A surviving case of mitochondrial cardiomyopathy diagnosed from the symptoms of multiple organ dysfunction syndrome.

A 49-year-old female cardiomyopathic patient with heart, hepatic, and renal failure and lactic acidosis was transferred to the intensive care unit without a unifying diagnosis. She was of short stature (145 cm tall), had difficulty in hearing, a past history of complete atrioventricular block, and had received a permanent pacemaker. She had been diagnosed and treated as dilated cardiomyopathy by her primary doctor. Treatment in the intensive care unit for 21 days including plasma exchange, continuous hemodiafiltration, artificial ventilation, and administration of catecholamine, carperitide, and a large amount of coenzyme Q10 (210 mg/day) improved the symptoms. Genetic analysis using mitochondrial DNA from leukocytes and sternocleidomastoid muscle revealed a 3243A>G mutation in the mitochondrial tRNA(Leu (UUR)) gene, which is related to mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS). The patient recovered through intensive care and could be discharged from hospital without any sequelae. This case was mitochondrial cardiomyopathy diagnosed from the symptoms of multiple organ dysfunction syndrome. Cardiomyopathy due to the mutation of mitochondrial DNA is not a common disease. However, it should be considered as a possible cause of heart failure.

A case of severe acute pancreatitis treated with CTR-001 direct hemoperfusion for cytokine apheresis.

Severe acute pancreatitis is a clinical entity that can develop into multiple organ failure (MOF), and still has a poor prognosis. It is generally agreed that excessive humoral mediators such as pro-inflammatory cytokines play important roles in the pathogenesis of organ failure in patients with severe acute pancreatitis (SAP). Furthermore, it has been reported that continuous hemodiafiltration (CHDF) can remove the excess humoral mediators during the hypercytokinemic state of systemic inflammatory response syndrome (SIRS). We experienced a case of severe acute pancreatitis induced by alcohol abuse, on whom we performed cytokine apheresis. The patient was a 46 year-old male. He received 14 cytokine apheresis procedures, for about 4 hours in each session, using a CTR-001 direct hemoperfusion (DHP) cartridge. His serum levels of pro-inflammatory cytokines such as interleukin-6 (IL-6; 1649.1+/-667.1-1257.1+/-489.4 pg/mL, P=0.013) decreased significantly after the CTR-001 procedures. However tumor necrosis factor-alpha (TNF-alpha) (26.2+/-1.7-24.3+/-1.9 pg/mL, P=0.087), IL-1beta (6.1+/-2.9-3.49+/-1.1 pg/mL, P=0.477), IL-8 (192.5+/-33.4-229.5+/-51.8 pg/mL, P=0.754) and IL-10 (14.4+/-2.7-14.0+/-1.9 pg/mL, P=0.726) did not decrease statistically. Therefore, we conclude that in this case, cytokine apheresis using a CTR-001 cartridge was effective for reducing the pro-inflammatory cytokines during severe acute pancreatitis.

Mice deficient in sphingosine kinase 1 are rendered lymphopenic by FTY720.

Sphingosine-1-phosphate (S1P), a lipid signaling molecule that regulates many cellular functions, is synthesized from sphingosine and ATP by the action of sphingosine kinase. Two such kinases have been identified, SPHK1 and SPHK2. To begin to investigate the physiological functions of sphingosine kinase and S1P signaling, we generated mice deficient in SPHK1. Sphk1 null mice were viable, fertile, and without any obvious abnormalities. Total SPHK activity in most Sphk1-/-tissues was substantially, but not completely, reduced indicating the presence of multiple sphingosine kinases. S1P levels in most tissues from the Sphk1-/- mice were not markedly decreased. In serum, however, there was a significant decrease in the S1P level. Although S1P signaling regulates lymphocyte trafficking, lymphocyte distribution was unaffected in lymphoid organs of Sphk1-/- mice. The immunosuppressant FTY720 was phosphorylated and elicited lymphopenia in the Sphk1 null mice showing that SPHK1 is not required for the functional activation of this sphingosine analogue prodrug. The results with these Sphk1 null mice reveal that some key physiologic processes that require S1P receptor signaling, such as vascular development and proper lymphocyte distribution, can occur in the absence of SPHK1.

The sphingosine-1-phosphate receptors S1P1, S1P2, and S1P3 function coordinately during embryonic angiogenesis.

Sphingosine-1-phosphate (S1P) elicits diverse cellular responses through a family of G-protein-coupled receptors. We have shown previously that genetic disruption of the S1P(1) receptor, the most widely expressed of the family, results in embryonic lethality because of its key role within endothelial cells in regulating the coverage of blood vessels by vascular smooth muscle cells. To understand the physiologic functions of the two other widely expressed S1P receptors, we generated S1P(2) and S1P(3) null mice. Neither the S1P(2) null mice nor the S1P(3) null mice exhibited significant embryonic lethality or obvious phenotypic abnormalities. To unmask possible overlapping or collaborative functions between the S1P(1), S1P(2), and S1P(3) receptors, we examined embryos with multiple S1P receptor mutations. We found that S1P(1) S1P(2) double null and S1P(1) S1P(2) S1P(3) triple null embryos displayed a substantially more severe vascular phenotype than did embryos with only S1P(1) deleted. We also found partial embryonic lethality and vascular abnormalities in S1P(2) S1P(3) double null embryos. Our results indicate that the S1P(1), S1P(2) and S1P(3) receptors have redundant or cooperative functions for the development of a stable and mature vascular system during embryonic development.

Protein kinase Cbeta selective inhibitor LY333531 attenuates diabetic hyperalgesia through ameliorating cGMP level of dorsal root ganglion neurons.

Streptozocin (STZ)-induced diabetic rats show hyperalgesia that is partially attributed to altered protein kinase C (PKC) activity. Both attenuated neuronal nitric oxide synthase (nNOS)-cGMP system and tetrodotoxin-resistant (TTX-R) Na channels in dorsal root ganglion neurons may be involved in diabetic hyperalgesia. We examined whether PKCbeta inhibition ameliorates diabetic hyperalgesia and, if so, whether the effect is obtained through action on neurons by testing nociceptive threshold in normal and STZ-induced diabetic rats treated with or without PKCbeta-selective inhibitor LY333531 (LY) and by assessing the implication of LY in either nNOS-cGMP system or TTX-R Na channels of isolated dorsal root ganglion neurons. The decreased nociceptive threshold in diabetic rats was improved either after 4 weeks of LY treatment or with a single intradermal injection into the footpads. The treatment of LY for 6 weeks significantly decreased p-PKCbeta and ameliorated a decrease in cGMP content in dorsal root ganglia of diabetic rats. The latter effect was confirmed in ex vivo condition. The treatment with NO donor for 4 weeks also normalized both diabetic hyperalgesia and decreased cGMP content in dorsal root ganglions. The expressions of nNOS and TTX-R Na channels were not changed with LY treatment. These results suggest that LY is effective for treating diabetic hyperalgesia through ameliorating the decrease in the nNOS-cGMP system.

Amelioration of retarded neurite outgrowth of dorsal root ganglion neurons by overexpression of PKCdelta in diabetic rats.

To examine which isoform of protein kinase C (PKC) may be associated with impaired nerve regeneration in diabetes, we compared neurite outgrowth of isolated dorsal root ganglion (DRG) neurons in streptozocin (STZ)-induced diabetic and control rats. Neurite outgrowth was significantly retarded in diabetic neurons. Rottlerin, a PKCdelta specific inhibitor, significantly retracted neurite outgrowth whereas Gö6976, an inhibitor specific for classical PKCs, had no effect, suggesting a significant role of PKCdelta in neurite outgrowth of DRG neurons. The expression of phosphorylated PKCdelta, but not total PKCdelta, in DRGs was decreased in diabetic rats. When this reduced expression was restored by overexpressing the PKCdelta in isolated DRG neurons, retardation of neurite outgrowth was significantly reversed in diabetic rats. These results suggest that a decrease in phosphorylated PKCdelta is at least in part responsible for impaired neurite outgrowth in diabetes, and that PKCdelta plays a significant role in the pathogenesis of diabetic neuropathy. This observation provides a useful clue for the treatment of diabetic neuropathy.