No abstract

M059J and M059K cells were isolated from different portions of the same human malignant glioma. M059J cells are more radiosensitive than M059K cells due to the absence of DNA-PKcs and low-expression of ATM. The mechanism concerning the absence of DNA-PKcs in M059J is due to the frameshift mutation in PRKDC (DNA-PKcs gene); however, the reason for the low expression of ATM in M059J cells remains unclear. We showed here that the main reason for the lower ATM level in M059J cells was not related to the transcriptional regulation or protein degradation but was related to post-transcriptional regulation. Based on database information, we found that the 3’-untranslational region (UTR) of ATM contains a miR-100-binding site. By using an RNase protection assay and qRT-PCR, we identified that miR-100 is highly-expressed in M059J cells. We further demonstrated that miR-100 bound to the 3’-UTR of ATM. Knocking-down miR-100 promotes ATM expression in M059J cells. Up-regulating miR-100 in M059K cells and other cancer cells reduces ATM expression and sensitizes these cells to ionizing radiation. These results indicate that ATM is a target of miR-100, elucidating that the low-expression of ATM in M059J cells is mainly due to the high-expression of miR-100. These results also suggest that miR-100 could be a useful tool to target ATM and sensitize tumor cells to ionizing radiation.

Alternatively activated macrophages (M2) regulate immune responses and ex vivo polarized splenic M2 are able to ameliorate renal injury including models of renal disease, such as adriamycin nephropathy. Whether M2 derived from other organs have similar protective efficacy is unknown. Here, we report adoptively transferred bone marrow M2 macrophages did not improve renal function or reduce renal injury in adriamycin nephropathy, whereas splenic M2 macrophages were protective. Bone marrow and splenic M2 macrophages showed similar regulatory phenotypes and suppressive functions in vitro. Within the inflamed kidney, suppressive phenotypes in bone marrow but not in splenic M2 macrophages, were dramatically reduced. Loss of the suppressive phenotype in bone marrow M2 was related to strong proliferation of bone marrow M2. Bone marrow M2 proliferation in vivo correlated with M-CSF expression by tubular cells in the inflamed kidney. Inhibition of M-CSF in vitro limited bone marrow M2 proliferation and prevented switch of phenotype. Proliferating cells derived from transfused bone marrow M2 were inflammatory rather than regulatory in their phenotype and function. Thus bone marrow in contrast to splenic M2 macrophages do not protect against renal structural and functional injury in murine adriamycin nephropathy. The failed renoprotection of bone marrow M2 is due to the switch of transfused M2 macrophages from a regulatory to an inflammatory phenotype.

No abstract

The kidney contains receptors for the cytokine IL-25, but the effects of IL-25 in CKD are unknown. Here, we induced adriamycin nephropathy in both BALB/c mice and severe combined immunodeficient (SCID) mice, and we injected IL-25 for 7 consecutive days starting at day 5 after adriamycin administration. BALB/c mice treated with IL-25 had less glomerulosclerosis, tubular atrophy, interstitial expansion, and proteinuria than control mice at day 28. IL-25 increased the levels of IL-4 and IL-13 in serum, kidney, renal draining lymph nodes, and CD4ϩ lymphocytes. IL-25 also directly suppressed effector macrophages in vitro and in vivo and induced alternatively activated (M2) macrophages in vivo. However, in SCID mice and in BALB/c mice treated with IL-4/13-neutralizing antibody, IL-25 failed to protect against renal injury and did not induce M2. In conclusion, IL-25 protects against renal injury in adriamycin nephropathy in mice by, at least in part, inducing Th2 immune responses.

Aims/IntroductionInsulin‐treated diabetes patients are at high risk for lipohypertrophy (LH), but this clinical problem has been overlooked by some medical professionals. In addition, studies differed from each other significantly in regard to the prevalence of LH. The present systematic review aimed to determine pooled prevalence levels of LH among insulin‐injecting diabetes patients.Materials and MethodsFour electronic databases (PubMed, EMBASE, The Cochrane Library and Scopus) were searched for eligible studies from their inception until April 2017, and reference lists were searched manually to identify additional studies. Studies containing data on LH in patients with diabetes mellitus were included. Meta‐analysis was carried out with a random effects model.ResultsA total of 26 studies with a total of 12,493 participants met the inclusion criteria. Meta‐analysis showed that the pooled prevalence of LH was 38% (95% confidence interval [CI] 29–46%, I 2 = 99.1%). The main influence on LH was the type of diabetes mellitus. The pooled prevalence of LH among patients with type 2 diabetes mellitus was higher than patients with type 1 diabetes mellitus (49%, 95% CI 23–74% vs 34%, 95% CI 19–49%). The pooled prevalence of LH of studies involving a mixed type of diabetes mellitus was 37% (95% CI 25–48%, I 2 = 98.3%).ConclusionThe prevalence of LH was high in insulin‐treated diabetes patients. It showed that diabetes nurses should screen for LH regularly in their patients, and teach them how to prevent LH in their daily management of diabetes mellitus.

Fragile Histidine Triad (Fhit) gene deletion, methylation, and reduced Fhit protein expression occur in about 70% of human epithelial tumors and, in some cancers, are clearly associated with tumor progression. Specific Fhit signal pathways have not been identified, although it has been shown that Fhit overexpression leads to apoptosis in many cancer cell lines. We report in this study that Fhit À/À cells derived from gene knockout mice show much stronger S and G2 checkpoint responses than their wild type counterparts. The strong checkpoint responses are regulated by the ATR/CHK1 pathway, which contributes to the radioresistance of Fhit À/À cells. These results indicate an association of Fhit gene inactivation with increased survival after DNA damage, which is related to the over-active checkpoints regulated by the ATR/ CHK1 pathway. These results also suggest the potential effects of Fhit-dependent DNA damage response on tumor progression.

Checkpoints respond to DNA damage by arresting the cell cycle to provide time for facilitating repair. In mammalian cells, the G 2 checkpoint prevents the Cdc25C phosphatase from removing inhibitory phosphate groups from the mitosis-promoting kinase Cdc2. Both Chk1 and Chk2, the checkpoint kinases, can phosphorylate Cdc25C and inactivate its in vitro phosphatase activity. Therefore, both Chk1 and Chk2 are thought to regulate the activation of the G 2 checkpoint. Here we report that A1-5, a transformed rat embryo fibroblast cell line, shows much more radioresistance associated with a much stronger G 2 arrest response when compared with its counterpart, B4, although A1-5 and B4 cells have a similar capacity for nonhomologous endjoining DNA repair. These phenotypes of A1-5 cells are accompanied by a higher Chk1 expression and a higher phosphorylation of Cdc2. On the other hand, Chk2 expression increases slightly following radiation; however, it has no difference between A1-5 and B4 cells. Caffeine or UCN-01 abolishes the extreme radioresistance with the strong G 2 arrest and at the same time reduces the phosphorylation of Cdc2 in A1-5 cells. In addition, Chk1 but not Chk2 antisense oligonucleotide sensitizes A1-5 cells to radiation-induced killing and reduces the G 2 arrest of the cells. Taken together these results suggest that the Chk1/Cdc25C/Cdc2 pathway is the major player for the radioresistance with G 2 arrest in A1-5 cells.