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1.
Curr Biol ; 33(7): 1358-1364.e4, 2023 04 10.
Article in English | MEDLINE | ID: mdl-36889318

ABSTRACT

Behavior is shaped by both the internal state of an animal and its individual behavioral biases. Rhythmic variation in gonadal hormones during the estrous cycle is a defining feature of the female internal state, one that regulates many aspects of sociosexual behavior. However, it remains unclear whether estrous state influences spontaneous behavior and, if so, how these effects might relate to individual behavioral variation. Here, we address this question by longitudinally characterizing the open-field behavior of female mice across different phases of the estrous cycle, using unsupervised machine learning to decompose spontaneous behavior into its constituent elements.1,2,3,4 We find that each female mouse exhibits a characteristic pattern of exploration that uniquely identifies it as an individual across many experimental sessions; by contrast, estrous state only negligibly impacts behavior, despite its known effects on neural circuits that regulate action selection and movement. Like female mice, male mice exhibit individual-specific patterns of behavior in the open field; however, the exploratory behavior of males is significantly more variable than that expressed by females both within and across individuals. These findings suggest underlying functional stability to the circuits that support exploration in female mice, reveal a surprising degree of specificity in individual behavior, and provide empirical support for the inclusion of both sexes in experiments querying spontaneous behaviors.


Subject(s)
Estrous Cycle , Exploratory Behavior , Mice , Male , Female , Animals , Estrous Cycle/physiology , Exploratory Behavior/physiology , Movement
2.
Cereb Cortex ; 33(6): 2838-2856, 2023 03 10.
Article in English | MEDLINE | ID: mdl-35788286

ABSTRACT

Focal cortical epilepsies are frequently refractory to available anticonvulsant drug therapies. One key factor contributing to this state is the limited availability of animal models that allow to reliably study focal cortical seizures and how they recruit surrounding brain areas in vivo. In this study, we selectively expressed the inhibitory chemogenetic receptor, hM4D, in GABAergic neurons in focal cortical areas using viral gene transfer. GABAergic silencing using Clozapine-N-Oxide (CNO) demonstrated reliable induction of local epileptiform events in the electroencephalogram signal of awake freely moving mice. Anesthetized mice experiments showed consistent induction of focal epileptiform-events in both the barrel cortex (BC) and the medial prefrontal cortex (mPFC), accompanied by high-frequency oscillations, a known characteristic of human seizures. Epileptiform-events showed propagation indication with favored propagation pathways: from the BC on 1 hemisphere to its counterpart and from the BC to the mPFC, but not vice-versa. Lastly, sensory whisker-pad stimulation evoked BC epileptiform events post-CNO, highlighting the potential use of this model in studying sensory-evoked seizures. Combined, our results show that targeted chemogenetic inhibition of GABAergic neurons using hM4D can serve as a novel, versatile, and reliable model of focal cortical epileptic activity suitable for systematically studying cortical ictogenesis in different cortical areas.


Subject(s)
Clozapine , Epilepsies, Partial , GABAergic Neurons , Neurons , Gene Expression Regulation, Viral , Clozapine/analogs & derivatives , Electroencephalography , Seizures , Animals
3.
Curr Opin Neurobiol ; 68: 67-75, 2021 06.
Article in English | MEDLINE | ID: mdl-33549950

ABSTRACT

Mammalian social interactions are orchestrated by a wide array of neural circuits. While some aspects of social behaviors are driven by subcortical circuits, and are considered to be highly conserved and hard-wired, others require dynamic and context-dependent modulation that integrates current state, past experience and goal-driven action selection. These cognitive social processes are known to be dependent on the integrity of the prefrontal cortex. However, the circuit mechanisms through which the prefrontal cortex supports complex social functions are still largely unknown, and it is unclear if and how they diverge from prefrontal control of behavior outside of the social domain. Here we review recent studies exploring the role of prefrontal circuits in mammalian social functions, and attempt to synthesize these findings to a holistic view of prefrontal control of sociability.


Subject(s)
Prefrontal Cortex , Social Behavior , Animals
4.
Front Neurosci ; 14: 585323, 2020.
Article in English | MEDLINE | ID: mdl-33328853

ABSTRACT

The vomeronasal organ (VNO) specializes in detection of chemosignals, mainly pheromones, which control social communication and reproduction in many mammals. These pheromones must solubilize with nasal fluids before entering the VNO, and it was suggested that they are delivered to and cleared from the VNO by active pumping. Yet, the details of this pheromone delivery process are unclear. In this study, we first constructed a high-resolution 3D morphological image of the whole adult mouse snout, by using ultra-high-resolution micro-CT. We identified a net of micro tunnels starting from the nostrils and extending around and through the VNO. These micro tunnels connect the nasal cavity with the VNO and the oral cavity via the nasopalatine ducts (NPD). Other micro tunnels connect the nasal cavity to the main olfactory epithelium. We next demonstrated that physical obstruction of the NPD severely impairs the clearance of dissolved compounds from the VNO lumen. Moreover, we found that mice with blocked NPD display alterations in chemosignaling-evoked neuronal activation in brain regions associated with the vomeronasal system. Finally, NPD-blocked male mice exhibit reduced preference for female chemosignals, and impaired social interaction behavior. Taken together, our findings indicate that the NPD in mice are connected to both the nasal and oral cavity, serving an essential role in regulating the flow of soluble chemosignals through the VNO, and are required for proper pheromone-mediated social communication.

5.
J Clin Med ; 9(9)2020 Aug 20.
Article in English | MEDLINE | ID: mdl-32825238

ABSTRACT

BACKGROUND: The aims of this study were to compare salivary cytokines and total protein between children with nephrotic syndrome (NS) and healthy children, and to examine whether saliva parameters can differentiate between steroid sensitivity and resistance and between disease remission and relapse. METHODS: Twenty-seven children with nephrotic syndrome were classified according to steroid sensitivity and resistance, and disease remission and relapse. Twenty healthy children served as controls. Whole saliva samples were collected from all the participants. Urine and blood tests done on the same day as the saliva collection were recorded. Salivary total protein was quantified using bicinchoninic acid and IFNγ, IL-4, IL-8, IL-6, and IL1ß levels using ELISA. RESULTS: The mean ages of the nephrotic syndrome and control groups were 11.3 ± 2.4 and 9 ± 4.2, respectively. Compared to the control group, for the nephrotic syndrome group, total salivary protein was significantly lower, as were the levels of all the cytokines examined except IFNγ. Statistically significant differences were not found in any of the salivary markers examined between the children with nephrotic syndrome who were treatment sensitive (n = 19) and resistant (n = 8). Protein and IL-8 salivary levels were lower in the active (n = 7) than in the remission (n = 20) group. CONCLUSIONS: Salivary parameters distinguished children with nephrotic syndrome in relapse from healthy children. This may be due to decreased salivary protein excretion, which reflects decreased plasma levels, consequent to proteinuria. Accordingly, salivary markers may be developed as a diagnostic or screening tool for NS activity.

6.
Nat Neurosci ; 23(4): 594, 2020 Apr.
Article in English | MEDLINE | ID: mdl-32127691

ABSTRACT

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

7.
Nat Neurosci ; 22(12): 2013-2022, 2019 12.
Article in English | MEDLINE | ID: mdl-31768051

ABSTRACT

The prefrontal cortex (PFC) plays an important role in regulating social functions in mammals, and its dysfunction has been linked to social deficits in neurodevelopmental disorders. Yet little is known of how the PFC encodes social information and how social representations may be altered in such disorders. Here, we show that neurons in the medial PFC of freely behaving male mice preferentially respond to socially relevant olfactory cues. Population activity patterns in this region differed between social and nonsocial stimuli and underwent experience-dependent refinement. In mice lacking the autism-associated gene Cntnap2, both the categorization of sensory stimuli and the refinement of social representations were impaired. Noise levels in spontaneous population activity were higher in Cntnap2 knockouts and correlated with the degree to which social representations were disrupted. Our findings elucidate the encoding of social sensory cues in the medial PFC and provide a link between altered prefrontal dynamics and autism-associated social dysfunction.


Subject(s)
Membrane Proteins/physiology , Nerve Tissue Proteins/physiology , Olfactory Perception/physiology , Prefrontal Cortex/physiology , Social Behavior , Animals , Cues , Male , Membrane Proteins/genetics , Mice , Mice, Knockout , Nerve Tissue Proteins/genetics , Olfactory Perception/genetics
8.
Nat Neurosci ; 21(3): 304-306, 2018 03.
Article in English | MEDLINE | ID: mdl-29476129
9.
J Thorac Dis ; 9(1): 205-210, 2017 Jan.
Article in English | MEDLINE | ID: mdl-28203425

ABSTRACT

Left ventricular assist devices (LVADs) have been successfully used in patients with heart failure. However, LVADs may trigger immune activation, leading to higher frequencies of autoantibodies. We describe the clinical, epidemiological, and laboratory characteristics of LVAD recipients with false positive hepatitis C (FPHC) serology among 39 consecutive adult LVAD recipients who bridged to heart transplantation from January 2007 to January 2013 at Montefiore Medical Center. FPHC patients were identified as those with post-LVAD positive hepatitis C ELISA antibody tests and negative confirmatory testing with hepatitis C RNA PCR and/or radioimmunoblot assay. Ten (26%) patients previously seronegative for hepatitis C were found to have FPHC after device placement. Of the 39 patients, 32 had HeartMate II devices. The mean age at LVAD placement was 55 years. FPHC correlated with older age at the time of LVAD implantation and with receipt of packed red blood cell transfusions, but not with gender, fresh frozen plasma transfusions, panel reactive antibodies, globulin fraction, rheumatoid factor, or anticardiolipin antibodies. Clinicians should be aware of this increased risk of FPHC in older LVAD patients and those more heavily transfused in order to avoid unnecessary apprehension and possible delay in transplantation. Further studies should be done to evaluate the possible relationship between transfused blood products and immunomodulation.

10.
Eat Disord ; 24(4): 338-53, 2016.
Article in English | MEDLINE | ID: mdl-27128883

ABSTRACT

Cognitive behavioral treatment (CBT) is the recommended intervention in bulimia nervosa (BN) and eating disorders not otherwise specified with binge/purge (EDNOS-B/P) symptoms. There are fewer data on its application in a group format. We sought to investigate the effect of group CBT in female soldiers with B/P symptomatology in an open trial design. For this purpose we assessed 64 female soldiers serving in the Israeli Defense Force diagnosed with BN and EDNOS-B/P who participated in a group CBT format of 16 weekly sessions and one follow-up session. In this study, 42 participants (65.6%) completed treatment and 22 participants (34.4%) did not. A total of 39 treatment completers (92.8% of treatment completers) and 19 non-completers (86.4% of treatment non-completers) were assessed around 12 months after treatment. Participants completed at baseline and following treatment questionnaires assessing eating-related symptoms, depression, anxiety, and overall functioning. At follow-up they were assessed for eating-related symptoms. Our findings show only minimal baseline differences between treatment completers and non-completers. Significant improvement from baseline to post-treatment was shown for B/P and restrictive symptoms, depression, anxiety, and overall functioning. At that time, more than a third of treatment completers were abstinent from binging and more than a half from vomiting. The improvement in B/P and restricting symptoms was maintained at 1 year follow-up for treatment completers. At that time around 60% were abstinent from binging and more than 70% from vomiting. Participants not completing treatment were also improved at follow-up but to a lesser extent. The findings of the present study suggest that group CBT may be effective for the treatment of female soldiers with BN and EDNOS-B/P.


Subject(s)
Binge-Eating Disorder/therapy , Bulimia Nervosa/therapy , Cognitive Behavioral Therapy/methods , Military Personnel/psychology , Psychotherapy, Group/methods , Adult , Female , Humans , Israel , Treatment Outcome , Young Adult
11.
ASAIO J ; 61(1): e5-10, 2015.
Article in English | MEDLINE | ID: mdl-25419830

ABSTRACT

Infection remains a well-established complication after the placement of left ventricular assist devices (LVADs). Defining the extent of infection is a challenging task as there are few effective imaging modalities and no standardized guidelines regarding imaging in the diagnosis of device-related infections (DRIs). The use of gallium with single photon emission tomography-computed tomography (Ga-SPECT-CT) has not been previously reported in localizing DRIs. We reviewed the charts and images of five patients with LVADs who underwent Ga-SPECT-CT for the diagnosis of various types of DRIs. Gallium SPECT-CT further clarified the extent of infections among LVAD patients, allowing for patient-specific tailored treatments including surgical debridement. Gallium SPECT-CT is a useful tool when diagnosing LVAD infections and could potentially be the imaging modality of choice in the near future. With improved imaging studies, such as Ga-SPECT-CT, allowing for earlier and more accurate diagnoses of DRIs, the outcome of such infections is likely to improve.


Subject(s)
Heart-Assist Devices/adverse effects , Prosthesis-Related Infections/diagnostic imaging , Prosthesis-Related Infections/etiology , Adult , Aged , Bacteremia/diagnostic imaging , Bacteremia/etiology , Gallium Radioisotopes , Humans , Male , Methicillin-Resistant Staphylococcus aureus , Middle Aged , Staphylococcal Infections/diagnostic imaging , Staphylococcal Infections/etiology , Tomography, Emission-Computed, Single-Photon , Tomography, X-Ray Computed
12.
IDCases ; 2(2): 59-62, 2015.
Article in English | MEDLINE | ID: mdl-26793457

ABSTRACT

INTRODUCTION: Nontuberculous mycobacteria are an uncommon cause of septic olecranon bursitis, though cases have increasingly been described in both immunocompromised and immunocompetent hosts. Guidelines recommend a combination of surgical resection and antimicrobials for treatment. This case is the first reported case of nontuberculous mycobacterial olecranon bursitis that resolved without medical or surgical intervention. CASE PRESENTATION: A 67-year-old female developed a painless, fluctuant swelling of the olecranon bursa following blunt trauma to the elbow. Due to persistent bursal swelling, she underwent three separate therapeutic bursal aspirations, two involving intrabursal steroid injection. After the third aspiration, the bursa became erythematous and severely swollen, and bursal fluid grew Mycobacterium avium complex. Triple-drug antimycobacterial therapy was initiated, but discontinued abruptly due to a rash. Surgery was not performed. The patient was observed off antimicrobials, and gradually clinically improved with a compressive dressing. By 14 months after initial presentation, clinical exam revealed complete resolution of the previously erythematous bursal mass. DISCUSSION: This is the first reported case of nontuberculous mycobacterial olecranon bursitis managed successfully without surgery or antimicrobials. Musculoskeletal nontuberculous mycobacterial infections are challenging given the lack of clinical data about optimal duration and choice of antimicrobials or the role of surgery. Additionally, the potential toxicity and drug interactions of antimycobacterials are not insignificant and warrant close monitoring if treatment is pursued. CONCLUSION: This case raises an important clinical question of whether close observation off antimicrobials is appropriate in select cases of immunocompetent patients with localized atypical mycobacterial disease of soft tissue and skeletal structures.

13.
Nat Commun ; 5: 4569, 2014 Aug 05.
Article in English | MEDLINE | ID: mdl-25090970

ABSTRACT

The laboratory mouse serves as an important model system for studying gene, brain and behavioural interactions. Powerful methods of gene targeting have helped to decipher gene-function associations in human diseases. Yet, the laboratory mouse, obtained after decades of human-driven artificial selection, inbreeding, and adaptation to captivity, is of limited use for the study of fitness-driven behavioural responses that characterize the ancestral wild house mouse. Here, we demonstrate that the backcrossing of wild mice with knockout mutant laboratory mice retrieves behavioural traits exhibited exclusively by the wild house mouse, thereby unmasking gene functions inaccessible in the domesticated mutant model. Furthermore, we show that domestication had a much greater impact on females than on males, erasing many behavioural traits of the ancestral wild female. Hence, compared with laboratory mice, wild-derived mutant mice constitute an improved model system to gain insights into neuronal mechanisms underlying normal and pathological sexually dimorphic social behaviours.


Subject(s)
Behavior, Animal , Mice, Knockout , Animals , Crosses, Genetic , Female , Gene Knockout Techniques , Genotype , Hormones/metabolism , Male , Mice , Mice, Inbred C57BL , Mutation , Phenotype , Polymorphism, Single Nucleotide , Smell/genetics , Social Behavior , TRPC Cation Channels/genetics
14.
PLoS One ; 9(6): e100880, 2014.
Article in English | MEDLINE | ID: mdl-24978597

ABSTRACT

Tumor cells upregulate many cell signaling pathways, with AKT being one of the key kinases to be activated in a variety of malignancies. GSK2110183 and GSK2141795 are orally bioavailable, potent inhibitors of the AKT kinases that have progressed to human clinical studies. Both compounds are selective, ATP-competitive inhibitors of AKT 1, 2 and 3. Cells treated with either compound show decreased phosphorylation of several substrates downstream of AKT. Both compounds have desirable pharmaceutical properties and daily oral dosing results in a sustained inhibition of AKT activity as well as inhibition of tumor growth in several mouse tumor models of various histologic origins. Improved kinase selectivity was associated with reduced effects on glucose homeostasis as compared to previously reported ATP-competitive AKT kinase inhibitors. In a diverse cell line proliferation screen, AKT inhibitors showed increased potency in cell lines with an activated AKT pathway (via PI3K/PTEN mutation or loss) while cell lines with activating mutations in the MAPK pathway (KRAS/BRAF) were less sensitive to AKT inhibition. Further investigation in mouse models of KRAS driven pancreatic cancer confirmed that combining the AKT inhibitor, GSK2141795 with a MEK inhibitor (GSK2110212; trametinib) resulted in an enhanced anti-tumor effect accompanied with greater reduction in phospho-S6 levels. Taken together these results support clinical evaluation of the AKT inhibitors in cancer, especially in combination with MEK inhibitor.


Subject(s)
Antineoplastic Agents/pharmacology , Diamines/pharmacology , Gene Expression Regulation, Neoplastic , Pancreatic Neoplasms/drug therapy , Protein Kinase Inhibitors/pharmacology , Pyrazoles/pharmacology , Tumor Burden/drug effects , Administration, Oral , Animals , Antineoplastic Agents/chemical synthesis , Blood Glucose/metabolism , Cell Line, Tumor , Diamines/chemical synthesis , Drug Evaluation, Preclinical , Drug Synergism , Female , Humans , MAP Kinase Kinase Kinases/antagonists & inhibitors , MAP Kinase Kinase Kinases/genetics , MAP Kinase Kinase Kinases/metabolism , Mice , Mice, SCID , PTEN Phosphohydrolase/antagonists & inhibitors , PTEN Phosphohydrolase/genetics , PTEN Phosphohydrolase/metabolism , Pancreatic Neoplasms/enzymology , Pancreatic Neoplasms/genetics , Pancreatic Neoplasms/pathology , Phosphatidylinositol 3-Kinases/genetics , Phosphatidylinositol 3-Kinases/metabolism , Phosphoinositide-3 Kinase Inhibitors , Protein Kinase Inhibitors/chemical synthesis , Proto-Oncogene Proteins c-akt/antagonists & inhibitors , Proto-Oncogene Proteins c-akt/genetics , Proto-Oncogene Proteins c-akt/metabolism , Pyrazoles/chemical synthesis , Ribosomal Protein S6 Kinases/antagonists & inhibitors , Ribosomal Protein S6 Kinases/genetics , Ribosomal Protein S6 Kinases/metabolism , Signal Transduction , Xenograft Model Antitumor Assays
15.
Hum Brain Mapp ; 35(4): 1491-502, 2014 Apr.
Article in English | MEDLINE | ID: mdl-23568328

ABSTRACT

Recent brain imaging research has highlighted a new global system of areas termed the Default Mode network (DM), which appears to specialize in intrinsically oriented functions. However, it is still unresolved to what extent this system contains functional subsystems as in the better known sensory and motor cortices. Here, we report that functional subdivisions can be revealed within individual nodes of the DM, such as the Inferior Parietal Lobule (IPL), through the use of different categories of self-oriented tasks. Subjects underwent BOLD fMRI scans during which they were asked to recall self-related positive and negative information in the categories of people and food. These tasks elicited distinct regions of activation within the DM. Importantly, the observed activations were above the activity level in the baseline, no-task condition for these regions. The main subdivision within the DM was observed in the inferior and posterior parietal cortex. Analysis of coherent resting state fluctuations (functional connectivity analysis) revealed that these regions of activation were part of a distinct network of regions within the DM. These results argue against viewing the DM as a unitary system, and are compatible with the notion that, similar to the rest of the cerebral cortex, the DM consists of distinct, functionally specialized subregions.


Subject(s)
Cerebral Cortex/physiology , Mental Recall/physiology , Self Concept , Adult , Brain/physiology , Brain Mapping , Female , Humans , Magnetic Resonance Imaging , Male , Neural Pathways/physiology , Neuropsychological Tests , Oxygen/blood , Rest/physiology , Young Adult
16.
Acad Psychiatry ; 36(1): 39-42, 2012 Jan 01.
Article in English | MEDLINE | ID: mdl-22362435

ABSTRACT

OBJECTIVE: The authors sought to determine the prevalence of threats and assaults by patients on psychiatry residents, their consequences, and the perceived adequacy of supports and institutional responses. METHOD: Authors conducted an anonymous survey of 519 psychiatry residents in 13 psychiatry programs across the United States. The survey questionnaire inquired about residents' experiences of threats and assaults by patients during their residency training. RESULTS: The response rate for this survey was 39% (N=204). Residents were most commonly threatened (N=175; 86%), physically intimidated (N=145; 71%) or received unwanted advances (N=118; 58%). One-quarter (N=51; 25%) were physically assaulted. Most of the incidents occurred in inpatient settings (N=92; 45%). CONCLUSION: This study, like previous studies on this topic, calls attention to the high number of residents that are affected by violence during their training, and it underscores the need to protect the safety of psychiatry residents and to support those who have been victimized.


Subject(s)
Aggression , Internship and Residency/statistics & numerical data , Physician-Patient Relations , Psychiatry/education , Surveys and Questionnaires , Violence/statistics & numerical data , Female , Humans , Male , Population Surveillance , Prevalence , Sex Distribution , Social Support , United States/epidemiology , Violence/psychology
17.
J Cogn Neurosci ; 23(7): 1597-608, 2011 Jul.
Article in English | MEDLINE | ID: mdl-20666593

ABSTRACT

The hippocampus and the striatum are thought to play distinct roles in learning and memory, each supporting an independent memory system. A fundamental question is whether, and how, these systems interact to jointly contribute to learning and memory. In particular, it remains unknown whether the striatum contributes selectively to implicit, habitual learning, or whether the striatum may also contribute to long-term episodic memory. Here, we show with functional magnetic resonance imaging (fMRI) that the hippocampus and the striatum interact cooperatively to support episodic memory formation. Participants were scanned during a memory encoding paradigm and, subsequently, were tested for memory of encoded items. fMRI data revealed that successful memory was associated with greater activity in both the hippocampus and the striatum (putamen) during encoding. Furthermore, activity in the hippocampus and the striatum was correlated within subjects for items that were later remembered, but not for items that were forgotten. Finally, across subjects, the strength of the correlation between the hippocampus and the striatum predicted memory success. These findings provide novel evidence for contributions of both the striatum and the hippocampus to successful episodic encoding and for a cooperative interaction between them.


Subject(s)
Corpus Striatum/cytology , Corpus Striatum/physiology , Hippocampus/cytology , Hippocampus/physiology , Mental Recall/physiology , Adult , Antigens, Viral , Brain Mapping/methods , Female , Humans , Learning/physiology , Male , Neural Pathways/physiology , Young Adult
18.
Bioorg Med Chem Lett ; 20(2): 684-8, 2010 Jan 15.
Article in English | MEDLINE | ID: mdl-20006500

ABSTRACT

The synthesis and evaluation of tetrasubstituted aminopyridines, bearing novel azaindazole hinge binders, as potent AKT inhibitors are described. Compound 14c was identified as a potent AKT inhibitor that demonstrated reduced CYP450 inhibition and an improved developability profile compared to those of previously described trisubstituted pyridines. It also displayed dose-dependent inhibition of both phosphorylation of GSK3beta and tumor growth in a BT474 tumor xenograft model in mice.


Subject(s)
Aminopyridines/chemistry , Cytochrome P-450 Enzyme System/metabolism , Ether-A-Go-Go Potassium Channels/metabolism , Protein Kinase Inhibitors/chemistry , Proto-Oncogene Proteins c-akt/antagonists & inhibitors , Pyrazines/chemistry , Pyridines/chemistry , Aminopyridines/chemical synthesis , Aminopyridines/pharmacokinetics , Animals , Cell Line, Tumor , Dogs , ERG1 Potassium Channel , Glycogen Synthase Kinase 3/antagonists & inhibitors , Glycogen Synthase Kinase 3/metabolism , Glycogen Synthase Kinase 3 beta , Haplorhini , Humans , Mice , Phosphorylation , Protein Kinase Inhibitors/chemical synthesis , Protein Kinase Inhibitors/pharmacokinetics , Proto-Oncogene Proteins c-akt/metabolism , Pyrazines/chemical synthesis , Pyrazines/pharmacokinetics , Rats , Structure-Activity Relationship , Xenograft Model Antitumor Assays
19.
Arthritis Rheum ; 60(10): 3028-37, 2009 Oct.
Article in English | MEDLINE | ID: mdl-19790068

ABSTRACT

OBJECTIVE: Transient receptor potential vanilloid 4 (TRPV4) is a Ca(2+)-permeable channel that can be gated by tonicity (osmolarity) and mechanical stimuli. Chondrocytes, the cells in cartilage, respond to their osmotic and mechanical environments; however, the molecular basis of this signal transduction is not fully understood. This study was undertaken to demonstrate the presence and functionality of TRPV4 in chondrocytes. METHODS: TRPV4 protein expression was measured by immunolabeling and Western blotting. In response to TRPV4 agonist/antagonists, osmotic stress, and interleukin-1 (IL-1), changes in Ca(2+) signaling, cell volume, and prostaglandin E(2) (PGE(2)) production were measured in porcine chondrocytes using fluorescence microscopy, light microscopy, or immunoassay, respectively. RESULTS: TRPV4 was expressed abundantly at the RNA and protein levels. Exposure to 4alpha-phorbol 12,13-didecanoate (4alphaPDD), a TRPV4 activator, caused Ca(2+) signaling in chondrocytes, which was blocked by the selective TRPV4 antagonist, GSK205. Blocking TRPV4 diminished the chondrocytes' response to hypo-osmotic stress, reducing the fraction of Ca(2+) responsive cells, the regulatory volume decrease, and PGE(2) production. Ca(2+) signaling was inhibited by removal of extracellular Ca(2+) or depletion of intracellular stores. Specific activation of TRPV4 restored the defective regulatory volume decrease caused by IL-1. Chemical disruption of the primary cilium eliminated Ca(2+) signaling in response to either 4alphaPDD or hypo-osmotic stress. CONCLUSION: Our findings indicate that TRPV4 is present in articular chondrocytes, and chondrocyte response to hypo-osmotic stress is mediated by this channel, which involves both an extracellular Ca(2+) and intracellular Ca(2+) release. TRPV4 may also be involved in modulating the production or influence of proinflammatory molecules in response to osmotic stress.


Subject(s)
Cartilage, Articular/metabolism , Chondrocytes/metabolism , Osmosis/physiology , TRPV Cation Channels/metabolism , Animals , Calcium/metabolism , Cartilage, Articular/pathology , Cell Size , Cells, Cultured , Chondrocytes/pathology , Dinoprostone/metabolism , Interleukin-1/metabolism , Models, Animal , Phorbol Esters/pharmacology , Signal Transduction/physiology , Swine , TRPV Cation Channels/antagonists & inhibitors , TRPV Cation Channels/drug effects
20.
Blood ; 113(8): 1723-9, 2009 Feb 19.
Article in English | MEDLINE | ID: mdl-19064730

ABSTRACT

The PI3K/AKT signaling is activated in various hematologic malignancies. We evaluated the effect of a novel, pan-AKT kinase inhibitor, GSK690693, on the proliferation of 112 cell lines representing different hematologic neoplasia. Fifty-five percent of all cell lines tested were sensitive to AKT inhibitor (EC(50)<1 microM), with acute lymphoblastic leukemia (ALL), non-Hodgkin lymphoma, and Burkitt lymphoma showing 89%, 73%, and 67% sensitivity to GSK690693, respectively. The antiproliferative effect was selective for the malignant cells, as GSK690693 did not inhibit the proliferation of normal human CD4(+) peripheral T lymphocytes as well as mouse thymocytes. Phosphorylation of downstream substrates of AKT was reduced in both sensitive and insensitive cell lines on treatment with GSK690693, suggesting that the cause of resistance was not related to the lack of AKT kinase inhibition. Consistent with the role of AKT in cell survival, GSK690693 also induced apoptosis in sensitive ALL cell lines. Overall, our data provide direct evidence for the role of AKT signaling in various hematologic malignancies, especially ALL and some lymphomas.


Subject(s)
Apoptosis/drug effects , Oxadiazoles/pharmacology , Precursor Cell Lymphoblastic Leukemia-Lymphoma/drug therapy , Proto-Oncogene Proteins c-akt/antagonists & inhibitors , Animals , B-Lymphocytes/cytology , B-Lymphocytes/drug effects , CD4-Positive T-Lymphocytes/cytology , CD4-Positive T-Lymphocytes/drug effects , Cell Division/drug effects , Cell Line, Tumor , Cell Survival/drug effects , Drug Resistance, Neoplasm , Female , Humans , Leukemia, B-Cell/drug therapy , Leukemia, B-Cell/pathology , Lymphoma/drug therapy , Lymphoma/pathology , Mice , Mice, Inbred C57BL , Phosphorylation/drug effects , Precursor Cell Lymphoblastic Leukemia-Lymphoma/pathology , Signal Transduction/drug effects
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