The SMC5/6 complex is the least understood of SMC complexes. In yeast, smc5/6 mutants phenocopy m... more The SMC5/6 complex is the least understood of SMC complexes. In yeast, smc5/6 mutants phenocopy mutations in sgs1, the BLM ortholog that is deficient in Bloom's syndrome (BS). We here show that NSMCE2 (Mms21, in Saccharomyces cerevisiae), an essential SUMO ligase of the SMC5/6 complex, suppresses cancer and aging in mice. Surprisingly, a mutation that compromises NSMCE2-dependent SUMOylation does not have a detectable impact on murine lifespan. In contrast, NSMCE2 deletion in adult mice leads to pathologies resembling those found in patients of BS. Moreover, and whereas NSMCE2 deletion does not have a detectable impact on DNA replication, NSMCE2-deficient cells also present the cellular hallmarks of BS such as increased recombination rates and an accumulation of micronuclei. Despite the similarities, NSMCE2 and BLM foci do not colocalize and concomitant deletion of Blm and Nsmce2 in B lymphocytes further increases recombination rates and is synthetic lethal due to severe chromos...
-A method allowing shrinkage of a herniated disc, without an open surgical approach has long been... more -A method allowing shrinkage of a herniated disc, without an open surgical approach has long been sought. Studies on the spontaneous disappearance of disc fragments have demonstrated autoim-mune responses with a chronic inflammatory reaction, and radicular pain has been shown to be mostly due to release of toxic acids '". Researchers in different fields surprisingly noted that a short, calculated, oxidative stress by ozone ad-ministration may correct a persistent imbalance due to excessive chronic oxidative injury 4. Oxygen-ozone gas injection in patients with pain has a dramatic effect on clinica l symptoms. On these bases the intradiscal injection of oxygen-ozone gas was conceived 1,7,9. We report the treatment of 6665 patients with disc pathology by intradiscal injection of an oxygen-ozone gas mixture. The effect on pain and radicular dysfunction was dramatic. The effect of the treatment has also been evaluated by pathological examination. Il trattamento delle ernie disc...
Oncogene-induced replicative stress activates an Atr- and Chk1-dependent response, which has been... more Oncogene-induced replicative stress activates an Atr- and Chk1-dependent response, which has been proposed to be widespread in tumors. We explored whether the presence of replicative stress could be exploited for the selective elimination of cancer cells. To this end, we evaluated the impact of targeting the replicative stress-response on cancer development. In mice (Mus musculus), the reduced levels of Atr found on a mouse model of the Atr-Seckel syndrome completely prevented the development of Myc-induced lymphomas or pancreatic tumors, both of which showed abundant levels of replicative stress. Moreover, Chk1 inhibitors were highly effective in killing Myc-driven lymphomas. By contrast, pancreatic adenocarcinomas initiated by K-Ras(G12V) showed no detectable evidence of replicative stress and were nonresponsive to this therapy. Besides its impact on cancer, Myc overexpression aggravated the phenotypes of Atr-Seckel mice, revealing that oncogenes can modulate the severity of replicative stress-associated diseases.
Oncogenic Ras and p53 loss-of-function mutations are common in many advanced sporadic malignancie... more Oncogenic Ras and p53 loss-of-function mutations are common in many advanced sporadic malignancies and together predict a limited responsiveness to conventional chemotherapy. Notably, studies in cultured cells have indicated that each of these genetic alterations creates a selective sensitivity to ataxia telangiectasia and Rad3-related (ATR) pathway inhibition. Here, we describe a genetic system to conditionally reduce ATR expression to 10% of normal levels in adult mice to compare the impact of this suppression on normal tissues and cancers in vivo. Hypomorphic suppression of ATR minimally affected normal bone marrow and intestinal homeostasis, indicating that this level of ATR expression was sufficient for highly proliferative adult tissues. In contrast, hypomorphic ATR reduction potently inhibited the growth of both p53-deficient fibrosarcomas expressing H-rasG12V and acute myeloid leukemias (AMLs) driven by MLL-ENL and N-rasG12D. Notably, DNA damage increased in a greater-than-additive fashion upon combining ATR suppression with oncogenic stress (H-rasG12V, K-rasG12D, or c-Myc overexpression), indicating that this cooperative genome-destabilizing interaction may contribute to tumor selectivity in vivo. This toxic interaction between ATR suppression and oncogenic stress occurred without regard to p53 status. These studies define a level of ATR pathway inhibition in which the growth of malignancies harboring oncogenic mutations can be suppressed with minimal impact on normal tissue homeostasis, highlighting ATR inhibition as a promising therapeutic strategy.
E2Fs are important regulators of proliferation, differentiation, and apoptosis. Here we character... more E2Fs are important regulators of proliferation, differentiation, and apoptosis. Here we characterize the phenotype of mice deficient in E2F2. We show that E2F2 is required for immunologic self-tolerance. E2F2(-/-) mice develop late-onset autoimmune features, characterized by widespread inflammatory infiltrates, glomerular immunocomplex deposition, and anti-nuclear antibodies. E2F2-deficient T lymphocytes exhibit enhanced TCR-stimulated proliferation and a lower activation threshold, leading to the accumulation of a population of autoreactive effector/memory T lymphocytes, which appear to be responsible for causing autoimmunity in E2F2-deficient mice. Finally, we provide support for a model to explain E2F2's unexpected role as a suppressor of T lymphocyte proliferation. Rather than functioning as a transcriptional activator, E2F2 appears to function as a transcriptional repressor of genes required for normal S phase entry, particularly E2F1.
This double-blind, randomized, multi-center study compared the metabolic tolerance of a combined ... more This double-blind, randomized, multi-center study compared the metabolic tolerance of a combined formulation containing estradiol (E2) and trimegestone (TMG) with a standard hormone replacement therapy (HRT) containing estradiol valerate (EV) and norgestrel (NG). Blood lipids, glucose and fibrinogen concentrations were measured in the study which was conducted over 13 cycles, each of 28 days, and included 634 subjects in two randomized groups. A total of 481 subjects completed the study. The circulating concentrations of high density lipoprotein (HDL), HDL2, HDL3 cholesterol and apolipoprotein A1 were increased in the E2 + TMG group and reduced in the EV + NG group. Total cholesterol, low density lipoprotein (LDL) cholesterol, apolipoprotein B and lipoprotein(a) concentrations were decreased in both treatment groups; however, the reduction in LDL cholesterol was greater in the E2 + TMG group. Similar lipid findings were found in a subgroup that excluded subjects who had less than 3 months washout from a previous HRT, who provided a blood sample outside the day 17-28 window, or who were taking beta-blockers or thiazide diuretics. Blood glucose concentrations were reduced slightly in both treatment groups. A significant reduction in fibrinogen was also seen in both groups over the course of the study. The changes in lipid profile, especially HDL cholesterol, were more beneficial in the E2 + TMG group in comparison with the EV + NG group. This reflects the lack of androgenic action of trimegestone in comparison with norgestrel, which exhibits an androgenic effect and prevents the estrogen-induced increase in HDL cholesterol. The results of the study suggest that the use of trimegestone in combination with E2 may be preferable to norgestrel because of the more favorable lipid profile.
Propionic acidaemia (PA) is an autosomal recessive disorder caused by mutations in either of the ... more Propionic acidaemia (PA) is an autosomal recessive disorder caused by mutations in either of the PCCA or PCCB genes which encode the alpha and beta subunits, respectively, of the mitochondrial enzyme propionyl-CoA carboxylase (PCC). In this work we have examined the biochemical findings and clinical outcome of 37 Spanish PA patients in relation to the mutations found in both PCCA and PCCB genes. We have detected 27 early-onset and 101 late-onset cases, showing remarkably similar biochemical features without relation to either the age of onset of the disease or the defective gene they have. Twenty-one of the patients have so far survived and three of them, now adolescents, present normal development. Different biochemical procedures allowed us to identify the defective gene in 9 PCCA deficient and 28 PCCB deficient patients. Nine putative disease-causing mutations accounting for 77.7% of mutant alleles were identified among PCCA deficient patients, each one carrying a unique genotypic combination. Of PCCB mutant alleles 98% were characterised. Four common mutations (ins/del, E168K, 1170insT and A497V) were found in 38/52 mutant chromosomes investigated, whereas the remainder of the alleles harbour 12 other different mutations. By examining the mutations identified both in PCCA and PCCB genes and the clinical evolution of patients, we have found a good correlation between certain mutations which can be considered as null with a severe phenotype, while certain missense mutations tend to be related to the late and mild forms of the disease. Expression studies, particularly of the missense mutations identified are necessary but other genetic and environmental factors probably contribute to the phenotypic variability observed in PA.
Blue-green 488-nm laser sources are widespread in flow cytometry but suffer some drawbacks for ce... more Blue-green 488-nm laser sources are widespread in flow cytometry but suffer some drawbacks for cell analysis, including their excitation of endogenous proteins (resulting in high cellular autofluorescence) and their less-than-optimal coincidence with the excitation maxima of commonly used fluorochromes, including the phycoerythrins (PE). Longer wavelength lasers such as green helium-neons and, more recently, diode-pumped solid state (DPSS) 532-nm sources have previously been employed to overcome these difficulties and improve overall sensitivity for PE. In this study, we evaluate an even longer wavelength DPSS 561-nm for its ability to improve PE and DsRed fluorescent protein detection sensitivity. A DPSS 561-nm laser emitting at 10 mW was mounted onto a BD LSR II. Mouse thymoma cells labeled with cell surface marker antibodies conjugated to the R- and B-forms of PE were analyzed and compared with conventional 488-nm excitation using the same bandpass filters and signal travel distances. A similar analysis was carried out with cell lines expressing the red fluorescent protein DsRed, several green-yellow excited low molecular weight fluorochromes, and a rhodamine-based caspase substrate. Additionally, cells labeled with PE and co-labeled with fluorescein or simultaneously expressing green fluorescent protein (GFP) were analyzed to determine if PE excitation at 561 nm with simultaneous fluorescein/GFP detection was feasible. The DPSS 561-nm laser gave a several-fold improvement in the fluorochrome to autofluorescence ratios between PE-labeled cells and unlabeled controls. Analysis of cells expressing the fluorescent protein DsRed with the DPSS 561-nm source gave a 6-7-fold improvement in sensitivity over 488-nm excitation, and gave excellent excitation of yellow-green excited fluorochromes and rhodamine-based physiological probes. Yellow-green laser light also caused virtually no impingement on the spatially separated fluorescein/GFP detector, a significant problem with green laser sources, and also allowed simultaneous analysis of GFP and PE with virtually no signal overlap or requirement for color compensation. DPSS 561-nm laser excitation gave significantly improved sensitivity for both PE-labeled and DsRed expressing cells, with little contamination of a typical fluorescein/GFP detector.
The SMC5/6 complex is the least understood of SMC complexes. In yeast, smc5/6 mutants phenocopy m... more The SMC5/6 complex is the least understood of SMC complexes. In yeast, smc5/6 mutants phenocopy mutations in sgs1, the BLM ortholog that is deficient in Bloom's syndrome (BS). We here show that NSMCE2 (Mms21, in Saccharomyces cerevisiae), an essential SUMO ligase of the SMC5/6 complex, suppresses cancer and aging in mice. Surprisingly, a mutation that compromises NSMCE2-dependent SUMOylation does not have a detectable impact on murine lifespan. In contrast, NSMCE2 deletion in adult mice leads to pathologies resembling those found in patients of BS. Moreover, and whereas NSMCE2 deletion does not have a detectable impact on DNA replication, NSMCE2-deficient cells also present the cellular hallmarks of BS such as increased recombination rates and an accumulation of micronuclei. Despite the similarities, NSMCE2 and BLM foci do not colocalize and concomitant deletion of Blm and Nsmce2 in B lymphocytes further increases recombination rates and is synthetic lethal due to severe chromos...
-A method allowing shrinkage of a herniated disc, without an open surgical approach has long been... more -A method allowing shrinkage of a herniated disc, without an open surgical approach has long been sought. Studies on the spontaneous disappearance of disc fragments have demonstrated autoim-mune responses with a chronic inflammatory reaction, and radicular pain has been shown to be mostly due to release of toxic acids '". Researchers in different fields surprisingly noted that a short, calculated, oxidative stress by ozone ad-ministration may correct a persistent imbalance due to excessive chronic oxidative injury 4. Oxygen-ozone gas injection in patients with pain has a dramatic effect on clinica l symptoms. On these bases the intradiscal injection of oxygen-ozone gas was conceived 1,7,9. We report the treatment of 6665 patients with disc pathology by intradiscal injection of an oxygen-ozone gas mixture. The effect on pain and radicular dysfunction was dramatic. The effect of the treatment has also been evaluated by pathological examination. Il trattamento delle ernie disc...
Oncogene-induced replicative stress activates an Atr- and Chk1-dependent response, which has been... more Oncogene-induced replicative stress activates an Atr- and Chk1-dependent response, which has been proposed to be widespread in tumors. We explored whether the presence of replicative stress could be exploited for the selective elimination of cancer cells. To this end, we evaluated the impact of targeting the replicative stress-response on cancer development. In mice (Mus musculus), the reduced levels of Atr found on a mouse model of the Atr-Seckel syndrome completely prevented the development of Myc-induced lymphomas or pancreatic tumors, both of which showed abundant levels of replicative stress. Moreover, Chk1 inhibitors were highly effective in killing Myc-driven lymphomas. By contrast, pancreatic adenocarcinomas initiated by K-Ras(G12V) showed no detectable evidence of replicative stress and were nonresponsive to this therapy. Besides its impact on cancer, Myc overexpression aggravated the phenotypes of Atr-Seckel mice, revealing that oncogenes can modulate the severity of replicative stress-associated diseases.
Oncogenic Ras and p53 loss-of-function mutations are common in many advanced sporadic malignancie... more Oncogenic Ras and p53 loss-of-function mutations are common in many advanced sporadic malignancies and together predict a limited responsiveness to conventional chemotherapy. Notably, studies in cultured cells have indicated that each of these genetic alterations creates a selective sensitivity to ataxia telangiectasia and Rad3-related (ATR) pathway inhibition. Here, we describe a genetic system to conditionally reduce ATR expression to 10% of normal levels in adult mice to compare the impact of this suppression on normal tissues and cancers in vivo. Hypomorphic suppression of ATR minimally affected normal bone marrow and intestinal homeostasis, indicating that this level of ATR expression was sufficient for highly proliferative adult tissues. In contrast, hypomorphic ATR reduction potently inhibited the growth of both p53-deficient fibrosarcomas expressing H-rasG12V and acute myeloid leukemias (AMLs) driven by MLL-ENL and N-rasG12D. Notably, DNA damage increased in a greater-than-additive fashion upon combining ATR suppression with oncogenic stress (H-rasG12V, K-rasG12D, or c-Myc overexpression), indicating that this cooperative genome-destabilizing interaction may contribute to tumor selectivity in vivo. This toxic interaction between ATR suppression and oncogenic stress occurred without regard to p53 status. These studies define a level of ATR pathway inhibition in which the growth of malignancies harboring oncogenic mutations can be suppressed with minimal impact on normal tissue homeostasis, highlighting ATR inhibition as a promising therapeutic strategy.
E2Fs are important regulators of proliferation, differentiation, and apoptosis. Here we character... more E2Fs are important regulators of proliferation, differentiation, and apoptosis. Here we characterize the phenotype of mice deficient in E2F2. We show that E2F2 is required for immunologic self-tolerance. E2F2(-/-) mice develop late-onset autoimmune features, characterized by widespread inflammatory infiltrates, glomerular immunocomplex deposition, and anti-nuclear antibodies. E2F2-deficient T lymphocytes exhibit enhanced TCR-stimulated proliferation and a lower activation threshold, leading to the accumulation of a population of autoreactive effector/memory T lymphocytes, which appear to be responsible for causing autoimmunity in E2F2-deficient mice. Finally, we provide support for a model to explain E2F2's unexpected role as a suppressor of T lymphocyte proliferation. Rather than functioning as a transcriptional activator, E2F2 appears to function as a transcriptional repressor of genes required for normal S phase entry, particularly E2F1.
This double-blind, randomized, multi-center study compared the metabolic tolerance of a combined ... more This double-blind, randomized, multi-center study compared the metabolic tolerance of a combined formulation containing estradiol (E2) and trimegestone (TMG) with a standard hormone replacement therapy (HRT) containing estradiol valerate (EV) and norgestrel (NG). Blood lipids, glucose and fibrinogen concentrations were measured in the study which was conducted over 13 cycles, each of 28 days, and included 634 subjects in two randomized groups. A total of 481 subjects completed the study. The circulating concentrations of high density lipoprotein (HDL), HDL2, HDL3 cholesterol and apolipoprotein A1 were increased in the E2 + TMG group and reduced in the EV + NG group. Total cholesterol, low density lipoprotein (LDL) cholesterol, apolipoprotein B and lipoprotein(a) concentrations were decreased in both treatment groups; however, the reduction in LDL cholesterol was greater in the E2 + TMG group. Similar lipid findings were found in a subgroup that excluded subjects who had less than 3 months washout from a previous HRT, who provided a blood sample outside the day 17-28 window, or who were taking beta-blockers or thiazide diuretics. Blood glucose concentrations were reduced slightly in both treatment groups. A significant reduction in fibrinogen was also seen in both groups over the course of the study. The changes in lipid profile, especially HDL cholesterol, were more beneficial in the E2 + TMG group in comparison with the EV + NG group. This reflects the lack of androgenic action of trimegestone in comparison with norgestrel, which exhibits an androgenic effect and prevents the estrogen-induced increase in HDL cholesterol. The results of the study suggest that the use of trimegestone in combination with E2 may be preferable to norgestrel because of the more favorable lipid profile.
Propionic acidaemia (PA) is an autosomal recessive disorder caused by mutations in either of the ... more Propionic acidaemia (PA) is an autosomal recessive disorder caused by mutations in either of the PCCA or PCCB genes which encode the alpha and beta subunits, respectively, of the mitochondrial enzyme propionyl-CoA carboxylase (PCC). In this work we have examined the biochemical findings and clinical outcome of 37 Spanish PA patients in relation to the mutations found in both PCCA and PCCB genes. We have detected 27 early-onset and 101 late-onset cases, showing remarkably similar biochemical features without relation to either the age of onset of the disease or the defective gene they have. Twenty-one of the patients have so far survived and three of them, now adolescents, present normal development. Different biochemical procedures allowed us to identify the defective gene in 9 PCCA deficient and 28 PCCB deficient patients. Nine putative disease-causing mutations accounting for 77.7% of mutant alleles were identified among PCCA deficient patients, each one carrying a unique genotypic combination. Of PCCB mutant alleles 98% were characterised. Four common mutations (ins/del, E168K, 1170insT and A497V) were found in 38/52 mutant chromosomes investigated, whereas the remainder of the alleles harbour 12 other different mutations. By examining the mutations identified both in PCCA and PCCB genes and the clinical evolution of patients, we have found a good correlation between certain mutations which can be considered as null with a severe phenotype, while certain missense mutations tend to be related to the late and mild forms of the disease. Expression studies, particularly of the missense mutations identified are necessary but other genetic and environmental factors probably contribute to the phenotypic variability observed in PA.
Blue-green 488-nm laser sources are widespread in flow cytometry but suffer some drawbacks for ce... more Blue-green 488-nm laser sources are widespread in flow cytometry but suffer some drawbacks for cell analysis, including their excitation of endogenous proteins (resulting in high cellular autofluorescence) and their less-than-optimal coincidence with the excitation maxima of commonly used fluorochromes, including the phycoerythrins (PE). Longer wavelength lasers such as green helium-neons and, more recently, diode-pumped solid state (DPSS) 532-nm sources have previously been employed to overcome these difficulties and improve overall sensitivity for PE. In this study, we evaluate an even longer wavelength DPSS 561-nm for its ability to improve PE and DsRed fluorescent protein detection sensitivity. A DPSS 561-nm laser emitting at 10 mW was mounted onto a BD LSR II. Mouse thymoma cells labeled with cell surface marker antibodies conjugated to the R- and B-forms of PE were analyzed and compared with conventional 488-nm excitation using the same bandpass filters and signal travel distances. A similar analysis was carried out with cell lines expressing the red fluorescent protein DsRed, several green-yellow excited low molecular weight fluorochromes, and a rhodamine-based caspase substrate. Additionally, cells labeled with PE and co-labeled with fluorescein or simultaneously expressing green fluorescent protein (GFP) were analyzed to determine if PE excitation at 561 nm with simultaneous fluorescein/GFP detection was feasible. The DPSS 561-nm laser gave a several-fold improvement in the fluorochrome to autofluorescence ratios between PE-labeled cells and unlabeled controls. Analysis of cells expressing the fluorescent protein DsRed with the DPSS 561-nm source gave a 6-7-fold improvement in sensitivity over 488-nm excitation, and gave excellent excitation of yellow-green excited fluorochromes and rhodamine-based physiological probes. Yellow-green laser light also caused virtually no impingement on the spatially separated fluorescein/GFP detector, a significant problem with green laser sources, and also allowed simultaneous analysis of GFP and PE with virtually no signal overlap or requirement for color compensation. DPSS 561-nm laser excitation gave significantly improved sensitivity for both PE-labeled and DsRed expressing cells, with little contamination of a typical fluorescein/GFP detector.
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