Cardiac natriuretic peptides: hormones with anticancer effects that localize to nucleus, cytoplasm, endothelium, and fibroblasts of human cancers.

Four cardiac peptide hormones, i.e., vessel dilator, long acting natriuretic peptide (LANP), kaliuretic peptide, and atrial natriuretic peptide (ANP) synthesized by the same gene decrease within 24 hours up to 97% the number of human breast, colon, pancreatic, and prostate adenocarcinoma cells as well as human small-cell and squamous carcinomas of the lung cells. These peptide hormones completely inhibit the growth of human pancreatic adenocarcinomas growing in athymic mice. Immunocytochemical investigations have revealed that LANP, vessel dilator, kaliuretic peptide and ANP localize to the nucleus and cytoplasm of human pancreatic adenocarcinomas, which is consistent with their ability to decrease DNA synthesis in the nucleus of this cancer mediated by the intracellular messenger cyclic GMP. These peptide hormones also localize to the endothelium of capillaries and fibroblasts within these cancers. These are the first growth-inhibiting peptide hormones ever demonstrated to localize to the nucleus. Their ability to decrease the activation of growth promoting substances such as Extracellular Receptor Kinase (ERK)-1/2 and Nuclear Factor Kappa Beta (NFkappaB) suggests that in addition to inhibiting DNA synthesis their ability to decrease the activation of growth promoting substances helps to mediate their ability to inhibit the growth of human cancers.

IL-1 and TNF independent pathways mediate ICAM-1/VCAM-1 up-regulation in ischemia reperfusion injury.

In vitro studies have suggested that targeting interleukin (IL)-1 and tumor necrosis factor (TNF) can be used to regulate intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) and potentially treat kidney inflammation. We therefore evaluated ICAM-1 and VCAM-1 regulation in knockout (KO) mice deficient in both IL-1 receptor 1 (R1) and TNF-R1 during renal ischemia reperfusion injury. ICAM-1 and VCAM-1 mRNA expression was measured with specific murine probes and Northern blotting (n =4/group). Protein expression was measured using immunohistochemistry. Serum creatinine (SCr), tubular histology, and neutrophil infiltration into postischemic kidneys were also quantified. ICAM-1 and VCAM-1 mRNA expression increased in both wild-type (WT) and KO mice at 2, 6, and 24 h. Protein expression of ICAM-1 and VCAM-1 was also increased at 24 h postischemia. SCr levels and tubular necrosis scores were comparable in WT and KO mice at 24 and 48 h. Neutrophil migration in KO mice was decreased at 24 h but comparable to WT at 48 h. These data demonstrate that IL-1 and TNF are not essential for postischemic increases in ICAM-1 and VCAM-1.

Pathophysiological role of T lymphocytes in renal ischemia-reperfusion injury in mice.

Mononuclear cell infiltrates are found in human renal ischemia-reperfusion injury (IRI), and peritubular T lymphocytes have been identified in experimental IRI. However, the role of T cells in the pathogenesis of renal IRI is unknown. We hypothesized that T cells are one of the important mediators of renal IRI. To test this hypothesis, we used an established mouse model of renal IRI, and evaluated mice with genetically engineered deficiency of both CD4+ and CD8+ T cells. At 48 h postischemia, CD4/CD8-knockout (KO) mice had marked improvement in renal function compared with control C57BL/6 mice (serum creatinine: 0.7 +/- 0.4 vs. 2.5 +/- 0.3 mg/dl, respectively; P < 0.05). Neutrophil infiltration into postischemic kidney was reduced in CD4/CD8 KO mice, compared with control mice, at both 24 h [polymorphonuclear neutrophils (PMNs)/10 high power fields: 714 +/- 354 vs. 3,514 +/- 660, respectively; P < 0.05] and 48 h (88 +/- 32 vs. 1,979 +/- 209, respectively; P < 0.05). Tubular necrosis score in CD4/CD8 KO mice, compared with control mice, was significantly less at 48 h (0.4 +/- 0.1 vs. 2.4 +/- 0.2, respectively; P < 0.05). Because adhesion between T cells and renal tubular epithelial cells (RTECs) may underlie the pathophysiological role of T cells in renal IRI, we also measured T cell adhesion to primary murine RTECs in vitro. Exposure of RTECs to 2 h of hypoxia followed by 1 h of reoxygenation increased T cell adhesion more than twofold. Phorbol ester treatment, which activates integrins, increased T cell adhesion threefold. These data suggest that T lymphocytes can mediate experimental renal IRI. Moreover, adhesion of infiltrating T cells to renal tubular cells may provide a potential mechanism underlying postischemic tubular dysfunction.

Amelioration with vessel dilator of acute tubular necrosis and renal failure established for 2 days.

Seventeen Sprague-Dawley rats had ischemic nonoliguric acute renal failure (ARF) induced by vascular clamping resulting in their preischemic blood urea nitrogen (BUN) and creatinine levels of 16 +/- 1 and 0.56 +/- 0.05 mg/dl to increase to 162 +/- 4 and 8.17 +/- 0.5 mg/dl, P < 0.001, respectively, at day 4 of postischemia. Vessel dilator, a 37-amino-acid cardiac peptide hormone (0.3 microg x kg(-1) x min(-1) ip), decreased the BUN and creatinine levels to 53 +/- 17 mg/dl and 0.98 +/- 0.12 mg/dl (P < 0.001) in another seven animals where ARF had been established for 2 days. Water excretion doubled with ARF and was further augmented by vessel dilator. Transthoracic echocardiography revealed left ventricular dilation as a probable cause of the increase in vessel dilator in the circulation with ARF, and vessel dilator infusion reversed this dilation. At day 6 of ARF, mortality decreased to 14% with vessel dilator from 88% without vessel dilator. Acute tubular necrosis was <5% in the vessel dilator-treated rats compared with 25% to >75% in the placebo-treated ARF animals. We conclude that vessel dilator improves acute tubular necrosis and renal function in established ARF.

Acute renal failure from multiple myeloma precipitated by ACE inhibitors.

Renal failure in multiple myeloma can be precipitated during hemodynamic perturbances of renal blood flow, as seen secondary to volume depletion, radiocontrast dye, and nonsteroidal anti-inflammatory agents. We report two cases of acute renal failure that developed suddenly after initiation of angiotensin-converting enzyme (ACE) inhibitor, both with biopsy-proven cast nephropathy. ACE inhibitors may contribute to the intratubular light chain cast formation and acute "myeloma kidney" in susceptible patients.

Role of IL-1 in renal ischemic reperfusion injury.

Interleukin-1 (IL-1) is a central component of many acute inflammatory processes. Blocking IL-1 receptor (IL-1R) with IL-1R antagonist (IL-1Ra) has attenuated ischemic reperfusion injury in brain, heart, and liver models. However, the role of IL-1 in renal ischemic reperfusion injury (IRI) is not known. Therefore, the role of IL-1 in renal IRI was evaluated using the complementary approaches of IL-1R blockade in wild-type mice in addition to the study of renal IRI in IL-1R knockout (KO) mice. Ischemia was induced by bilateral renal pedicle clamping for 30 min. IL-1Ra was administered at 10 mg/kg every 4 h, high doses that have been protective in previous organ injury models in mice. IL-1R KO animals, previously characterized as insensitive to IL-1, had the absence of IL-1R1 confirmed by DNA blots. IL-1Ra, IL-1R KO, and control groups had similar elevations of blood urea nitrogen (114 +/- 13, 133 +/- 11, and 120 +/- 11 mg/dl) and serum creatinine (1.7 +/- 0.3, 2.1 +/- 0.2, and 1.6 +/- 0.3 mg/dl) 24 h after ischemia. Furthermore, acute tubular necrosis scores were also similar in IL-1Ra-treated mice (3.0 +/- 0.3), IL-1R KO mice (2.7 +/- 0.3), and control mice (3.1 +/- 0.2). However, both IL-1Ra and IL-1R KO groups, compared with control animals, developed significantly less infiltration of polymorphonuclear leukocytes per 10 high-power fields in postischemic renal tissue (1111 +/- 228 and 967 +/- 198 versus 1820 +/- 190, P < 0.05). In contrast to the comparable renal functions at 24 h, recovery of renal function was significantly accelerated in the IL-1R KO group compared with control at both 48 (P < 0.05) and 72 (P < 0.05) h. Recovery in the IL-1Ra group was similar to that in the control animals. These data demonstrate that IL-1 is unlikely to be beneficial in the recovery of renal function after ischemia and may play a deleterious role.

Renal ischemic-reperfusion injury in L-selectin-deficient mice.

L-selectin on leukocyte surfaces mediates cell rolling on endothelium. L-selectin blockade with antibodies attenuated ischemic-reperfusion injury (IRI) in heart and skeletal muscle, but its role in renal IRI is unknown. We evaluated the role of L-selectin in renal IRI using L-selectin-deficient mice. Neutrophil migration to chemically inflamed peritoneum was reduced by 47% (P < 0.01) in L-selectin-deficient mice. Ischemia was induced by bilateral renal pedicle clamping for 30 min. Control and L-selectin groups had similar elevations of serum creatinine (1.8 +/- 0.3 vs. 1.7 +/- 0.2 mg/dl) and blood urea nitrogen (111 +/- 17 vs. 128 +/- 12 mg/dl) 24 h postischemia. Pathological assessment showed comparable degrees of tubular necrosis at 24 h. The postischemic increase in peritubular neutrophils per 10 high-power field was similar in control and L-selectin-deficient groups at 4 (28 +/- 10 vs. 22 +/- 5), 12 (245 +/- 80 vs. 236 +/- 78), and 24 h (130 +/- 12 vs. 156 +/- 18). These data argue against a significant role for L-selectin in renal IRI. Patho-physiological roles of L-selectin in vivo appear to be more complex than in vitro data would suggest.

Antibodies to ICAM-1 protect kidneys in severe ischemic reperfusion injury.

ICAM-1 has been implicated in the pathophysiology of ischemic-reperfusion injury in a number of organs, but its role in mediating severe ischemic-reperfusion injury in the kidney has not been extensively studied. Uninephrectomized Sprague Dawley rats were pretreated with either control monoclonal antibody (mAb) or mAb to ICAM-1 and subjected to 60 min of renal artery occlusion. The serum creatinine, complete blood count and kidney histo-pathological damage scores (PDS) (Scale:0-4) were assessed prior to and 24 hours after ischemia. Mean serum creatinine (mg/dl) 24 hours after ischemia was significantly decreased in the anti-ICAM-1 group (1.38 +/- 0.23, p < 0.001) compared to control (2.87 +/- 0.34). PDS was also reduced in anti-ICAM-1 (2.55 +/- 0.20, p < 0.05) group compared to control (3.35 +/- 0.30). These data demonstrate that blocking ICAM-1 significantly mitigates severe ischemic acute renal failure, findings which may lead to improved therapy for this condition.

Role of CD11a and CD11b in ischemic acute renal failure in rats.

Leukocytes, particularly neutrophils, have been implicated in ischemic-reperfusion organ injury (IRI). However, their role in kidney IRI is controversial. Leukocytes express the adhesion molecules CD11/CD18 on their surface, which mediate many functions that can lead to tissue damage. To determine the role of CD11a and CD11b in IRI in the kidney, uninephrectomized Sprague-Dawley rats were pretreated with monoclonal antibodies (MAbs) directed against CD11a and CD11b or control MAbs. The serum creatinine (SCr), complete blood count, and kidney histopathological damage scores (PDS) (scale: 0-4) were assessed prior to and 24 h after 60 min of ischemia. Mean SCr 24 h after ischemia was significantly decreased in the anti-CD11a- and -CD11b-treated group compared with the control MAb-treated group (2.5 +/- 0.3 mg/dl vs. 3.4 +/- 0.2 mg/dl, P < 0.05). PDS were also reduced in the CD11a and CD11b group compared with controls (2.7 +/- 0.2 vs. 3.5 +/- 0.1, P < 0.001). These data show that the CD11/CD18 leukocyte adhesion pathway plays a role in mediating ischemic acute renal failure in rats.

Immunocytochemical localization of ProANF 1-30, ProANF 31-67, atrial natriuretic factor and urodilatin in the human kidney.

Whether ProANF 1-30 [first 30 amino acids (a.a.) of the 126-a.a. atrial natriuretic factor (ANF) prohormone] and ProANF 31-67 (a.a. 31-67 of this prohormone) with their natriuretic and diuretic properties are present within the human kidney is unknown. In the present investigation, ProANFs 1-30 and 31-67 as well as ANF (a.a. 99-126) of the ANF prohormone localized to the subbrush border of the pars convoluta and pars recta of the proximal tubules of the human kidney with immunoperoxidase staining. Immunofluorescent studies revealed that each of these peptides had a strong inclination for the perinuclear region in the proximal and distal tubules. ProANFs 1-30, 31-67 and 99-126 (i.e. ANF) also localized with both immunoperoxidase and immunofluorescent staining to the coritcal collecting ducts, glomeruli, and peritubular and interstitial blood vessels. ANF immunoperoxidase staining was particularly striking in the endothelium of interstitial arteries and vasa recta. In the glomeruli, prominent staining was noted in the peripheral glomerular capillary wall and in some of the visceral epithelial cells. In contrast, urodilatin (i.e. a.a. 95-126 of the ANF prohormone) was not found in the proximal tubules, but weak staining was found in the distal tubules and interstitial vessels with some but not all glomeruli, peritubular vessels, cortical collecting tubules and outer medullary nephrons weakly staining by immunoperoxidase and immunofluorescent methods. The whole prohormone being present in the kidney was suggested by immunological recognition of both the N- and C-termini of the ANF prohormone by radioimmunoassays.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunocytochemical localization of proANF 1-30, proANF 31-67 and atrial natriuretic factor in the kidney.

ProANF [1-30 first 30 amino acids (a.a) of the 126 a.a atrial natriuretic factor (ANF) prohormone], ProANF 31-67 (a.a 31-67) as well as atrial natriuretic factor (a.a 99-126), of the ANF prohormone localized to the sub-brush border of the pars convoluta and pars rectus of the proximal tubules of hydrated and dehydrated rat kidneys with immunoperoxidase staining. Immunofluorescent studies revealed that each of these peptides and especially ProANF 31-67 had a strong predilection for the perinuclear region in the proximal and distal tubules. ProANFs 1-30, 31-67, and 99-126 (that is, ANF) also localized with both immunoperoxidase and immunofluorescent staining to the cortical collecting ducts, glomeruli, peritubular, and interstitial blood vessels. ProANF 31-67 immunoperoxidase staining was particularly striking in the elastica of the small and large interstitial arteries. The whole prohormone being present was suggested by immunological recognition in the rat kidney of both the N-terminus and C-terminus of the ANF prohormone by radioimmunoassays. The concentration of the N-terminus in the kidney was 1.0 +/- 0.03 ng/g of kidney weight, while the C-terminus of the ANF prohormone concentration was 0.4 +/- 0.01 ng/g of kidney tissue. These findings of a sub-brush border and perinuclear location of the N-terminal and C-terminal ANF prohormone peptides suggest that the atrial natriuretic factor prohormone may be synthesized in and/or the respective peptides are captured by the proximal tubules, but also to a lesser extent by the distal tubules of the kidney.

Spontaneous platelet aggregation in type IIB Tampa von Willebrand disease is inhibited by the 52/48-kDa fragment of normal von Willebrand factor, which contains the GPIb binding domain.

The association of Type IIB von Willebrand disease (vWD) with chronic persistent thrombocytopenia and spontaneous platelet aggregation has recently been recognized. It has been shown that IIB von Willebrand factor (vWF) can initiate platelet aggregation by binding to the platelet glycoprotein (GP) lb receptor and inducing exposure of the GpIIb/IIIa fibrinogen receptor. In this study we demonstrate the increased binding of Type IIB Tampa vWF with normal platelets when compared with nonthrombocytopenic Type IIB vWF. Studies further demonstrate that spontaneous platelet aggregation initiated by IIB Tampa vWF can be blocked by a 52/48-kDa fragment of normal vWF, which contains the binding domain.

Occupational exposure to organic solvents causing chronic tubulointerstitial nephritis.

We describe a patient with a history of ulcerative colitis and long-standing occupational exposure to organic solvents. Over a follow-up period of almost four years he had progression of tubulointerstitial damage documented by two kidney biopsies. We propose that long-term exposure to organic solvents can lead to the development of chronic tubulointerstitial nephritis. We describe experimental evidence that supports our conclusion.

Proteinuria in hypertension.

It had been previously thought that protein excretion in hypertensive nephrosclerosis was less than 0.5 to 1.0 g/24 h. Furthermore, it was believed that proteinuria in the nephrotic range associated with hypertension was probably due to primary renal disease, malignant hypertension, renal artery stenosis, or pheochromocytoma. We report eight patients with biopsy-proven hypertensive nephropathy and heavy proteinuria in the absence of malignant hypertension or renal artery stenosis. The 24-hour protein excretion ranged from 2.7 to 4.3 g. All patients had renal insufficiency, with serum creatinine ranging from 2.0 (176.8) to 7.8 mg/dL (689.5 mumol/L). Renal function worsened in most patients during the follow-up period despite adequate control of the hypertension, and three patients had to be started on hemodialysis. Three patients died during the follow-up period. We conclude that hypertensive nephrosclerosis must be included in the differential diagnosis of marked proteinuria in patients with essential hypertension and that heavy proteinuria, along with renal insufficiency, are poor prognostic indicators in such patients.

Hypocomplementemic vasculitis and renal involvement.

Hypocomplementic urticarial vasculitis is a disorder that not only affects the skin, but other organs as well. We are describing a patient with this rare disorder and serious renal involvement that was treated with immunosuppressive therapy with good response and stabilization of the renal function. We emphasize the fact that renal involvement can occur with this disease and that the renal involvement is of the immune-mediate type and cannot be considered as benign as thought in the past.

Hypernephroma associated with multiple endocrine neoplasia type I: a case report.

We report a case of multiple endocrine neoplasia type I and hypernephroma. Parathyroid hyperplasia, adrenocortical hyperplasia, a nodular goiter, multiple lipomas, a chromophobe adenoma of the pituitary and hypernephroma had all been diagnosed previously. All but the last are features consistent with the diagnosis of multiple endocrine neoplasia type I (Wermer's syndrome). The association of multiple endocrine neoplasia type I and hypernephroma may represent a new manifestation of this pleiotropic syndrome.

Antiheparin activity in human endothelial cells.

Human endothelial cells possess antiheparin activity that neutralizes the anticoagulant action of heparin as measured by different tests of the clotting system. The antiheparin activity appears to be associated with an acid-soluble basic protein present in the particulate fraction of the endothelial cell cytoplasm. This finding might have some relevance in the maintenance of hemostasis. Furthermore, it might also have a pharmacological role in terms of resistance to exogenously infused heparin in patients with thromboembolic disorders.

Coagulation and immunology.

One of the most vital functions of the vertebrates is to maintain hemostasis through coagulation and fibrinolysis. This is achieved by the interaction of vascular walls with blood components such as cells and proteins (coagulation factors, immunoglobulins, and complement). Deficiency of coagulation factors results in bleeding disorders. The immune system, in response to foreign proteins or defective self proteins, produces antibodies triggering an Ag-Ab interaction with the related host of different reactions including abnormal coagulation leading to hemorrhagic diathesis.

Heparin-mediated neutralization of platelet antiaggregatory activity of prostacyclin (PGI2): studies on mechanism.

Prostacyclin (PGI2) is a well-known potent inhibitor of platelet aggregation. Its role has been implicated in physiological and pathological states of hemostasis. Heparin blocks the prostacyclin-mediated antiaggregatory activity on platelets. Prior treatment of heparin with heparinase as well as with protamine destroyed heparin's ability to neutralize PGI2. Studies on the mechanism of heparin blocking of PGI2 activity suggested that heparin interacted directly with PGI2, as shown by the loss of PGI2 mobility on thin layer chromatography concomitant with the loss of PGI2-mediated inhibition of platelet aggregation. PGI2 in this combination with heparin, nevertheless, retained its time-dependent ability to be hydrolyzed to 6-keto-PGF1 alpha. Findings of these studies may have implications in thrombosis and hemostasis, particularly in heparin-mediated abnormalities of circulating platelets.