One-Year Chromaffin Cell Allograft Survival in Cancer Patients with Chronic Pain: Morphological and Functional Evidence

The control of chronic pain through transplantation of chromaffin cells has been reported over the past few years. Analgesic effects are principally due to the production of opioid peptides and catecholamines by chromaffin cells. Clinical trials have been reported with allografts consisting of whole-tissue fragments implanted into the subarachnoid space of the lumbar spinal cord (14,19,36). In the present study, allogeneic grafts were successfully used to control chronic pain in two patients over a period of 1 yr based on patient reported pain scores, morphine intake, and CSF levels of Met-enkephalin. Macroscopic examination at autopsy located the transplanted tissue fragments in the form of multilobulated nodules at the level of the spinal axis and cauda equina. Immunocytochemical microscopy showed neuroendocrine cells are positive for chromagranin A (CGA), and enzymes tyrosine hydroxylase (TH) and dopamine-β-hydroxylase (DβH). The results suggest that there is a relationship between analgesic effect, Met-enkephalin levels in CSF, and the presence of chromaffin cells surviving in spinal subarachnoid space.

KSHV reduces autophagy in THP-1 cells and in differentiating monocytes by decreasing CAST/calpastatin and ATG5 expression

We have previously shown that Kaposi sarcoma-associated herpesvirus (KSHV) impairs monocyte differentiation into dendritic cells (DCs). Macroautophagy/autophagy has been reported to be essential in such a differentiating process. Here we extended these studies and found that the impairment of DC formation by KSHV occurs through autophagy inhibition. KSHV indeed reduces CAST (calpastatin) and consequently decreases ATG5 expression in both THP-1 monocytoid cells and primary monocytes. We unveiled a new mechanism put in place by KSHV to escape from immune control. The discovery of viral immune suppressive strategies that contribute to the onset and progression of viral-associated malignancies is of fundamental importance for finding new therapeutic approaches against them.

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.

Reprogramming cancer cells in endocrine-related tumors: open issues

Reprogramming technologies have been developed to revert somatic differentiated cells into pluripotent stem cells that can be differentiated into different lineages potentially useful in stem cell therapy. Reprogramming methods have been progressively refined to increase their efficiency, to obtain a cell population suitable for differentiation, and to eliminate viral plasmid which could be responsible for many unwanted side-effects when used in personalized medicine. All these methods are aimed to introduce into the cell genes or mRNAs encoding a set of four transcription factors (OCT- 4, SOX-2, KLF-4 and c-MYC) or a set of three lincRNAs (large intragenic non-coding RNAs) acting downstream of the reprogramming transcription factors OCT-4, SOX-2 and NANOG. Translational clinical applications in human pathologies and in developmental, repair and cancer biology have been numerous. Cancer cells can be, at least in principle, reprogrammed into a normal phenotype. This is a recently raised issue, rapidly advancing in many human tumors, especially endocrine-related cancers, such as breast, prostate and ovarian ca. The present review aims to describe basic phenomena observed in reprogramming tumor cells and solid tumors and to discuss their meaning in human hormone-related cancers. We will also discuss the fact that some of the targeted transcription factors are "normally" activated in a number of physiological processes, such as morphogenesis, hypoxia and wound healing, suggesting an in vivo role of reprogramming for development and homeostasis. Finally, we will review concerns and warnings raised for in vivo reprogramming of human tumors and for the use of induced pluripotent stem cells (iPSCs) in human therapy.

Influence of age and physical exercise on sirtuin activity in humans

Sirtuins are NAD+-dependent lysine deacetylases. Sirtuins acquired worldwide attention because of their ability to increase yeast, flies, worms and mice lifespan. Recently, this assumption has been challenged. However, their beneficial role on the quality of ageing is widely accepted. In this work we aimed to study how and if sirtuins expression and activity levels varies in function of age and, in the case of young subjects, of exercise. Fifteen blood donors of different ages and fifteen athletes of the Italian rowing male team were enrolled and peripheral blood mononuclear cells (PBMCs) isolated from blood samples. Our results show that sirtuins deacetylases activity measured in PBMCs increases from 18 to 40 years of age and then decreases during the following 20 years. Moreover, physical exercise in professional athletes can upregulate sirtuin activity. Thus, for the first time in humans, we demonstrate that sirtuin activity is a function of age and can be altered through physical exercise.

Mechanisms of ocular neuroprotection by antioxidant molecules in animal models

This work was conducted to evaluate the efficacy of a treatment on retinal ganglion cells (RGC) and on astrocytes of the optic nerve of glaucomatous eyes, using a combination of alpha-lipoic acid (ALA) and superoxide dismutase (SOD). Thirty-two male Wistar rats were fed with a diet supplemented with ALA, SOD, ALA and SOD or with no product for 8 weeks. Ocular hypertension was induced with 2% methylcellulose (MTC) and then rats were sacrificed. TUNEL assay showed a marked fluorescence in the ganglion cells and astrocytes of MTC-treated rats evidencing induction of apoptosis. In contrast, sections of eyes pretreated with ALA and SOD showed a lack of fluorescence quite similar to that of the controls. Similarly, eyes sections from rats pre-treated with ALA and SOD showed reduced differential expression of inducible nitric oxide synthase (iNOS) and of caspase-3 in compared to normally-fed/MTC-inoculated cases. An increase of ALA and SOD exerts an antiapoptotic effect and protects against oxidative stress and hence against the structural remodelling of the RGCs and astrocytes of the optic nerve in the presence of an ischemic and pressure stress.

Topotecan hydrochloride effects on retinal vessels in newborn rats

A physiological system, i.e. rodent retina during vessel formation and hierarchical organization, was utilised for assaying antiangiogenic properties of Topotecan, a topoisomerase I inhibitor, capable of inhibiting tumoral growth in animal models of retinoblastoma. In particular we analysed possible differences in effectiveness and side effects among different drug dosages and ways of administration. In the present research only qualitative analyses were undertaken. After preliminary experiments, in which suckling animals subcutaneously treated with Topotecan dosages comprised between 9 and 3 mg/kg underwent high lethality and extremely severe systemic damages, 7 day-old rats were subcutaneously, intravenously or peribulbary injected with a single dose of 1 mg/kg; retinal vessels were visualized in retinal fluorangio-graphies taken 1 and 2 weeks after treatment. The most important and frequent alterations were found to affect radial vessels, which showed non-perfused and/or regionally mislocated segments, together with abnormal branching and enlargements in retinal periphery; persistence of capillary-free periarteriolar regions, non-vascularised regions and spots of extravascular FITC were also detected. Despite the high individual variability the alterations were substantially similar among the different ways of drug administration, while they appeared milder in 21 day-old rats, with respect to younger ones. The extensive vascular remodelling found after Topotecan administration, besides demonstrating the antiangiogenic properties of this chemioterapic drug, confirms the rodent retina as a highly valuable model system for studying angiogenesis modulation.

A new clinical approach: use of blood-derived stem cells (BDSCs) for superficial digital flexor tendon injuries in horses

AIMS

In this study, we present an innovative therapy using stem cells that were obtained from the peripheral blood of racehorses affected by uninduced superficial digital flexor tendon (SDFT) injuries.

MAIN METHODS

Blood-derived stem cells (BDSCs) were generated from the blood samples of three horses in the presence of macrophage colony-stimulating factor (M-CSF). The racehorses received a single autologous BDSC treatment, which resulted in the successful repair of the tendons injuries.

KEY FINDINGS

The results demonstrated that the BDSCs injection into the damaged tendon stimulated the regeneration of normal tissue. Furthermore, a relationship may exist between the speed and the quality of new tissue formation and the welfare and management of the treated animals.

SIGNIFICANCE

This study demonstrates that stem cell technology offers new tools for tissue repair that in many cases is considered incurable, and provides additional evidence that BDScs injections increase the speed and quality of the regeneration process in different animal tissues.

A multicancer-like syndrome in a dog characterized by p53 and cell cycle-checkpoint kinase 2 (CHK2) mutations and sirtuin gene (SIRT1) down-regulation

INTRODUCTION

We have investigated SIRT1, p53 and cell cycle-checkpoint kinase 2 (CHK2) gene dysfunction in a dog with a multicancer syndrome-like in order to evaluate their potential role in the determinism of the disease and to establish a possible correlation between SIRT1 transcript level and p53 expression status.

MATERIAL AND METHODS

Blood sample and tumour samples from a pure breed English Setter dog with different tumours were used for this study. Nucleotide sequence analysis was performed with a DNA autosequencer in order to examine p53 and CHK2 mutations. In addition, the expression level of SIRT1 was quantified by Southern Blot analysis of Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR).

RESULTS

Cytological examination revealed five different tumours: a cutaneous sebaceous epithelioma, a cutaneous mast cell tumour, a testicular Sertoli cell tumour, an oral malignant melanoma, and a cutaneous squamous cell carcinoma. Sequencing analysis revealed the presence of a nucleotide substitution, (CGG>CAG) exon 7 of the p53 gene in DNA from peripheral blood mononuclear cells (PBMCs) as well as in the melanoma; whereas the other four cancers showed the loss of the wild-type allele. Furthermore, CHK2 mutation at codon 311 has been identified in the melanoma and sebaceous epithelioma. In addition, SIRT1 cDNA expression decreased in all tumour samples compared to cDNA SIRT1expression level in peripheral blood mononuclear cells (PBMCs) in the same dog.

CONCLUSIONS

These results suggest that the germ line mutation of the p53 gene at codon 248 might be, at least, one cause of the multicancer syndrome-like in our dog; furthermore, we show a possible correlation between SIRT1 transcript level and p53 mutations status. The regulatory role of SIRT1 in tumour suppressor pathways suggests that the net effect seen may represent both direct and indirect downstream regulation and it is likely to depend on the presence or absence of functional p53.

Grafts of immortalized chromaffin cells bio-engineered to improve met-enkephalin release also reduce formalin-evoked c-fos expression in rat spinal cord

Transplantation of adrenal medullary tissue for terminal cancer pain has been tested clinically, but this approach is not practical for routine use because of the shortage of organ donors and lack of tissue homogeneity. As a first alternative step, we have generated immortalized chromaffin cells over-expressing opioid peptides, namely met-enkephalin. Rat chromaffin cells have been genetically modified with vectors containing expression cassettes with either synthetic met-enkephalin or pro-enkephalin gene coding regions, fused with the nerve growth factor signal peptide for secretion. After stable transfection and differentiation in vitro, met-enkephalin and pro-enkephalin cells had higher met-enkephalin immunoreactivity and secreted met-enkephalin levels, compared to control cells containing the expression vector only. In the formalin hindpaw-injection model, 15 days after subarachnoid transplant of cells, grafts of met-enkephalin and pro-enkephalin cells significantly reduced the number of formalin-evoked c-fos immunoreactive spinal neurons in the spinal cord, compared to grafts of vector-alone chromaffin cells. The use of such expandable cell lines, for chronic spinal delivery of opiates, could offer an attractive and safe alternative strategy based on ex vivo gene therapy for the control of opioid-sensitive chronic pain.

Intrathecal xenogeneic chromaffin cell grafts reduce nociceptive behavior in a rodent tonic pain model

Adrenal medullary chromaffin cells synthetize and secrete a combination of pain-reducing neuroactive compounds including catecholamines and opioid peptides. Previous reports have shown that implantation of chromaffin cells into the spinal subarachnoid space can reduce both acute and chronic pain in several animal models. We recently demonstrated that human chromaffin cell grafts in the cerebrospinal fluid (CSF) could alleviate intractable cancer pain after failure of systemic opiates. However, wider application of this approach was limited by the limited availability of allogeneic donor material. Alternatively, chromaffin cells from xenogeneic sources such as bovine adrenal medulla were successful in the experimental treatment of pain, but recent concern over risk of prion transmission precluded use of bovine grafts in human clinical trials. The objective of the present study was to investigate the possibility of developing a new xenogeneic porcine source of therapeutic chromaffin cells because this strategy is currently considered the safest for transplantation in man. In the present study, we report the isolation and the characterization of primary porcine chromaffin cells (PCC) compared to bovine cells. We show, for the first time, that these cells grafted in the rat subarachnoid space can attenuate pain-related behaviors as assessed by the formalin test, a model of tonic pain. Moreover, in addition to behavioral studies, immunohistochemical analysis revealed robust survival of chromaffin cells 35 days after transplantation. Taken together, these results support the concept that porcine chromaffin cells may offer an alternative xenogeneic cell source for transplants delivering pain-reducing neuroactive substances.

A new method for encapsulation of living cells: preliminary results with PC12 cell line

A new method is described for encapsulation of living cells. PC12 rat adrenal pheochromocytoma cells, which have been shown to synthesize, store and release dopamine were employed. The particles are made first and the cells then incorporated in a gentle mechanical procedure. The morphology (by light and electron microscopic observation), stability, rheology, texture and permeability of these microcapsules provided by Kappa Biotech were investigated. Membrane permeability studies demonstrated exclusion of 69,000 Da human serum albumin, but equilibrium of D-glucose and inulin was within 24h, indicating a molecular weight cut-off in the 5000-70,000 Da range. The viability and the function of the encapsulated cells were evaluated by measuring the spontaneous release of dopamine by high performance liquid chromatography with electrochemical detection. The results show that dopamine-secreting cells can be sequestered in a semi-permeable capsule and still display good viability and proliferation for at least 1 month.

Induction of the mitochondrial permeability transition mediates the killing of HeLa cells by staurosporine

The role of the mitochondrial permeability transition (MPT) in the killing of HeLa cells by staurosporine (STR) was assessed with the use of bongkrekic acid (BK), an inhibitor of the MPT. BK prevented cell killing as well as biochemical manifestations of the MPT: (a) the loss of the mitochondrial membrane potential (deltapsim); (b) the release of cytochrome c from the intramembranous space to the cytosol; and (c) the release of malate dehydrogenase from the mitochondrial matrix. Stable transfectants that overexpressed Akt were also resistant to cell killing and did not develop an MPT. STR inhibited the phosphorylation of Bad, whereas Bad phosphorylation was preserved in cells that overexpress Akt. In wild-type HeLa cells treated with STR, the content of Bax in the cytosol decreased as that in the mitochondria increased, a result that was again prevented by overexpression of Akt. Bid accumulation in the mitochondria with STR was not affected by overexpression of Akt. The pan-caspase inhibitor Z-Val-Ala-Val-Asp(OMe) fluoromethylketone prevented cell killing bu not induction of the MPT. The data document the central role of the MPT in the killing of HeLa cells by STR. The data are consistent with the hypothesis that induction of the MPT is a consequence of the movement of Bax to the mitochondria. Phosphorylation of Bad prevents Bax translocation. Caspases participate in the events related to cell killing that occur subsequent to induction of the MPT.

[Management of intractable cancer pain: from intrathecal morphine to cell allograft]

The durable effectiveness of intrathecal morphine administration is well established for the management of intractable cancer pain, after failure of systemic opioids, secondary to the persistence of non-reversible undesirable side effects. Many patients are referred to late in the disease course. This conservative method to control pain of malignant origin must not be reserved for last resort treatment for terminal patients. Intra-cerebro-ventricular morphine administration is a very effective and generally safe method for controlling intractable cancer pain. Because of the chronic implantation of an intra-ventricular catheter this method is somewhat invasive. Its indications remain a simple and effective alternative when the topography of nociceptive pain is diffuse or cephalic. In clinical practice, intrathecal and/or intra-cerebro-ventricular administration of opioids is limited by cost, the need for specialized maintenance and mechanical malfunctions if implantable drug delivery systems, or by the risk of bacterial contamination and ambulatory constraints when repeated daily injections via an intrathecal access port are used. To answer these limitations, cell therapy using intrathecal chromaffin cell allograft is a promising approach for the management of cancer pain refractory to traditional drug therapy and pain lesion surgery. The basic rationale and preclinical studies on experimental pain models have enabled starting prospective clinical trials. Prior to transplantation, handling and preparation of the chromaffin tissue is critical for allograft viability. The initial results of clinical trials with human chromaffin cell grafts from intractable cancer pain have reported long-lasting pain relief, in correlation with met-enkephalin release into the CSF. Convincing evidence will require controlled studies. The limitations of this innovative cell therapy and especially the lack of human adrenal gland availability point to the need for new sources of cells. Perspectives include xenogenic or engineered cell lines.

Adrenal medullary explants as an efficient tool for pain control: adhesive biomolecular components are involved in graft function ex vivo

Adrenal medullary (AM) tissue transplantation into the central nervous system has been reported as a potential source of opioid peptides and catecholamines, which have analgesic effects useful in the control of chronic pain. Clinical trials, involving allogeneic graft of whole tissue explants into the subarachnoid space of the lumbar spinal cord, have already been reported. The aim of the present study was to determine whether adhesion and function of AM explants were related in some extent and how this relationship could account for improvement of AM tissue in terms of analgesic activity before grafting. Our experiments demonstrated a significant correlation between the adherent state of AM organoids during culture and a sustained secretion of Met-enkephalin and catecholamines by chromaffin cells (CC). These findings suggest that optimal culture condition for AM organoid adhesion can be defined for maintenance of tissue, prior to transplantation. Using immunocytochemistry, flow cytometry, and ELISA assays we showed that different cell adhesion molecules (CAMs) and extracellular matrix ECM proteins were expressed and released by AM cells during culture. Adherent AM organoids expressed increased levels of specific neural CAMs (NCAM and HNK-1 epitope) and integrin chains (beta1, alpha1, alpha2, alpha4, alpha5) and deposited markedly higher levels of fibronectin, but also laminin and collagen IV. Those molecules and probably adhesion processes they control might be involved in the maintenance of the CC-secreting neuroendocrine phenotype through cellular signaling pathways.

Cytochrome c-dependent activation of caspase-3 by tumor necrosis factor requires induction of the mitochondrial permeability transition

The killing of L929 mouse fibroblasts by tumor necrosis factor-alpha (TNF-alpha) in the presence of 0.5 microg/ml actinomycin D (Act D) is prevented by inhibition of the mitochondrial permeability transition (MPT) with cyclosporin A (CyA) in combination with the phospholipase A(2) inhibitor aristolochic acid (ArA). The MPT is accompanied by the release of cytochrome c from the mitochondria, caspase-8 and caspase-3 activation in the cytosol, cleavage of the nuclear enzyme poly(ADP-ribose)polymerase (PARP), and DNA fragmentation, all of which were inhibited by CyA plus ArA. The caspase-3 inhibitor z-Asp-Glu-Val-aspartic acid fluoromethyl-ketone (Z-DEVD-FMK) did not prevent the loss of viability or the redistribution of cytochrome c, but it did prevent caspase-3 activation, PARP cleavage, and DNA fragmentation. Inhibition of the MPT reduced the activation of caspase-8 to the level occurring with TNF-alpha alone (no ActD). The caspase-8 inhibitor z-Ile-Glu(OMe)-Thr-Asp(OMe) fluoromethylketone (Z-IETD-FMK) did not prevent the cell killing and decreased only slightly the translocation of Bid to the mitochondria. These data indicate that induction of the MTP by TNF-alpha causes a release of cytochrome c, caspase-3 activation with PARP cleavage and DNA fragmentation. The loss of viability is dependent on the MPT but independent of the activation of caspase-3. The activation of caspase-8 is not dependent on the MPT. There is no evidence linking this enzyme to the loss of viability. Thus, the killing of L929 fibroblasts by TNF-alpha can occur in the absence of either caspase-3 or caspase-8 activity. Alternatively, cell death can be prevented despite an activation of caspase-8.

Intrathecal grafting of unencapsulated adrenal medullary tissue can bring CD4 T lymphocytes into CSF: a potentially deleterious event for the graft

Adrenal medullary tissue including chromaffin cells was grafted intrathecally in cancer patients to relieve intractable pain. The central nervous system (CNS) is considered an immune privileged site. Therefore, non-HLA-matched and unencapsulated tissue was grafted in 15 patients and 1 sham control in a series of at least 20 grafts. We observed an increase in CSF lymphocyte counts in 15/20 allografts (75%). In contrast to peripheral blood, CD4 T cells predominated in the CSF, but failed to exhibit an activated phenotype (CD25+ CD45RO+ HLA-DR+). The positive effect of graft on pain, the high met-enkephalin levels, the absence of any increase in CSF cytokine levels particularly for IFN-gamma or IL-2 (but not IL-10 and IL-6), indirectly indicated that the graft was tolerated despite the presence of CSF lymphocytes. The single treatment failure and three of four cases of partial efficacy occurred in grafts where CSF lymphocytes were present. Moreover, when assayed (n = 7), the CD4+ CSF lymphocytes still retained the capacity to exhibit ex vivo a normal or enhanced frequency of T CD4 cells producing IFN-gamma and IL-2. Taken together, our observations indicate that impairment of the local immunosuppressive balance can lead to activation of those CSF CD4 T cells and drive a rejection process. This study suggests further work on the purification and/or the immunoisolation of tissues grafted in the CNS will be necessary, particularly when the possibility of long-term and repeated grafting is considered.

Functional consequences of the sustained or transient activation by Bax of the mitochondrial permeability transition pore

The overexpression of Bax kills cells by a mechanism that depends on induction of the mitochondrial permeability transition (MPT) (Pastorino, J. G., Chen, S.-T., Tafani, M., Snyder, J. W., and Farber, J. L. (1998) J. Biol. Chem. 273, 7770-7775). In the present study, purified, recombinant Bax opened the mitochondrial permeability transition pore (PTP). Depending on its concentration, Bax had two distinct effects. At a concentration of 125 nM, Bax caused the release of the intermembranous proteins cytochrome c and adenylate kinase and the release from the matrix of sequestered calcein, effects prevented by the inhibitor of the PTP cyclosporin A (CSA). At this concentration of Bax, there was no detectable mitochondrial swelling or depolarization. These effects of low Bax concentrations are interpreted as the consequence of transient, non-synchronous activation of the PTP followed by a prompt recovery of mitochondrial integrity. By contrast, Bax concentrations between 250 nM and 1 microM caused a sustained opening of the PTP with consequent persistent mitochondrial swelling and deenergization (the MPT). CSA prevented the MPT induced by Bax. Increasing concentrations of calcium caused a greater proportion of the mitochondria to undergo the MPT in the presence of Bax. Importantly, two known mediators of apoptosis, ceramide and GD3 ganglioside, potentiated the induction by Bax of the MPT. The data imply that Bax mediates the opening of the mitochondrial PTP with the resultant release of cytochrome c from the intermembranous space.

Paclitaxel induces apoptosis in Saos-2 cells with CD95L upregulation and Bcl-2 phosphorylation

We examined the effect of paclitaxel on human osteoblastic cells Saos-2 to determine if paclitaxel can affect proliferation and apoptosis. We used a p53-negative cell line in order to mimic the loss of function frequently observed at the clinical level. Paclitaxel induced cell death in a dose- and time-dependent manner. Marked nuclear condensation and fragmentation of chromatin were observed by Hoechst 33258 stain, DNA ladder formation, electron microscopy, and flow cytometry at concentrations as low as 100 nM, a concentration which can be achieved by infusion in human plasma. At 100 nM, paclitaxel induced a G2 arrest at 8 h of treatment. The cells then continued to accumulate in G2 until 72 h when the percentage of apoptotic events reached 54%. At the molecular level, Bcl-2 protein was phosphorylated at 16 h and PARP protein was cleaved, indicating the activation of caspase-3-like proteases. Caspase inhibitors Z-VAD-FMK and Z-DEVD-FMK rescued Saos-2 cells from paclitaxel-induced apoptosis. CD95 expression was constantly high, while CD95L showed a threefold increase in expression. This suggests that, following the G2 arrest, apoptosis is induced through the CD95/CD95L system.

Tumor necrosis factor induces phosphorylation and translocation of BAD through a phosphatidylinositide-3-OH kinase-dependent pathway

Tumor necrosis factor (TNF) induced the phosphorylation of BAD at serine 136 in HeLa cells under conditions that are not cytotoxic. BAD phosphorylation by TNF was dependent on phosphatidylinositide-3-OH kinase (PI3K) and was accompanied by the translocation of BAD from the mitochondria to the cytosol. Blocking the phosphorylation of BAD and its translocation to the cytosol with the PI3K inhibitor wortmannin activated caspase-3 and markedly potentiated the cytotoxicity of TNF. Transient transfection with a PI3K dominant negative mutant or a dominant negative mutant of the serine-threonine kinase Akt, the downstream target of PI3K and the enzyme that phosphorylates BAD, similarly potentiated the cytotoxicity of TNF. By contrast, transfection with a constitutively active Akt mutant protected against the cytotoxicity of TNF in the presence of wortmannin. Phosphorylation of BAD prevents its interaction with the antiapoptotic protein Bcl-XL. Transfection with a Bcl-XL expression vector protected against the cytotoxicity of TNF in the presence of wortmannin. The mechanism by which the inhibition of the phosphorylation of BAD is likely linked to the induction of lethal mitochondrial damage in TNF-intoxicated cells is discussed.

Assembled IgG molecules are exported from the endoplasmic reticulum in myeloma cells despite the retention signal SEKDEL

The KDEL retention signal, when added at the C-terminal of the constant region of light and heavy chains of immunoglobulins is able to efficiently retain assembled immunoglobulins only in cells of nonlymphoid origin. In transfected myeloma cells the wild type and the KDEL-Ig mutants are secreted with the same efficiency. This phenomenon is not due to a proteolytic cleavage of the KDEL signal nor to a lack of intermolecular disulfide bond formation and is not due to an impaired recognition of the KDEL signal in myeloma cells. Thus, the constitutive secretion of assembled immunoglobulins, currently considered to follow a default process, appears to be regulated by a mechanism that is able to overcome an efficient ER retention system.

The overexpression of Bax produces cell death upon induction of the mitochondrial permeability transition

Stably transfected Jurkat T cells were produced in which Bax expression is inducible by muristerone A. The cell death resulting from induction of the overexpression of Bax was prevented by inhibition of the mitochondrial permeability transition (MPT) with cyclosporin A (CyA) in combination with the phospholipase A2 inhibitor aristolochic acid (ArA). The caspase-3 inhibitor Z-Asp-Glu-Val aspartic acid fluoromethylketone (Z-DEVD-FMK) had no effect on the loss of viability. The MPT was measured as the CyA plus ArA-preventable loss of the mitochondrial membrane potential (DeltaPsim). The MPT was accompanied by the release of cytochrome c from the mitochondria, caspase-3 activation in the cytosol, cleavage of the nuclear enzyme poly(ADP-ribose)polymerase (PARP), and DNA fragmentation, all of which were inhibited by CyA plus ArA. Z-DEVD-FMK had no effect on the loss of DeltaPsim and the redistribution of cytochrome c but did prevent caspase-3 activation, PARP cleavage, and DNA fragmentation. It is concluded that Bax induces the MPT, a critical event in the loss of cell viability. In addition to the cell death, the MPT mediates other typical manifestations of apoptosis in this model, namely release of cytochrome c, caspase activation with PARP cleavage, and DNA fragmentation.

Relief of intractable cancer pain by human chromaffin cell transplants: experience at two medical centers

In addition to its possible role as a replacement source in CNS degenerative diseases, neural transplantation may be used to augment the normal production of neuroactive substances. Our laboratory at the University of Illinois at Chicago has shown, in both acute and chronic pain models, that transplantation of adrenal medullary tissue or isolated chromaffin cells into CNS pain modulatory regions can reduce pain sensitivity in rodents. Chromaffin cells were chosen as the donor source since they produce high levels of both opioid peptides and catecholamines, substances which reduce pain sensitivity when injected locally into the spinal subarachnoid space. The analgesia produced by these transplants probably results from the release of both opioid peptides and catecholamines since it can be blocked or attenuated by both opiate and adrenergic antagonists. Studies indicate that even over long periods there is no apparent development of tolerance. Promising results have been obtained in preliminary clinical studies using allografts of adrenal medulla to relieve cancer pain. This clinical review encompasses results at two Medical Centers-University of Illinois at Chicago and University Paul Sabatier, Toulouse, France-in assessing efficacy of subarachnoid adrenal medullary transplantation for alleviating cancer pain. Our clinical and autopsy data strongly support our previous laboratory studies, i.e., that chromaffin cell transplants into the subarachnoid space represent a promising new approach to the alleviation of chronic pain. It is suggested that further clinical studies are now warranted.

Neuroendocrine system and immune responses after confinement

A confinement experiment in a normobaric diving chamber was undertaken to obtain more understanding of the effects of confinement and isolation on human psychology and physiology. Pre- and post-confinement blood samples were obtained from four test subjects and five control subjects for the analysis of plasma proteins, hormone levels and immune responses. The absence of significant changes in the immune responses correlates with the absence of major changes in neurohormones and other hormones such as cortisol, prolactin, growth hormone, insulin-like growth factor 1, triiodothyronin, thyrotrophin and 1,25-dihydroxyvitamin D. It is increasingly recognized that the immune system is not an independent physiological system, but a system that interacts multidirectionally with other organs and body functions. It seems that the conditions of this confinement experiment were not stressful from a psychological point of view. The presence of a female crew member had probably a positive effect on group behavior of the test subjects. In conclusion, the data suggest that confinement for 60 days in a small habitat without particularly stressful situations has no significant impact on a variety of neuroimmunological parameters.

Redox state of single chain Fv fragments targeted to the endoplasmic reticulum, cytosol and mitochondria

In this paper we have engineered the targeting of ScFv fragments to mitochondria and demonstrated that this can occur efficiently. This extends the range of subcellular compartments where antibody domains can be targeted in order to interfere with the action of the corresponding antigen. Moreover, we have compared the redox state of ScFv fragments targeted to the secretory compartment, the cytosol and the mitochondria, and demonstrated that cysteine residues in ScFv targeted to the secretory compartments and to the mitochondria are oxidized. On the contrary, cytosolic antibody domains are expressed in a reduced state, which is probably the reason for their lower expression levels. These pitfalls, however, do not prevent their successful utilization for intracellular immunization.

Transplantation of human chromaffin cells for control of intractable cancer pain

Adrenal medullary chromaffin cells produce high levels of endogenous opioid peptides. Recent data suggest that transplantation injected locally into the spinal subarachnoid space reduced intractable malignant pain. In order to determine the feasibility, the efficacy and the risks of using adrenal medullary tissue for control of irreducible pain, we have developed a transplantation protocol on cancer pain patients selected when they required chronic intrathecal injection of morphine and progressively increasing doses to maintain the level of analgesic effects. At the present time, our clinical trial involves 8 patients. We report here our initial results (mean follow-up: 5 months). The various data collected before and after the intrathecal administration of chromaffin cells included: 1) Pain evaluation over time, with concomitant narcotic intake, 2) CSF sampling through an implanted access port to determine the following biological parameters: biochemical assay for opioid peptides, cell count and phenotyping of lymphocytes, 3) peripheral blood samples for lymphocyte typing. The results confirm the efficacy of adrenal medullary transplantation into spinal CSF for controlling irreducible cancer pain. Complementary intrathecal and oral morphine were totally stopped in 2 cases and stabilized in 5 others. It seems essential to have an important volume of grafted tissue to achieve analgesia with high levels of metenkephalin in CSF. A progressive decrease in metenkephalin release was observed from 2 to 4 months after the transplantation. Two patients with a long-term follow-up (8 and 12 months) needed another intrathecal chromaffin cell graft.

Placental kappa binding site : interaction with dynorphin and its possible implication in hCG secretion

We have previously demonstrated that human placenta contains a homogenous population of kappa binding sites. The selective interaction of dynorphin with these opiate binding sites suggests a possible physiological implication of this endogenous opioid system in the placenta physiology. Ethylketocyclazocine stimulate K+-induced hCG release. This fact favours the hypothesis of a participation of placental opiate receptor on hCG secretion.

Localization of human placental opiate binding sites on the syncytial brush border membrane

Opiate binding sites were measured in different placental membrane fractions which were characterized by marker enzyme analysis and electron microscopic examination. The distribution pattern of opiate binding sites in the different fractions closely parallels that of placental alkaline phosphatase. These results clearly show that opiate binding sites are mainly located on the syncytial brush border membrane. The opiate binding sites found on microvillus membrane fraction have the same pharmacological characteristics as the Kappa opiate binding site previously characterized on placental crude membrane fraction.