrates and stromal cells. On the other hand, a heterogeneous pattern of nuclear, cytoplasmic, and cell membrane staining was observed for Annexin A1 for all specimens in the suprabasal layers of epithelium and, to varying extent, for inflammatory and stromal cells. Semi-quantitative analyses indicated generally similar fractional areas of staining for both GILZ and Annexin A1 among the groups, but normalized staining for GILZ, but not Annexin A1, was reduced for OC and OLP compared to the control specimens. Thus, while the cellular expression pattern of GILZ and Annexin A1 does not differentiate among these conditions, differential cellular profiles for GILZ vs. Annexin A1 are suggestive of their distinct physiological functions in the oral mucosa.</jats:p

    Expression Profiles of GILZ and Annexin A1 in Human Oral Candidiasis and Lichen Planus

    No full text
    Adrenal glands are the major source of glucocorticoids, but recent studies indicate tissue-specific production of cortisol, including that in the oral mucosa. Both endogenous and exogenous glucocorticoids regulate the production of several proteins, including the glucocorticoid-induced leucine zipper (GILZ) and Annexin A1, which play important roles in the regulation of immune and inflammatory responses. Common inflammation-associated oral conditions include lichen planus and candidiasis, but the status of GILZ and Annexin A1 in these human conditions remains to be established. Accordingly, archived paraffin-embedded biopsy samples were subjected to immunohistochemistry to establish tissue localization and profile of GILZ and Annexin A1 coupled with the use of hematoxylin–eosin stain for histopathological assessment; for comparison, fibroma specimens served as controls. Histopathological examination confirmed the presence of spores and pseudohyphae for oral candidiasis (OC) specimens and marked inflammatory cell infiltrates for both OC and oral lichen planus (OLP) specimens compared to control specimens. All specimens displayed consistent and prominent nuclear staining for GILZ throughout the full thickness of the epithelium and, to varying extent, for inflammatory infiltrates and stromal cells. On the other hand, a heterogeneous pattern of nuclear, cytoplasmic, and cell membrane staining was observed for Annexin A1 for all specimens in the suprabasal layers of epithelium and, to varying extent, for inflammatory and stromal cells. Semi-quantitative analyses indicated generally similar fractional areas of staining for both GILZ and Annexin A1 among the groups, but normalized staining for GILZ, but not Annexin A1, was reduced for OC and OLP compared to the control specimens. Thus, while the cellular expression pattern of GILZ and Annexin A1 does not differentiate among these conditions, differential cellular profiles for GILZ vs. Annexin A1 are suggestive of their distinct physiological functions in the oral mucosa

    Expression Profiles of GILZ and SGK-1 in Potentially Malignant and Malignant Human Oral Lesions

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    Glucocorticoid-induced leucine zipper and serum-glucocorticoid-regulated kinase-1 (SGK-1) are major glucocorticoid-inducible proteins. Recent studies indicate the local production of cortisol in oral mucosa, which can impact the tissue generation of glucocorticoid-induced leucine zipper (GILZ) and SGK-1. Furthermore, GILZ and SGK-1 play pathogenic roles in a variety of cancers, but their status in potentially malignant (e.g., epithelial dysplasia) or malignant oral lesions remains unknown. This study tested the hypothesis that expression profiles of GILZ and SGK-1, along with the phosphorylated (active) form of SGK-1 (pSGK-1), are different in epithelial dysplasia than squamous cell carcinoma. Accordingly, archived paraffin-embedded biopsy samples were subjected to immunohistochemistry to establish tissue localization and the profile of proteins of interest, while hematoxylin-eosin stained tissues were used for histopathological assessment. Based on histopathological examinations, tissue specimens were categorized as displaying mild-moderate or severe epithelial dysplasia and squamous cell carcinoma; benign keratosis specimens served as controls. All the tissue specimens showed staining for SGK-1 and pSGK-1; however, while SGK-1 staining was primarily cytoplasmic, pSGK-1 was mainly confined to the cell membrane. On the other hand, all the tissue specimens displayed primarily nuclear staining for GILZ. A semi-quantitative analysis of immunohistochemistry staining indicates increased GILZ expression in epithelial dysplasia but reversal in squamous cell carcinoma to a level seen for benign keratosis. On the other hand, the SGK-1 and pSGK-1 expressions decreased for squamous cell carcinoma specimens compared with benign keratosis or dysplastic specimens. Collectively, in this cross-sectional study, immunostaining patterns for proteins of interest do not seemingly differentiate epithelial dysplasia from squamous cell carcinoma. However, subcellular localization and expression profiles for GILZ, SGK-1, and pSGK-1 are suggestive of differential functional roles in dysplastic or malignant oral lesions compared with benign keratosis.</jats:p
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