ABO-incompatible adult living donor liver transplantation for hepatocellular carcinoma.

Living donor liver transplantation (LDLT) offers timely transplantation for patients with hepatocellular carcinoma (HCC). If ABO-incompatible LDLT is feasible, the need for pretransplantation treatment may be eliminated, which may reduce overall morbidity. In this article, we have described 8 adult HCC patients who successfully underwent LDLT from ABO-incompatible donors. Antirejection therapy included multiple preoperative plasmaphereses, splenectomy, and an immunosuppressive regimen with tacrolimus, methylprednisolone, and mycophenolate mofetil. The maintenance dose of immunosuppression did not differ from that of the ABO-identical cases. In addition, we also performed intrahepatic arterial infusion of prostaglandin E1. In 5 patients, we administered a single dose of rituximab, a chimeric CD20 monoclonal antibody. As a result of this treatment, 6/8 patients are still alive. Our experience has shown that it is possible to control antibody-mediated humoral rejection and other complications in adult ABO-incompatible LDLT.

Biliary complications after 52 adult living donor liver transplantations: a single-center experience.

OBJECTIVE: The incidence of biliary complications after adult living donor liver transplantation (ALDLT) are still high even though various devices have been reported to overcome them. METHOD: From October 2000 to April 2007, we performed 52 ALDLTs which included 15 ABO-incompatible grafts. Median follow-up was 565 days. In 49 procedures, we used duct-to-duct anastmosis with a stent inserted in the recipient duct and out through the common bile duct wall as an external stent, and in 3 procedures, we used duct-to-jejunostomy anastomosis. We investigated postoperative biliary complications and their management. RESULTS: Forty-four patients received right lobe grafts and 8 received left lobe grafts. Among patients in whom duct-to-duct anastomosis was used, nine (20.5%) developed biliary complications including bile leakage in five and biliary strictures in four. All bile leakage was treated with reoperation. Three biliary strictures were treated with stent placement, and one biliary stricture was treated with magnetic compression anastomosis. Among the three patients in whom duct-to-jejunostomy was used, two (66.7%) had bile leakage and stricture, respectively. Two of four ABO-incompatible patients (50%) had hepatic artery thrombosis with biliary complications, a high incidence. CONCLUSION: In our series of ABO-incompatible patients undergoing ALDLT, those who developed hepatic artery thrombosis exhibited a high incidence of biliary complications.

How can we increase living related donor renal transplantations?

BACKGROUND: In Japan, living donor renal transplantation has gained momentum due to an increased number of patients with end-stage renal disease. Living donation not only provides better outcomes, but also the recipients usually need less medications, thereby increasing the quality of life and reducing the potential side effects of immunosuppression. MATERIALS AND METHODS: For the past 25 years, our center had performed 140 open donor nephrectomy (OPNx) renal transplantations. Since July 2003, we changed our procurement operation to living hand-assisted laparoscopic donor nephrectomy (HALNx) in 49 cases. Our operative technique consisted of two 12-mm ports placed in the midaxillary line at the superior and inferior levels of the umbilicus. Next, a 5-cm incision was made in the midline periumbilicus and the hand port system fitted through a midline abdominal incision. RESULTS: In 49 cases, HALNx was completed successfully; no patient required conversion to laparotomy. The estimated blood loss was 33.0 +/- 43.4 g and no patient required blood transfusion. In comparison, in OPNx the blood loss was 426.5 +/- 247.6 g (P < .001). The mean operative times were 167.4 +/- 39.7 minutes for HALNx and 228.4 +/- 35.7 minutes for OPNx (P < .001). The postoperative hospital stays were 9.1 +/- 3.8 days for HALNx and 13.0 +/- 1.9 days for OPNx (P < .001). For 3 years prior to introduction of HALNx, we had performed only 10 living donor renal transplantations. Since the introduction of HALNx in 2003, the number of living donors has tripled during the following 3 years. CONCLUSIONS: Herein we have reported that HALNx was superior in terms of less operative time and blood loss, postoperative pain and recovery, and shorter hospital stay. Overall donor patient satisfaction was also better in the HALNx group. HALNx is a safe procedure that makes kidney donation more appealing to potential live donors and has increased the living donor pool at our center.

Similar Outcomes of Kidney Transplantations Using Organs From Donors After Cardiac Death and Donors After Brain Death.

BACKGROUND: To increase the number of cadaveric kidney transplants in Japan, it is necessary to proactively use organs from all donors. Since the revision of the Organ Transplant Law, the number of organ donors after cardiac death (DCD) has decreased but the number of organ donors after brain death (DBD) has increased; however, the number of donor organs and awareness of cadaveric transplantation have increased. METHODS: At our institution, 28 patients underwent cadaveric kidney transplantation from January 2001 to December 2016. These patients were classified into 2 groups according to DBD or DCD. Furthermore, 10 patients received transplants from expanded criteria donors (ECD) and 18 received them from standard criteria donors (SCD). RESULTS: Kidney graft survival and engraftment were observed for all patients. There were no significant differences in renal function at 6 months for DBD and DCD transplant recipients. Renal function at 1, 3, and 5 years and serum creatinine levels were better for the ECD group. Renal function at 5 years after transplantation was significantly better for the SCD group than for the ECD group; however, there was no difference in delayed graft function between the SCD and ECD groups. Comparisons of the 3 groups showed good renal function for transplants from DBDs, but there was no significant difference in survival rates. CONCLUSIONS: Results were good for all patients. There were no significant differences in outcomes of our patients who received transplants from ECD or SCD.

An Examination of Pregnancy Cases After Kidney Transplantation: Single-Center Experience.

INTRODUCTION: The number of young women who wish to become pregnant opting for kidney transplants is increasing, as becoming pregnant under hemodialysis or peritoneal dialysis is associated with many risks. However, there have been reports indicating that these patients are subject to a higher risk of miscarriage compared to women with normal renal function. We examine and report cases of patients that experienced pregnancy after undergoing kidney transplantation at our hospital. SUBJECTS AND METHOD: Of the kidney transplantation cases that were performed at our hospital between 1985 and 2016, there were 7 cases of pregnancy. The serum creatinine levels, urine protein findings, etc, of these 7 cases were examined during the pre-pregnancy, pregnancy, childbirth, and postpartum periods. RESULTS: All 7 cases were able to give birth. There were two cases of transient postpartum hypertension. There were no cases of obvious pregnancy toxemia or fetal growth retardation. Two of the cases resulted in the failure of the transplanted kidneys. DISCUSSION: According to previous studies on pregnancy and childbirth after kidney transplantation, the presence of high blood pressure and proteinuria as well as the renal function at the time of pregnancy is closely associated with postpartum renal function. Urine protein was detected prior to pregnancy in both cases and resulted in the failure of the transplanted kidneys. The influence of immunosuppressants on the mother and fetus is also an important consideration. CONCLUSION: We believe it is extremely important to ensure a thorough informed consent process prior to pregnancy and systematic use of immunosuppressants for young female transplant recipients.

Early Outcomes of Living-Donor Kidney Transplantation With Immunosuppression Therapy Induction With Tacrolimus Extended-Release: A Comparison With Cyclosporine.

BACKGROUND: Extended-release tacrolimus (TacER), administered once daily, offers improved adherence with reduced side effects while still maintaining an immunosuppressive potency equivalent to that of conventional tacrolimus preparations. METHODS: The study included 83 patients who received consecutive living-donor kidney transplants at our facility from June 2013 to December 2016. Comparisons were made between 48 cases of induction with TacER and 35 cases of induction with cyclosporine (CyA). The observation period was 3 months after transplantation. Transplanted kidney function, rejection, infectious disease, lipid abnormalities, and glucose tolerance were compared. RESULTS: The 2 groups showed no significant difference in donor background or transplanted kidney function. Within the 3-month observation period, an acute rejection response was observed in 2 cases in the TacER group and in 8 cases in the CyA group. After transplantation, hyperlipidemia requiring medication was observed more frequently in the CyA group. The 2 groups did not show a marked difference in systemic infection or renal calcineurin inhibitor toxicity in histopathologic examination of the transplanted kidneys 3 months after surgery. DISCUSSION: Proactive use of TacER leads to improved adherence while yielding immunosuppressive potency equivalent to that of conventional tacrolimus preparations; however, tacrolimus has a potent blood sugar-elevating effect; thus, direct comparison with the CyA group is important for assessing the side effects. CONCLUSION: TacER has the potential to also reduce side effects in the early stages after surgery, suggesting its potential as a drug of first choice.

Sodium/calcium exchange modulates intracellular calcium overload during posthypoxic reoxygenation in mammalian working myocardium. Evidence from aequorin-loaded ferret ventricular muscles.

We tested the hypothesis that the intracellular Ca2+ overload of ventricular myocardium during the period of posthypoxic reoxygenation is mediated by transsarcolemmal Ca2+ influx via Na+/Ca2+ exchange. In aequorin-loaded, ferret right ventricular papillary muscles, blockers of the sarcolemmal and the sarcoplasmic reticulum Ca2+ channels, slowed the Cai2+ transient, producing a convex ascent during membrane depolarization, followed by a concave descent during repolarization. The magnitude of the Cai2+ transient was affected by changes in the membrane potential, Nai+, Nao+, and Cao2+, and was blocked by Ni2+, or dichlorbenzamil. The calculated Na+/Ca2+ exchange current was in the reverse mode (Ca2+ influx) during the ascending phase of the Cai2+ transient, and was abruptly switched to the forward mode (Ca2+ efflux) at repolarization, matching the time course of the Cai2+ transient. During hypoxic superfusion, the Cai2+ transient was abbreviated, which was associated with a shorter action potential duration. In contrast, immediately after reoxygenation, the Cai2+ transient increased to a level greater than that of the control, even though the action potential remained abbreviated. This is the first demonstration on a beat-to-beat basis that, during reoxygenation, Ca2+ influx via Na+/Ca2+ exchange is augmented and transports a significant amount of Ca2+ into the ventricular myocardial cell. The activation of the exchanger at the time of reoxygenation appears to be mediated by Nai+ accumulation, which occurs during hypoxia.

The role of plasmapheresis therapy for perioperative management in ABO-incompatible adult living donor liver transplantation.

BACKGROUND: Although living donor liver transplantation (LDLT) was established as a treatment for end-stage liver disease in Japan, the indication for LDLT across an ABO-incompatible barrier remains controversial. The purpose of this study was to elucidate the role of plasmapheresis in incompatible LDLT. METHODS: Eleven adult patients (seven men and four women) who underwent incompatible LDLT were enrolled in this study. Of these three patients had hepatocellular carcinoma, three chronic hepatitis C, one Wilson's disease, one autoimmune hepatitis, one chronic hepatitis B, one hemochromatosis, and one fulminant hepatic failure. The immunosuppressive regimen consisted of tacrolimus, prednisolone, mycophenolate mofetil (or cyclophosphamide), and prostaglandin E1 in all patients. Multiple plasmapheresis was performed perioperatively to reduce the recipient's antibody titers against the donor's blood type. RESULTS: Plasmapheresis was useful for the reduction of the recipient's antibody titers to x 16 or lower before and after transplantation. There was no difference in transplant outcome between the 11 patients with incompatible blood group and 30 patients with identical or compatible blood groups. DISCUSSION: Major postoperative complications such as intrahepatic biliary complications and hepatic necrosis may occur in incompatible transplantation. Several investigators suggested that anti-immunoglobulin (Ig) M and anti-IgG antibody titers sustained these complications. The antibody titers must be decreased sufficiently with plasmapheresis. An elevation of anti-ABO titers after transplantation may be a predictive risk factor for increased mortality and morbidity. In order to perform LDLT in a safer manner, plasmapheresis is an indispensable treatment to improve the outcome of ABO-incompatible cases.

Biological sludge solubilisation for reduction of excess sludge production in wastewater treatment process.

A novel sludge disintegration system (JFE-SD system) was developed for the reduction of excess sludge production in wastewater treatment plants. Chemical and biological treatments were applied to disintegrate excess sludge. At the first step, to enhance biological disintegration, the sludge was pretreated with alkali. At the second step, the sludge was disintegrated by biological treatment. Many kinds of sludge degrading microorganisms integrated the sludge. The efficiency of the new sludge disintegration system was confirmed in a full-scale experiment. The JFE-SD system reduced excess sludge production by approximately 50% during the experimental period. The quality of effluent was kept at quite a good level. Economic analysis revealed that this system could significantly decrease the excess sludge treatment cost.

Postoperative Compensatory Changes and Blood Flow Parameter of the Preserved Kidney in Elderly Living Related Donors Evaluated by Doppler Ultrasonography.

INTRODUCTION: Elderly kidney donors have recently become more common in living related kidney transplantation in Japan. Therefore, it is important to evaluate whether kidney function in elderly donors after nephrectomy is preserved over long periods of time. Doppler ultrasonography measurement is practical for donors after nephrectomy because it involves simple and noninvasive examinations. Doppler ultrasonography can detect compensatory hypertrophy and blood flow parameters, namely resistive index (RI) and pulsatility index (PI), of the preserved kidney in living donors. PATIENTS AND METHODS: Our study included 58 donors, divided into 2 groups according to age; the elderly donor group was comprised of those 65 years old or older. We measured length, width, and short diameter of the preserved kidney using Doppler ultrasonography, and calculated kidney volume. RESULTS: The elderly group was comprised of 13 patients. In this group, the median preserved kidney volume was 145.0 cm(3) (101.8-193.5) before nephrectomy, and 127.6 cm(3) (99.0-183.4) and 145.5 cm(3) (141.3-148.6) at 1 and 12 months after nephrectomy, respectively. We did not observe significant compensatory hypertrophy in the preserved kidneys of elderly donors postoperatively. Both the mean PI and RI values of elderly donors increased progressively after nephrectomy. No compensatory hypertrophy occurred in the preserved kidneys of elderly donors, although the PI and RI did increase in these donors. CONCLUSION: Our results indicate that nephrectomy caused nephrosclerosis in the preserved kidneys of elderly donors and that prevention of hypertension may be important after nephrectomy in elderly donors.

Study of Cadaveric Kidney Transplantation: A Single Center Experience.

BACKGROUND: To increase the number of cadaveric kidney transplants in Japan, it is necessary to proactively perform transplantation from marginal donors. We had the opportunity to frequently perform kidney transplantation from expanded-criteria donors (ECDs), and it is anticipated that there will be increases in the number of ECD kidney transplants. METHODS: In our institution, 18 patients underwent cadaveric kidney transplantation from January 2001 to December 2011. Sixteen of those patients were classified into 2 groups according to donation after brain death (BD) or after cardiac death (CD). We also classified donors as ECDs or standard-criteria donors (SCDs). RESULTS: Kidney graft survival and engraftment were observed in all of the patients. Renal function at 1 year after transplantation was significantly better in the BD group than in the CD group. However, there was no significant difference between the groups in renal function at 3 and 5 years. Renal function at 1 and 3 years after transplantation was significantly better in the SCD group than in the ECD group, but there was no difference in renal function between the SDC and ECD groups at 5 years. CONCLUSIONS: The results were good for all of the patients. There are many reports that graft survival rate at 3-5 years after transplantation from ECDs is poorer than from SCDs. However, no statistically significant difference was found in kidney function at ≥5 years between the ECD and SCD groups in our patients.

Clinical Outcomes and Results of Pathological Findings of 1-year Protocol Biopsy in Recipients of ABO-Incompatible Living Donor Kidney Transplantants.

OBJECTIVES: ABO-incompatible kidney transplantation has increased the possibility of finding suitable living donors for patients with renal failure. However, there are inevitable immunological risks, including a high risk of early post-transplantation complications. The purpose of this study was to evaluate recipient outcomes following ABO-incompatible kidney transplantation. METHODS: Seventy-one patients who had undergone living-donor kidney transplantation (LDKT) at our center between January 2008 and December 2013 were divided into ABO-incompatible (ABOi; n = 21) and ABO-compatible (ABOc; n = 50) groups. Baseline data, graft function, immunosuppressant use, and the results of biopsy 1 year after LDKT were compared between the groups. RESULTS: Recipient preemptive LDKT rates were significantly different between groups (P = .017). Graft function, incidence of infection, and rates of T-cell-mediated rejection and borderline changes requiring medication were not significantly different. There was no acute antibody-mediated rejection. Selectivity of the immunosuppressant, tacrolimus, was significantly different between groups (P < .01); however, steroid withdrawal rates, mycophenolate mofetil doses, and calcineurin inhibitor trough levels were not different. Regarding biopsy data, interstitial fibrosis scores were significantly different between groups (P = .011), as were interstitial fibrosis and tubular atrophy scores (P = .045) and arteriolar hyalinosis score (P = .022). CONCLUSION: ABOi LDKT was relatively safe, with no significant difference in the incidence of rejection compared to ABOc LDKT. Managing chronic pathological changes and arteriolar hyalinosis prophylaxis after ABOi LDKT may result in more successful outcomes.

Immunosuppressive Therapy for Elderly Kidney Transplant Recipients.

OBJECTIVES: In elderly kidney transplant (KT) recipients, the incidence of acute rejection is decreased, while that of fatal infections is increased. There are currently no guidelines for an upper age limit for KT, which is very difficult to determine. Here we examined several cases of elderly KT recipients. METHODS: We evaluated 127 KT patients treated at our department between 2003 and 2012 and followed them for 3 years post-transplant. The subjects were divided into two groups by age: ≥60 years (elderly group; n = 24); and <59 years (non-elderly group; n = 103). The presence or absence of acute rejection and infection, dose of immunosuppressive drugs, trough calcineurin inhibitor level, renal function, and graft and patient survival rates were retrospectively examined. RESULTS: Our basic immunosuppressive regimen was a combination of calcineurin inhibitor, methylprednisolone, mycophenolate mofetil, and basiliximab. At 1 year post-transplantation, the average tacrolimus and cyclosporine dose and trough levels were not significantly different. The mean dose of mycophenolate mofetil in the elderly group at 1 year post-transplantation was significantly lower than that of the non-elderly group. The incidences of cytomegalovirus infection and acute rejection during follow-up did not differ significantly between groups. There were no significant differences in creatinine level between the two groups. In the elderly group, the graft survival rates at 1 and 5 years were 100% and 95.4%, respectively, while those in the non-elderly group were 98.1% and 92.5%, respectively. CONCLUSION: Using our current immunosuppressive protocol, the outcomes of patients in the elderly group were considered acceptable.

A Novel Assessment of Vascular Regions Using an Intraoperative Near-Infrared Fluorescence.

INTRODUCTION: The risk of complications and transplant renal function increases in multiple arterial renal transplantations compared with single arterial renal transplantations. Even when multiple arteries are involved, with the introduction of laparoscopic nephrectomy, I mainly choose the left side kidney. Therefore, the number of renal artery reconstructions is increasing, and simultaneous imaging of arterial rebuilding during the donor nephrectomy is important. MATERIAL: Between 2006 and 2015, we performed 132 living donor kidney transplantations at our center and analyzed 32 cases that were diagnosed pre- and intraoperatively. METHOD: We compared the single renal artery (SRA) and multiple renal arteries (MRA) groups and analyzed the number of renal arteries, reconstruction methods, donor and recipient ages, sex, total ischemic times, and 1-month serum creatinine values. RESULT: In the MRA and SRA groups, the average recipient age was 52.3 and 47.0 years, respectively, while the average donor age was 52.9 and 53.1 years, respectively. In SRA and MRA groups, total ischemic time (TIT) was 96.1 and 143.6 min (P < .01). Serum creatinine level 1 month post-transplantation was 1.54 and 1.25, respectively (P < .001). Here we experienced 12 cases of living renal donor nephrectomy with multiple vessels in which the vascular supply territory was first assessed in April 2013 using an intraoperative near-infrared fluorescence camera system. In addition, regarding TIT, it is possible to shorten surgery by using individual anastomosis and ligation. CONCLUSION: By managing multiple donors; arteries by nephrectomy, it is possible to improve kidney transplantation results.

Arylsulfatase of human tissue. Studies on a form of arylsulfatase B found predominantly in brain.

The distribution of soluble arylsulfatase (aryl-sulfate sulfohydrolases, EC 3.1.6.1) in human tissues was investigated by DEAE-cellulose chromatography, All tissues examined contained arylsulfatase A and arylsulfatase B. In addition, brain singularly contained significant quantities (15-25% of total arylsulfatase) of a minor anionic arylsulfatase from designated arylsulfatase Bm, whereas only trace amounts of arylsulfatase Bm were found in liver, kidney, testis and placenta. Arylsulfatase B and arylsulfatase Bm had equal activity toward methyl-umbelliferyl sulfate, nitrocatechol sulfate and a physiological substrate UDP-N-acetylgalactosamine 4-sulfate, but both forms were inactive toward the arylsulfatase A substrates cerebroside sulfate and ascorbic acid 2-sulfate. Purified preparations of placental arylsulfatase B, brain arylsulfatase Bm, and urinary arylsulfatase A did not hydrolyze estrone sulfate, dehydroepiandrosterone sulfate or pregnenolone sulfate. The physico-chemical properties of arylsulfatase Band arylsulfatase Bm differed with respect to thermal lability, DEAE-cellulose chromatography, polyacrylamide gel electrophoresis and isoelectric focussing. In the latter technique, utilizing thin polyacrylamide slab gels, the isoelectric point for placental arylsulfatase B was 8.2, while brain arylsulfatase Bm resolved into 3 activity bands with pI values 6.8, 7.0 and 7.2. Although the physico-chemical properties differed, arylsulfatase B and arylsulfatase Bm appear to be functionally equivalent as well as generically related.

Endothelin-1 has a unique oxygen-saving effect by increasing contractile efficiency in the isolated rat heart.

BACKGROUND: The effect of endothelin (ET)-1 on cardiac energetics is not fully understood. METHODS AND RESULTS: In isolated, coronary-perfused rat hearts, we measured left ventricular contractility index (E(max)), pressure-volume area (PVA), and myocardial oxygen consumption (MVO(2)) before and after administration of ET-1 (1x10(-)(9) mol/L). ET-1 increased E(max) by 48+/-16% (P<0.01) and the total MVO(2) by 24+/-11% (P<0.01). The MVO(2)-PVA relations were linear both before and after ET-1 (r>0.99). ET-1 shifted MVO(2)-PVA upward, increasing the MVO(2) intercept by 24+/-13%. At the same time, ET-1 decreased the slope (S), with 1/S (contractile efficiency) being 46+/-5% before and 56+/-5% after ET-1 (P<0.01). ET-1-induced increases in E(max) and in contractile efficiency were abolished by an ET(A) receptor blocker (S-0139) but not by an ET(B) blocker (BQ-788). Although high [Ca(2+)] perfusion increased E(max) and the intercept to the same extent as ET-1, it did not change S. N(G)-Nitro-L-arginine (an inhibitor of nitric oxide synthase) increased the coronary perfusion pressure as much as ET-1, but S again remained unchanged. Dimethylamyloride (Na(+)/H(+) exchanger inhibitor) partially blocked the positive inotropic effect of ET-1 but not the ET-1-induced increase in the contractile efficiency. CONCLUSIONS: Agonistic effects of ET-1 on the ET(A) receptor economized the chemomechanical conversion efficiency of the left ventricular unit myocardium by a mechanism independent of the Na(+)/H(+) exchanger. This unique oxygen-saving effect of ET-1 may play an adaptive role in the failing myocardium, in which local accumulation of ET-1 is present.

Differential effects of angiotensin II versus endothelin-1 inhibitions in hypertrophic left ventricular myocardium during transition to heart failure.

BACKGROUND: In view of their mutual crosstalk, the roles of angiotensin II (Ang II) and endothelin-1 (ET-1) in the myocardium are assumed to be synergistic and supplemental. METHODS AND RESULTS: In the phase of compensated left ventricular (LV) hypertrophy of Dahl salt-sensitive rats, Ang II peptide and the ACE mRNA in the LV were increased by 1.6- and 3.8-fold, respectively. In contrast, ET-1 peptide and the preproET-1 mRNA remained unchanged. In subsequent congestive heart failure (CHF), Ang II and ACE mRNA did not show further increases. But ET-1 and the mRNA were increased de novo by 5.3- and 4.1-fold, respectively. In ascending aorta-banded rats, the local activations of Ang II and ET-1 also showed a differential time course between LV hypertrophy and CHF. Long-term treatments of Dahl salt-sensitive rats with temocapril (an ACE inhibitor) and with bosentan (a mixed ET receptor blocker) equally improved long-term survival. Temocapril reduced the LV/body weight ratio and ameliorated LV fractional shortening. Conversely, although bosentan equally improved fractional shortening, it did not reduce the increase in LV mass. Combined treatment with these 2 drugs further ameliorated the animal's survival without additional decreases in systolic pressure. CONCLUSIONS: The pathophysiological roles in the myocardium during the transition to CHF differ qualitatively between Ang II and ET-1. Thus, long-term therapy with a combination of ACE inhibition and ET antagonism may provide a new approach for heart failure in humans.

Activation of lectin-like oxidized low-density lipoprotein receptor-1 induces apoptosis in cultured neonatal rat cardiac myocytes.

BACKGROUND: Lectin-like oxidized LDL receptor-1 (LOX-1) was originally identified as a receptor expressed predominantly in endothelial cells. LOX-1 can also be expressed in other cell types, and the activation of the LOX-1 pathway has been implicated in apoptosis. There have been no reports, however, about LOX-1 expression in cardiac myocytes or regulation of myocardial cell apoptosis by LOX-1. METHODS AND RESULTS: In primary cardiac myocytes from neonatal rats, immunohistochemical analyses using a specific monoclonal antibody against LOX-1 demonstrated that LOX-1 expression was markedly induced by stimulation with norepinephrine and endothelin-1. LOX-1 expression was upregulated in cardiac myocytes as well as in vessel walls of failing rat hearts in vivo. In the presence of a low concentration of oxidized LDL that did not induce apoptosis by itself, artificial overexpression of LOX-1 in cardiac myocytes in culture resulted in apoptosis. LOX-1 overexpression induced activation of p38 mitogen-activated protein kinase (MAPK) and oxidative stress in cardiac myocytes, as demonstrated by an increase in positive immunostaining for 8-hydroxy-2'-deoxyguanosine. Inhibition of p38 MAPK by cotransfection of a dominant-negative form of MKK6 as well as by administration of a specific inhibitor, SB203580 or FR167653, almost completely blocked the induction of apoptosis by LOX-1 activation. Antioxidant catalase also blocked LOX-1-induced apoptosis as well as activation of p38 MAPK. CONCLUSIONS: These findings demonstrate that LOX-1 expression in cardiac myocytes is induced by neurohormonal factors activated in heart failure and that LOX-1-dependent apoptosis in these cells requires p38 MAPK, a component of oxidant stress-sensitive signaling pathways.

Anti-ischemic effect of a novel cardioprotective agent, JTV519, is mediated through specific activation of delta-isoform of protein kinase C in rat ventricular myocardium.

BACKGROUND: A new 1,4-benzothiazepine derivative, JTV519, has a strong protective effect against Ca(2+) overload-induced myocardial injury. We investigated the effect of JTV519 on ischemia/reperfusion injury in isolated rat hearts. METHODS AND RESULTS: At 30 minutes of reperfusion after 30-minute global ischemia, the percent recovery of left ventricular developed pressure was improved, and the creatine phosphokinase and lactate dehydrogenase leakage was reduced in a concentration-dependent manner when JTV519 was administered in the coronary perfusate both at 5 minutes before the induction of ischemia and at the time of reperfusion. The myocardial protective effect of JTV519 was completely blocked by pretreatment of the heart with GF109203X, a specific protein kinase C (PKC) inhibitor. In contrast, the effect of JTV519 was not affected by alpha(1)-, A(1)-, and B(2)-receptor blockers that couple with PKC in the cardiomyocyte. Both immunofluorescence images and immunoblots of JTV519-treated left ventricular myocardium and isolated ventricular myocytes demonstrated that this agent induced concentration-dependent translocation of the delta-isoform but not the other isoforms of PKC to the plasma membrane. CONCLUSIONS: The mechanism of cardioprotection by JTV519 against ischemia/reperfusion injury involves isozyme-specific PKC activation through a receptor-independent mechanism. This agent may provide a novel pharmacological approach for the treatment of patients with acute coronary diseases via a subcellular mechanism mimicking ischemic preconditioning.

Modulation of in vivo cardiac hypertrophy with insulin-like growth factor-1 and angiotensin-converting enzyme inhibitor: relationship between change in myosin isoform and progression of left ventricular dysfunction.

OBJECTIVES: Supplemental myocardial hypertrophy induced by insulin-like growth factor (IGF)-1 may prevent transition from hypertrophy to heart failure under chronic mechanical overload. BACKGROUND: Several studies have suggested that IGF-1 treatment may be beneficial in chronic heart failure. In addition, recent studies indicated that the amount of alpha-myosin heavy chain (MHC) plays a significant hemodynamic role in large animals including humans. METHODS: We treated Dahl salt-sensitive hypertensive rats on a long-term basis with IGF-1. The effects were compared with those produced by treatment using a sub-antihypertensive dose of temocapril, an angiotensin-converting enzyme (ACE) inhibitor. At 11 weeks, when these rats displayed compensated left ventricular hypertrophy (LVH), they were randomized to three groups: 1) IGF group (3 mg/kg/day); 2) temocapril group (1 mg/kg/day); and 3) vehicle (control) group. RESULTS: After 15 weeks, the control rats showed left ventricular (LV) enlargement and severe LV dysfunction and rapidly died of pulmonary congestion (mean survival time: 16.8+/-0.5 weeks). The survival time was significantly shortened (15.6+/-0.3 weeks) in the IGF-1 group but significantly prolonged (19.5+/-0.6 weeks) in the temocapril group. The rats in the IGF-1 group showed accelerated LV dilation and dysfunction. Of the several parameters investigated, it was found that the relative amounts of MHC isoforms differed among the three groups. The alpha-MHC mRNA level was decreased by 52% (p<0.01) in the IGF group, while it increased by 58% (p<0.01) in the temocapril group compared with the control group. These changes were related to the progression of LV dysfunction. CONCLUSIONS: Supplemental myocardial hypertrophy with long-term IGF-1 treatment may not be beneficial if concentric LVH already exists. Our data suggest that IGF-1 may not protect myocardial performance when its hypertrophic effect aggravates the reduction of alpha-MHC. By contrast, the ACE inhibitor may improve myocardial function and prognosis by preventing the down-regulation of this isoform.