Orthopaedic manifestations of pseudoachondroplasia.

PURPOSE: In 1959, Maroteaux and Lamy initially designated pseudoachondroplasia as a distinct dysplasia different from achondroplasia the most common form of skeletal dysplasia. Pseudoachondroplasia is caused by a mutation in the collagen oligomeric matrix protein gene (COMP) gene on chromosome 19p13.1-p12 encoding the COMP. The COMP gene mutations result in rendering the articular and growth plate cartilages incapable of withstanding routine biomechanical loads with resultant deformity of the joints. The purpose of the study was to characterize the typical orthopaedic findings in pseudoachondroplasia. METHODS: The charts and radiographs of 141 patients with pseudoachondroplasia were analyzed. This cohort, to our knowledge, represents the largest group of patients describing the typical orthopaedic manifestations of pseudoachondroplasia. RESULTS: Patients with pseudoachondroplasia have normal craniofacial appearance with normal intelligence. Short stature is not present at birth and generally appears by two to four years of age. The condition is a form of spondyloepiphyseal dysplasia and the long bones are characterized by dysplastic changes in the epiphysis, metaphysis and vertebral bodies. Radiographically the long bones have altered the appearance and structure of the epiphyses with small irregularly formed or fragmented epiphyses or flattening. The metaphyseal regions of the long bones show flaring, widening or 'trumpeting'. The cervical (89%) and thoracic and lumbar vertebrae show either platyspondyly, ovoid, 'cod-fish' deformity or anterior 'beaking'. Kyphosis (28%), scoliosis (58%) and lumbar lordosis (100%) are commonly seen. The femoral head and acetabulum are severely dysplastic (100%). The knees show either genu valgum (22%), genu varum (56%) or 'windswept' deformity (22%). CONCLUSION: Most commonly these distortions of the appendicular and the axial skeleton lead to premature arthritis particularly of the hips and often the knees not uncommonly in the 20- to 30-year-old age group. LEVEL OF EVIDENCE: III.

Defective positioning in granulomas but not lung-homing limits CD4 T-cell interactions with Mycobacterium tuberculosis-infected macrophages in rhesus macaques.

Protection against Mycobacterium tuberculosis (Mtb) infection requires CD4 T cells to migrate into the lung and interact with infected macrophages. In mice, less-differentiated CXCR3+ CD4 T cells migrate into the lung and suppress growth of Mtb, whereas CX3CR1+ terminally differentiated Th1 cells accumulate in the blood vasculature and do not control pulmonary infection. Here we examine CD4 T-cell differentiation and lung homing during primary Mtb infection of rhesus macaques. Mtb-specific CD4 T cells simultaneously appeared in the airways and blood ∼21-28 days post exposure, indicating that recently primed effectors are quickly recruited into the lungs after entering circulation. Mtb-specific CD4 T cells in granulomas display a tissue-parenchymal CXCR3+CX3CR1-PD-1hiCTLA-4+ phenotype. However, most granuloma CD4 T cells are found within the outer lymphocyte cuff and few localize to the myeloid cell core containing the bacilli. Using the intravascular stain approach, we find essentially all Mtb-specific CD4 T cells in granulomas have extravasated across the vascular endothelium into the parenchyma. Therefore, it is unlikely to be that lung-homing defects introduced by terminal differentiation limit the migration of CD4 T cells into granulomas following primary Mtb infection of macaques. However, intralesional positioning defects within the granuloma may pose a major barrier to T-cell-mediated immunity during tuberculosis.

Urinary Markers of Fibrosis and Risk of Cardiovascular Events and Death in Kidney Transplant Recipients: The FAVORIT Trial.

Cardiovascular risk remains high in kidney transplant recipients (KTRs) despite improved kidney function after transplant. Urinary markers of kidney fibrosis and injury may help to reveal mechanisms of this risk. In a case-cohort study among stable KTRs who participated in the FAVORIT trial, we measured four urinary proteins known to correlate with kidney tubulointerstitial fibrosis on biopsy (urine alpha 1 microglobulin [α1m], monocyte chemoattractant protein-1 [MCP-1], procollagen type I [PINP] and type III [PIIINP] N-terminal amino peptide) and evaluated associations with cardiovascular disease (CVD) events (n = 300) and death (n = 371). In adjusted models, higher urine α1m (hazard ratio [HR] per doubling of biomarker 1.40 [95% confidence interval [CI] 1.21, 1.62]), MCP-1 (HR 1.18 [1.03, 1.36]), and PINP (HR 1.13 [95% CI 1.03, 1.23]) were associated with CVD events. These three markers were also associated with death (HR per doubling α1m 1.51 [95% CI 1.32, 1.72]; MCP-1 1.31 [95% CI 1.13, 1.51]; PINP 1.11 [95% CI 1.03, 1.20]). Higher concentrations of urine α1m, MCP-1, and PINP may identify KTRs at higher risk for CVD events and death. These markers may identify a systemic process of fibrosis involving both the kidney and cardiovascular system, and give new insights into mechanisms linking the kidney with CVD.

Filtration Markers, Cardiovascular Disease, Mortality, and Kidney Outcomes in Stable Kidney Transplant Recipients: The FAVORIT Trial.

Cystatin C and beta-2-microglobulin (B2M) are filtration markers associated with adverse outcomes in nontransplant populations, sometimes with stronger associations than for creatinine. We evaluated associations of estimated glomerular filtration rate from cystatin C (eGFRcys ), B2M (eGFRB2M ), and creatinine (eGFRcr ) with cardiovascular outcomes, mortality, and kidney failure in stable kidney transplant recipients using a case-cohort study nested within the Folic Acid for Vascular Outcome Reduction in Transplantation (FAVORIT) Trial. A random subcohort was selected (N = 508; mean age 51.6 years, median transplant vintage 4 years, 38% women, 23.6% nonwhite race) with enrichment for cardiovascular events (N = 306; 54 within the subcohort), mortality (N = 208; 68 within the subcohort), and kidney failure (N = 208; 52 within the subcohort). Mean eGFRcr , eGFRcys , and eGFRB2M were 46.0, 43.8, and 48.8 mL/min/1.73m2 , respectively. After multivariable adjustment, hazard ratios for eGFRcys and eGFRB2M <30 versus 60+ were 2.02 (95% confidence interval [CI] 1.09-3.76; p = 0.03) and 2.56 (1.35-4.88; p = 0.004) for cardiovascular events; 3.92 (2.11-7.31) and 4.09 (2.21-7.54; both p < 0.001) for mortality; and 9.49 (4.28-21.00) and 15.53 (6.99-34.51; both p < 0.001) for kidney failure. Associations persisted with additional adjustment for baseline eGFRcr . We conclude that cystatin C and B2M are strongly associated with cardiovascular events, mortality, and kidney failure in stable kidney transplant recipients.

A tailored automated nutrition screening tool for rapid identification of risk in acute-care hospital settings.

Malnourishment is prevalent in hospitalized patients and associated with adverse medical outcomes. Thus, nutrition screening to identify high-risk patients is widespread. However, no single universal tool has been shown to be suitable for all hospital departments. To address this challenge, a novel, tailored, electronic tool for nutritional screening was developed and evaluated. The Rambam Automated Nutrition Computerized Screening tool efficiently screens all newly admitted patients and does not rely on self-reported height and weight estimates. Validation was carried out in medical wards (n=94), and compared to the Malnutrition Universal Screening Tool, length of stay and an independent assessment by a professional dietician. Results from this research support the use of automated, flexible tools that instantaneously incorporate relevant available data from the electronic health record. Tools that are adaptable to meet the needs of individual hospital departments, can save valuable time and ensure full screening of all admitted patients.

Novel and enhanced anti-melanoma DNA vaccine targeting the tyrosinase protein inhibits myeloid-derived suppressor cells and tumor growth in a syngeneic prophylactic and therapeutic murine model.

Melanoma is the most deadly type of skin cancer, constituting annually ∼ 75% of all cutaneous cancer-related deaths due to metastatic spread. Currently, because of metastatic spread, there are no effective treatment options for late-stage metastatic melanoma patients. Studies over the past two decades have provided insight into several complex molecular mechanisms as to how these malignancies evade immunological control, indicating the importance of immune escape or suppression for tumor survival. Thus, it is essential to develop innovative cancer strategies and address immune obstacles with the goal of generating more effective immunotherapies. One important area of study is to further elucidate the role and significance of myeloid-derived suppressor cells (MDSCs) in the maintenance of the tumor microenvironment. These cells possess a remarkable ability to suppress immune responses and, as such, facilitate tumor growth. Thus, MDSCs represent an important new target for preventing tumor progression and escape from immune control. In this study, we investigated the role of MDSCs in immune suppression of T cells in an antigen-specific B16 melanoma murine system utilizing a novel synthetic tyrosinase (Tyr) DNA vaccine therapy in both prophylactic and therapeutic models. This Tyr vaccine induced a robust and broad immune response, including directing CD8 T-cell infiltration into tumor sites. The vaccine also reduced the number of MDSCs in the tumor microenvironment through the downregulation of monocyte chemoattractant protein 1, interleukin-10, CXCL5 and arginase II, factors important for MDSC expansion. This novel synthetic DNA vaccine significantly reduced the melanoma tumor burden and increased survival in vivo, due likely, in part, to the facilitation of a change in the tumor microenvironment through MDSC suppression.

DNA vaccine cocktail expressing genotype A and C HBV surface and consensus core antigens generates robust cytotoxic and antibody responses in mice and Rhesus macaques.

There are well over a quarter of a billion chronic hepatitis B virus (HBV) carriers across the globe. Most carriers are at high risk for development of liver cirrhosis and subsequent progression to hepatocellular carcinoma. It is therefore imperative to develop new approaches for immunotherapy against this infection. Antibodies and cytotoxic T cells to different HBV antigens are believed to be important for reducing viral load and clearing HBV-infected cells from the liver. Some of the major challenges facing current vaccine candidates have been their inability to induce both humoral and cellular immunity to multiple antigenic targets and the induction of potent immune responses against the major genotypes of HBV. In this study, highly optimized synthetic DNA plasmids against the HBV consensus core (HBc) and surface (HBs) antigens genotypes A and C were developed and evaluated for their immune potential. These plasmids, which encode the most prevalent genotypes of the virus, were observed to individually induce binding antibodies to HBs antigens and drove robust cell-mediated immunity in animal models. Similar responses to both HBc and HBs antigens were observed when mice and non-human primates were inoculated with the HBc-HBs cocktails. In addition to the cytotoxic T lymphocyte activities exhibited by the immunized mice, the vaccine-induced responses were broadly distributed across multiple antigenic epitopes. These elements are believed to be important to develop an effective therapeutic vaccine. These data support further evaluation of multivalent synthetic plasmids as therapeutic HBV vaccines.

Hydrodynamic immunization leads to poor CD8 T-cell expansion, low frequency of memory CTLs and ineffective antiviral protection.

Hepatotropic pathogens, such as hepatitis B (HBV) and hepatitis C (HCV), often escape cellular immune clearance resulting in chronic infection. As HBV and HCV infections are the most common causes of hepatocellular carcinoma (HCC), prevention of these infections is believed to be key to the prevention of HCC. It is believed that an effective immune therapy must induce strong cytotonic T lymphocytes (CTLs) that can migrate into the liver, where they can clear infected hepatocytes. Here, we compared the induction of CD8 T cells by two different DNA immunization methods for T-cell differentiation, function, memory programming and their distribution within relevant tissues in a highly controlled fashion. We used hydrodynamic tail vein injection of plasmid to establish liver-specific LCMV-gp antigen (Ag) transient expression, and studied CD8 T cells induced using the P14 transgenic mouse model. CD8 T cells from this group exhibited unique and limited expansion, memory differentiation, polyfunctionality and cytotoxicity compared with T cells generated in intramuscularly immunized mice. This difference in liver-generated expansion resulted in lower memory CD8 T-cell frequency, leading to reduced protection against lethal viral challenge. These data show an unusual induction of naive CD8 T cells contributed to the lower frequency of Ag-specific CTLs observed after immunization in the liver, suggesting that limited priming in liver compared with peripheral tissues is responsible for this outcome.

Inducing humoral and cellular responses to multiple sporozoite and liver-stage malaria antigens using exogenous plasmid DNA.

A vaccine candidate that elicits humoral and cellular responses to multiple sporozoite and liver-stage antigens may be able to confer protection against Plasmodium falciparum malaria; however, a technology for formulating and delivering such a vaccine has remained elusive. Here, we report the preclinical assessment of an optimized DNA vaccine approach that targets four P. falciparum antigens: circumsporozoite protein (CSP), liver stage antigen 1 (LSA1), thrombospondin-related anonymous protein (TRAP), and cell-traversal protein for ookinetes and sporozoites (CelTOS). Synthetic DNA sequences were designed for each antigen with modifications to improve expression and were delivered using in vivo electroporation (EP). Immunogenicity was evaluated in mice and nonhuman primates (NHPs) and assessed by enzyme-linked immunosorbent assay (ELISA), gamma interferon (IFN-γ) enzyme-linked immunosorbent spot (ELISpot) assay, and flow cytometry. In mice, DNA with EP delivery induced antigen-specific IFN-γ production, as measured by ELISpot assay and IgG seroconversion against all antigens. Sustained production of IFN-γ, interleukin-2, and tumor necrosis factor alpha was elicited in both the CD4(+) and CD8(+) T cell compartments. Furthermore, hepatic CD8(+) lymphocytes produced LSA1-specific IFN-γ. The immune responses conferred to mice by this approach translated to the NHP model, which showed cellular responses by ELISpot assay and intracellular cytokine staining. Notably, antigen-specific CD8(+) granzyme B(+) T cells were observed in NHPs. Collectively, the data demonstrate that delivery of gene sequences by DNA/EP encoding malaria parasite antigens is immunogenic in animal models and can harness both the humoral and cellular arms of the immune system.

Synthetic DNA immunogen encoding hepatitis B core antigen drives immune response in liver.

The prevalence of hepatitis B virus (HBV) infection in Asia and sub-Sahara Africa is alarming. With quarter of a billion people chronically infected worldwide and at risk of developing liver cancer, the need for a prophylactic or therapeutic vaccination approach that can effectively induce protective responses against the different genotypes of HBV is more important than ever. Such a strategy will require both the induction of a strong antigen-specific immune response and the subsequent deployment of immune response towards the liver. Here, we assessed the ability of a synthetic DNA vaccine encoding a recombinant consensus plasmid from genotype A through E of the HBV core antigen (HBcAg), to drive immunity in the liver. Intramuscular vaccination induced both strong antigen-specific T cell and high titer antibody responses systematically and in the liver. Furthermore, immunized mice showed strong cytotoxic responses that eliminate adoptively transferred HBV-coated target cells. Importantly, vaccine-induced immune responses provided protection from HBcAg plasmid-based liver transfection in a hydrodynamic liver transfection model. These data provide important insight into the generation of peripheral immune responses that are recruited to the liver-an approach that can be beneficial in the search for vaccines or immune-therapies to liver disease.

Effects of cigarette smoke on salivary protein tyrosine nitration.

INTRODUCTION: Nitration of tyrosine and tyrosine-containing proteins and their roles in pathophysiology have just recently been reviewed. Despite low yields of tyrosine modifications, nitration of tyrosine residues may inactivate important proteins. Nitrotyrosine can be formed by various nitrating agents, including peroxynitrite. Thus, the occurrence of nitrotyrosine-containing proteins in vivo should be regarded as a general indication of tissue damage induced by reactive nitrogen species such as peroxynitrite. This strongly suggests that peroxynitrite could be formed in vivo under certain pathophysiological conditions. OBJECTIVE: Our aim in this study was to elucidate the effect of cigarette smoke (CS) on nitrotyrosine formation in saliva proteins. METHODS: We exposed saliva to CS, in vitro, and used Western Blotting (WB) and monoclonal anti-nitrotyrosine antibody to assess the level of saliva protein nitration. RESULTS: As saliva contains extensive amounts of nitrites, it was no surprise that at basal levels, saliva proteins, albumin, and α-amylase all were already nitrated. The WB also revealed that with continuous exposure to CS the tyrosine nitration of both albumin and α-amylase is declining significantly after 3 h. A quite similar effect was seen after exposure to aldehydes, but to a less extent as compared to CS. Exposure of nitrotyrosine-modified bovine serum albumin (BSA-N) to aldehydes, produced a similar effect, meaning a decrease in tyrosine nitration. CONCLUSIONS: These findings might be explained by the possible ability of CS aldehydes to reduce protein-bound nitro group to an amine. Another proposed mechanism is that CS unsaturated aldehydes react with proteins mainly through Michael addition reaction; leading to the generation of stable aldehyde-protein adducts (APA). Thus, it may react with nitro groups of saliva proteins, like albumin or α-amylase, to generate APA, which ultimately, may not be recognized by our antibody. Another possible mechanism, is interaction between the aldehyde group with the hydroxyl group of the 3-nitrotyrosine, forming a hemiacetal, which is not recognized by the antibody. This mechanism might explain the difference in the denitration effects caused by the saturated aldehyde acetaldehyde, which exists in large amounts in CS, and unsaturated aldehydes. Therefore, it is possible that the main player in the CS smoke denitration effect on salivary proteins is the aldehyde group and not the double bond of unsaturated aldehydes.

Increased pro-inflammatory activity and impairment of human monocyte differentiation induced by in vitro exposure to cigarette smoke.

Cigarette smoking (CS) is associated with a variety of human pathologies including cardiovascular disease and cancer. Human monocytes are prevalent in oral and respiratory mucosa and may be affected by exposure to CS, which induces oxidative stress. As a result, up-regulation of nuclear factor-kappaB (NF-kappaB) may occur. Our aims were to analyze a possible regulatory effect of CS on NF-kappaB activity in human monocytes. Human monocyte cell lines were exposed to CS in vitro. Our findings show that in vitro exposure to CS did not affect viability of human monocytes and was associated with increased production and secretion of IL-8 and up-regulation of certain C-C chemokines. Inhibition of NF-kappaB with curcumin or parthenolide resulted in a decrease of IL-8 secretion. CS also impaired the differentiation of monocytes. However, induced secretion of IL-8 from differentiated monocytes was not impaired. Our results indicate that exposure to CS stimulates pro-inflammatory activity of human monocytes through the activation of NF-kappaB pathway and also interferes with monocyte differentiation, which could play a role in the carcinogenic effects of cigarette smoking.

Effects of cigarette smoke borne reactive nitrogen species on salivary alpha-amylase activity and protein modifications.

Cigarette smoke (CS) is associated with a variety of human pathologies including cardiovascular disease and cancer. Oral squamous cell carcinoma (OSCC) is the most common malignancy of the head and neck. The major inducer of OSCC is exposure to tobacco. Recent studies demonstrated that oxidative and nitrosative stress contributes to the development of oral carcinogenesis through DNA damage. All salivary reactive nitrogen species (RNS) analyzed from OSCC patients are significantly higher in comparison with healthy subjects. Our findings show that CS and external RNS addition induced reduction in alpha-amylase activity and produced some excited carbonyl formation, but to a much less extant than CS. The addition of epigallocatechine-3-gallate (EGCG) to saliva produced no protective effect against damage to alpha-amylase activity. Our proposed mechanism for the decrease in alpha-amylase activity is the formation of adducts at SH groups of the alpha-amylase active site. In this case, EGCG was unable to counteract this phenomenon, as it does not reduce the concentration of disulfides, and does not alter the amount of protein-SH moieties. However, EGCG did reduce the levels of excited carbonyl formation. Our results indicate that although RNS are abundant in CS, a significant decrease in amylase activity is due to other components in CS, probably aldehydes, reacting with the thiol group of proteins by the Michael addition reaction.

Advances in understanding the mechanisms and management of persistent pain in older adults.

Older adults with persistent pain are not simply a chronologically older version of younger pain patients. Pain-related disability in older adults may be driven by pain 'homeostenosis', that is, diminished ability to effectively respond to the stress of persistent pain. Some of the comorbidities of ageing that can contribute to pain homeostenosis include cognitive and physical impairments, increased sensitivity to suprathreshold pain stimuli, medical and psychological comorbidities, altered pharmacokinetics and pharmacodynamics, and social isolation. A key distinction between older and younger individuals with persistent pain is the normal and pathological ageing-associated brain changes. These may alter the expression and experience of pain with impaired descending inhibition and dysfunction of pain gating mechanisms. Cognizance of these brain changes is needed to guide appropriate evaluation and treatment approaches. This paper reviews data that support these ageing-associated phenomena. Specifically, we discuss age-related changes in the brain (both normal and pathological) and in pain physiology; changes in experience and expression of pain that occur with dementia and contribute to pain homeostenosis; and unique aspects of age and pain-associated psychological function and their contribution to disability. We also present data demonstrating changes in brain morphology and neuropsychological performance that accompany persistent non-malignant pain in older adults and the treatment implications of these brain changes. Finally, preliminary data are presented on the efficacy of mindfulness meditation, a treatment that has been examined explicitly in older adults and targets optimizing brain function and descending inhibition.

Inhibition of salivary amylase activity by cigarette smoke aldehydes.

Cigarette smoke (CS) is a leading known cause of cancer and cardiovascular diseases worldwide. The mechanisms by which CS produces its damaging effects seem to be multifactorial. Among others, CS toxicity is due also to several compounds like alpha,beta-unsaturated aldehydes (acrolein, crotonaldehyde) and saturated aldehydes (acetaldehyde). Aldehydes could interact with thiol compounds of salivary proteins, leading to structural and functional alterations of these molecules. Prior in vitro studies have shown that there is a significant decrease in several known enzymatic activities following exposure to CS. Additionally, it was found that glutathione (GSH) has protective effect against the damaging role of CS to salivary enzymes, emphasizing the role of thiol groups in the mechanism of inactivation of these enzymes. In this study, salivary amylase activity showed a significant inhibition following exposure to CS, and to external addition of purified aldehydes known to be present in CS, due probably to the interaction between aldehydes and -SH groups of the enzyme. Our results indicate that although saturated aldehydes are the chief aldehydes present in CS, a significant decrease in amylase activity was due to unsaturated aldehydes, reacting, probably, through their double bond with the thiol group of proteins by the Michael addition reaction.

Macaques co-immunized with SIVgag/pol-HIVenv and IL-12 plasmid have increased cellular responses.

BACKGROUND: The cell mediated immune profiles following immunization with a recombinant DNA vaccine was assessed in the simian-human immunodeficiency virus (SHIV) and Macaque model. Earlier work demonstrated increased numbers of antigen specific CD8 and CD4 effector cells able to secrete IFN-gamma. METHOD: The vaccine strategy included co-immunization of a DNA based vaccine alone or in combination with a macaque IL-12 expressing plasmid (pmacIL12). Antigen activated lymphocytes were studied for activation of a set of immunological molecules. RESULTS: The current study demonstrates lymphocytes isolated and activated from the group that was immunized with DNA and pmacIL12 had a higher level of IFN-gamma producing cells. We also observed a different immunological profile when comparing the cells isolated from macaques immunized with DNA as compared to those animals that also received pmacIL12. CONCLUSION: The observed immune profiles are reflective of the co-delivery of pmacIL12 and demonstrates that IL-12 can increase the magnitude and polyfunctionality of the cellular immune response.

Regression of subcutaneous B16 melanoma tumors after intratumoral delivery of an IL-15-expressing plasmid followed by in vivo electroporation.

In vivo electroporation has been used to efficiently deliver drugs and 'therapeutic' genes to tumors, including melanoma lesions. This study reports on the effect of intratumoral delivery of an optimized DNA plasmid expressing interleukin-15 (pIL-15) on established murine melanoma tumors. IL-15 has been demonstrated to have a pivotal role in the function of memory CD8+ T cells and natural killer cells, which are critical for tumor immunosurveillance. In this study, C57BL/6 mice were injected with B16.F10 melanoma cells and randomized into different experimental groups: untreated (P-V-E-), treated with pIL-15 (P+) or backbone plasmid (V+), with or without electroporation (E+ or E-). Treatment was performed intratumorally with 50 microg of plasmid on days 0, 4 and 7 and tumor volume/size, tumor regression and long-term survival were measured. At day 100 after initiation of treatment, the percentage of mice surviving with complete tumor regression in the P-V+E+, P+V-E-, P+V-E+ and P-V-E- treatment groups were 0, 12.5, 37.5 and 0%, respectively. These results demonstrate the ability of pIL-15 to mediate B16 melanoma regression, with the effect being significantly enhanced by electroporative delivery. This is the first description of the ability of a naked DNA plasmid expressing IL-15 to alone mediate complete regression of B16 melanoma tumors and underscores the potential clinical use of these plasmids for the treatment of malignant tumors when delivered with in vivo electroporation.

Identification of gene clusters differentially expressed during the cellular injury responses (CIR) to cisplatin.

The goal of this study was to identify changes in mRNA levels in tumour cells after a toxic exposure to cisplatin (IC(99)dose). Using suppression-subtractive hybridization (SSH) 2 cDNA libraries were created, an UP library (202 cDNA fragments) and a DOWN library (153 cDNA fragments). Using reversed Northern hybridization 16 and 30 fragments were truly differentially expressed in the UP and DOWN libraries, respectively. Most prominent in the UP library were the mitochondrial and injury response clusters and in the DOWN library the cytoskeletal, protein synthesis and signalling clusters. These distinct clusters potentially represent an expression profile of the cisplatin-induced cellular injury response.

Nicotine affects the signaling of the death pathway, reducing the response of head and neck cancer cell lines to DNA damaging agents.

BACKGROUND: Growing evidence suggests that tobacco can affect the responsiveness of cancer cells to treatment, particularly those of head and neck cancer. This article describes the effects of nicotine on the signaling of the death pathway, resulting in a decreased cytotoxicity of various anticancer agents such as cisplatin and gamma-radiation. METHODS: Colony-forming assays (CFA), using the head and neck cancer cell lines UMSCC10b and UMSCC5 and DNA fragmentation assays, were used to determine the effect of nicotine on cytotoxicity of various anticancer agents, whereas PCR and a JNK activity test were used to study the effect of nicotine on message expression levels and activity of the JNK signaling pathway. RESULTS: Nicotine consistently reduced the cytotoxic effect of DNA-damaging agents, such as cisplatin, UV, and gamma radiation, in UMSCC10b cells, increasing their IC(50) values by twofold, 1.7-fold, and 1.8-fold, respectively. These results were confirmed in a second squamous cell carcinoma cell line (UMSCC5), demonstrating an increase in IC(50) values for cDDP by twofold and 1.9-fold in the UMSCC10b andUMSCC5, respectively. In addition, nicotine reduced the DNA fragmentation 48 h after cDDP exposure in UMSCC10b and UMSCC5 cell lines by 30% and 33%, respectively. The latter, however, was not the result of an effect of nicotine on either the uptake of cDDP or repair of the cDDP-DNA-adducts. To further substantiate the adverse effect of nicotine, the JNK and gadd153 signaling pathways were studied. JNK activity was decreased by 1.8-fold, as well as the expression of its downstream target c-jun (1.9-fold), when tumor cells were exposed to cisplatin in the presence of nicotine. In addition, the gadd153 message was affected and reduced by 1.8-fold. CONCLUSIONS: Nicotine adversely affects the cytotoxicity of DNA-damaging agents. Nicotine does not interfere with the repair of the damage but directly affects the signaling of the death pathway, reducing the signaling of the JNK1 pathway. The latter results in a decrease in efficacy of the anticancer treatment in tumors exposed to nicotine.

RNA editing of the human serotonin 5-HT2C receptor alters receptor-mediated activation of G13 protein.

The recent completion of the human genome predicted the presence of only 30,000 genes, stressing the importance of mechanisms that increase molecular diversity at the post-transcriptional level. One such post-transcriptional event is RNA editing, which generates multiple protein isoforms from a single gene, often with profound functional consequences. The human serotonin 5-HT(2C) receptor undergoes RNA editing that creates multiple receptor isoforms. One consequence of RNA editing of cell surface receptors may be to alter the pattern of activation of heterotrimeric G-proteins and thereby shift preferred intracellular signaling pathways. We examined the ability of the nonedited 5-HT(2C) receptor isoform (INI) and two extensively edited isoforms, VSV and VGV, to interact with various G-protein alpha subunits. Two functional assays were utilized: the cell-based functional assay, Receptor Selection/Amplification Technology(TM), in which the pharmacological consequences of co-expression of 5HT(2C) receptor isoforms with G-protein alpha subunits in fibroblasts were studied, and 5HT(2C) receptor-mediated rearrangements of the actin cytoskeleton in stable cell lines. These studies revealed that the nonedited 5-HT(2C) receptor functionally couples to G(q) and G(13). In contrast, coupling to G(13) was not detected for the extensively edited 5-HT(2C) receptors. Thus, RNA editing represents a novel mechanism for regulating the pattern of activation of heterotrimeric G-proteins, molecular switches that control an enormous variety of biological processes.