Aldosterone rapidly activates p-PKC delta and GPR30 but suppresses p-PKC epsilon protein levels in rat kidney.

OBJECTIVES: Aldosterone rapidly enhances protein kinase C (PKC) alpha and beta1 proteins in the rat kidney. The G protein-coupled receptor 30 (GPR30)-mediated PKC pathway is involved in the inhibition of the potassium channel in HEK-239 cells. GPR30 mediates rapid actions of aldosterone in vitro. There are no reports available regarding the aldosterone action on other PKC isoforms and GPR30 proteins in vivo. The aim of the present study was to examine rapid actions of aldosterone on protein levels of phosphorylated PKC (p-PKC) delta, p-PKC epsilon, and GPR30 simultaneously in the rat kidney. METHODS: Male Wistar rats were intraperitoneally injected with normal saline solution or aldosterone (150 µg/kg body weight). After 30 minutes, abundance and immunoreactivity of p-PKC delta, p-PKC epsilon, and GPR30 were determined by Western blot analysis and immunohisto-chemistry, respectively. RESULTS: Aldosterone administration significantly increased the renal protein abundance of p-PKC delta by 80% (p<0.01) and decreased p-PKC epsilon protein by 50% (p<0.05). Aldosterone injection enhanced protein immunoreactivity of p-PKC delta but suppressed p-PKC epsilon protein intensity in both kidney cortex and medulla. Protein abundance of GPR30 was elevated by aldosterone treatment (p<0.05), whereas the immunoreactivity was obviously changed in the kidney cortex and inner medulla. Aldosterone translocated p-PKC delta and GPR30 proteins to the brush border membrane of proximal convoluted tubules. CONCLUSIONS: This is the first in vivo study simultaneously demonstrating that aldosterone administration rapidly elevates protein abundance of p-PKC delta and GPR30, while p-PKC epsilon protein is suppressed in rat kidney. The stimulation of p-PKC delta protein levels by aldosterone may be involved in the activation of GPR30.

Vanadate-Induced Renal cAMP and Malondialdehyde Accumulation Suppresses Alpha 1 Sodium Potassium Adenosine Triphosphatase Protein Levels.

It has been demonstrated that vanadate causes nephrotoxicity. Vanadate inhibits renal sodium potassium adenosine triphosphatase (Na, K-ATPase) activity and this is more pronounced in injured renal tissues. Cardiac cyclic adenosine monophosphate (cAMP) is enhanced by vanadate, while increased cAMP suppresses Na, K-ATPase action in renal tubular cells. There are no in vivo data collectively demonstrating the effect of vanadate on renal cAMP levels; on the abundance of the alpha 1 isoform (α1) of the Na, K-ATPase protein or its cellular localization; or on renal tissue injury. In this study, rats received a normal saline solution or vanadate (5 mg/kg BW) by intraperitoneal injection for 10 days. Levels of vanadium, cAMP, and malondialdehyde (MDA), a marker of lipid peroxidation were measured in renal tissues. Protein abundance and the localization of renal α1-Na, K-ATPase was determined by Western blot and immunohistochemistry, respectively. Renal tissue injury was examined by histological evaluation and renal function was assessed by blood biochemical parameters. Rats treated with vanadate had markedly increased vanadium levels in their plasma, urine, and renal tissues. Vanadate significantly induced renal cAMP and MDA accumulation, whereas the protein level of α1-Na, K-ATPase was suppressed. Vanadate caused renal damage, azotemia, hypokalemia, and hypophosphatemia. Fractional excretions of all studied electrolytes were increased with vanadate administration. These in vivo findings demonstrate that vanadate might suppress renal α1-Na, K-ATPase protein functionally by enhancing cAMP and structurally by augmenting lipid peroxidation.

Rapid Action of Aldosterone on Protein Levels of Sodium-Hydrogen Exchangers and Protein Kinase C Beta Isoforms in Rat Kidney.

Previous in vitro studies demonstrated that aldosterone rapidly activates sodium-hydrogen exchangers 1 and 3 (NHE 1 and 3). In vitro investigations revealed that protein kinase C (PKC) regulates NHE properties. We previously demonstrated that aldosterone rapidly enhances PKCα protein abundance in the rat kidney. There are no reports of renal PKCß (I and II) protein levels related to the regulation by aldosterone. There are also no in vivo data regarding the rapid effects of aldosterone on renal protein levels of NHE (1 and 3) and PKCß (I and II), simultaneously. In the current study, rats received normal saline solution or aldosterone (150 µg/kg BW, i.p.). After 30 minutes, abundance and immunoreactivity of these proteins were determined by Western blot analysis and immunohistochemistry, respectively. Aldosterone increased NHE1 and NHE3 protein abundance to 152% and 134%, respectively (P < 0.05). PKCßI protein level was enhanced by 30%, whereas PKCßII declined slightly. Aldosterone increased NHE protein expression mostly in the medulla. PKCßI immunostaining intensity was increased in the glomeruli, renal vasculature, and thin limb of the loop of Henle, while PKCßII was reduced. This is the first in vivo study to simultaneously demonstrate that aldosterone rapidly elevates PKCßI and NHE (1 and 3) protein abundance in the rat kidney. Aldosterone-induced NHE (1 and 3) protein levels may be related to PKCßI activation.

Parakeratosis in skin is associated with loss of inhibitor of differentiation 4 via promoter methylation.

Parakeratosis refers to incomplete maturation of epidermal keratinocytes, resulting in abnormal retention of nuclei in the stratum corneum. It occurs in many diseases of the skin, particularly in psoriasis. Down-regulation of inhibitor of differentiation 4 messenger RNA has been demonstrated in psoriatic skin, but the specificity and mechanism for this finding are unknown. In this study, we addressed specificity by immunohistochemical staining for inhibitor of differentiation 4 protein in skin disorders showing parakeratosis, including: psoriasis (n = 9), chronic eczema (n = 6), and squamous cell carcinoma (n = 7). In these conditions, parakeratotic keratinocytes in the upper layers of the skin lacked inhibitor of differentiation 4 protein expression, whereas keratinocytes in the lower layers were densely stained, in contrast to diffuse expression in normal skin. Because promoter hypermethylation of inhibitor of differentiation 4 has been described in several cancers, we determined the methylation pattern of the inhibitor of differentiation 4 promoter in psoriasis and compared this with squamous cell carcinoma. We found a novel methylation pattern of the inhibitor of differentiation 4 promoter in both conditions. Inhibitor of differentiation 4 promoter methylation was significantly increased in psoriasis (34.8%) and squamous cell carcinoma (21.8%), compared with normal skin (0%). Moreover, cells in the upper and lower parts of psoriatic epidermis were, respectively, hypermethylated and nonmethylated, at the inhibitor of differentiation 4 promoter. Comparable studies in several cell lines confirmed that hypermethylation of the promoter was associated with loss of inhibitor of differentiation 4 messenger RNA and protein expression. Our study demonstrates a previously unreported link between gene-specific promoter hypermethylation and abnormal cellular differentiation in several skin diseases. This mechanism might provide clues for novel therapies for skin disorders characterized by parakeratosis.

Mixed embryonal/alveolar rhabdomyosarcoma of the prostate: report of a case with molecular genetic studies and literature review.

Alveolar rhabdomyosarcoma (RMS) is 1 of 2 main subtypes of RMS in the pediatric age group and tends to occur in the extremities. The urogenital tract is another common site for RMS, but this typically involves the embryonal subtype including sarcoma botryoides. We report a 28-year-old male with a prostatic tumor that was excised en bloc and showed a RMS with separate areas of embryonal and solid alveolar morphologies at the light microscopic level. Both areas showed diffuse nuclear expression for myogenin, and both areas expressed the PAX3-FKHR fusion gene, a genetic change associated with alveolar but not embryonal RMS. A review of the literature documented only 5 cases of RMS primary to the prostate showing alveolar or mixed histology. Ours is the 6th case and the 1st with molecular findings. Although the diagnostic category of mixed embryonal/alveolar RMS remains in use, the nature of this type of RMS is incompletely understood. In our case, although the morphology was mixed embryonal/alveolar, at the genetic level this tumor was alveolar in nature.

Rosai-Dorfman disease and juvenile xanthogranuloma in a Thai boy: report of a case.

A 3-year-old Thai boy suffered from two histiocytoses, Rosai-Dorfman disease (RDD) and juvenile xanthogranuloma (JXG). The patient first presented with massive cervical lymphadenopathy at the age of one year. Biopsy revealed typical RDD; abnormally large CD68- and S-100 protein-positive histiocytes with occasional emperipolesis filled up the sinuses. Two years later, he developed polyuria and polydypsia. Skull film demonstrated osteolytic lesions at the occiput and left parietal region. Enlargement of the pituitary stalk was found on the magnetic resonance imaging. Despite the clinical impression of Langerhans cell histiocytosis, biopsy of the occipital lesion disclosed numerous large histiocytes with foamy cytoplasm. Several Touton giant cells with wreath-like arrangement of the nuclei were also observed. The abnormal cells expressed CD68 and factor XIIIa, but were non-reactive with S-100 protein and CD1a. Biopsy of the pituitary stalk was not performed According to the authors' literature search, this represents the first report of RDD and JXG affecting the same person.

Congenital nasopharyngeal immature teratoma: a first case report in Thailand.

The authors report the very rare case of a congenital immature teratoma arising from the nasopharyx in a full term female neonate. The tumor also extended to the oral cavity, particularly the right tonsillar fossa without intracranial involvement leading to upper airway obstruction and secondary Escherichia coli pneumonia. The immature part of the tumor in the head and neck region is not a poor prognostic indicator and chemotherapy is useless. In the presented case, the mass was widely excised without postoperative complications. To the best of our knowledge, this is the first reported case in Thailand.

Expression of neuronal nuclear antigen (NeuN) in epithelial neuroendocrine carcinoma.

Expression of neuronal nuclei (NeuN), a mouse-derived neuronal-specific monoclonal antibody, has been found in almost all neuronal cell types throughout the nervous system. The authors have demonstrated NeuN immunoreactivity in 56% of epithelial neuroendocrine carcinomas (ENEC) (19/34): 4 of 7 (57%) grade 1 ENECs (carcinoid), 4 of 5 (90%) grade 2 ENECs (atypical carcinoid), and 11 of 22 (50%) grade 3 ENECs (small and large cell neuroendocrine carcinoma). Of the NeuN-positive cases, the immunoreactivity was localized primarily in the cytoplasm in 11 cases and in the nucleus in the remaining. Even though NeuN is not a highly sensitive marker for solo use, it would be useful as an adjunct in the panel immunohisto- chemistry of cases with histologic features suspicious of neuroendocrine differentiation.

Extranodal malignant lymphoma of the upperaerodigestive tract in King Chulalongkorn Memorial Hospital according to WHO classification.

BACKGROUND: The Working Formulation commonly used to classify NHL in Thailand has been recognized as imperfect for primary extranodal lymphoma, especially in head and neck regions. OBJECTIVE: To study the clinicopathological and immunohistochemical features of extranodal malignant lymphoma of the upper aerodigestive tract according to WHO classification. SETTING: King Chulalongkorn Memorial Hospital. DESIGN: Descriptive study. PATIENTS: 77 Thai patients who presented between 1998 and 2003. METHODS: Routine histology was performed and stained with H&E and immunohistochemistry, and clinical characteristics were recorded. RESULTS: The patients included 42 males and 35 females, with an average age of 53.87 years. Tumor sites were as follows: Waldeyer ring (n = 42, 54.55%), sinonasal areas (n = 19, 24.67%), oral cavity (n = 9, 11.69%), hypopharynx (n = 4, 5.19%), and larynx (n = 3, 3.90%). Immunohistochemically, 57 tumors (74.02%) were of B-cell phenotype and 19 tumors (24.68%) were of T-cell phenotype. According to the WHO classification, 45 cases (58.43%) were large B-cell, 3 (3.90%) were Burkitt, 3 (3.90%) were marginal zone B-cell lymphomas of mucosa-associated lymphoid tissue (MALT), 4 (5.19%) were follicular lymphoma, 1 (1.30%) was precursor B-lymphoblastic lymphoma, and 1 (1.30%) were mantle cell lymphoma. Among the T-cell lymphomas, 9 (11.69%) were of peripheral T-cell lymphoma, unspecified, 9 (11.69%) were extranodal NK/T cell lymphoma, nasal type, and 1 (1.30%) were anaplastic large-cell lymphomas. In nasal cavity, 8 tumors (42.11%) were extranodal NK/T-cell lymphoma, nasal type, 5 (26.32%) were diffuse large B-cell lymphoma, 4 (21.05%) were peripheral T-cell lymphoma, unclassified, and 1 (5.26%) was Burkitt lymphoma. CONCLUSION: Our data correspond with series from Japan, Hong Kong, and Korea, but there is a significant difference from Western population in T-cell lymphomas of sinonasal area especially extranodal NK/T cell lymphoma of nasal type and peripheral T-cell lymphoma, unspecified which had a higher frequency in Thailand, Japan, Hong Kong, and Korea.

Cytokeratin 7 and 20 as immunohistochemical markers in identification of primary tumors in craniospinal metastases: do they have a significant role?

Cytokeratin (CK)7 and CK20, the low molecular weight cytokeratins, have been found to have a benefit in the differential diagnosis of some epithelial neoplasms. In the present study, the actual role of these markers in the search of primary tumors in 32 patients with craniospinal metastasis of an unknown primary site at presentation, is evaluated. A series of 36 patients with a known primary tumor were presented for comparison. In the first group, two CK7 and CK20 expression profiles were observed; 87% of metastatic tumors were CK7+/CK20- and 13% CK7-/CK20-. The lung was the major source (82%) of CK7+/CK20- metastatic tumors, whereas it represented only 38% of primary tumor in the second group of a known primary site (P=0.006). Given the fact that metastatic tumors to the craniospinal axis of an unknown primary site are frequently CK7+/CK20-, and they have commonly metastasized from the lung, it is doubtful that immunohistochemistry is really helpful. However, CT scan and MRI of the chest still play an important role. Many patients in the present study had to undertake these imaging studies, regardless of the CK7/CK20 result. The immunostains may be useful in cases with other expression profiles, but such examples constituted only a minority in the present study.