Disruption of TGF-β signaling pathway is required to mediate effective killing of hepatocellular carcinoma by human iPSC-derived NK cells.

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer. Transforming growth factor beta (TGF-β) is highly expressed in the liver tumor microenvironment and is known to inhibit immune cell activity. Here, we used human induced pluripotent stem cells (iPSCs) to produce natural killer (NK) cells engineered to mediate improved anti-HCC activity.

Diversification of PAR signaling through receptor crosstalk.

Protease activated receptors (PARs) are among the first receptors shown to transactivate other receptors: noticeably, these interactions are not limited to members of the same family, but involve receptors as diverse as receptor kinases, prostanoid receptors, purinergic receptors and ionic channels among others. In this review, we will focus on the evidence for PAR interactions with members of their own family, as well as with other types of receptors. We will discuss recent evidence as well as what we consider as emerging areas to explore; from the signalling pathways triggered, to the physiological and pathological relevance of these interactions, since this additional level of molecular cross-talk between receptors and signaling pathways is only beginning to be explored and represents a novel mechanism providing diversity to receptor function and play important roles in physiology and disease.

The PKC-ζ pseudosubstrate peptide induces glutamate release from retinal pigment epithelium cells through kinase- independent activation of Best1.

Aims: The retinal pigment epithelium (RPE) is a highly specialized cell monolayer, that plays a key role in the maintenance of photoreceptor function and the blood-retina barrier (BRB). In this study, we found that a myristoylated pseudosubstrate of PKC-ζ (PKCζ PS), considered as a PKC-ζ inhibitor, plays a distinct role in RPE.

Main Methods: We demonstrated that PKCζ PS stimulates the release of Glutamate (Glu) using in vitroH-Glutamate release experiments.

Thrombin-activated PAR1 membrane expression is regulated by Rab11a-RCP complex dissociation.

PAR1 activation by thrombin promotes intracellular signaling leading to RPE cell transformation, proliferation, and migration, characteristic of fibroproliferative eye diseases. Due to the cleavage of PAR1 N-terminal domain, carried by thrombin, the arrest of PAR1 signaling is achieved by transport into lysosomes and degradation. Recent findings suggest that the GTPase Rab11a in conjunction with its effector RCP may direct PAR1 to lysosomes.

Thrombin induces Ca-dependent glutamate release from RPE cells mediated by PLC/PKC and reverse Na/Ca exchange.

Purpose: We analyzed the molecular mechanisms leading to glutamate release from rat primary cultures of RPE cells, under isosmotic conditions. Thrombin has been shown to stimulate glutamate release from astrocytes and retinal glia; however, the effect of thrombin on glutamate release from RPE cells has not been examined. Our previous work showed that upon the alteration of the blood-retina barrier, the serine protease thrombin could contribute to the transformation, proliferation, and migration of RPE cells.

Antisense oligonucleotides targeting mutant Ataxin-7 restore visual function in a mouse model of spinocerebellar ataxia type 7.

Spinocerebellar ataxia type 7 (SCA7) is an autosomal dominant neurodegenerative disorder characterized by cerebellar and retinal degeneration, and is caused by a CAG-polyglutamine repeat expansion in the gene. Patients with SCA7 develop progressive cone-rod dystrophy, typically resulting in blindness. Antisense oligonucleotides (ASOs) are single-stranded chemically modified nucleic acids designed to mediate the destruction, prevent the translation, or modify the processing of targeted RNAs.

OCT Angiography Helps Distinguish Between Proliferative Macular Telangiectasia Type 2 and Neovascular Age-Related Macular Degeneration.

Background And Objective: To demonstrate the advantage of optical coherence tomography angiography (OCTA) for the diagnosis and management of proliferative macular telangiectasia type 2 (MacTel2) masquerading as neovascular age-related macular degeneration (AMD).

Patients And Methods: This is an observational cases series. Three patients referred with the diagnosis of neovascular AMD were identified in this retrospective study.

Thrombin-Induced Calpain Activation Promotes Protease-Activated Receptor 1 Internalization.

The serine protease thrombin activates Protease-Activated Receptors (PARs), a family of G-protein-coupled receptors (GPCRs) activated by the proteolytic cleavage of their extracellular N-terminal domain. Four members of this family have been identified: PAR1-4. The activation of Protease-Activated Receptor 1(PAR1), the prototype of this receptor family, leads to an increase in intracellular Ca concentration ([Ca]i) mediated by G coupling and phospholipase C (PLC) activation.

Paxillin: a crossroad in pathological cell migration.

Paxilllin is a multifunctional and multidomain focal adhesion adapter protein which serves an important scaffolding role at focal adhesions by recruiting structural and signaling molecules involved in cell movement and migration, when phosphorylated on specific Tyr and Ser residues. Upon integrin engagement with extracellular matrix, paxillin is phosphorylated at Tyr31, Tyr118, Ser188, and Ser190, activating numerous signaling cascades which promote cell migration, indicating that the regulation of adhesion dynamics is under the control of a complex display of signaling mechanisms. Among them, paxillin disassembly from focal adhesions induced by extracellular regulated kinase (ERK)-mediated phosphorylation of serines 106, 231, and 290 as well as the binding of the phosphatase PEST to paxillin have been shown to play a key role in cell migration.

PKC-ζ Regulates Thrombin-Induced Proliferation of Human Müller Glial Cells.

Purpose: To investigate the effect of thrombin on the proliferation of human Müller glial cells (MCs) and define the possible signaling mechanisms involved in this process.

Methods: Protease-activated receptor (PARs 1-4) expression was analyzed using RT-PCR and Western blot in the MIO-M1 Müller cell line (MC). Müller cell proliferation was assessed by the MTS reduction method.

Glutamate Receptor Stimulation Up-Regulates Glutamate Uptake in Human Müller Glia Cells.

Glutamate, the main excitatory amino acid in the vertebrate retina, is a well know activator of numerous signal transduction pathways, and has been critically involved in long-term synaptic changes acting through ionotropic and metabotropic glutamate receptors. However, recent findings underlining the importance of intensity and duration of glutamate stimuli for specific neuronal responses, including excitotoxicity, suggest a crucial role for Na(+)-dependent glutamate transporters, responsible for the removal of this neurotransmitter from the synaptic cleft, in the regulation of glutamate-induced signaling. Transporter proteins are expressed in neurons and glia cells, albeit most of glutamate uptake occurs in the glial compartment.

Thrombin promotes the expression of Ccnd1 gene in RPE cells through the activation of converging signaling pathways.

The breakdown of the blood-retina barrier exposes retinal pigment epithelium (RPE) to serum components, thrombin among them. In addition to coagulation, thrombin acting through Protease-Activated Receptors (PARs 1-4) participates in a number of processes including cell proliferation, transformation, and migration. The purpose of this study was to identify interacting signaling pathways by which the activation of PAR1 by thrombin triggers cyclin D1 gene (Ccnd1) expression and the proliferation of RPE cells, characteristic of proliferative vitreoretinopathy (PVR).

Muscle expression of mutant androgen receptor accounts for systemic and motor neuron disease phenotypes in spinal and bulbar muscular atrophy.

X-linked spinal and bulbar muscular atrophy (SBMA) is characterized by adult-onset muscle weakness and lower motor neuron degeneration. SBMA is caused by CAG-polyglutamine (polyQ) repeat expansions in the androgen receptor (AR) gene. Pathological findings include motor neuron loss, with polyQ-AR accumulation in intranuclear inclusions.

A broad phenotypic screen identifies novel phenotypes driven by a single mutant allele in Huntington's disease CAG knock-in mice.

Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder caused by the expansion of a CAG trinucleotide repeat in the HTT gene encoding huntingtin. The disease has an insidious course, typically progressing over 10-15 years until death. Currently there is no effective disease-modifying therapy.

Mismatch repair genes Mlh1 and Mlh3 modify CAG instability in Huntington's disease mice: genome-wide and candidate approaches.

The Huntington's disease gene (HTT) CAG repeat mutation undergoes somatic expansion that correlates with pathogenesis. Modifiers of somatic expansion may therefore provide routes for therapies targeting the underlying mutation, an approach that is likely applicable to other trinucleotide repeat diseases. Huntington's disease Hdh(Q111) mice exhibit higher levels of somatic HTT CAG expansion on a C57BL/6 genetic background (B6.

ERK1/2-dependent activation of mTOR/mTORC1/p70S6K regulates thrombin-induced RPE cell proliferation.

Epithelial-mesenchymal transition (EMT), proliferation and migration of RPE cells characterize the development of proliferative vitreoretinopathy (PVR) and other fibro-proliferative eye diseases leading to blindness. A common event in these pathologies is the alteration of the BRB which allows the interaction of RPE cells with thrombin, a pro-inflammatory protease contained in serum. Thrombin promotion of cytoskeletal reorganization, proliferation, and migration has been reported in different cell types, although the molecular mechanisms involved in these processes remain poorly understood.

Glutamate transporter-dependent mTOR phosphorylation in Müller glia cells.

Glu (glutamate), the excitatory transmitter at the main signalling pathway in the retina, is critically involved in changes in the protein repertoire through the activation of signalling cascades, which regulate protein synthesis at transcriptional and translational levels. Activity-dependent differential gene expression by Glu is related to the activation of ionotropic and metabotropic Glu receptors; however, recent findings suggest the involvement of Na+-dependent Glu transporters in this process. Within the retina, Glu uptake is aimed at the replenishment of the releasable pool, and for the prevention of excitotoxicity and is carried mainly by the GLAST/EAAT-1 (Na+-dependent glutamate/aspartate transporter/excitatory amino acids transporter-1) located in Müller radial glia.

Large-scale phenotyping of an accurate genetic mouse model of JNCL identifies novel early pathology outside the central nervous system.

Cln3(Δex7/8) mice harbor the most common genetic defect causing juvenile neuronal ceroid lipofuscinosis (JNCL), an autosomal recessive disease involving seizures, visual, motor and cognitive decline, and premature death. Here, to more thoroughly investigate the manifestations of the common JNCL mutation, we performed a broad phenotyping study of Cln3(Δex7/8) mice. Homozygous Cln3(Δex7/8) mice, congenic on a C57BL/6N background, displayed subtle deficits in sensory and motor tasks at 10-14 weeks of age.

Thrombin stimulates stress fiber assembly in RPE cells by PKC/CPI-17-mediated MLCP inactivation.

Most retinal proliferative diseases involve blood-retinal barrier (BRB) breakdown, exposing the retinal pigment epithelium (RPE) to thrombin, which triggers cell transformation, proliferation and migration through the activation of PAR-1. These processes require the assembly of contractile stress fibers containing actin and non-muscle myosin II, which allow cell movement upon phosphorylation of the myosin light chains (MLCs). PKC family of kinases promotes agonist-mediated contraction in smooth muscle and endothelial cells through the activation of its downstream target, the PKC-potentiated inhibitory protein of 17 kDa (CPI-17), which specifically inhibits MLC phosphatase.

Thrombin promotes actin stress fiber formation in RPE through Rho/ROCK-mediated MLC phosphorylation.

The retinal pigment epithelium (RPE) forms the outer blood-retina barrier (BRB). Most retinal diseases involve BRB breakdown, whereupon thrombin contained in serum directly contacts the RPE. Thrombin is known to promote actin stress fiber formation, an important determinant in eye diseases involving the epithelial-mesenchymal transition (EMT) and migration of RPE cells, such as proliferative vitreoretinopathy.

Thrombin stimulates RPE cell motility by PKC-zeta- and NF-kappaB-dependent gene expression of MCP-1 and CINC-1/GRO chemokines.

Retinal pigment epithelial cells (RPE) are the major cell type involved in the pathogenesis of proliferative vitreoretinopathy (PVR), which involves the epithelial-mesenchymal transition, proliferation, and directional migration of transformed RPE cells to the vitreous upon RPE exposure to serum components, thrombin among them. Although the aqueous humor and vitreous of PVR patients contain high levels of chemokines, their possible involvement in PVR development has not been explored. We here analyzed the effect of thrombin on chemokine gene expression and its correlation with RPE cell migration using rat RPE cells in culture as a model system.

A novel approach to investigate tissue-specific trinucleotide repeat instability.

Background: In Huntington's disease (HD), an expanded CAG repeat produces characteristic striatal neurodegeneration. Interestingly, the HD CAG repeat, whose length determines age at onset, undergoes tissue-specific somatic instability, predominant in the striatum, suggesting that tissue-specific CAG length changes could modify the disease process. Therefore, understanding the mechanisms underlying the tissue specificity of somatic instability may provide novel routes to therapies.

Thrombin stimulates RPE cell proliferation by promoting c-Fos-mediated cyclin D1 expression.

The retinal pigment epithelium (RPE) plays an essential role in the maintenance and normal functioning of the neural retina. Alterations in RPE function are involved in several ocular pathologies involving the breakdown of the blood-retina barrier (BRB), which exposes RPE to serum components, thrombin among them. Our previous work has shown that thrombin stimulates the proliferation of RPE cells.

Intergenerational and striatal CAG repeat instability in Huntington's disease knock-in mice involve different DNA repair genes.

Modifying the length of the Huntington's disease (HD) CAG repeat, the major determinant of age of disease onset, is an attractive therapeutic approach. To explore this we are investigating mechanisms of intergenerational and somatic HD CAG repeat instability. Here, we have crossed HD CAG knock-in mice onto backgrounds deficient in mismatch repair genes, Msh3 and Msh6, to discern the effects on CAG repeat size and disease pathogenesis.

PKC isoenzymes differentially modulate the effect of thrombin on MAPK-dependent RPE proliferation.

Thrombin signalling through PAR (protease-activated receptor)-1 is involved in cellular processes, such as proliferation, differentiation and cell survival. Following traumatic injury to the eye, thrombin signalling may participate in disorders, such as PVR (proliferative vitreoretinopathy), a human eye disease characterized by the uncontrolled proliferation, transdifferentiation and migration of otherwise quiescent RPE (retinal pigment epithelium) cells. PARs activate the Ras/Raf/MEK/ERK MAPK pathway (where ERK is extracellular-signal-regulated kinase, MAPK is mitogen-activated protein kinase and MEK is MAPK/ERK kinase) through the activation of G(alpha) and G(betagamma) heterotrimeric G-proteins, and the downstream stimulation of the PLC (phospholipase C)-beta/PKC (protein kinase C) and PI3K (phosphoinositide 3-kinase) signalling axis.