The role of hSWI/SNF complexes in transcriptional activation is well characterized; however, little is known about their function in transcriptional repression. We have previously shown that subunits of the mSin3A/ histone deacetylase 2 (HDAC2) corepressor complex copurify with hSWI/SNF complexes. Here we show that the type II arginine-specific methyltransferase PRMT5, which is involved in cyclin E repression, can be found in association with Brg1 and hBrm-based hSWI/SNF complexes. We also show that hSWI/SNF-associated PRMT5 can methylate hypoacetylated histones H3 and H4 more efficiently than hyperacetylated histones H3 and H4. Protein-protein interaction studies indicate that PRMT5 and mSin3A interact with the same hSWI/ SNF subunits as those targeted by c-Myc. These observations prompted us to examine the expression profile of the c-Myc target genes, carbamoyl-phosphate synthase-aspartate carbamoyltransferase-dihydroorotase (cad) and nucleolin (nuc). We found that cad repression is altered in cells that express inactive Brg1 and in cells treated with the HDAC inhibitor depsipeptide. Using chromatin immunoprecipitation assays, we found that Brg1, mSin3A, HDAC2, and PRMT5 are directly recruited to the cad promoter. These results suggest that hSWI/SNF complexes, through their ability to interact with activator and repressor proteins, control expression of genes involved in cell growth and proliferation.During cell growth and differentiation several genes become either repressed or activated. These variations in expression often correlate with changes in chromatin structure and occur in the context of the cell cycle. Recruitment of the highly related Brg1 and hBrm chromatin remodeling complexes, which can disrupt nucleosome structure and increase accessibility to DNA, has been implicated in transcriptional activation of many inducible genes (21, 41). However, in view of recent findings, which show that subunits of mSin3/histone deacetylase (HDAC) corepressor complexes can be found in association with Brg1 and hBrm chromatin remodelers and that HDACs 1 and 2 are integral components of the NuRD complex, it appears that ATP-dependent chromatin remodeling might also be involved in transcriptional repression (32,51,56,63,65). Consistent with this notion, mutation of yeast SWI2/ SNF2 can lead to gene derepression (28,35,53). Furthermore, Brg1, hBrm, and

The mitochondrial Ca 2؉ -independent phospholipase A 2 is activated during energy-dependent Ca 2؉ accumulation under conditions where there is a sustained depression of the membrane potential. This activation is not dependent on induction of the mitochondrial permeability transition. Bromoenol lactone, which inhibits the phospholipase, is effective as an inhibitor of the transition, and this action can be overcome by low levels of exogenous free fatty acids. Apparently, activation of the Ca 2؉ -independent phospholipase is a factor in the mechanisms by which depolarization and Ca 2؉ accumulation promote opening of the permeability transition pore. Sustained activity of the Ca 2؉ -independent phospholipase A 2 promotes rupture of the outer mitochondrial membrane and spontaneous release of cytochrome c on a time scale similar to that of apoptosis occurring in cells. However, more swelling of the matrix space must occur to provoke release of a given cytochrome c fraction when the enzyme is active, compared with when it is inhibited. Through its effects on the permeability transition and release of intermembrane space proteins, the mitochondrial Ca 2؉ -independent phospholipase A 2 may be an important factor governing cell death caused by necrosis or apoptosis.Mitochondria from rat liver and rabbit heart have been shown to contain a Ca 2ϩ -independent phospholipase A 2 (iPLA 2 ) 3 that has a molecular mass of ϳ80 kDa (1, 2). Like phospholipases of this type from other sources (3, 4), the mitochondrial enzyme is inactivated by bromoenol lactone (BEL), which acts through an activity-dependent mechanism, leading to a covalent modification within the active site (5). No physiological function of the iPLA 2 in mitochondria has been established, but it has been shown that pretreatment with BEL attenuates the loss of phospholipids that accompanies ischemia/reperfusion injury and reduces the size of infarcts by ϳ50% (2).The relationship between mitochondrial energetic status and iPLA 2 activity is an important factor to consider when contemplating potential physiological and pathophysiological roles of the enzyme. More specifically, activity is not seen in mitochondria that are respiring under state 4 conditions but is manifest upon the addition of uncoupler and is fully manifest following the development of inner membrane pores (1). The former property suggests that transient periods of deenergization might cause a transient activation of the iPLA 2 in vivo, with a resulting accumulation of free fatty acids in mitochondria. Such an accumulation could be of interest in many regards, including opening of the permeability transition pore, which is favored by low levels of these compounds (6 -8). Occurrence of the permeability transition leads to apoptosis in many cell types (9 -11), so scenarios arise in which the iPLA 2 contributes to the control of apoptosis by influencing the permeability transition and wherein the facilitative effects of depolarization on the transition (12, 13) might occur through activity of this enzyme...

Microwave (MW) radiation produced by wireless telecommunications and a number of electrical devices used in household or in healthcare institutions may adversely affects the reproductive pattern. Present study aimed to investigate the protective effects of melatonin (is well known antioxidant that protects DNA, lipids and proteins from free radical damage) against oxidative stress-mediated testicular impairment due to long-term exposure of MWs. For this, 70-day-old male Wistar rats were divided into four groups (n = 6/group): Sham exposed, Melatonin (Mel) treated (2 mg/kg), 2.45 GHz MWs exposed and MWs + Mel treated. Exposure took place in Plexiglas cages for 2 h a day for 45 days where, power density (0.21 mW/cm(2)) and specific absorption rate (SAR 0.14 W/Kg) were estimated. After the completion of exposure period, rats were sacrificed and various stress related parameters, that is LDH-X (lactate dehydrogenase isoenzyme) activity, xanthine oxidase (XO), ROS (reactive oxygen species), protein carbonyl content, DNA damage and MDA (malondialdehyde) were performed. Result shows that melatonin prevent oxidative damage biochemically by significant increase (p < 0.001) in the levels of testicular LDH-X, decreased (p < 0.001) levels of MDA and ROS in testis (p < 0.01). Meanwhile, it reversed the effects of MWs on XO, protein carbonyl content, sperm count, testosterone level and DNA fragmentation in testicular cells. These results concluded that the melatonin has strong antioxidative potential against MW induced oxidative stress mediated DNA damage in testicular cells.

Introduction and Objective:Among the surgical complications in renal transplantation, the vascular complications are probably most dreaded, dramatic, and likely to cause sudden loss of renal allograft. We present our experience and analysis of the outcome of such complications in a series of 1945 live related renal transplants.Materials and Methods:One thousand nine hundred and forty five consecutive live related renal transplants were evaluated retrospectively for vascular complications. Complications were recorded and analyzed for frequency, time of presentation, clinical presentation, and their management.Results:The age of patients ranged from 6 to 56 years (mean = 42). Vascular complications were found in 25 patients (1.29%). Most common among these was transplant renal artery stenosis found in 11 (0.58%), followed by transplant reznal artery thrombosis in 9 (0.46%), renal vein thrombosis in 3 (0.15%), and aneurysm formation at arterial anastmosis in 2 (0.10%) patient. The time of presentation also varied amongst complications. All cases of arterial thrombosis had sudden onset anuria with minimal or no abdominal discomfort, while venous thrombosis presented as severe oliguria associated with intense graft site pain and tenderness. Management of cases with vascular thrombosis was done by immediate surgical exploration. Two patients of renal artery stenosis were managed with angioplasty and stent placement.Conclusions:Major vascular complications are relatively uncommon after renal transplantation but still constitute an important cause of graft loss in early postoperative period. Aneurysm and vessel thrombosis usually require graft nephrectomy. Transplant renal artery stenosis is amenable to correction by endovascular techniques.

BackgroundChimeric antigen receptor (CAR) T-cell therapy is an emerging option for cancer treatment, but its efficacy is limited, especially in solid tumors. This is partly because the CAR T cells become dysfunctional and exhausted in the tumor microenvironment. However, the key pathways responsible for impaired function of exhausted cells remain unclear, which is essential to overcome CAR T-cell exhaustion.MethodsAnalysis of RNA-sequencing data from CD8+ tumor-infiltrating lymphocytes (TILs) led to identification of Cbl-b as a potential target. The sequencing data were validated using a syngeneic MC38 colon cancer model. To analyze the in vivo role of Cbl-b in T-cell exhaustion, tumor growth, % PD1+Tim3+ cells, and expression of effector cytokines were analyzed in cbl-b+/+ and cbl-b–/– mice. To evaluate the therapeutic potential of Cbl-b depletion, we generated a new CAR construct, hCEAscFv-CD28-CD3ζ.GFP, that recognizes human carcinoembryonic antigen (CEA). cbl-b+/+ and cbl-b–/– CEA-CAR T cells were generated by retroviral transduction. Rag–/– mice bearing MC38-CEA cells were injected with cbl-b+/+ and cbl-b–/–; CEA-CAR T cells, tumor growth, % PD1+Tim3+ cells and expression of effector cytokines were analyzed.ResultsOur results show that the E3 ubiquitin ligase Cbl-b is upregulated in exhausted (PD1+Tim3+) CD8+ TILs. CRISPR-Cas9-mediated inhibition of Cbl-b restores the effector function of exhausted CD8+ TILs. Importantly, the reduced growth of syngeneic MC38 tumors in cbl-b–/– mice was associated with a marked reduction of PD1+Tim3+ CD8+ TILs. Depletion of Cbl-b inhibited CAR T-cell exhaustion, resulting in reduced MC38-CEA tumor growth, reduced PD1+Tim3+ cells and increased expression of interferon gamma, tumor necrosis factor alpha, and increased tumor cell killing.ConclusionOur studies demonstrate that deficiency of Cbl-b overcomes endogenous CD8+ T-cell exhaustion, and deletion of Cbl-b in CAR T cells renders them resistant to exhaustion. Our results could facilitate the development of efficient CAR T-cell therapy for solid tumors by targeting Cbl-b.