[Efficacy of venetoclax-based induction regimen in newly diagnosed pediatric acute myeloid leukemia].

Objective: To explore the efficacy of venetoclax-based induction regimen for children with newly diagnosed acute myeloid leukemia (AML). Methods: Children with newly diagnosed AML in Beijing Children's Hospital Affiliated to Capital Medical University and Baoding Hospital Affliliated to Capital Medical University from November 2019 and December 2023 were prospectively included. The patients were divided into DAH group (daunorubicin, cytarabine and homoharringtonine) and VAH group (venetoclax, cytarabine and homoharringtonine) according to induction regimen. The clinical data of the children were collected, the clinical characteristics and induced remission rate between the two groups were compared, and multivariate logistic regression was used to analyze the related factors affecting the induced remission rate. Results: A total of 135 patients were enrolled, including 96 cases in the DAH group (54 males and 42 females), aged [M (Q1, Q3)] 6.4 (3.9, 11.6) years and 39 cases in the VAH group (26 males and 13 females), aged 8.0 (6.2, 13.2) years. Among patients initially diagnosed with low-medium risk AML, the morphologic complete remission rates were 94.7% (18/19) in the VAH group and 84.4% (38/45) in the DAH group, respectively, and the negativity conversion rates of minirnal residual disease (MRD) were 57.9% (11/19) and 46.7% (21/45), respectively, with no statistically difference (all P>0.05). Among patients initially diagnoised with high-risk AML, the morphologic complete remission rates in the VAH group was higher than that in the DAH group [95.0% (19/20) vs 70.6% (36/51), P=0.027], and negativity conversion rates of MRD were 45.0% (9/20) and 33.3% (17/51), respectively, with no statistically difference (P=0.359). The induction regimen (venetoclax, cytarabine and homoharringtonin) was beneficial to morphological remission (OR=0.126, 95%CI: 0.025-0.629). FLT3 mutation was not conducive to morphological remission (OR=5.832, 95%CI: 1.778-19.124) and negative MRD (OR=4.166, 95%CI: 1.396-12.433). Conclusion: Venetoclax-based induction regimen is more effective than traditional chemotherapy regimen for newly diagnosed pediatric AML.

[Clinical characteristics and prognosis of 28 cases of infant acute lymphoblastic leukemia].

Objective: To analyze the clinical characteristics and prognosis of patients with infant acute lymphoblastic leukemia (IALL). Methods: A retrospective cohort study.Clinical data, treatment and prognosis of 28 cases of IALL who have been treated at Beijing Children's Hospital, Capital Medical University and Baoding Children's Hospital from October 2013 to May 2023 were analyzed retrospectively. Based on the results of fluorescence in situ hybridization (FISH), all patients were divided into KMT2A gene rearrangement (KMT2A-R) positive group and KMT2A-R negative group. The prognosis of two groups were compared. Kaplan-Meier method and Log-Rank test were used to analyze the survival of the patients. Results: Among 28 cases of IALL, there were 10 males and 18 females, with the onset age of 10.9 (9.4,11.8) months. In terms of immune classification, 25 cases were B-ALL (89%), while the remaining 3 cases were T-ALL (11%). Most infant B-ALL showed pro-B lymphocyte phenotype (16/25,64%). A total of 22 cases (79%) obtained chromosome karyotype results, of which 7 were normal karyotypes, no complex karyotypes and 15 were abnormal karyotypes were found. Among abnormal karyotypes, there were 4 cases of t (9; 11), 2 cases of t (4; 11), 2 cases of t (11; 19), 1 case of t (1; 11) and 6 cases of other abnormal karyotypes. A total of 19 cases (68%) were positive for KMT2A-R detected by FISH. The KMT2A fusion gene was detected by real-time PCR in 16 cases (57%). A total of 24 patients completed standardized induction chemotherapy and were able to undergo efficacy evaluation, 23 cases (96%) achieved complete remission through induction chemotherapy, 4 cases (17%) died of relapse. The 5-year event free survival rate (EFS) was (46±13)%, and the 5-year overall survival rate (OS) was (73±10)%.The survival time was 31.3 (3.3, 62.5) months. There was no significant statistical difference in 5-year EFS ((46±14)% vs. (61±18)%) and 5-year OS ((64±13)% vs. (86±13)%) between the KMT2A-R positive group (15 cases) and the KMT2A-R negative group (9 cases) (χ2=1.88, 1.47, P=0.170, 0.224). Conclusions: Most IALL patients were accompanied by KMT2A-R. They had poor tolerance to traditional chemotherapy, the relapse rate during treatment was high and the prognosis was poor.

lncRNA-RMRP promotes proliferation, migration and invasion of bladder cancer via miR-206.

OBJECTIVE: The incidence of bladder cancer (BC) is common in the world, but its detail mechanisms for occurrence and development remain unclear. Recently, long non-coding RNAs (lncRNAs) have been observed to play an important role in many different diseases. In this research, we mainly explored the role of the RNA component of mitochondrial RNA processing endoribonuclease (lncRNA-RMRP) in bladder cancer. MATERIALS AND METHODS: We used qRT-PCR to detect the expression of lncRNA-RMRP in bladder cancer patients and tumor cells, and the clinical significance was also analyzed. The methyl thiazolyl tetrazolium (MTT) assay was used to detect the cell proliferation, and we used transwell to detect the migration and invasion, after the lncRNA RMRP was inhibited. Western-blot was used to measure the relative protein expression level in bladder cancer cells after transfection with siRNA-NC or siRNA-RMRP. RESULTS: We found that the lncRNA RMRP was highly expressed in bladder cancer tissue, compared with adjacent tissue. We also found that the expression of RMRP was closely related with the size, lymph node metastasis and survival time of patients. What's more, RMRP could promote the proliferation, migration and invasion of BC cell lines via regulating miR-206 as a sponge. CONCLUSIONS: According to the results, we found that lncRNA RMRP was closely related to the progression of bladder cancer, which could be a potential target for treating BC patients.

[Effects of CdTe quantum dots on the content of cytochrome P450 in rat liver].

Objective: The effect and mechanism of cadmium telluride quantum dots (CdTe QDs) on cytochrome P450 (CYP450) in the liver of rat were investigated. Methods: CdTe QDs (Ex 350 nm, Em 600 nm) were incubated with microsomes in final concentrations (0.5, 5, 50 µmol/L) using rat liver. And the content of CYP450 was determined by mixed incubation system as time (15, 30, 45 min) went on. Relationship also was detected between particle sizes (Em 620, 580, 540 nm; CdTe QDs-2, CdTe QDs-3, CdTe QDs-4) and expression of CYP450. Twenty male Wistar rats were randomly divided into exposed groups at various concentrations (0.25, 2.5 and 12.5 µmol/kg) of CdTe QDs via tail vein injection, the control group was injected with PBS. Results: In vitro, CdTe QDs(0.5, 5, 50 µmol/L) could significantly increase the content of CYP450 in rat liver microsomes(P<0.05), which increased first and then decreased with the dose adding. Moreover, the trend along with the exposure time (15, 30, 45 min) was the same as that in dosages at certain concentration (P<0.01). For different particle sizes, the smaller CdTe QDs were, the higher content increased, the content of CYP450 in group CdTe QDs-4 was the highest (P<0.05). In vivo, experiment proved that CdTe QDs (0.25, 2.5 and 12.5 µmol/kg) could obviously induce the expression of CYP450 (P<0.01). The content level showed a tendency to rise and then fall. Conclusion: CdTe QDs could promote the content of CYP450 in rat liver microsomes, it indicated that CdTe QDs had dose-effect relationship both in vivo and vitro. There was a certain relationship in time-effect. In addition, the smaller particle size was, the greater impact had.

KrasG12D-LOH promotes malignant biological behavior and energy metabolism of pancreatic ductal adenocarcinoma cells through the mTOR signaling pathway.

Oncogenic Kras with loss of heterozygosity (LOH) is frequently detected in various tumours. However, the exact function and mechanism by which KrasG12D-LOH operates remain unclear. Therefore, the current study investigated the effect of KrasG12D-LOH on the malignant phenotype of pancreatic ductal adenocarcinoma (PDAC) cells. Our investigation revealed that KrasG12D-LOH is associated with increased proliferation, invasion and reduced apoptosis in PDAC cells. The results also exhibited enhanced glycolytic phenotype of KrasG12D-LOH PDAC cells. Hyperactive mTOR plays a significant role in the initiation and maintenance of tumors. To investigate the correlation between KrasG12D-LOH and mTOR, the mTOR signaling pathway was detected by western blot analysis. We found that KrasG12D-LOH up-regulated Akt, AMPK, REDD1 and mTOR in PDAC cells. In summary, our results demonstrated that KrasG12D-LOH promotes oncogenic Kras-induced PDAC by regulating energy metabolism and mTOR signaling pathway. These data may provide novel therapeutic perspectives for PDAC.

[Oxidative damage effects induced by CdTe quantum dots in mice].

Objective: To investigate Oxidative damage effects induced by CdTe Quantum Dots (QDs) in mice. Methods: 40 ICR mice were randomly divided into 5 groups: one control group (normal saline) ; four CdTe QDs (exposed by intravenous injection of 0.2 ml of CdTe QDs at the concentration of 0、0.5、5.0、50.0 and 500.0 nmol/ml respectively) . After 24 h, the mice were decapitated and the blood was collected for serum biochemically indexes、hematology indexes, the activities of SOD、GSH-Px and the concentration of MDA were all detected. Results: The results showed in the four CdTe QDs exposure groups, the level of CRE、PLT and the concentration of MDA were all significantly lower than those of the control group (P<0.05 or P<0.01) ; the activities GSH-Px in 50.0 and 500.0 nmol/ml CdTe QDs group were significantly higher than those of control group (P<0.01) . Conclusion: It was suggested that CdTe QDs at 0.5 nmol/ml could induce Oxidative damage effects in mice.

[Size exclusionchromatography-high-performance liquid chromatography-inductively coupled plasma mass spectrometry for measuring the stability of cadmium telluridequantum dots].

Objective: To investigate the peak time and peak area of elements in cadmium telluride quantum dots (CdTe QDs) using size exclusion chromatography-high-performance liquid chromatography-inductively coupled plasma mass spectrometry, as well as the biological stability of CdTe QDs in vivo and in vitro. Methods: Transmission electron microscope and ultraviolet fluorescence were used for characterization and synthesis of water-soluble CdTe QDs, and CdTe QDs were added to double-distilled water, mobile phase, or bovine serum medium to observe the change in stability after different periods of time. CdTe QDs were injected into the vein of mice, and the changes in the morphology of CdTe QDs in serum and the liver were measured at 1, 24, and 72 hours after exposure. Size exclusion chromatography-high-performance liquid chromatography was used for the elution of the compounds in the solution based on their volume, and then inductively coupled plasma mass spectrometry was performed for the eluent. The flow time of (114)Cd and (130)Te and molar ratio were used for qualitative analysis of CdTe QDs, and the peak area was used to judge whether CdTe QDs were degraded. Results: CdTe QDs were diluted to a concentration of 0.5 mmol/L with double-distilled water and then placed in a dark place at room temperature; CdTe QDs were completely degraded after 60 minutes. CdTe QDs were diluted to a concentration of 0.005 mmol/L with a mobile phase, and the peak of CdTe QDs was not detected. After CdTe QDs were placed in a dark place at room temperature for 48 hours at a concentration of 0.005 mmol/L in bovine serum mediumin vitro, the peak area of (114)Cd was 6179841-7346084, and the peak area of (130)Te was 1077913-1191066. CdTe QDs had the highest peak area at 1 hour after exposure, and the peak areas of (114)Cd and (130)Te were 18183894 and 25187987, respectively. CdTe QDs were quickly degraded in the liver; at 1 hour after exposure, the degradation products of CdTe QDs containing Cd were observed in liver tissue homogenate, and CdTe QDs were largely degradedat 24 hours. Conclusion: This method can be used to investigate the biological stability of CdTe QDs. CdTe QDs are degraded in the liver and produce Cd(2+), which may cause toxic reaction.

Enhanced T cell immunity by B7-H4 downregulation in nonsmall-cell lung cancer cell lines.

OBJECTIVES: T cell immunity plays a critical role in host immune surveillance of tumour cell growth and metastatic spread. This study used small hairpin (sh)RNA-mediated gene silencing to target VTCN1 (B7-H4) expression in a nonsmall-cell lung cancer (NSCLC) cell line (A549) and evaluated the effects on T cell immune activity using an in vitro coculture system. METHODS: VTCN1-specific shRNA-expressing plasmid was transfected into A549 cells. Mock transfected and empty plasmid-transfected A549 cells served as controls. VTCN1 expression in A549 cells was determined by reverse transcription-polymerase chain reaction (RT-PCR) for VTCN1 mRNA and Western blotting for B7-H4 protein. Transfected A549 cells were cocultured with Jurkat cells. Jurkat cells were examined for proliferation, apoptosis, cell cycle distribution and intracellular cytokine mRNA and protein levels. RESULTS: VTCN1-specific shRNA efficiently knocked down VTCN1 mRNA and B7-H4 protein levels in A549 cells. This downregulation led to enhanced Jurkat cell proliferation, decreased apoptosis, stimulated cell cycle progression and elevated production of interferon-γ, interleukin (IL)-10 and IL-2. CONCLUSIONS: B7-H4 negatively regulates T cell-mediated antitumour immunity in NSCLC.

Ezetimibe potently reduces vascular inflammation and arteriosclerosis in eNOS-deficient ApoE ko mice.

OBJECTIVE: Hypercholesterolemia is associated with decreased vascular nitric oxide bioavailability and deletion of endothelial nitric oxide synthase (eNOS) markedly accelerates atherosclerosis development in apolipoprotein E knockout (apoE ko) mice. The current study tests whether atheroprotection provided by a lipid lowering therapy with Ezetimibe depends on eNOS. METHODS/RESULTS: ApoE ko and apoE/eNOS double ko (dko) mice received a high fat diet with or without 0.05% Ezetimibe. Ezetimibe significantly reduced plasma cholesterol concentrations and atherogenic lipoproteins in both genotypes to a similar extent. Moreover, the drug reduced vascular inflammation, as it significantly reduced vascular cell adhesion molecule-1 (VCAM-1) expression and vascular CD14 expression, a marker for mononuclear cell infiltration, in both genotypes. Neither NOS protein expression nor vascular reactivity of aortic rings was changed in apoE ko mice following Ezetimibe treatment. Significant lesion reduction was seen in Ezetimibe-treated male and female apoE ko and apoE/eNOS dko animals (p

In vivo quantification of transvascular water exchange during the acute phase of permanent stroke.

Mechanisms that underlie early ischemic damages to the blood-brain-barrier (BBB) are not well understood. This study presents a novel magnetic resonance imaging (MRI) technique using a widely available pulse sequence and a long-circulating intravascular contrast agent to quantify water movements across the BBB at early stages of stroke progression. We characterized the integrity of the BBB by measuring the flip angle dependence of the water exchange-affected MRI signal intensity, to generate an efficient quantitative index of vascular permeability (WEI, or water exchange index). We performed in vivo MRI experiments to measure the transvascular WEI immediately after the permanent filament occlusion of the middle cerebral artery of mice (n = 5), in which we monitored changes in blood volume (V(b)), apparent diffusion coefficient (ADC), and intra-/extravascular WEI for 4 hours. Statistically significant elevations (P < 0.05) of WEI in the ischemic tissue were observed as early as 1 hour after ischemic onset. Initial reduction of the apparent blood volume (V(app)) in the infarct cortex was followed by a continuous increase of V(app) over time. Although the measured ADC in the ipsilesional cortex continuously decreased, the abnormally high intra-/extravascular WEI remained constant at a significantly elevated level, indicating apparent BBB injury at this early stage of stroke.

Reduction of hippocampal cell death and proteolytic responses in tissue plasminogen activator knockout mice after transient global cerebral ischemia.

Knockout mice deficient in tissue plasminogen activator (tPA) are protected against hippocampal excitotoxicity. But it is unknown whether similar neuroprotection occurs after transient global cerebral ischemia, which is known to selectively affect the hippocampus. In this study, we tested the hypothesis that hippocampal cell death in tPA knockout mice would be reduced after transient global cerebral ischemia, and this neuroprotection would occur concomitantly with amelioration of both intra- and extracellular proteolytic cascades. Wild-type and tPA knockout mice were subjected to 20 min of transient bilateral occlusions of the common carotid arteries. Three days later, Nissl and terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling staining demonstrated that hippocampal cell death was significantly reduced in tPA knockout brains compared with wild-type brains. Caspase-3 and the two major brain gelatinases (matrix metalloproteinase (MMP)-9 and MMP-2) were assessed as representative measurements of intra- and extracellular proteolysis. Post-ischemic levels of caspase-3, MMP-9 and MMP-2 were similarly reduced in tPA knockouts compared with wild-type hippocampi. Taken together, these data suggest that endogenous tPA contributes to hippocampal injury after cerebral ischemia, and these pathophysiologic pathways may involve links to aberrant activation of caspases and MMPs.

Mouse model of microembolic stroke and reperfusion.

BACKGROUND AND PURPOSE: To test the role of fibrinolysis in stroke, we used a mouse model in which preformed 2.5- to 3-microm-diameter fibrin microemboli are injected into the cerebral circulation. The microemboli lodge in the downstream precapillary vasculature and are susceptible to fibrinolysis. METHODS: We injected various doses of microemboli into the internal carotid artery in mice and characterized their distribution, effects on cerebral blood flow, neurological deficit, infarct area, and spontaneous dissolution. By comparing wild-type and tissue plasminogen activator (tPA) knockout (tPA-/-) mice, we analyzed the role of endogenous tPA in acute thrombotic stroke. RESULTS: Microemboli cause dose-dependent brain injury. Although moderate doses of microemboli are followed by spontaneous reperfusion, they result in reproducible injury. Gene knockout of tPA markedly delays dissolution of cerebral emboli and restoration of blood flow and aggravates ischemic thrombotic infarction in the brain. CONCLUSIONS: We describe a microembolic model of stroke, in which degree of injury can be controlled by the dose of microemboli injected. Unlike vessel occlusion models, this model can be modulated to allow spontaneous fibrinolysis. Application to tPA-/- mice supports a key role of endogenous tPA in restoring cerebral blood flow and limiting infarct size after thrombosis.

Nonsteroidal anti-inflammatory drugs increase expression of inducible COX-2 isoform of cyclooxygenase in spinal cord of rats with adjuvant induced inflammation.

Several lines of evidence have accumulated that release of excitatory amino acids, nitric oxide and prostaglandin E2 (PGE2) play a critical role in the development of peripheral tactile and thermal hypersensitivity in chronic inflammatory pain models. Synthesis of PGE2 is controlled by cyclooxygenase (COX), either the COX-1 or COX-2 isoform. COX-2 plays a central role in the inflammatory reactions. The relationship between central sensitization of a complete Freund's adjuvant (CFA) induced inflammation and expressions of COX-2 were assessed in a rat model of CFA injection induced inflammation. Moreover, the time course of analgesia and spinal COX-2 expression following intrathecal (IT) injection with a nonspecific COX inhibitor (ketorolac) and COX-2 inhibitor (celecoxib) were determined using Western blot and immunohistochemistry. COX-2 protein was slightly increased in the lumbosacral spinal cord at 24 h following subcutaneous injection of CFA in the plantar surface of the left hindpaw (p > 0.05). COX-1 was not detected in normal and CFA injection rats. Surprisingly, IT ketorolac or celecoxib significantly increased spinal COX-2 levels at 1 h post-IT injection (p < 0.05) both in inflamed and non-inflamed rats. Then, spinal COX-2 levels declined at 3 and 6 h post-IT injection. These results provide strong in vivo evidence that COX-2 activity but not level may play a central role in the Freund's adjuvant-induced inflammation. However, spinal COX-2 level was upregulated following IT ketorolac and celecoxib injection. These data implies that suppression of PGE2 activity may induce the expression of spinal COX-2 in Freund's adjuvant-induced pain model. Our study concludes that IT administration of COX-2 inhibitor or nonspecific COX inhibitor is associated with significant short-term increase in spinal COX-2 expression.

Contributions of endothelial and neuronal nitric oxide synthases to cerebrovascular responses to hyperoxia.

Hyperoxia causes a transient decrease in CBF, followed by a later rise. The mediators of these effects are not known. We used mice lacking endothelial or neuronal nitric oxide synthase (NOS) isoforms (eNOS-/- and nNOS-/- mice) to study the roles of the NOS isoforms in mediating changes in cerebral vascular tone in response to hyperoxia. Resting regional cerebral blood flow (rCBF) did not differ between wild type (WT), eNOS-/- mice, and nNOS-/- mice. eNOS-/- mice showed decreased cerebrovascular reactivities to NG-nitro-L-arginine methyl ester (L-NAME), PAPA NONOate, acetylcholine (Ach), and SOD1. In response to hyperbaric oxygen (HBO2) at 5 ATA, WT and nNOS-/- mice showed decreases in rCBF over 30 minutes, but eNOS-/- mice did not. After 60 minutes HBO2, rCBF increased more in WT mice than in eNOS-/- or nNOS-/- mice. Brain NO-metabolites (NOx) decreased in WT and eNOS-/- mice within 30 minutes of HBO2, but after 45 minutes, NOx rose above control levels, whereas they did not change in nNOS-/- mice. Brain 3NT increased during HBO2 in WT and eNOS-/- but did not change in nNOS-/- mice. These results suggest that modulation of eNOS-derived NO by HBO2 is responsible for the early vasoconstriction responses, whereas late HBO2-induced vasodilation depends upon both eNOS and nNOS.

Hypertension does not account for the accelerated atherosclerosis and development of aneurysms in male apolipoprotein e/endothelial nitric oxide synthase double knockout mice.

BACKGROUND: Apolipoprotein E (apoE)/endothelial nitric oxide synthase (eNOS) double knockout (DKO) mice demonstrate accelerated atherosclerosis and develop abdominal aortic aneurysms and aortic dissection, suggesting a role for eNOS in suppressing atherogenesis. To test whether accelerated atherosclerosis and aortic aneurysms were due to hypertension, we administered hydralazine to male apoE/eNOS DKO mice to reduce blood pressure. METHODS AND RESULTS: Male apoE/eNOS DKO mice were treated with hydralazine in their drinking water (250 mg/L) using a dose that lowers the blood pressure to levels seen in apoE KO mice. The mice were fed a Western-type diet for 16 weeks, and lesion formation was assessed by inspection of the vessel and staining with Sudan IV. Hydralazine-treated, normotensive male apoE/eNOS DKO mice developed increased aortic lesion areas (30.0+/-2.8%, n=11) compared with male apoE KO mice (14.6+/-0.8%, n=7). The extent of lesion formation was not significantly different from male apoE/eNOS DKO mice that were not given hydralazine (28.3+/-3.1%, n=9). Four of 11 hydralazine-treated male apoE/eNOS DKO mice developed abdominal aortic aneurysms. CONCLUSIONS: Hypertension is not required for the accelerated atherosclerosis seen in apoE/eNOS DKO animals, and control of hypertension during a 16-week period does not prevent aortic aneurysm formation.

Lack of endothelial nitric oxide synthase aggravates murine pneumococcal meningitis.

Nitric oxide (NO) plays a central role in the pathogenesis of bacterial meningitis. However, the role of NO produced by endothelial NO synthase (eNOS) in meningitis is still unclear. We investigated the influence of eNOS depletion on the inflammatory host response, intracranial complications, and outcome in experimental pneumococcal meningitis. Leukocyte accumulation in the cerebrospinal fluid was more pronounced in infected eNOS-deficient mice than in infected wild type mice. This effect could be attributed to an increased expression of P-selectin, macrophage inflammatory protein-2, keratinocyte-derived cytokine, and interleukin (IL)-1beta in the brain of infected eNOS-deficient mice. However, no differences in the cerebral expression of intercellular adhesion molecule-1, tumor necrosis factor-alpha, and IL-6 as well as of neuronal NOS and inducible NOS could be detected between infected wild type and mutant mice. In addition to enhanced leukocyte infiltration into the CSF, meningitis-associated intracranial complications including blood-brain barrier disruption and the rise in intracranial pressure were significantly augmented in infected eNOS-deficient mice. The aggravation of intracranial complications was paralleled by a worsening of the disease, as evidenced by a more pronounced hypothermia, an enhanced weight reduction, and an increased death rate. The current data indicate that eNOS deficiency is detrimental in bacterial meningitis. This effect seems to be related to an increased expression of (certain) cytokines/chemokines and adhesion molecules; thus leading to increased meningeal inflammation and, subsequently, to aggravated intracranial complications.

Lack of neuronal NOS has consequences for the expression of POMC and POMC-derived peptides in the mouse pituitary.

The relevance of NO in neuroendocrine signalling has been investigated by analysis of cellular expression of pro-opiomelanocortin (POMC) and the POMC-derived peptides beta-endorphin, alpha-melanocyte stimulating hormone and adrenocorticotropin. Expression patterns were studied in the pituitary gland of 150-day old wild-type and neuronal-NOS (nNOS) knock-out mice by using immunohistochemistry, in situ hybridization and Northern blot analysis. Remaining NO-generating capacities in the knock-out mice were demonstrated by immunohistochemical localization of inducible, endothelial and neuronal NOS isoforms. Quantitative analysis revealed that cellular expression of POMC mRNA was drastically reduced in the pituitary of knock-out mice in comparison to controls. In situ hybridization studies demonstrated that this reduction was most pronounced in the intermediate lobe, while the anterior lobe was much less affected. Immunostaining for the proteolytic fragments of POMC was significantly reduced in the intermediate lobe cells of knock-out mice. A moderate reduction of immunostaining for these peptides was also observed in adenopituitary cells of nNOS knock-out mice. Our data demonstrate that the lack of nNOS substantially affects cellular levels of pituitary opioid peptides, which may have consequences for the response of these animals to stress and pain.

Anti-HIV agent MAP30 modulates the expression profile of viral and cellular genes for proliferation and apoptosis in AIDS-related lymphoma cells infected with Kaposi's sarcoma-associated virus.

The anti-HIV agent MAP30 (Momordica anti-HIV protein, 30 kDa) inhibits the proliferation of BC-2, an AIDS-related primary effusion lymphoma (PEL) cell line derived from an AIDS patient. BC-2 cells are latently infected with Kaposi's sarcoma-associated herpes virus (KSHV), also known as human herpes virus 8 (HHV8). We examined the effect of MAP30 on the expression of viral and cellular genes in BC-2 during latent and lytic states of the viral life cycle. By Northern analysis and RT-PCR, we found that MAP30 downregulates the expression of viral cyclin D (vCD), viral interleukin-6 (vIL-6), and viral FLIP (vFLIP), genes involved in cell cycle regulation, viral pathogenesis, and apoptosis. By pathway-specific cDNA microarray analysis, we found that BC-2 cells express high levels of egr-1, ATF-2, hsp27, hsp90, IkappaB, mdm2, skp1, and IL-2, cellular genes involved in mitogenesis, tumorigenesis, and inhibition of apoptosis in NFkappaB and p53 signaling pathways. These results define for the first time the specific cellular pathways involved in AIDS-related tumorigenesis and suggest specific novel targets for the treatment. Furthermore, we found that MAP30 downregulates the expression of egr-1, ATF-2, hsp27, hsp90, IkappaB, mdm2, and Skp1, while it upregulates the pro-apoptotic-related genes Bax, CRADD, and caspase-3. Thus, MAP30 modulates the expression of both viral and cellular genes involved in KS pathogenesis. These results provide valuable insight into the molecular mechanisms of MAP30 anti-KS action and suggest its utility as a therapeutic agent against AIDS-related tumors.

Endothelial nitric oxide synthase limits left ventricular remodeling after myocardial infarction in mice.

Background- To investigate the role of endothelial nitric oxide synthase (NOS3) in left ventricular (LV) remodeling after myocardial infarction (MI), the impact of left anterior descending coronary artery ligation on LV size and function was compared in 2- to 4-month-old wild-type (WT) and NOS3-deficient mice (NOS3(-/-)). Methods and Results- Two days after MI, both strains of mice had a similar LV size, fractional shortening, and ejection fraction by echocardiography. Twenty-eight days after MI, both strains had dilated LVs with decreased fractional shortening and lower ejection fractions. Although the infarcted fraction of the LV was similar in both strains, LV end-diastolic internal diameter, end-diastolic volume, and mass were greater, but fractional shortening, ejection fraction, and the maximum rate of developed LV pressure (dP/dt(max)) were lower in NOS3(-/-) than in WT mice. Impairment of diastolic function, as measured by the time constant of isovolumic relaxation (tau) and the maximum rate of LV pressure decay (dP/dt(min)), was more marked in NOS3(-/-) than in WT mice. Mortality after MI was greater in NOS3(-/-) than in WT mice. Long-term administration of hydralazine normalized blood pressure in NOS3(-/-) mice, but it did not prevent the LV dilatation, impaired systolic and diastolic function, and increased LV mass that followed MI. In WT mice, capillary density and myocyte width in the nonischemic portion of the LV did not differ before and 28 days after MI, whereas in NOS3(-/-) mice, capillary density decreased and myocyte width increased after MI, whether or not hydralazine was administered. Conclusions- These results suggest that the presence of NOS3 limits LV dysfunction and remodeling in a murine model of MI by an afterload-independent mechanism, in part by decreasing myocyte hypertrophy in the remote myocardium.