Effect of SMTP-7 on Cisplatin-Induced Nephrotoxicity in Mice.

SMTP-7, a fungal metabolite, is reported to have a high degree of availability for the ischemia-reperfusion (IR)-induced acute kidney injury (AKI) model. Cisplatin, a widely used anticancer drug, has serious side effects, such as AKI. Hence, we aimed to examine the effect of SMTP-7 on cisplatin-induced AKI in this study. Significant increases in blood urea nitrogen (BUN) and serum creatinine (Scr) were observed at 72 h after the intravenous infusion of cisplatin (20 mg/kg). Histologically, necrosis and dilatation (hyaline casts) as well as regeneration were observed in proximal tubules. SMTP-7 inhibited the elevation on BUN and Scr caused by cisplatin dose dependently. The efficacy of SMTP-7 was notable when the drug was administered on the day after cisplatin treatment, whereas the repeated administration of the drug did not result in an enhanced efficacy. Moreover, 10 mg/kg of SMTP-7 considerably ameliorated tubular necrosis and dilatation. The cisplatin treatment also caused an up-regulation of tumor necrosis factor-α (TNF-α) mRNA expression prior to the elevation of the levels of BUN and Scr. Administration of SMTP-7 (10 mg/kg) at 24 h after the cisplatin infusion alleviated the up-regulation of TNF-α mRNA expression. These findings suggest that SMTP-7 exhibits a renoprotective effect against cisplatin infusion based on the inhibition of the expression of pro-inflammatory cytokines such as TNF-α and may be expected a new effective drug for the treatment of cisplatin-induced AKI.

Acetic acid treatment causes renal inflammation and chronic kidney disease in mice.

We established a novel mouse model of chronic kidney disease (CKD) using acetic acid and compared it with the 5/6-nephrectomized mouse model. In our novel model, significant increases were observed in blood biochemical values and urinary parameters. Moreover, a decrease in creatinine clearance (Ccr) was observed. This model also demonstrated a higher survival rate than the 5/6-nephrectomized model. Observed histological changes in our model included cell infiltration in the renal interstitium, tubular dilation, regenerated tubules, and glomerulosclerosis. Inflammation of the renal interstitium was particularly remarkable. TNF-α, IL-1ß, and ICAM-1 mRNA expression were up-regulated prior to elevation of mean blood pressure and prior to changes in blood biochemical values and urinary parameters. Up-regulation of TGF-ß mRNA and down-regulation of nephrin mRNA were also observed at 12 weeks after acetic acid treatment. However, no correlation between the progression of CKD and the decrease in renal blood flow was observed. Finally, repeated losartan administration attenuated the effects of acetic acid-induced renal injury. Our findings suggest that chronic kidney conditions associated with this model may be triggered by interstitial inflammation. Moreover, we suggest that this model is useful for understanding the pathophysiological mechanisms of CKD, and for evaluating the effects of therapeutic agents.

[A Case of Stage IV Breast Cancer with Long-Term Survival by Chemotherapy Developing Pulmonary Tumor Thrombotic Microangiopathy during the Treatment Course].

Pulmonary tumor thrombotic microangiopathy(PTTM)caused by pulmonary artery microscopic tumor emboli and fibrocellular and/or fibromuscular proliferation leads to progressive pulmonary hypertension and respiratory failure.The prognosis is extremely poor and most patients die shortly after onset.We report a patient with Stage IV breast cancer and long-term survival who developed PTTM during chemotherapy treatment.A 63-year-old woman with multiple metastases in her cerebellum, bone, lung, and lymph node after left breast conserving surgery started to experience dyspnea and malaise 7 years after the surgery.Two months later, she was urgently admitted to hospital because of respiratory failure and was diagnosed with pulmonary hypertension.However, pulmonary thrombosis and tumor thrombus were not observed.We clinically diagnosed her with PTTM and administered chemotherapy in addition to treatment for pulmonary hypertension.Her medical condition improved gradually and she survived for the subsequent 2 years.When observing progressive hypoxia and pulmonary hypertension without obvious pulmonary embolism findings on imaging, PTTM should be considered.Early diagnosis and immediate induction of chemotherapy for primary disease can improve the survival of patients with PTTM.

Two types of overcontraction are involved in intrarenal artery dysfunction in type II diabetic mouse.

Contractile responses in small intrarenal arteries are associated with diabetic nephropathy. However, the mechanisms that induce and maintain altered small vessel contraction are not clearly understood. To further understand intrarenal artery dysfunction in diabetes, phenylephrine (PE)-induced force development was assessed in the intrarenal artery [interlobar artery (ILA)] in control (lean) and type II diabetic (ob/ob) mice. PE-induced dose-dependent force development in the ILA was significantly greater in ob/ob mice than in lean mice (592.8 ± 5.2 and 770.1 ± 12.1 µ/mm tissue, respectively, following administration of 30 µM PE, n = 5). Under high-glucose conditions (twice the normal concentration of glucose), PE-induced force development in the ILA was only enhanced in ob/ob mice (946.0 ± 18.2 µN/mm tissue; n = 5). ILA dysfunction reduces blood flow to the glomerulus and may induce diabetic nephropathy. Basal overcontraction of the ILA in ob/ob mice under normal-glucose conditions was reduced by pretreatment with rottlerin, a calcium-independent protein kinase C (PKCδ) inhibitor. Total PKC activity was also reduced by rottlerin. Under high-glucose conditions, the enhanced ILA contraction in diabetic mice was suppressed by rho A and rho kinase inhibitors. Our results indicate two types of ILA dysfunction in diabetes, as follows: 1) a basal increase in PE-induced contraction under normal-glucose conditions, and 2) extracellular glucose-dependent enhancement of PE-induced contraction. We believe that these dysfunctions are mediated by the activation of the PKCδ and rho A-rho kinase pathways, respectively.

Altered gene expression in an embolic stroke model after thrombolysis with tissue plasminogen activator and Stachybotrys microspora triprenyl phenol-7.

The present study compares gene expression and infarct area in a mouse model of embolic stroke after thrombolysis with t-PA and SMTP-7. Embolic occlusion was induced by transfer of acetic acid-induced embolus into the brain. t-PA or SMTP-7 was administered 3 h after embolization. Changes in gene expression were evaluated using microarray and RT-PCR analysis. To determine the involvement of reactive oxygen species in the response to t-PA, the free radical scavenger edaravone was infused immediately before t-PA administration. The expressions of 459 genes involved in the inflammatory response, cell-to-cell signaling, cell movement, and inflammatory disease were altered by embolic occlusion. Twenty-two of those genes were upregulated after t-PA but not SMTP-7 administration. Differences between the t-PA- and SMTP-7-treated groups in the expression of genes including the proinflammatory genes Il6, Stat3, S100a8, and Mmp9 were confirmed with RT-PCR. Edaravone ameliorated the overexpression of these genes. Our data demonstrate differences in gene expression following treatment with SMTP-7 or t-PA that likely explain the difference in therapeutic time windows of the two drugs. ROS are involved in the overexpression of proinflammatory genes. The wide therapeutic time window may be achieved through an anti-oxidative effect and inhibition of proinflammatory gene overexpression.

Involvement of the nigrostriatal system in Gerstman-Sträussler-Scheinker disease with the PRNP-P102L mutation.

INTRODUCTION: Gerstmann-Sträussler-Scheinker disease (GSS) is an autosomal-dominant inherited prion disease most often associated with the human prion protein gene (PRNP)-P102L mutation. Although patients manifest considerable phenotypic heterogeneity, the involvement of the nigrostriatal system has not been well-studied. METHODS: We performed dopamine transporter single-photon emission computed tomography (DAT-SPECT) using 123I-ioflupane to investigate the nigrostriatal system function in nine patients with the PRNP-P102L mutation. We also examined the pathological findings in another patient whose predominant feature was ataxia and who died 5 years after disease onset. RESULTS: Striatum uptake of 123I-ioflupane indicated by specific binding ratio (SBR) values was significantly reduced in two patients. The DAT-SPECT examination was performed 6 months after disease onset in one of these patients who manifested rapidly developing cognitive decline mimicking Creutzfeldt-Jakob disease. DAT-SPECT was also performed 9 years after disease onset in another patient who manifested the conventional features of GSS involving ataxia and dementia in the initial phase but showed akinetic mutism at the examination time. Another patient examined 2 years after disease onset who predominantly manifested ataxia showed marginally abnormal SBR values. An autopsy case showed moderate neuronal loss in the substantia nigra, and the degree of neuronal loss was similar in most other parts of the brain. CONCLUSION: Nigrostriatal system involvement may occur in patients with GSS associated with the PRNP-P102L mutation, even though parkinsonism is not the predominant feature.

Adiponectin enhances calcium dependency of mouse bladder contraction mediated by protein kinase Cα expression.

Adiponectin is an adipose tissue-secreted protein and is a multifunctional adipocytokine. However, the association of adiponectin with bladder contraction has not been investigated. In this study, the adiponectin-sense transgenic mouse (Adip-Sen mouse; age, 16-24 weeks; male) and age-matched controls (C57Bl mouse) were studied. The Adip-Sen mouse showed a significant increase in plasma adiponectin levels (56.2%; P < 0.01), compared with those in the C57Bl mouse, without affecting other lipid parameters. Isometric force development in bladder smooth muscle tissues were detected using an organ-bath system. Although carbachol (CCh)-induced (0.1-100 µM) time- and dose-dependent contractions in Adip-Sen mouse bladder were slightly enhanced, compared with those in the C57Bl mouse during a low range (0.3-1.0 µM) of CCh, differences could not be detected with other CCh concentrations. However, the reduction in contraction under Ca(2+)-replaced conditions was significantly different between Adip-Sen and C57Bl mice (94.1 and 66.3% of normal contraction, respectively; n = 5). A parameter of Ca(2+) sensitivity, the relation between intracellular Ca(2+) concentration and contraction, was increased in the Adip-Sen mouse, compared with that in the C57B1 mouse. This Ca(2+) dependency in the Adip-Sen mouse was reduced by a protein kinase C (PKC) inhibitor, but not by a Rho kinase inhibitor. Expression of the calcium-dependent isoform of PKC, PKCα, was increased in the Adip-Sen mouse bladder, and CCh-induced phosphorylation of PKCα was also enhanced, compared with those in the C57Bl mouse. In conclusion, adiponectin is associated with bladder smooth muscle contraction, which involves an increase in Ca(2+) dependency of contraction mediated by PKCα expression.

Lysophosphatidic acid induces shear stress-dependent contraction in mouse aortic strip in situ.

We previously reported that lysophosphatidic acid (LPA) regulates Ca²âº influx of fluid flow in stimulated endothelial cells and that LPA and shear stress showed increment and suppressive effects on phenylephrine-induced vasoconstriction and acetylcholine-induced vasodilatation, respectively. However, a vasoconstrictive effect of LPA alone in the presence of shear stress was not found. The present study examined the effect of LPA alone in the presence of shear stress on Ca²âº responses in endothelial and smooth muscle cells and contraction in mouse aortic strip using real-time 2-photon laser scanning microscopy and a custom-made parallel-plate flow chamber. Application of micromolar LPA and high shear stress elicited movement of endothelial cells after Ca²âº responses. The endothelial cells moved along the major axis of smooth muscle cells, a direction that was identical to that found during vasoconstriction evoked by the application of phenylephrine. The frequency of Ca²âº oscillations in smooth muscle cells was highest according to endothelial movement. Vasoconstriction evoked by LPA and shear stress was significantly reduced by the application of a thromboxane A2 receptor antagonist, a cyclooxygenase inhibitor, and a thromboxane synthase inhibitor. These results suggest that micromolar LPA and high shear stress elicit vasoconstriction that is caused by Ca²âº-dependent contraction in medial smooth muscle cells. Thromboxane A2 may be involved in that response.

Spatiotemporal dynamics of intracellular calcium in the middle cerebral artery isolated from stroke-prone spontaneously hypertensive rats.

The spatiotemporal dynamics of intracellular calcium within the middle cerebral artery (MCA) isolated from stroke-prone spontaneously hypertensive rats (SHR-SP) were investigated using real-time confocal laser microscopy. At 3 months of age (prestroke), rhythmical changes in the [Ca(2+)](i) during the tonic phase were found to precede vasomotion following application of 5-HT, but not other stimuli. These responses were not observed at 1 month of age; moreover, the MCA lost both responses post-stroke (5 months of age). When [Ca(2+)](i) was analysed in arteriolar smooth muscle cells, rhythmical changes in [Ca(2+)](i) occurred during the same cycle. Thus, these processes were synchronized. The synchronized rhythmical changes in [Ca(2+)](i) were abolished following application of 100 nM ketanserin and 10 µM nicardipine. Treatment with 60 nM charybdotoxin and 10 µM cyclopiazonic acid also significantly reduced rhythmical elevations in [Ca(2+)](i). In addition, rhythmical changes in [Ca(2+)](i) became unsynchronized following treatment with 100 µM carbenoxolone, a gap junction blocker. Connexin 45 mRNA and protein expression were both elevated in the MCA of SHR-SP. Taken together, these findings suggest that rhythmical changes in [Ca(2+)](i) of the MCA are dependent upon the 5-HT(2) receptor-mediated release of calcium from intracellular stores which, in turn, activates voltage-dependent calcium channels to enable an influx of calcium into smooth muscle cells. Subsequently, charybdotoxin-sensitive potassium channels are activated and provide a negative feedback pathway to regulate [Ca(2+)](i). Moreover, the co-ordinated synchronization of rhythmical changes in [Ca(2+)](i) across smooth muscle cells was found to be dependent upon gap junctions.

Distinct effects of tissue-type plasminogen activator and SMTP-7 on cerebrovascular inflammation following thrombolytic reperfusion.

BACKGROUND AND PURPOSE: Thrombolysis therapy using tissue-type plasminogen activator (t-PA) is occasionally accompanied by harmful outcomes, including intracerebral hemorrhage. We have reported that Stachybotrys microspora triprenyl phenol-7 (SMTP-7), a candidate thrombolytic drug, has excellent therapeutic effect on cerebral infarction in embolic stroke model in mice; however, little is known regarding whether this agent influences cerebrovascular inflammation following thrombolytic reperfusion. The current study aimed to compare the effects of recombinant t-PA (rt-PA) and SMTP-7 on cerebrovascular inflammation. METHODS: The impact of rt-PA- and SMTP-7-induced thrombolytic reperfusion on leukocyte dynamics was investigated in a photochemically induced thrombotic middle cerebral artery occlusion (tMCAo) model in mice. RESULTS: Both rt-PA and SMTP-7 administration in tMCAo mice (each 10 mg/kg) resulted in thrombolytic reperfusion. The SMTP-7-administered mice showed relatively mild rolling and attachment of leukocytes to the vascular wall in the middle cerebral vein, with weak peroxynitrite reactions and proinflammatory gene expression (IL-1ß, TNF-α, ICAM-1, and VCAM-1); thus, a small infarct volume compared with rt-PA-administered mice. In vitro study suggested that rt-PA at 20 µg/mL, but not SMTP-7 at a similar concentration, promotes cytokine-induced reactive oxygen species generation in cultured endothelial cells; moreover, SMTP-7 suppressed cytokine-induced VCAM-1 induction in the cells and leukocyte/ endothelial cell adhesions. CONCLUSIONS: Relatively mild cerebrovascular inflammation and cerebral infarction in the SMTP-7 mice, compared with in rt-PA mice, is thought to be caused at least in part by direct antioxidative actions of SMTP-7 in ECs.