Metformin Impairs Glutamine Metabolism and Autophagy in Tumour Cells

Metformin has been shown to inhibit glutaminase (GLS) activity and ammonia accumulation thereby reducing the risk of hepatic encephalopathy in type 2 diabetic patients. Since tumour cells are addicted to glutamine and often show an overexpression of glutaminase, we hypothesize that the antitumoral mechanism of metformin could be ascribed to inhibition of GLS and reduction of ammonia and ammonia-induced autophagy. Our results show that, in different tumour cell lines, micromolar doses of metformin prevent cell growth by reducing glutamate, ammonia accumulation, autophagy markers such as MAP1LC3B-II and GABARAP as well as degradation of long-lived proteins. Reduced autophagy is then accompanied by increased BECN1/BCL2 binding and apoptotic cell death. Interestingly, GLS-silenced cells reproduce the effect of metformin treatment showing reduced MAP1LC3B-II and GABARAP as well as ammonia accumulation. Since metformin is used as adjuvant drug to increase the efficacy of cisplatin-based neoadjuvant chemotherapy, we co-treated tumour cells with micromolar doses of metformin in the presence of cisplatin observing a marked reduction of MAP1LC3B-II and an increase of caspase 3 cleavage. In conclusion, our work demonstrates that the anti-tumoral action of metformin is due to the inhibition of glutaminase and autophagy and could be used to improve the efficacy of chemotherapy.

Hypoxia Promotes the Inflammatory Response and Stemness Features in Visceral Fat Stem Cells From Obese Subjects

Low-grade chronic inflammation is a salient feature of obesity and many associated disorders. This condition frequently occurs in central obesity and is connected to alterations of the visceral adipose tissue (AT) microenvironment. Understanding how obesity is related to inflammation may allow the development of therapeutics aimed at improving metabolic parameters in obese patients. To achieve this aim, we compared the features of two subpopulations of adipose-derived stem cells (ASC) isolated from both subcutaneous and visceral AT of obese patients with the features of two subpopulations of ASC from the same isolation sites of non-obese individuals. In particular, the behavior of ASC of obese versus non-obese subjects during hypoxia, which occurs in obese AT and is an inducer of the inflammatory response, was evaluated. Obesity deeply influenced ASC from visceral AT (obV-ASC); these cells appeared to exhibit clearly distinguishable morphology and ultrastructure as well as reduced proliferation, clonogenicity and expression of stemness, differentiation and inflammation-related genes. These cells also exhibited a deregulated response to hypoxia, which induced strong tissue-specific NF-kB activation and an NF-kB-mediated increase in inflammatory and fibrogenic responses. Moreover, obV-ASC, which showed a less stem-like phenotype, recovered stemness features after hypoxia. Our findings demonstrated the peculiar behavior of obV-ASC, their influence on the obese visceral AT microenvironment and the therapeutic potential of NF-kB inhibitors. These novel findings suggest that the deregulated hyper-responsiveness to hypoxic stimulus of ASC from visceral AT of obese subjects may contribute via paracrine mechanisms to low-grade chronic inflammation, which has been implicated in obesity-related morbidity.

SIRT5 regulation of ammonia-induced autophagy and mitophagy

In liver the mitochondrial sirtuin, SIRT5, controls ammonia detoxification by regulating CPS1, the first enzyme of the urea cycle. However, while SIRT5 is ubiquitously expressed, urea cycle and CPS1 are only present in the liver and, to a minor extent, in the kidney. To address the possibility that SIRT5 is involved in ammonia production also in nonliver cells, clones of human breast cancer cell lines MDA-MB-231 and mouse myoblast C2C12, overexpressing or silenced for SIRT5 were produced. Our results show that ammonia production increased in SIRT5-silenced and decreased in SIRT5-overexpressing cells. We also obtained the same ammonia increase when using a new specific inhibitor of SIRT5 called MC3482. SIRT5 regulates ammonia production by controlling glutamine metabolism. In fact, in the mitochondria, glutamine is transformed in glutamate by the enzyme glutaminase, a reaction producing ammonia. We found that SIRT5 and glutaminase coimmunoprecipitated and that SIRT5 inhibition resulted in an increased succinylation of glutaminase. We next determined that autophagy and mitophagy were increased by ammonia by measuring autophagic proteolysis of long-lived proteins, increase of autophagy markers MAP1LC3B, GABARAP, and GABARAPL2, mitophagy markers BNIP3 and the PINK1-PARK2 system as well as mitochondrial morphology and dynamics. We observed that autophagy and mitophagy increased in SIRT5-silenced cells and in WT cells treated with MC3482 and decreased in SIRT5-overexpressing cells. Moreover, glutaminase inhibition or glutamine withdrawal completely prevented autophagy. In conclusion we propose that the role of SIRT5 in nonliver cells is to regulate ammonia production and ammonia-induced autophagy by regulating glutamine metabolism.

Muscle LIM protein/CSRP3: a mechanosensor with a role in autophagy

Muscle LIM protein (MLP) is a microtubule-associated protein expressed in cardiac and muscle tissues that belongs to the cysteine-rich protein (CSRP/CRP) family. MLP has a central role during muscle development and for architectural maintenance of muscle cells. However, muscle cells rely on autophagy during differentiation and for structural maintenance. To study the role of MLP in autophagy, we have used C2C12 mouse myoblasts silenced or overexpressing MLP. Our results show that MLP contributes to the correct autophagosome formation and flux by interacting with LC3 as demonstrated by co-immunoprecipitation and PLA assay. In fact, MLP silencing results in decreased LC3-II staining and absent degradation of long-lived proteins. Moreover, MLP silencing impaired myoblasts differentiation as measured by decreased expression of MyoD1, MyoG1 and myosin heavy chain. Ultrastructural analysis revealed the presence of large empty autophagosomes in myoblasts and multimembranous structures in myotubes from MLP-silenced clones. Impaired autophagy in MLP-silenced cells resulted in increased susceptibility to apoptotic cell death. In fact, treatment of MLP-silenced C2C12 myoblasts and myotubes with staurosporine resulted in increased caspase-3 and PARP cleavage as well as increased percentage of cell death. In conclusion, we propose that MLP regulates autophagy during muscle cell differentiation or maintenance through a mechanism involving MLP/LC3-II interaction and correct autophagosome formation.

Pathology and Function of Conduction Tissue in Fabry Disease Cardiomyopathy

Background—

Cardiac arrhythmias are common in Fabry disease (FD) and may occur in prehypertrophic cardiomyopathy suggesting an early compromise of conduction tissue (CT). Therefore, FD X-linked and CT may be variously involved in male and female patients with FD cardiomyopathy, affecting CT function.

Methods and Results—

Among 74 patients with endomyocardial biopsy diagnosis of FD cardiomyopathy, 13 (6 men; 7 women; mean age, 50.1±13.5 years; maximal wall thickness, 16.7±3.7 mm) had CT included in histological specimens and 6 also at electron microscopy. CT glycolipid infiltration was defined as focal, moderate, extensive, or massive, if involved ≤30%, ≤50%, >50%, or 100% of cells; identified as loosely arranged small myocytes positive to HCN4 immunostaining, supplied by a centrally placed thick-walled arteriole. CT involvement was correlated with age, sex, and α- Gal gene mutation. CT function was evaluated by electrophysiological study and arrhythmias at Holter registration. CT infiltration was focal/moderate in 4 women with no arrhythmias and normal electrophysiological study, extensive in 3 women with atrial or ventricular arrhythmias and short HV interval, and massive in 6 men with atrial fibrillation or ventricular arrhythmias and short HV. Short PR/AH with increased refractoriness was additionally found in 3 patients with extensive/massive CT infiltration. A male patient with the shortest HV presented infra-Hissian block during decremental atrial stimulation. There was no correlation with age, maximal wall thickness, and type of gene mutation.

Conclusions—

CT infiltration in FD cardiomyopathy is constant in men and variable in women because of skewed X-chromosome inactivation; its extensive/massive involvement causes accelerated conduction with prolonged refractoriness and electric instability.

Effects of medium calcium, and agents affecting cytoskeletal function, on cellular volume and morphology in liver tissue in vitro

The possible role of an exocytotic, vesicular mechanism in cellular volume regulation under iso-osmotic conditions has been studied in slices of rat liver. The effects of incubation conditions and agents affecting the actin cytoskeleton were examined for changes of water, ionic composition, and ultrastructure. Slices were pre-incubated at 1°C in an iso-osmotic buffered medium to induce swelling. Upon restoration to 37°C in the same medium, tissue lost water. The Na+-K+ adenosine triphosphatase (ATPase) inhibitor ouabain inhibited water extrusion of about 50%, an effect that was accompanied by the formation of characteristic vesicles in the cytoplasmic region between the Golgi apparatus and the bile canaliculi. Water extrusion in the presence of ouabain was partially inhibited by trifluoroperazine and completely inhibited when the medium was free of Ca2+. In the presence of ouabain, brefeldin A caused a small reduction of water extrusion, whereas phalloidin and cytochalasins A, D, or E caused a marked inhibition. In these conditions there was a marked increase in size and number of cytoplasmic vesicles and a more widespread distribution of them within the cells, lacking the more specific orientation to the Golgi and canalicular regions that was seen in the presence of ouabain alone. Water extrusion was inhibited by phalloidin and cytochalasins in the absence of ouabain. In conclusion, our results are consistent with the hypothesis that iso-osmotic expulsion of water from hepatocytes can proceed partly through an accumulation of water in cytoplasmic vesicles, followed by exocytosis. This mechanism does not depend on Na+-K+ ATPase activity.

Cardiac and skeletal myopathy in Fabry disease: a clinicopathologic correlative study

Skeletal muscle disturbances are commonly reported in patients with Fabry disease. Whether they derive from cardiac dysfunction or direct muscle involvement is still unclear. Clinical, noninvasive, and invasive cardiac and muscle studies, including an endomyocardial and muscle biopsy, were obtained in 12 patients (mean age, 42.1 ± 12.6 years; range, 24-58 years) with Fabry disease. In the youngest patients (group A, 4 men aged <35 years), results of cardiac and skeletal noninvasive studies were normal, except for reduced velocities in tissue Doppler imaging. Histologic examination indicated that muscle myocytes were unaffected, whereas muscle vessels showed the presence of mild glycosphingolipid accumulation in endothelial and smooth muscle cells. In the heart, cardiomyocytes and endothelial and smooth muscle cells of intramural cardiac vessels were involved by the disease. The oldest patients (group B, 6 men and 2 women aged >35 years) showed ultrasound muscle disarray and electromyography signs of myopathy, increased left ventricular mass, and normal cardiac function. Histologic examination showed that muscle myocytes contained mild glycosphingolipid accumulation compared with severe engulfment of cardiomyocytes. Moreover, similar infiltration of myocardial and muscle intramural vessels, causing lumen narrowing and fibrofatty tissue replacement, was observed. Direct muscle involvement occurs in patients with Fabry disease. It is milder and delayed compared with that in the heart. The difference in organ function and the need of residual α-galactosidase A activity are the likely causes.

Cell-to-cell signaling influences the fate of prostate cancer stem cells and their potential to generate more aggressive tumors

An increasing number of malignancies has been shown to be initiated and propelled by small subpopulations of cancer stem cells (CSC). However, whether tumor aggressiveness is driven by CSC and by what extent this property may be relevant within the tumor mass is still unsettled. To address this issue, we isolated a rare tumor cell population on the basis of its CD44⁺CD24⁻ phenotype from the human androgen-independent prostate carcinoma cell line DU145 and established its CSC properties. The behavior of selected CSC was investigated with respect to the bulk DU145 cells. The injection of CSC in nude mice generated highly vascularized tumors infiltrating the adjacent tissues, showing high density of neuroendocrine cells and expressing low levels of E-cadherin and β-catenin as well as high levels of vimentin. On the contrary, when a comparable number of unsorted DU145 cells were injected the resulting tumors were less aggressive. To investigate the different features of tumors in vivo, the influence of differentiated tumor cells on CSC was examined in vitro by growing CSC in the absence or presence of conditioned medium from DU145 cells. CSC grown in permissive conditions differentiated into cell populations with features similar to those of cells held in aggressive tumors generated from CSC injection. Differently, conditioned medium induced CSC to differentiate into a cell phenotype comparable to cells of scarcely aggressive tumors originated from bulk DU145 cell injection. These findings show for the first time that CSC are able to generate differentiated cells expressing either highly or scarcely aggressive phenotype, thus influencing prostate cancer progression. The fate of CSC was determined by signals released from tumor environment. Moreover, using microarray analysis we selected some molecules which could be involved in this cell-to-cell signaling, hypothesizing their potential value for prognostic or therapeutic applications.

Angina in fabry disease reflects coronary small vessel disease

BACKGROUND

Chest pain is frequently reported in Fabry disease (FD). However, its mechanism and clinical relevance are unclear.

METHODS AND RESULTS

Basal troponin I level, exercise stress test, single-photon emission computed tomography imaging with (99m)Tc sestamibi, coronary angiography with thrombolysis in myocardial infarction (TIMI) frame count and left ventricular angiography and endomyocardial biopsy were obtained in 13 patients with FD with angina. Ratio of external to lumen diameter of intramural arteries (E/L ratio), myocyte diameter, and extent of fibrosis were morphometrically evaluated by using tissue sections. Controls for coronary angiography and histology were 25 patients with FD without angina and 20 mitral stenosis patients with normal left ventricular function. Troponin I level was elevated in 6 of the 13 patients. Exercise stress test showed evidence of myocardial ischemia, and single-photon emission computed tomography was positive for stress-induced perfusion defects in all patients with FD with angina. Epicardial coronaries were structurally normal but showed slow flow in all and were associated with aneurisms of posterior left ventricular wall in 3 cases. Histology showed remarkable lumen narrowing of most intramural arteries (mean E/L ratio=3.5+/-1.2; P<0.001 versus both control groups), because of hypertrophy and proliferation of smooth muscle and endothelial cells, both engulfed by glycosphingolipids. Replacement fibrosis exceeded that of both controls (P<0.001). Small vessel disease correlated with coronary slow flow and extent of fibrosis, but did not with patients' age, sex, and degree of left ventricular hypertrophy.

CONCLUSIONS

patients with FD with angina have perfusion defects, slow coronary flow, and luminal narrowing of intramural arteries. Small vessel disease may contribute to symptomatic limitation and progressive myocardial dysfunction.

Peculiar subcellular localization of Fas antigen in human and mouse spermatozoa

The highly polarized structure and function of mammalian spermatozoa dictate that these cells compartmentalize specific metabolic and signaling pathways to regions where they are needed. Fas was initially identified as membrane receptor for pro-apoptotic signals, has been recently recognized as a molecule with pleiotropic functions. In this article, we provide evidence of a peculiar Fas localization: it is closely associated to the perinucleus, mainly at the level of the inner acrosomal membrane, as well as in the inner compartment of mitochondria. Immunoelectron microscopy and Western blot analysis indicated that intracellular Fas was associated with mitochondria in mouse epididymal spermatozoa. Accordingly, also in human ejaculated sperm, immunofluorescence analysis showed Fas localized in the middle piece of sperm flagellum where mitochondria are grouped. The potential functional implications of these findings are discussed.

Lipido-sterolic extract of Serenoa repens (LSESr, Permixon) treatment affects human prostate cancer cell membrane organization

The molecular mechanism by which the lipido-sterolic extract of Serenoa repens (LSESr, Permixon) affects prostate cells remains to be fully elucidated. In androgen-independent PC3 prostate cancer cells, the LSESr-induced effects on proliferation and apoptosis were evaluated by counting cells and using a FACScan cytofluorimeter. PC3 cells were stained with JC-1 dye to detect mitochondrial membrane potential. Cell membrane lipid composition was evaluated by thin layer chromatography and gas chromatographic analysis. Akt phosphorylation was analyzed by Western blotting and cellular ultrastructure through electron microscopy. LSESr (12.5 and 25 microg/ml) administration exerted a biphasic action by both inhibiting proliferation and stimulating apoptosis. After 1 h, it caused a marked reduction in the mitochondrial potential, decreased cholesterol content and modified phospholipid composition. A decrease in phosphatidylinositol-4,5-bisphosphate (PIP2) level was coupled with reduced Akt phosphorylation. After 24 h, all of these effects were restored to pre-treatment conditions; however, the saturated (SFA)/unsaturated fatty acid (UFA) ratio increased, mainly due to a significant decrease in omega 6 content. The reduction in cholesterol content could be responsible for both membrane raft disruption and redistribution of signaling complexes, allowing for a decrease of PIP2 levels, reduction of Akt phosphorylation and apoptosis induction. The decrease in omega 6 content appears to be responsible for the prolonged and more consistent increase in the apoptosis rate and inhibition of proliferation observed after 2-3 days of LSESr treatment. In conclusion, LSESr administration results in complex changes in cell membrane organization and fluidity of prostate cancer cells that have progressed to hormone-independent status.

Induction of autophagic cell death by a novel molecule is increased by hypoxia

Adaptation to hypoxia through activation of the hypoxia inducible factor-1 (HIF-1) is crucial for tumor cells survival. Here we describe the antitumoral effects of the new molecule CR 3294 on tumor cells in the presence of hypoxia. Treatment of the breast carcinoma cell line MDA-MB-231 with CR 3294 in 1% O(2) resulted in an in vivo and in vitro inhibition of tumor growth. CR 3294 induced accumulation of autophagosomes in hypoxic MDA-MB-231 cells as assessed by both transmission electron microscopy (TEM) and the autophagic marker LC3-II. TEM analysis revealed the presence of invaginations of the cytoplasm into the nucleus. Autophagosomes were present in such invaginations. Moreover, CR 3294 inhibited both the DNA binding of HIF-1alpha and VEGF mRNA synthesis. Immunoprecipitation and immunofluorescence studies showed an interaction between LC3 and HIF-1alpha. We next detailed the effect of inhibitors and activators of autophagy on both HIF-1alpha and LC3. In particular, 3 methyladenine (3MA) and wortmannin, two macroautophagic inhibitors, prevented both the decrease of HIF-1alpha protein levels and LC3 processing in cells treated with CR 3294. Bafilomycin and leupeptin, inhibitors of lysosomes, prevented HIF-1alpha decrease without affecting LC3 processing. By contrast, treating hypoxic MDA-MB-231 cells with trifluoperazine (TFP) or serum withdrawal (SW), two activators of autophagy, diminished HIF-1alpha levels and stimulated LC3 processing. These results indicate that activation of the autophagic pathway in hypoxic cells by the new molecule CR 3294, as well as by TFP or SW, can have potentially important implications for cancer treatment.

Sorbitol-induced apoptosis of human leukemia is mediated by caspase activation and cytochrome c release

It has been reported that sorbitol induces apoptosis in several cancer cell lines. However, the molecular mechanism underlying the sorbitol-induced apoptotic process is not yet clearly understood. In the present study, the intracellular signaling pathways of sorbitol-induced apoptosis in human K562 cells were investigated using both morphological analysis and DNA fragmentation technique. In this study, we demonstrated that sorbitol-induced apoptosis in human K562 cells is a concentration- and time-dependent manner. This sorbitol-induced apoptosis in human K562 cells was also accompanied by the up-regulation of Bax, and down-regulation of p-Bcl-2, but no effect on the levels of Bcl-X(L). Moreover, the sorbitol treatment resulted in a significant reduction of mitochondria membrane potential, increase in the release of mitochondrial cytochrome c (cyt c), and activation of caspase 3. Furthermore, treatment with caspase 3 inhibitor (z-DEVD-fmk) was capable of preventing the sorbitol-induced caspase 3 activity and cell death. These results clearly demonstrate that the induction of apoptosis by sorbitol involves multiple cellular/molecular pathways and strongly suggest that pro- and anti-apoptotic Bcl-2 family proteins, mitochondrial membrane potential, mitochondrial cyt c, and caspase 3, they all participate in sorbitol-induced apoptotic process in human K562 cells.

PYRROLO[1,2-b][1,2,5]BENZOTHIADIAZEPINES (PBTDs) induce apoptosis in K562 cells

BACKGROUND

The objective of this study was to gain insight into the molecular mechanism of induced cell death (apoptosis) by PYRROLO [1,2-b][1,2,5]BENZOTHIADIAZEPINES (PBTDs) series compounds, using human (K562) cells as a model.

METHODS

We focused our attention on some members of the PBTDs family to test their potential apoptotic activity in K562 cells. Important apoptotic activity was demonstrated, as evidenced by the concentration and percentage of cell death quantified by measuring PI-uptake by flow cytometry, and DNA fragmentation analyzed by agarose gel electrophoresis, generating a characteristic ladder pattern of discontinuous DNA fragments. The expression of Bcl-2 family was tested using western blotting and transfection method.

RESULTS

PBTDs-mediated suppression of K562 cell proliferation was induced by apoptosis characterized by the appearance of DNA fragmentation and was associated with the poly(ADP-ribose)polymerase (PARP) cleavage. PBTD-1 and -3 treatment resulted in caspase-3 activation through down-regulation of Bcl-2 and up-regulation of Bax. Furthermore, we used K562/vector and K562/bcl-2 cells, which were generated by transfection of the cDNA of the Bcl-2 gene. As compared with K562/vector, K562/Bcl-2 cells exhibited a 4-fold greater expression of Bcl-2. Treatment with 10 muM PBTD-1 and -3 for 24 h produced morphological features of apoptosis and DNA fragmentation in K562/vector cells, respectively. In contrast, PBTD-1 and -3-induced caspase-3 activation and apoptosis were inhibited in K562/Bcl-2. Furthermore, Bcl-2 overexpressing cells exhibited less cytocrome c release during PBTDs-induced apoptosis.

CONCLUSION

These results indicate that PBTDs effectively induce apoptosis of K562 leukemia cells through the activation of caspase cascades. In addition, these findings indicate that Bcl-2 inhibits PBTD-1 and -3 induced-apoptosis via a mechanism that interferes with cytocrome c release, and the activity of caspase-3, which is involved in the execution of apoptosis.

Pyrrolo[1,2-b][1,2,5]benzothiadiazepines (PBTDs): A New Class of Agents with High Apoptotic Activity in Chronic Myelogenous Leukemia K562 Cells and in Cells from Patients at Onset and Who Were Imatinib-Resistant

Pyrrolo[1,2-b][1,2,5]benzothiadiazepine 5,5-dioxides (PBTDs) induced apoptosis in human BCR-ABL-expressing leukemia cells. The apoptotic activity was also observed in primary leukemic blasts, obtained from chronic myelogenous leukemia (CML) patients at onset or from patients in blast crisis and who were imatinib-resistant. Compounds 5 and 14 induced apoptosis before BCR-ABL protein expression and tyrosin phosphorylation were affected and activated different caspases in the apoptotic pathway. PBTDs are a new class of valid candidates for the treatment of CML.

Cell death, proliferation and repair in human myocarditis responding to immunosuppressive therapy

In this study, we evaluate cell death, proliferation and repair in left ventricular endomyocardial biopsies from 20 patients with active lymphocytic myocarditis worsening or recovering from cardiac dysfunction after 6-months immunosuppression. Apoptosis and necrosis were assessed by in situ ligation of hairpin probes, proliferation by Ki67 and MCM5 labelling of myocytes, repair by electron microscopy, morphometric study of percent myofibrillar area and real-time polymerase chain reaction of alpha-and beta-Myosin Heavy Chain (MHC). Apoptosis and necrosis decreased in post- vs pretreatment biopsies by 85 and 62%, respectively in responders, while increased by 42 and 46% in nonresponders. Ki67 and MCM5-positive myocytes were higher vs controls at baseline and increased by 43 and 38% at follow-up in responders and by 75 and 63% in nonresponders. Myofibrillar area reduced in pretreatment samples, increased by 33% at follow-up in responders, correlated with percent enhancement of ejection fraction and was associated with increased alpha-MHC expression and alpha/beta-MHC ratio. In follow-up biopsies of nonresponders, myofibrillar area diminished by 36% and correlated with percent decrease of ejection fraction. Our results suggest that recovery of cardiac function in myocarditis responding to immunosuppression is associated with inhibition of cell death, activation of cell proliferation and with newly synthesized contractile material.

Fabry's disease cardiomyopathy: echocardiographic detection of endomyocardial glycosphingolipid compartmentalization

OBJECTIVES

We sought to identify echocardiographic hallmarks of Fabry's disease cardiomyopathy (FC).

BACKGROUND

The recognition of FC from other forms of left ventricular hypertrophy (LVH) by noninvasive imaging techniques is not yet available, and diagnosis, mostly in the absence of systemic manifestations, still relies on genetic and invasive studies.

METHODS

Forty consecutive patients (mean age 39 +/- 15 years, 22 men and 18 women) with an established diagnosis of Fabry's disease were submitted to echocardiographic evaluation. Control population consisted of 40 consecutive patients with hypertrophic cardiomyopathy (HCM), 40 hypertensive patients with echocardiographic evidence of LVH, and 40 age- and gender-matched healthy subjects with no LVH. All HCM patients and FC with LVH and/or cardiac symptoms underwent cardiac catheterization with left ventricular endomyocardial biopsy.

RESULTS

Echocardiography showed in 83% of FC patients (95% of FC patients with LVH) a binary appearance of endocardial border absent in all HCM, hypertensive, and healthy subjects. The sensitivity and specificity of this echocardiographic feature in detecting Fabry patients in study population were 94% and 100%, respectively. Comparison of echocardiographic with histologic and ultrastructural findings showed the binary appearance to reflect an endomyocardial glycosphingolipids compartmentalization, consisting of thickened glycolipid-rich endocardium, free glycosphingolipid subendocardial storage, and an inner severely affected myocardial layer with a clear subendocardial-midwall layer gradient of disease severity.

CONCLUSIONS

Echocardiographic binary appearance of left ventricular endocardial border, reflecting endomyocardial glycosphingolipids compartmentalization, represents a sensitive and specific diagnostic hallmark of Fabry's disease cardiomyopathy.

C3-induced 3LL cell proliferation is mediated by C kinase

It has been demonstrated that the third component of complement (C3)(1) and its peptides increase normal and tumour cell proliferation. However, the signal cascade responsible for this phenomenon is still unknown. In this study, we elucidate some of the mechanisms involved in the signalling of C3 stimulation of cell proliferation. We have first investigated the in and out traffic of C3 peptides, then we have identified the subcellular localisation of internalised C3 and, finally, we have explored the role of protein phosphorylation in C3 traffic and in the proliferation of the Lewis lung carcinoma (3LL) cells. Our results indicate that traffic of C3 is not dependent on cytoskeletal integrity and requires protein kinase C-dependent phosphorylation. In addition, proliferation of 3LL cells stimulated by C3 depends on both C3 internalisation and protein-kinase C phosphorylation.

Prevalence of Fabry disease in female patients with late-onset hypertrophic cardiomyopathy

BACKGROUND

Fabry disease (FD) has been recognized as the cause of left ventricular hypertrophy in 6% of men with late-onset hypertrophic cardiomyopathy (HCM). Although FD is considered a recessive X-linked disorder, affected women are increasingly reported. The aim of our study was to determine the prevalence of FD in female patients with HCM.

METHODS AND RESULTS

Thirty-four consecutive women (mean age, 50+/-13.6 years) who received an ECG and echocardiographic diagnosis of HCM were submitted to an invasive cardiac study that included a biventricular endomyocardial biopsy. Tissue samples were analyzed for histology and electron microscopy. Peripheral blood activity of alpha-galactosidase (alpha-Gal) A was assessed in all patients. None of them had a family history of FD. Histology and electron microscopy showed in 4 patients (12%; mean age, 51.5+/-3.9 years) the presence of cell vacuoles characterized by the accumulation of glycolipid material organized in concentric lamellar structures, diagnostic for FD. In the remaining patients, histology was consistent with HCM. In all the female carriers, the heart was the only organ clinically involved in the disease, showing concentric hypertrophy in 2 patients, asymmetric hypertrophy in 1, and apical hypertrophy in 1. The alpha-Gal A enzymatic activity was 44+/-14% of control values. Genetic analysis showed the presence of alpha-Gal A gene mutation in all 4 cases.

CONCLUSIONS

FD may account for up to 12% of females with late-onset HCM. Those heterozygous for FD with left ventricular hypertrophy are potential candidates for enzyme enhancement/replacement therapy.

Effects of long-term treatment with the anti-androgen bicalutamide on human testis: an ultrastructural and morphometric study

AIMS

To assess the effects of more than 4 years' treatment with the anti-androgen bicalutamide on human testis by clinical, ultrastructural and morphometric analysis.

METHODS AND RESULTS

Two patients (aged 74 and 69 years) with prostate cancer were treated for more than 4 years with bicalutamide 50 mg daily. Clinical characterization and follow-up included luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone and prostate-specific antigen (PSA) measurements and clinical response of the tumours. Due to progression of the disease, patients underwent surgical orchidectomy as a further androgen withdrawal therapy. Testis biopsies were studied by light and electron microscopy and analysed by morphometry. Control samples were obtained from the normal testis of two patients with testicular cancer who underwent orchidectomy. Clinical follow-up showed a good response in the control of tumour growth and serum PSA decreased to < 4 ng/mL; concentrations of serum LH, FSH and testosterone were within the normal range. Testicular morphology of treated patients was unexpectedly well preserved; the organization of seminiferous tubules was normal with all the germ line elements and mature spermatozoa present. In some areas, a net increase of peritubular connective tissue was evident which may be a consequence of the age of the patients.

CONCLUSIONS

Long-term bicalutamide (50 mg) treatment appears to have very little impact on testis ultrastructure and sperm maturation, while it is effective in the control of androgen-dependent prostatic tumours.

C3 molecules internalize and enhance the growth of Lewis lung carcinoma cells

C3 molecules from normal murine serum are mainly bound to Lewis lung carcinoma cells (3LL) that do not express CRs, mainly through covalent binding as determined by the appearance of bands stained with anti-C3 and larger than 190 kD in immunoblots of proteins in whole cell extracts. Methylamine-treated, or zymosan-treated normal mouse serum, heat inactivated, or EDTA-treated murine serum resulted in low C3 deposition on 3LL cells, as indicated by fluorescence tests and immunoblotting. Cytofluorimetric studies showed that C3 molecules bound to 3LL cells were internalized in a time- and temperature-dependent process. This was confirmed by electronmicroscopic studies. The conditions allowing C3 fixation to acceptor sites and subsequent internalization increased cell proliferation. This was also true, when serum from mice genetically deficient in C5 was used which stresses the role of C3 in contrast to effects of membrane attack complex formation.

Histological substrate of atrial biopsies in patients with lone atrial fibrillation

BACKGROUND

Lone atrial fibrillation (LAF) is a common clinical syndrome, but its origin remains unknown.

METHODS AND RESULTS

We performed endomyocardial biopsies of the right atrial septum (2 to 3 per patient; mean, 2.8) and of the two ventricles (6 per patient) in 12 patients (10 men, 2 women; mean age, 32 years) with paroxysmal LAF refractory to conventional antiarrhythmic treatment. As controls, we used endomyocardial biopsies (3 to 5 per patient; mean, 4.4) from the right atrial septum of 11 patients with Wolff-Parkinson-White syndrome (WPW) undergoing resection of the abnormal AV pathway. The weight of the biopsies ranged from 2.8 to 4.5 mg. Biopsy samples were processed for histology and electron microscopy and were read by a pathologist blinded to clinical data. All patients underwent two-dimensional Doppler echocardiography; cardiac catheterization; coronary angiography; and hormonal, virologic, and electrophysiological studies. All tests and WPW biopsies were normal, but all LAF atrial biopsy specimens (average, 2.8 per patient) showed abnormalities (P<.0001). The type of abnormalities varied: Two patients had a severe hypertrophy with vacuolar degeneration of the atrial myocytes and ultrastructural evidence of fibrillolysis occupying >50% of the areas assessed morphometrically (P=.50), 8 had lymphomononuclear infiltrates with necrosis of the adjacent myocytes (5 with fibrosis and 3 without; P<.003), and 2 had only nonspecific patchy fibrosis (P=.50). Biventricular biopsies were abnormal in only 3 patients and showed inflammatory infiltrates similar to those found in atrial biopsies.

CONCLUSIONS

Abnormal atrial histology was uniformly found in multiple biopsy specimens in all patients with LAF. It was compatible with a diagnosis of myocarditis in 66% of patients (active in 25%) and of noninflammatory localized cardiomyopathy in 17% and was represented by patchy fibrosis in 17%. The cause of the pathological changes, which were found only in atrial septal biopsies but not in biventricular biopsies, in 75% of patients remains unknown.

Numerical taxonomy applied to Leonhard's classification of endogenous psychoses

Among the existing classifications in the field of psychiatry, Leonhard's comprises 35 forms of endogenous psychoses, allowing a more precise differentiation. Computerassisted mathematical methods of numerical taxonomy, frequently used in other fields of biological sciences, were used to check its coherence, definitely proving its taxonomic validity. Numerical values were assigned to signs and symptoms described by Leonhard, taking into account their frequency and diagnostical importance. The resulting data matrix was processed, obtaining the dissimilitude coefficients and the main components which validate Leonhard classification. This method can be applied to other psychiatric classifications validating them or displaying their weaknesses.

Effects of the lipidosterolic extract of Serenoa repens (Permixon) on human prostatic cell lines

BACKGROUND

Permixon is a drug used in the treatment of benign prostatic hyperplasia. We studied its androgenic and antiandrogenic effects in the prostatic cell lines LNCaP and PC3, respectively responsive and unresponsive to androgen stimulation.

METHODS

We performed FACScan analysis to investigate toxicity, 3H thymidine and 35S methionine incorporation to determine antiproliferative and metabolic effects, electron microscopy to study ultrastructural changes and cotransfection experiments to elucidate the role of wild type androgen receptor.

RESULTS

In LNCaP cell line, Permixon induced a double proliferative/differentiative effect, not observed in PC3 cells. In PC3 cells cotransfected with wild-type androgen receptors and CAT reporter genes under the control of a androgen responsive element, the drug inhibited androgen-induced CAT transcription.

CONCLUSIONS

Our data indicate a role of the androgen receptor in mediating the effects of Permixon in LNCaP cells. Cotransfection experiments in PC3 cells support a clear antiandrogenic action of the drug.

Effects of ouabain and chloride-free medium on isoosmotic volume control and ultrastructure of hepatocytes in primary culture

Rat hepatocytes in primary monolayer culture have been studied by a combination of physiological and morphological approaches under conditions affecting ion transport and cell volume. A concentration of ouabain completely inhibiting the coupled transport of Na+ and K+ had little effect on cell volume, as indicated by cell water content, but induced the formation of many vesicles in the cytoplasm. Apparent fusion of vesicles was often observed. By itself, replacement of medium Cl by NO3- had little effect on cell volume or morphology. However, when NO3- replaced Cl- in the presence of ouabain the cells swelled and the numbers and size of vesicles were much reduced. The vesicles accumulating in the presence of ouabain showed a yellow fluorescence after the cells were loaded with acridine orange, implying that the vesicular contents were acidic. Total fluid-phase endocytosis, determined by uptake of Lucifer yellow, was not affected by ouabain or the absence of Cl-. However, ouabain considerably retarded the subsequent release of Lucifer yellow; this suggests that the dye originally taken into endocytotic vesicles became diluted by mixing with contents of ouabain-induced vesicles, an explanation consistent with the vesicle fusion seen by electron microscopy. The Cl-free medium also retarded Lucifer yellow efflux, to the same extent as ouabain, and the effects of the two treatments were not additive. These observations are consistent with the activity in hepatocytes of an ouabain-resistant, Cl(-)-dependent mechanism for cell volume control. It is suggested that this depends on the accumulation of water into acidic vesicles, which is driven by the Cl(-)-coupled activity of the vacuolar ATPases of the organelles, followed by exocytotic expulsion of their contents.

Catecholamine-induced cardiomyopathy in multiple endocrine neoplasia. A histologic, ultrastructural, and biochemical study

A catecholamine-induced dilated cardiomyopathy is reported in a patient with multiple endocrine neoplasia, type 3. A histologic and ultrastructural study has been undertaken in cardiac biopsy samples, together with determination of myocardial Ca++ and cellular membrane fatty acids. Contraction band necrosis of cardiocytes with supercontraction of sarcomeres progressing to myofibrolysis and increased levels of myocardial Ca++ have been found as morphologic and biochemical abnormalities, respectively. No lipoperoxidation of cellular membranes or an alpha-adrenergic mediated reduction of coronary supply could be recognized in the study. We indicate a receptor-mediated intracellular Ca++ overload as the main abnormality responsible for myocardial impairment.