Reduced Granule Cell Proliferation and Molecular Dysregulation in the Cerebellum of Lysosomal Acid Phosphatase 2 (ACP2) Mutant Mice.

Lysosomal acid phosphatase 2 (Acp2) mutant mice (naked-ataxia, nax) have a severe cerebellar cortex defect with a striking reduction in the number of granule cells. Using a combination of in vivo and in vitro immunohistochemistry, Western blotting, BrdU assays, and RT-qPCR, we show downregulation of MYCN and dysregulation of the SHH signaling pathway in the nax cerebellum. MYCN protein expression is significantly reduced at P10, but not at the peak of proliferation at around P6 when the number of granule cells is strikingly reduced in the nax cerebellum. Despite the significant role of the SHH-MycN pathway in granule cell proliferation, our study suggests that a broader molecular pathway and additional mechanisms regulating granule cell development during the clonal expansion period are impaired in the nax cerebellum. In particular, our results indicate that downregulation of the protein synthesis machinery may contribute to the reduced number of granule cells in the nax cerebellum.

Loss of prostatic acid phosphatase and α-synuclein cause motor circuit degeneration without altering cerebellar patterning.

Prostatic acid phosphatase (PAP), which is secreted by prostate, increases in some diseases such as prostate cancer. PAP is also present in the central nervous system. In this study we reveal that α-synuclein (Snca) gene is co-deleted/mutated in PAP null mouse. It is indicated that mice deficient in transmembrane PAP display neurological alterations. By using immunohistochemistry, cerebellar cortical neurons and zone and stripes pattern were studied in Pap-/- ;Snca-/- mouse cerebellum. We show that the Pap-/- ;Snca-/- cerebellar cortex development appears to be normal. Compartmentation genes expression such as zebrin II, HSP25, and P75NTR show the zone and stripe phenotype characteristic of the normal cerebellum. These data indicate that although aggregation of PAP and SNCA causes severe neurodegenerative diseases, PAP -/- with absence of the Snca does not appear to interrupt the cerebellar architecture development and zone and stripe pattern formation. These findings question the physiological and pathological role of SNCA and PAP during cerebellar development or suggest existence of the possible compensatory mechanisms in the absence of these genes.

Anxiety- and Depressive-Like Behaviors are Associated with Altered Hippocampal Energy and Inflammatory Status in a Mouse Model of Crohn's Disease.

Depression and anxiety are common comorbid disorders observed in patients with inflammatory bowel disease (IBD). Increasing line of evidence indicates that immune-inflammatory responses are involved in co-occurrence of mood disorders and IBD. However, the mechanisms through which immune-inflammatory pathways modulate this comorbidity are not yet understood. This study investigated the role of innate immunity in the development of behavioral abnormalities associated with an animal model of Crohn's disease (CD). To do this, we induced colitis in male adult mice by intrarectal (i.r.) injection of DNBS (Dinitrobenzene sulfonic acid). After 3 days, we performed behavioral tests for anxiety- and depressive-like behaviors as well as tissue collection. Our results showed that DNBS-induced colonic inflammatory responses were accompanied by infiltration of inflammatory cells, and increased expression of genes involved in toll-like receptor signaling pathway in intestinal tissue. Furthermore, the DNBS-treated mice showed depressive- and anxiety-like behaviors which were associated with increased expression of the inflammatory genes and abnormal mitochondrial function in the hippocampus. These results suggest that peripheral inflammation is able to increase the transcriptional level of the genes in toll-like receptor pathway, induces abnormal mitochondrial function in the hippocampus, and these negative effects may be involved in the co-occurrence of anxiety and depression in early stages of CD.

Morphine Attenuated the Cytotoxicity Induced by Arsenic Trioxide in H9c2 Cardiomyocytes.

Arsenic trioxide (ATO) is an efficient drug for the treatment of the patients with acute promyelocytic leukemia (APL). Inhibition of proliferation as well as apoptosis, attenuation of migration, and induction of differentiation in tumor cells are the main mechanisms through which ATO acts against APL. Despite advantages of ATO in treatment of some malignancies, certain harmful side effects, such as cardiotoxicity, have been reported. It has been well documented that morphine has antioxidant, anti-apoptotic, and cytoprotective properties and is able to attenuate cytotoxicity. Therefore, in this study, we aimed to investigate the protective effects of morphine against ATO toxicity in H9c2 myocytes using multi-parametric assay including thiazolyl blue tetrazolium bromide (MTT) assay, reactive oxygen species (ROS) generation, caspase 3 activity, nuclear factor kappa B (NF-κB) phosphorylation assay, and expression of apoptotic markers. Our results showed that morphine (1 µM) attenuated cytotoxicity induced by ATO in H9c2 cells. Results of this study suggest that morphine may have protective properties in management of cardiac toxicity in patients who receive ATO as an anti-cancer treatment.

Metformin improves skin flap survival through nitric oxide system.

BACKGROUND: Metformin has shown cardioprotective effects in experimental models of ischemia reperfusion, which is partially mediated through nitric oxide (NO) synthesis. We investigated the effects of metformin pretreatment in a rat model of random-pattern skin flap, and the probable role of NO system. MATERIALS AND METHODS: In the first experiment, the rats received increasing doses of metformin (150, 200, and 300 mg/kg), 4 h before the procedure. Dorsal skin flaps with caudal pedicles were elevated at the midline and flap survival was measured 7 d after surgery. Pathologic review of the skin flap specimen was performed in a subset of animals. In the second experiment, for evaluation of the role of NO, an NO synthase inhibitor N-nitro-L-arginine methyl ester hydrochloride (L-NAME) was administered with and without the effective dose of metformin. In the next experiment, subtherapeutic dose of NO precursor, L-Arginine, was administered with and without subeffective dose of metformin. RESULTS: Metformin pretreatment at doses of 200 and 300 mg/kg significantly increased skin flap survival rate. However, administration of L-NAME abolished the protective effects of metformin. On the other hand, subtherapeutic dose of L-arginine augmented the effects of low-dose metformin and significantly increased skin flap survival. Skin flaps from those rats that received 300 mg/kg metformin pretreatment and those treated with subtherapeutic doses of L-arginine and metformin showed increased vasodilation compared with control group. CONCLUSIONS: Metformin pretreatment can improve skin flap survival through an NO dependent pathway.

Purkinje cell compartmentation in the cerebellum of the lysosomal Acid phosphatase 2 mutant mouse (nax - naked-ataxia mutant mouse).

The Acp2 gene encodes the beta subunit of lysosomal acid phosphatase, which is an isoenzyme that hydrolyzes orthophosphoric monoesters. In mice, a spontaneous mutation in Acp2 results in severe cerebellar defects. These include a reduced size, abnormal lobulation, and an apparent anterior cerebellar disorder with an absent or hypoplastic vermis. Based on differential gene expression in the cerebellum, the mouse cerebellar cortex can normally be compartmentalized anteroposteriorly into four transverse zones and mediolaterally into parasagittal stripes. In this study, immunohistochemistry was performed using various Purkinje cell compartmentation markers to examine their expression patterns in the Acp2 mutant. Despite the abnormal lobulation and anterior cerebellar defects, zebrin II and PLCß4 showed similar expression patterns in the nax mutant and wild type cerebellum. However, fewer stripes were found in the anterior zone of the nax mutant, which could be due to a lack of Purkinje cells or altered expression of the stripe markers. HSP25 expression was uniform in the central zone of the nax mutant cerebellum at around postnatal day (P) 18-19, suggesting that HSP25 immunonegative Purkinje cells are absent or delayed in stripe pattern expression compared to the wild type. HSP25 expression became heterogeneous around P22-23, with twice the number of parasagittal stripes in the nax mutant compared to the wild type. Aside from reduced size and cortical disorganization, both the posterior zone and nodular zone in the nax mutant appeared less abnormal than the rest of the cerebellum. From these results, it is evident that the anterior zone of the nax mutant cerebellum is the most severely affected, and this extends beyond the primary fissure into the rostral central zone/vermis. This suggests that ACP2 has critical roles in the development of the anterior cerebellum and it may regulate anterior and central zone compartmentation.

The modulatory effect of lithium on doxorubicin-induced cardiotoxicity in rat.

Doxorubicin is an effective anti-neoplastic agent application of which has been limited due to its cardiotoxic side effects. Lithium is widely used for treatment of neuropsychiatric symptoms in bipolar disorders. Lines of evidence point to the cardioprotective effects of lithium against heart injuries. The current study aims to investigate the protective effects of lithium against doxorubicin-induced cardiotoxicity in rat model. Male Wistar rats were treated with 300 mg/kg p.o. lithium in their water supply and/or doxorubicin (1.25 mg/kg, i.p.), four times per week for four weeks. General conditions, mortality rate and body weight were measured during the experiment. At the end of the experiment, ECG parameters and papillary muscle contractility force were assessed. Serum samples were collected to measure the lithium concentrations as well as cardiac troponin T level (cTNT, a biomarker of cardiac injury). In addition, heart weight was measured and the cardiac tissues were evaluated both macroscopically and microscopically. The results of the present study indicate that lithium might diminish mortality rate, general toxicity (edema, alopecia and cachexia), improve S(alpha)-T segment and QT interval prolongations as well as heart contractility force. Application of lithium could inhibit the increase of cardiac troponin T and formation of myocardial lesions. These outcomes show the protective effects of lithium against doxorubicin-induced cardiotoxicity in rat. On the whole, the results of the present study suggest that lithium might be considered as a new indication for the prevention of doxorubicin-induced cardiotoxicity.

Arsenic trioxide induces apoptosis in NB-4, an acute promyelocytic leukemia cell line, through up-regulation of p73 via suppression of nuclear factor kappa B-mediated inhibition of p73 transcription and prevention of NF-kappaB-mediated induction of XIAP, cIAP2, BCL-XL and survivin.

The purpose of the present study is to evaluate the effects of arsenic trioxide (ATO) on human acute promyelocytic leukemia NB-4 cells. Microculture tetrazolium test, bromodeoxyuridine (BrdU) cell proliferation assay, caspase 3 activity assay, cell-based nuclear factor kappa B (NF-kappaB) phosphorylation measurement by ELISA and real-time RT-PCR were employed to appraise the effects of ATO on metabolic activity, DNA synthesis, induction of programmed cell death and NF-kappaB activation. The suppressive effects of ATO on metabolic potential, cell proliferation and NF-kappaB activation were associated with induction of apoptosis in NB-4 cells. In addition, an expressive enhancement in mRNA levels of p73, cyclin-dependent kinase inhibitor 1A (p21), tumor protein 53-induced nuclear protein 1 (TP53INP1), WNK lysine deficient protein kinase 2 (WNK2) and lipocalin 2 coupled with a significant reduction in transcriptional levels of NF-kappaB inhibitor beta (IKK2), Nemo, BCL2-like 1 (BCL-X(L)), inhibitor of apoptosis protein 1 (cIAP2), X-linked inhibitor of apoptosis protein (XIAP), survivin, Bcl-2, TIP60, ataxia telangiectasia (ATM), SHP-2 and sirtuin (SIRT1) were observed. Altogether, these issues show for the first time that ATO treatment could trammel cell growth and proliferation as well as induces apoptosis in NB-4 cells through induction of transcriptional levels of p73, TP53INP1, WNK2, lipocalin 2 as well as suppression of NF-kappaB-mediated induction of BCL-X(L), cIAP2, XIAP and survivin. Furthermore, the inductionary effects of ATO on transcriptional stimulation of p73 might be through cramping the NF-kappaB module (through suppression of p65 phosphorylation as well as transcriptional hindering of IKK2, ATM and Nemo) along with diminishing the mRNA expression of TIP60, SHP-2 and SIRT1.