The α-mangostin prevention on cisplatin-induced apoptotic death in LLC-PK1 cells is associated to an inhibition of ROS production and p53 induction

Cisplatin (CDDP) is a widely useful chemotherapeutic agent for the treatment of tumors including lung, ovary and testis. Acute renal injury, however, is the main side effect observed after CDDP treatment. This side effect is related to the apoptotic death in proximal tubular cells in the kidney and p53 protein has a central role in this process. On the other hand, α-mangostin (α-M), a xanthone derived from the pericarp of mangosteen, exerts a renoprotective effect against cisplatin-induced renal damage in rats. The aim of this study was to evaluate whether α-M protects proximal tubule renal epithelial cells (LLC-PK1) from CDDP-induced apoptotic death. Cells were co-incubated with 5 μM α-M and 100 μM CDDP for 24 h. It was found that α-M attenuated the following alterations: the apoptotic cell death, the increase in reactive oxygen species (ROS), the glutathione depletion and the increase in p53 expression induced by CDDP. In conclusion, the preventive effect of α-M on CDDP-induced apoptotic death is associated to the inhibition of p53 expression and ROS generation.     

Ischemia in the isolated erythrocyte-perfused rat kidney. Protective effect of hypothermia

We have examined the effects of 25 min of ischemia in the isolated erythrocyte-perfused rat kidney (IEPK). We have previously shown that, in this model, perfusate flow rate is close to blood flow rates in vivo and morphology is normal. The functional and morphological consequences of both warm ischemia (at 37 degrees C) and ischemia induced during mild hypothermia (27 degrees C) were compared. (1) Warm ischemia resulted in a 51% increase in renal vascular resistance (RVR) during the reflow period, while glomerular filtration rate (GFR) was reduced to 24% of control levels. (2) Kidneys subjected to warm ischemia showed marked morphological damage localized to the proximal tubule. There was dilatation of the proximal segments and widespread loss of the proximal brush border due both to shedding into the lumen and interiorization into the cell. In contrast to the proximal tubular damage, the cells of the medullary thick ascending limb segments were intact. However, the lumena of many of these segments were filled with cytoplasmic blebs and necrotic cell debris. There was also pronounced vascular congestion of the capillary plexus in the inner stripe of the outer medulla. (3) Hypothermia to 27 degrees C resulted in almost complete protection against ischemic injury: RVR and GFR were not different from control values. Also, kidneys subjected to cold ischemia showed only isolated areas of mild brush border damage; no evidence of tubular obstruction or vascular congestion was present. (4) Thus, warm ischemia in the IEPK results in functional and morphological effects comparable to those found in vivo. Post-ischemic vasoconstriction as well as medullary congestion occur in the absence of systemic hormones and renal nerves. These consequences of ischemia are prevented by modest hypothermia.     

Precision-cut dog renal cortical slices in dynamic organ culture for the study of cisplatin nephrotoxicity

The dog is the non-rodent species the most often used in preclinical drug safety evaluation. In this study, we established a new system of precision-cut dog renal cortical slices, evaluated their biochemical, functional, and morphological integrity, and determined the effects of cisplatin (cis-diamminedichloroplatinum (II), CDDP), a very potent nephrotoxic antineoplastic agent used to treat a variety of solid tumors, on the viability and histopathology of slices. Precision-cut renal cortical slices were made perpendicular to the cortical-papillary axis. Slices were incubated in DMEM/Ham's F12 culture medium containing 1 g/L glucose, 2 mmol/L glutamine, and 2 mmol/L heptanoic acid at 37°C in an atmosphere of 5% CO₂-70% O₂-25% N₂ in dynamic organ culture. Our results showed that slices maintained ATP and GSH content, protein synthesis, Na⁺-dependent uptake of glucose inhibited by phlorizin, PAH (p-aminohippuric acid) uptake inhibited by probenecid, and TEA (tetraethylammonium) uptake inhibited by mepiperphenidol for at least 6 h of culture, and morphological integrity up to 24 h. After 6 h of exposure, CDDP induced vacuolation and cell necrosis in the epithelial tubular cells of slices with a concentration-related increase in extension but not in severity. The development of the lesions started in the proximal tubules and extended to the distal tubules. The location and the extension of the lesions confirmed the observations in dog kidneys after in vivo treatment with CDDP by the intravenous route. The concentration-related decrease in slice viability after 6 h exposure to CDDP was in keeping with the extension of the histopathological lesions in the renal parenchyma. The slice viability was unaffected up to 0.63 mmol/L CDDP. At 1.25 and 2.5 mmol/L CDDP, slice viability fell by 35% and 75%, respectively. These results suggest that precision-cut dog renal cortical slices in culture may be suitable for addressing the specific nephrotoxicity issues encountered in this species.Abbreviations CDDP cis-diamminedichloroplatinum (II) - FIS freshly isolated slices - GSH glutathione - GSSG glutathione disulfide - Hepes 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid - MGP methyl--D-glucopyranoside - MTT 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide - PAH p-aminohippuric acid - PBS phosphate-buffered saline - TEA tetraethylammonium     

Effect of leukemia inhibitory factor in experimental cisplatin neuropathy in mice

In this study, the effect of leukemia inhibitory factor (LIF) on cisplatin (CDDP)-induced neuropathy was evaluated. Mice were treated with CDDP, 2 mg/kg i.p. twice a week nine times. During the last week some of the mice were also injected with LIF, 2 mug/kg s.c. every other day for a total of four injections. Development of neuropathy was evaluated with changes in tail flick latency and sensory nerve conduction velocity (NCV). At the end of the treatment period dorsal root ganglia (DRG) were microscopically examined. Some of the DRGs were explanted into extracellular matrix, covered with culture medium and incubated for 3 days. During and at the end of the incubation, cellular migration and axonal outgrowth from the DRGs were quantified. LIF proved effective in reversing the increase in tail flick latency (p<0.05) and improving the reduction in NCV induced by CDDP. CDDP led to smaller nuclear and somatic size in neurons, while with LIF, the latter was restored to control values (p<0.01). No apoptotic nucleus was observed among DRG neurons while very few and moderate numbers detected among satellite and Schwann cells, respectively. With LIF, none of the cells had apoptosis. CDDP caused a decrease in the number of migrating cells and in the length of outgrowing axons while LIF treatment restored both capacities (p<0.05) In conclusion, in CDDP-induced neuropathy, LIF was found to be effective in correcting some functional and morphological deteriorations related with major involvement of Schwann cells.     

Flamingo, a seven-pass transmembrane cadherin, regulates planar cell polarity under the control of Frizzled.

We identified a seven-pass transmembrane receptor of the cadherin superfamily, designated Flamingo (Fmi), localized at cell-cell boundaries in the Drosophila wing. In the absence of Fmi, planar polarity was distorted. Before morphological polarization of wing cells along the proximal-distal (P-D) axis, Fmi was redistributed predominantly to proximal and distal cell edges. This biased localization of Fmi appears to be driven by an imbalance of the activity of Frizzled (Fz) across the proximal/distal cell boundary. These results, together with phenotypes caused by ectopic expression of fz and fmi, suggest that cells acquire the P-D polarity by way of the Fz-dependent boundary localization of Fmi.     

5-Aminolevulinic Acid Protects against Cisplatin-Induced Nephrotoxicity without Compromising the Anticancer Efficiency of Cisplatin in Rats In Vitro and In Vivo

Background/Aims

Nephrotoxicity is a frequent and major limitation in cisplatin (CDDP)-based chemotherapy. 5-Aminolevulinic acid (ALA) is widely distributed in animal cells, and it is a precursor of tetrapyrole compounds such as heme that is fundamentally important in aerobic energy metabolism. The aim of this study is to evaluate the protective role of ALA in CDDP-induced acute kidney injury (AKI).

Method

We used CDDP-induced AKI rat model and cultured renal tubular cells (NRK-52E). We divided four groups of rats: control, CDDP only, CDDP + ALA(post);(ALA 10 mg/kg + Fe in drinking water) after CDDP, CDDP + ALA(pre & post).

Result

CDDP increased Cr up to 6.5 mg/dl, BUN up to 230 mg/dl, and ALA significantly reduced these changes. ALA ameliorates CDDP-induced morphological renal damages, and reduced tubular apoptosis evaluated by TUNEL staining and cleaved caspase 3. Protein and mRNA levels of ATP5α, complex(COX) IV, UCP2, PGC-1α in renal tissue were significantly decreased by CDDP, and ALA ameliorates reduction of these enzymes. In contrast, Heme Oxigenase (HO)-1 level is induced by CDDP treatment, and ALA treatment further up-regulates HO-1 levels. In NRK-52E cells, the CDDP-induced reduction of protein and mRNA levels of mitochondrial enzymes was significantly recovered by ALA + Fe. CDDP-induced apoptosis were ameliorated by ALA + Fe treatment. Furthermore, we evaluated the size of transplantated bladder carcinoma to the rat skin, and ALA did not change the anti cancer effects of CDDP.

Conclusion

These data suggested that the protective role of ALA in cisplatin-induced AKI is via protection of mitochondrial viability and prevents tubular apoptosis. Also there are no significant effects of ALA on anticancer efficiency of CDDP in rats. Thus, ALA has the potential to prevent CDDP nephrotoxicity without compromising its anticancer efficacy.     

Simultaneous GDNF and BDNF application leads to increased motoneuron survival and improved functional outcome in an experimental model for obstetric brachial plexus lesions

Motoneurons of the neonate rat respond to proximal axonal injury with morphologic and functional changes and ultimately with neuronal death. Recent studies showed that both glial cell-line-derived neurotrophic factor (GDNF) and brain-derived neurotrophic factor (BDNF) reduce induced degeneration of motoneurons after axotomy and avulsion. Whether rescued motoneurons are functionally intact has been argued. In the present investigation, the authors have used a proximal crush lesion of the brachial plexus in neonatal rats as the experimental model of neuronal injury. This allowed the authors to study the effects of trophic factor administration on injured motoneurons and the relationship between motoneuron survival and extremity function. Trophic factors were locally released by small polymer implants in a low-dose slow-release mode. Six groups of 10 animals were prepared: BDNF, GDNF, GDNF/BDNF, control, sham, and normals. The number of surviving motoneurons was determined by retrograde tracer techniques using Fluorogold and Fastblue. Extremity function was quantitatively evaluated with functional muscle testing at day 56. The results of this study demonstrate that trophic factors applied separately had no effect, whereas combined trophic factor application (GDNF/BDNF group) had a dramatic rescue effect on motoneuron survival as compared with the control groups, which also effected significantly greater strength. The authors conclude that a combination of trophic factors leads to enhanced motoneuron survival, with improved voluntary function as the animal enters adulthood so that exogenous trophic support of motoneurons might have a role in the treatment of all types of severe neonatal plexopathies, maintaining the viability of motoneurons until reconstructive surgery provides them with a pathway for regeneration and endogenous trophic support.     

Effect of cisplatin on H+ transport by H+ -ATPase and Na+/H+ exchanger in rat renal brush-border membrane

The effect of the potent anticancer drug cisplatin, cis-diamminedichloroplatinum (II) (CDDP), on H+ -ATPase and Na+/H+ exchanger in rat renal brush-border membrane was examined. To measure H+ transport by vacuolar H+ -ATPase in renal brush-border membrane vesicles, we employed a detergent-dilution procedure, which can reorientate the catalytic domain of H+ -ATPase from an inward-facing configuration to outward-facing one. ATP-driven H+ pump activity decreased markedly in brush-border membrane prepared from rats two days after CDDP administration (5 mg/kg, i.p.). In addition, N-ethylmaleimide and bafilomycin A1 (inhibitors of vacuolar H+ -ATPase)-sensitive ATPase activity also decreased in these rats. The decrease in ATP-driven H+ pump activity was observed even at day 7 after the administration of CDDP. Suppression of ATP-driven H+ pump activity was also observed when brush-border membrane vesicles prepared from normal rats were pretreated with CDDP in vitro. In contrast with H+ -ATPase, the activity of Na+/H+ exchanger, which was determined by measuring acridine orange fluorescence quenching, was not affected by the administration of CDDP. These results provide new insights into CDDP-induced renal tubular dysfunctions, especially such as proximal tubular acidosis and proteinuria.     

Localization of alpha 2u-globulin within protein droplets of male rat kidney: immunohistochemistry using perfusion-fixed, GMA-embedded tissue sections

We investigated the light microscopic subcellular localization and quantitation of alpha 2u-globulin (alpha 2uG) in male rat kidney after 2,2,4-trimethylpentane exposure using a monoclonal antibody to alpha 2uG. Slices of perfusion-fixed kidney were cold-processed in glycolmethacrylate and the antigen localized after an avidin-biotin-horseradish peroxidase procedure with Hanker-Yates reagent as the chromagen. Light microscopic examination revealed resolution comparable to low-magnification electron microscopy, with excellent morphological detail of tissue architecture, including subcellular localization of alpha 2uG within lysosomes of P2 segment cells of the proximal tubule epithelium. The anatomical relationship between alpha 2uG and TMP-induced protein droplets observed after staining with Lee's methylene blue-basic fuchsin was studied using serial sections. Image analysis of selected P2 segments in treated and control rats revealed a high correlation between subcellular localization of alpha 2uG and protein droplet deposition in the cytoplasm of P2 segment cells of the proximal tubule epithelium. Quantitative morphometry of alpha 2uG-stained proximal tubule epithelium 72 hr after treatment with 50 mg/kg 2,2,4-trimethylpentane p.o. demonstrated a 1.5- to 2-fold increase in staining area of tubules from treated rats compared with controls. Similar increases of Lee's methylene blue-basic fuchsin-stained protein droplets were also observed, but quantitative morphometry of the protein droplets was technically more difficult owing to a lower staining contrast between droplets and the surrounding cytoplasm. This immunohistochemical procedure provides a valuable technique for further studies on the pathological role of alpha 2uG in protein droplet nephropathy of male rats induced by many environmental chemicals, and demonstrates the value of cold glycolmethacrylate processing to improve morphological detail.     

L-arginine ameliorates kidney function and urinary bladder sensitivity in experimentally-induced renal dysfunction in rats

Effects of L-arginine and NG-nitro-L-arginine methyl ester (L-NAME) on the renal dysfunction that is induced by cisplatin (CDDP) were investigated. A single dose of CDDP (7.5 mg/kg i.p.) induced renotoxicity, which was manifested by increasing the sensitivity of isolated urinary bladder rings to acetylcholine (ACh), together with a significant elevation of serum urea and creatinine, and a severe decrease in serum albumin. Moreover, renal dysfunction was further confirmed by a significant decrease of enzyme activities, such as glutathione peroxidase, GSH-Px (E.C 1.11.1.9), catalase (E.C 1.11.1.6), as well as a significant increase in lipid peroxides that were measured as malondialdhyde (MDA) in kidney tissue homogenates. The administration of L-arginine (70 mg/kg/d p.o in drinking water 5 d before and 5 d after the CDDP injection) significantly ameliorated the renotoxic effects of CDDP, as judged by restoring the normal responses of isolated bladder rings to Ach, and also by an improvement in a range of renal function indices, which included serum urea and creatinine concentrations and kidney weight. In addition, L-arginine prevents the rise of MDA, as well as a reduction of GSH-Px and catalase activities in kidney tissues homogenates. On the other hand, the administration of L-NAME (4 mg/kg/d p.o) resulted in no protection against renal dysfunction that was induced by CDDP treatment. The findings of this study suggest that L-arginine can attenuate kidney injury that is produced by CDDP treatment. In addition, L-arginine may be a beneficial remedy for CDDP-induced renal toxicity, and could be used to improve the therapeutic index of CDDP.     

Renal ischemia�Creperfusion injury causes intercalated cell-specific disruption of occludin in the collecting duct

Renal ischemic events open tight junctions and disrupt epithelial polarity. The purpose of this study was to examine the effects of ischemia-reperfusion (IR) injury on expression and distribution of the tight junction proteins, occludin and ZO-1, in the rat kidney. IR injury was induced by clamping both renal pedicles for 30 min and animals were killed at 6 h after the reperfusion. IR injury decreased blood bicarbonate level, but did not persistently alter pH, Na(+), K(+), or Cl(-). In control kidneys, occludin immunoreactivity was intense in the tight junctions in the thick ascending limb, distal convoluted tubule, and collecting duct, moderate in the thin limbs of the loop of Henle, and was not detected in the proximal tubule, glomerulus, and blood vessels. ZO-1 was expressed in the same sites in which occludin was expressed, and additionally was also expressed in the proximal tubule, glomerulus, and vascular endothelial cells. IR kidneys exhibited damaged renal tubular epithelial cells in both proximal tubule and collecting duct segments in the outer medulla. In the collecting duct, the response of intercalated cells and principal cells differed. Following IR injury, intercalated cells, but not principal cells, lost their normal epithelial polarity and were frequently extruded into the tubule lumen. Occludin, instead of being localized to tight junctions, was localized diffusely in the cytoplasm in intercalated cells of IR kidneys. Principal cells, in contrast, were not detectably affected and neither occludin nor ZO-1 expression were altered in response to IR injury. The normal localization of ZO-1 expression to tight junction sites in both the proximal tubule and collecting duct was altered in response to IR, and, instead, ZO-1 expression was present diffusely in the cytoplasm. IR injury did not alter detectably either occludin or ZO-1 localization to the tight junction of the thick ascending limb cells. The abundance of total occludin protein by immunoblot analysis was not changed with IR injury. These results demonstrate that renal IR injury causes tight junction disruptions in both the proximal tubule and the collecting duct, and that altered distribution of the tight junction protein, occludin, may play a critical role in the collecting duct dysfunction which IR induces.     

The Effects of Granulocyte-Colony Stimulating Factor on Regeneration in Nerve Crush Injuries in Rats

Granulocyte-colony stimulating factor (G-CSF) is widely known to have a neuroprotective effect, but its effects on function and morphology in mechanical nerve injury are not well understood. The aim of this study was to confirm the time course of the functional changes and morphological effects of G-CSF in a rat model of nerve crush injury. Twelve-eight rats were divided into three group: sham-operated control group, G-CSF-treated group, and saline treated group. 2 weeks after the nerve crush injury, G-CSF was injected for 5 days. After 4 weeks, functional tests such as motor nerve conduction velocity (MNCV), mechanical and cold allodynia tests, and morphological studies were performed. G-CSF-treated rats had significantly improved nerve function including MNCV and mechanical and cold allodynia. In addition, G-CSF-treated rats had significantly higher the density of myelinated fibers than saline-treated rats. In conclusion, we found that 100 μg/kg administration of G-CSF promoted long-term functional recovery in a rat model of nerve crush injury.     

Toxicity of adenine nucleotides in the isolated perfused kidney: selective destruction of the S2 segment of the proximal tubule.

In an attempt to ameliorate the morphological abnormalities and decreased renal function produced by hypoxia in the isolated perfused rat kidney, adenosine triphosphate (ATP) was added to the perfusate medium. No improvement was noted in the histological changes or renal function. Paradoxically, however, in oxygenated control kidneys, ATP (2.5-10 mM), caused a severe injury remarkably limited to the S2 segments of proximal tubule. This injury was more destructive than that observed with complete ischemia for the same period of time or with inhibitors of glycolysis, intermediary metabolism, or respiratory chain function. Tubular damage produced by ATP was paradoxically prevented by hypoxia and mitochondrial inhibition. The mechanism of this selective toxic injury to the proximal tubule remains unclear and may depend upon intact transport metabolism of the cell.     

Monoclonal antibodies to rat renal tissue: an approach to the immunohistological analysis of the nephron-collecting duct system, and ultra-structural localization of antigens

Summary To obtain more accurate information on the nephron-collecting duct system, monoclonal antibodies against renal tissue were prepared. BALB/c mice were immunized every two weeks with rat renal tissue, either cortex or medulla. Spleen cells were collected and fused with myeloma cells sensitive to hypoxanthine-aminopterin-thymidine medium. Hybrids were selected for production of antibodies by indirect immunofluorescence and cloned by the limiting dilution method. Tissue reactivity of the antibodies obtained was defined by immunofluorescence. The intracellular localization of antigenic determinants was ascertained by immunoelectron microscopy. The antibodies were classified into four major groups: (1) antibodies against proximal tubules; (2) antibodies against distal tubules and the loop of Henle; (3) antibodies against collecting duct system; and (4) antibodies against glomeruli. Using immunoelectron microscopy, various intracellular antigenic determinants were recognized, such as brush border, apical canaliculi, vacuolar apparatus, luminal and basolateral plasma membranes. The results obtained indicated that electron microscopy is indispensable for the immunohistological study of the nephroncollecting duct system. The observations help to understand morphological and functional diversity of the nephron-collecting duct system.     

Epididymal phenotype in luteinizing hormone receptor knockout animals and its response to testosterone replacement therapy

Previous studies reported that epididymis contains functional LH receptors. The LH receptor knockout mice, which have epididymal phenotypes, gave us an opportunity to test the hypothesis that testosterone replacement alone may not be sufficient to reverse phenotypes to wild-type epididymis. The morphological phenotype in knockout animals includes a decrease in luminal diameter of the proximal and distal caput and cauda epididymis, the absence of clear and halo cells in the epithelial lining, a decrease in the height of principal cells and the number of cells containing cilia, a decrease in cilia length, and a change from basal to central location of nuclei in the principal cells. The biochemical phenotype includes a decrease in periodic acid-Schiff reaction product, reflecting the glycogen and glycoprotein synthesis and secretion, a decrease in androgen receptor (AR) and estrogen receptor (ER)beta, and an increase in ERalpha levels. Twenty-one-day testosterone replacement therapy in 30-day-old knockout animals reversed some, but not all, morphological and biochemical phenotypes. Those that did not reverse include luminal diameters of proximal and distal caput and cauda epididymis, the percentage of ciliated principal cells in caput epididymis, and nuclear AR localization. In summary, while our results reaffirm that androgens are important for normal epididymal morphology and function, they indicate that LH could be required for certain facets of epididymal morphology and/or function.     

Exploring the cardioprotective effects of canagliflozin against cisplatin-induced cardiotoxicity: Role of iNOS/NF-κB,Nrf2, and Bax/cytochrome C/Bcl-2 signals

Cardiotoxicity is a severe considerable side effect of cisplatin (CDDP) that requires much medical attention. The current study investigates the cardioprotective effects of canagliflozin (CA) against CDDP-induced heart toxicity. Rats were allocated to the control group; the CA group was administered CA 10 mg/kg/day orally for 10 days; the CDDP group was injected with 7 mg/kg, intraperitoneal as a single dose on the 5th day, and the CDDP + CA group. Compared to the CDDP-treated group, CA effectively attenuated CDDP-induced heart injury as evidenced by a decrease of serum aspartate aminotransferase, alkaline phosphatase, creatine kinase-MB, and lactate dehydrogenase enzymes and supported by the alleviation of histopathological changes in cardiac tissues. Biochemically, CA attenuated cardiac oxidative injury through upregulation of the nuclear factor-erythroid 2 related factor 2 (Nrf2) signal. CA suppressed inflammation by decreasing cardiac NO₂⁻, MPO, iNOS, nuclear factor kappa B (NF-κB), tumor necrosis factor-alpha, and interleukin 1-beta levels. Besides, CA significantly upregulated cardiac levels of phosphoinositide 3-kinase (PI3K), protein kinase B (AKT), and p-AKT proteins. Moreover, CA remarkably mitigated CDDP-induced apoptosis via modulation of Bax, cytochrome C, and Bcl-2 protein levels. Together, the present study revealed that CA could be a good candidate for preventing CDDP-induced cardiac injury by modulating iNOS/NF-κB, Nrf2, PI3K/AKT, and Bax/cytochrome C/Bcl-2 signals.     

Renoprotective effects of angiotensin receptor blocker and stem cells in acute kidney injury: Involvement of inflammatory and apoptotic markers

Cisplatin, Cis-diamminedichloroplatinum (CDDP), is a platinum-based chemotherapy drug, and its chemotherapeutic use is restricted by nephrotoxicity. Inflammatory and apoptotic mechanisms play a central role in the pathogenesis of CDDP-induced acute kidney injury (AKI). The aim of this study was to compare the therapeutic potential of candesartan, angiotensin II receptor blocker, versus bone marrow-derived mesenchymal stem cells (BM-MSCs) in a rat model of CDDP-induced nephrotoxicity. Adult male Wistar rats (n = 40) were divided into four groups; Normal control: received saline injection, CDPP group: received CDDP injection (6 mg/kg single dose), Candesartan group: received candesartan (10 mg/kg/day) for 10 days + CDDP at day 3, and Stem cells group: received CDDP + BM-MSCs intravenously one day after CDDP injection. The rats were sacrificed seven days after CDDP injection. Significant elevation in serum creatinine and urea, renal levels of tumor necrosis factor (TNF)-α and monocyte chemoattractant protein (MCP)-1, renal expressions of nuclear factor kappa B (NF-κB), p38-mitogen-activated protein kinase (MAPK), caspase-3 and Bcl-2-associated x protein (Bax) were found in CDDP-injected rats when compared to normal rats. Both candesartan and BM-MSCs ameliorated renal function and reduced significantly the inflammatory markers (TNF-α , NF-κB, p38-MAPK and MCP-1) and apoptotic markers (caspase-3 and Bax) in renal tissue after CDDP injection. Candesartan as well as BM-MSCs have anti-inflammatory and anti-apoptotic actions and they can be used as nephroprotective agents against CDDP-induced nephrotoxicity. BM-MSCs is more effective than candesartan in amelioration of AKI induced by CDDP.     

中心体异常在咖啡因增强顺铂杀伤人肝癌细胞系中的作用

为了探讨咖啡因是否影响细胞周期检验点而增强顺铂杀伤肿瘤细胞及其作用机制 ,选取同步化于S期的肝癌细胞系SMMC 772 1,用顺铂和咖啡因进行不同方式的处理 ,包括顺铂处理、咖啡因处理以及先经顺铂 ,再用咖啡因处理 .利用相关方法对不同处理的细胞进行了分析 ,包括细胞形态 ,细胞生长速率 ,多核细胞的形成与死亡 ,中心体的异常等 .结果显示 ,顺铂与咖啡因联合处理的细胞出现明显的多核化现象 ,多核细胞占总细胞的百分比可以达到 30 %以上 ,高于用顺铂或用咖啡因处理的细胞 .同时观察到多核细胞生存能力较差 ,它们会通过细胞凋亡的形式死亡 .抗中心体人自身免疫血清的免疫荧光结果显示 ,中心体异常与多核细胞的形成直接相关 .在部分多核细胞的核周围有多个不同强度的荧光点 ,在另部分多核细胞中 ,在其中央有一个大的荧光点 ,被多个细胞核围绕 ,荧光较强 .根据结果推测 ,由多个不完整的中心体导致的多极分裂形成多核细胞 ,随后多个中心体聚集到中央形成大的中心体 ,负责间期微管的组装 .结果表明 ,受到顺铂损伤的细胞由于检验点的作用而使细胞周期阻断 ,咖啡因可消除周期的阻断 ,使细胞在中心体未完成正常复制状态下进入有丝分裂 ,产生大量多核细胞 ,这些多核细胞最终发生凋亡 .