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Maraviroc alleviates neuropathic pain symptoms in a mouse model of spared nerve injury.

Chronic pain represents a major health problem in the health care system. According to the CDC data brief in 2020, 20.4% of adults have chronic pain. There has been no promising therapy for chronic pain. Currently available treatments include medications such as nonsteroidal anti-inflammatory drugs, antiepileptic drugs, tricyclic antidepressants, corticosteroids, opioids, and cannabinoids, all of which may cause various negative side effects. Thus, there is an urgent need to develop novel, efficacious, and safe interventions for treating pain. Studies have shown that proinflammatory cytokines and chemokines make important contributions to the initiation and persistence of pain. We have found that C-C motif chemokine ligand 5 levels increased at day 14 post-spared nerve injury (SNI). This study was designed to investigate the effect of maraviroc (MVC), an FDA-approved CCR5 antagonist, on neuropathic pain in a mouse model of SNI. We found that MVC alleviated SNI-induced mechanical allodynia at 3, 7, and 14 days postinjury. MVC treatment also prevented SNI-mediated thermal hypersensitivity at 7 and 14 days postinjury in both male and female cohorts. SNI resulted in weight-bearing deficits, which were corrected by MVC administration in male mice. RNA sequencing analysis revealed that MVC rescued SNI-induced dysregulation of sex-specific canonical pathways in the spinal cord. Collectively, our findings showed that MVC could reduce neuropathic pain following peripheral nerve injury, providing a base for the repurposing of this FDA-approved human immunodeficiency virus drug as a pain reducer in clinical applications. SIGNIFICANCE STATEMENT: Spared nerve injury-induced neuropathic pain is associated with upregulation of the C-C motif chemokine ligand 5. Targeting the C-C motif chemokine ligand 5-CCR5 axis with FDA-approved maraviroc alleviated pain phenotype through modulating different pathways in male and female mice.

Animals↗

HIF-2alpha expression in human fetal paraganglia and neuroblastoma: relation to sympathetic differentiation, glucose deficiency, and hypoxia.

Solid tumors are frequently necrotic and hypoxic due to poor vascularization. Tumor cells adapt to hypoxia by modulating their phenotype. Key players in this process are the hypoxia-inducible factors (HIF-1alpha to 3alpha). HIFs are also expressed during normal development; for example, HIF-2alpha is specifically expressed and appears to be involved in the development of the murine sympathetic nervous system (SNS). Here, we demonstrate that HIF-2alpha protein is selectively present in human fetal week 8.5 SNS paraganglia. Neuroblastoma is derived from SNS precursors. In a subset of neuroblastomas, a spontaneous neuronal to neuroendocrine differentiation occurs in areas adjacent to necrotic zones. As HIF-2alpha activity has been associated not only with hypoxic but also with hypoglycemic conditions, we have investigated putative effects of hypoxia, glucose depletion, and HIF-2alpha on the neuroblastoma phenotype. HIF-2alpha was detected in hypoxic and in well-oxygenized neuroblastoma cells and tissue, presumably reflecting their embryonic features. With regard to differentiation, hypoxic cells lost their neuronal/neuroendocrine features and gained marker gene expression associated with an immature, neural crest-like phenotype. Low glucose potentiated the effect of hypoxia. These findings suggest that poorly vascularized neuroblastomas become immature and maintain a more aggressive phenotype, which possibly could involve a sustained stabilization and activation of HIF-2alpha.

Base Sequence↗

Calcification and cellularity in human aortic heart valve tissue determine the differentiation of bone-marrow-derived cells.

Human bone-marrow-derived mesenchymal stem cells (MSC) are responsible the remodeling of human tissue. However, damaged aortic valves are lack the ability to regenerate which is an active cell-mediated process. Diseased aortic valve remodeling has similarities even to bone formation. In this study, the prerequisites for cultured MSCs to undergo osteoblastic differentiation on aortic valves were explored. An ex vivo model using a human aortic valve microenvironment was developed. The expression of type I procollagen, alkaline phosphatase activity, osteocalcin secretion and osteocalcin immunostaining were studied to evaluate the induction of osteogenesis of the MSCs on noncalcified and calcified human aortic valves. Aortic valves were exposed to freeze-thaw injury to devitalize valves in order to separately study the role of valve matrix vs. endothelial cells in the explants. Thus, valves were assigned to 1 of 4 treatment groups: noncalcified uninjured valves, calcified uninjured valves, noncalcified injured and calcified injured. Finally, valves were decalcified to separately explore the effect of a calcified matrix on the osteogenesis. In this co-culture system, the noncalcified uninjured valves inhibited osteogenesis of MSCs, whereas the calcified valves promoted differentiation towards osteoblastic lineage. Devitalization of the valve matrix inflicted a significant increase in the osteogenesis of co-cultured MSCs. Calcified matrix in the valves seemed to have a role in the spontaneous osteogenesis of the MSCs. This spontaneous matrix induced differentiation of MSCs into osteoblast lineage could not be inhibited by pravastatin, indomethacin or tetracycline. In conclusion, these results suggest that interactions between MSCs and aortic valve matrix components and cells modulate MSC phenotype in this environment. Further studies are required to characterize this interesting phenomenon in greater detail.

Anti-Bacterial Agents↗

Future horizons in cardiovascular molecular therapeutics.

In the past 2 decades, significant progress has been made in cardiovascular therapeutics. Effective drug therapies have been developed for hypertension, hypercholesterolemia, coronary artery disease, myocardial infarction, and congestive heart failure. Novel therapeutic strategies to treat cardiovascular disease consist of 3 major approaches: (1) changing the biology of vascular disease; (2) intervening in the ischemic event; or (3) modifying the post-ischemic course. The development of future therapies depends on continuing advancements in our understanding of the molecular mechanisms of vascular pathobiology. Novel therapies are aimed at the critical steps in vascular disease progression, which include reversing endothelial cell dysfunction, modulating thrombosis and inflammation, correcting dysregulated cell growth and apoptosis, modulating vascular phenotype, and modifying mechanicotransduction in vascular remodeling. Targeting these steps at the molecular level will stimulate the development of numerous therapeutic agents. Ongoing research will further define the role of the agents in the treatment of cardiovascular disease.

Animals↗

Norepinephrine and neuropeptide Y promote proliferation and collagen gene expression of hepatic myofibroblastic stellate cells.

The mechanisms initiating and perpetuating the fibrogenic response in the injured liver are not well understood. Hepatic stellate cells are activated by liver injury to become proliferative and fibrogenic myofibroblasts. Emerging evidence suggests that the sympathetic nervous system may play a role in the development of cirrhosis. It is not known, however, whether this requires a direct interaction between sympathetic neurotransmitters and stellate cell receptors, or results indirectly, from sympathetic effects on the vasculature. Using cultured hepatic stellate cells, we show that the sympathetic neurotransmitters, norepinephrine and neuropeptide Y, markedly stimulate the proliferation of activated, myofibroblastic, hepatic stellate cells. Norepinephrine, but not neuropeptide Y, also induces collagen gene expression. In conclusion, physiologically relevant concentrations of sympathetic neurotransmitters directly modulate the phenotype of hepatic stellate cells. This suggests that targeted interruption of sympathetic nervous system signaling in hepatic stellate cells may be useful in constraining the fibrogenic response to liver injury.

Adrenergic alpha-Agonists↗

Differentiation of vascular myofibroblasts induced by transforming growth factor-beta1 requires the involvement of protein kinase Calpha.

In response to vascular injury, adventitial fibroblasts can modulate their phenotype to myofibroblasts, cells that participate in arterial remodeling. However, the signaling mechanisms underlying the vascular myofibroblast differentiation remain unknown. Since protein kinase C (PKC) is a key enzyme for cell differentiation, we examined whether PKC isoforms were involved in the vascular myofibroblast differentiation. The association between PKCalpha and myofibroblast differentiation was investigated in cultured rat aortic fibroblasts treated with transforming growth factor-beta1 (TGFbeta1). Confocal immunofluorescence microscopy indicated that fibroblasts expressed alpha-smooth muscle actin (alpha-SM actin) after TGFbeta1 treatment. Moreover, TGFbeta1 stimulation increased both PKCalpha mRNA expression (measured by real-time quantitative RT-PCR) and PKC activity (determined by histone-like pseudosubstrate phosphorylation) in adventitial fibroblasts. Western blot analysis indicated that PKCalpha protein expression was higher in TGFbeta1-treated fibroblasts than in untreated cells. TGFbeta1-induced expression of alpha-SM actin was inhibited in a dose-dependent manner by treating cells with a PKC inhibitor, calphostin C, and was abolished by depleting PKCalpha with antisense PKCalpha oligodeoxynucleotides. Our results demonstrate that TGFbeta1 induces adventitial myofibroblast differentiation via a PKCalpha-dependent process.

Actins↗

Plasminogen deficiency results in poor clearance of non-fibrin matrix and persistent activation of hepatic stellate cells after an acute injury.

BACKGROUND/AIMS: Plasminogen directs matrix proteolysis during liver repair. Based on the role of hepatic stellate cells (HSCs) on matrix production, we investigated whether plasminogen-driven matrix proteolysis modulates the phenotype of HSCs. METHODS: Carbon tetrachloride was injected intraperitoneally into mice deficient in plasminogen, fibrinogen, or both, and to normal littermates, followed by determination of the phenotype of HSCs, matrix deposition, and apoptosis. RESULTS: Activation of HSCs was restricted to the zone of injury and increased >ten-fold above baseline regardless of the plasminogen status 2 days after toxin. Thereafter, the number of activated HSCs decreased to baseline levels between 7 and 14 days in normal mice, but remained elevated in plasminogen-deficient livers approximately ten-fold above non-targeted littermates. Despite the zonal increase in activated HSCs, the total number of desmin-stained HSCs was similar along the lobule in both genotypes. No appreciable difference in apoptosis of perisinusoidal cells was found between genotypes; however, fibrillary material was present in the subsinusoidal space of Plg(0) livers. This fibrillary material was not fibrin, as demonstrated by similar findings in Plg(0)/Fib(0) mice, which accumulated fibronectin in injured areas. CONCLUSIONS: Proteolytic clearance of non-fibrin matrix components by plasminogen must occur for HSCs to restore the quiescent phenotype during liver repair.

Animals↗

Can hepatocytes serve as 'activated' immunomodulating cells in the immune response?

During the last few years, there has been a growing evidence that hepatocytes are not merely 'passive' target cells for immunological attack by effector T-cells, but may play a more 'active' role in the initiation and perpetuation of the immune response. Immune modulators released by inflammatory cells at the site of inflammation, as well as the eliciting antigen itself, are able to modulate the phenotype of hepatocytes. This would result in abnormal cytokine production and/or cytokine/receptor expression, as well as active synthesis and display of surface immune 'activation' markers and adhesion molecules, which act as co-stimulatory signals for T-cell activation. These accessory functions involve multiple molecular pathways of cell-cell interactions, which in turn will enable hepatocytes to play a role as 'accessory' cells in both the afferent and efferent arms of the cell-mediated immune response.

Adjuvants, Immunologic↗

Neuroprotection by estradiol.

This review highlights recent evidence from clinical and basic science studies supporting a role for estrogen in neuroprotection. Accumulated clinical evidence suggests that estrogen exposure decreases the risk and delays the onset and progression of Alzheimer's disease and schizophrenia, and may also enhance recovery from traumatic neurological injury such as stroke. Recent basic science studies show that not only does exogenous estradiol decrease the response to various forms of insult, but the brain itself upregulates both estrogen synthesis and estrogen receptor expression at sites of injury. Thus, our view of the role of estrogen in neural function must be broadened to include not only its function in neuroendocrine regulation and reproductive behaviors, but also to include a direct protective role in response to degenerative disease or injury. Estrogen may play this protective role through several routes. Key among these are estrogen dependent alterations in cell survival, axonal sprouting, regenerative responses, enhanced synaptic transmission and enhanced neurogenesis. Some of the mechanisms underlying these effects are independent of the classically defined nuclear estrogen receptors and involve unidentified membrane receptors, direct modulation of neurotransmitter receptor function, or the known anti-oxidant activities of estrogen. Other neuroprotective effects of estrogen do depend on the classical nuclear estrogen receptor, through which estrogen alters expression of estrogen responsive genes that play a role in apoptosis, axonal regeneration, or general trophic support. Yet another possibility is that estrogen receptors in the membrane or cytoplasm alter phosphorylation cascades through direct interactions with protein kinases or that estrogen receptor signaling may converge with signaling by other trophic molecules to confer resistance to injury. Although there is clear evidence that estradiol exposure can be deleterious to some neuronal populations, the potential clinical benefits of estrogen treatment for enhancing cognitive function may outweigh the associated central and peripheral risks. Exciting and important avenues for future investigation into the protective effects of estrogen include the optimal ligand and doses that can be used clinically to confer benefit without undue risk, modulation of neurotrophin and neurotrophin receptor expression, interaction of estrogen with regulated cofactors and coactivators that couple estrogen receptors to basal transcriptional machinery, interactions of estrogen with other survival and regeneration promoting factors, potential estrogenic effects on neuronal replenishment, and modulation of phenotypic choices by neural stem cells.

Estradiol↗

Migration and gap junctional intercellular communication determine the metastatic phenotype of human tumor cell lines.

Gap junctional intercellular communication (GJIC) as well as cell migration play an essential role in the metastatic cascade of human tumors. We show a dependence of metastatogenic phenotypes of human tumor cells (cell lines T 24, SCC-25, MDA-MB-361 and SK-BR-3) from the GJIC and the migration activity. The GJIC was studied by microinjection of the fluorescent dye Lucifer Yellow (LY) and cell migration was studied by investigating the locomotion of the tumor cells in 3-dimensional collagen matrices. Diminished GJIC seems to be more influential for the metastatic phenotype than modulation of the locomotory behavior of the tumor cells.

Breast Neoplasms↗

Insulin receptor substrate-1 is over-expressed in glycogenotic but not in amphophilic preneoplastic hepatic foci induced in rats by N-nitrosomorpholine and dehydroepiandrosterone.

Insulin receptor substrate-1 (IRS-1) is over-expressed in preneoplastic glycogenotic hepatic foci (GSF) and is gradually down-regulated during progression of these lesions, via mixed cell foci (MCF), to the basophilic neoplastic phenotype. The aim of the present study was to investigate the effect of dehydroepiandrosterone (DHEA), a weak hepatocarcinogen and tumour enhancer, on IRS-1 expression. Hepatocellular lesions were induced by N-nitrosomorpholine followed by DHEA. Under these conditions, many glycogen-poor amphophilic (APF) and intermediate cell foci (ICF) appear, in addition to GSF and MCF. IRS-1 was over-expressed in 215 out of 295 GSF, in 50 out of 53 MCF and in a glycogen-rich mixed cell adenoma. IRS-1 expression was not shown in 147 APF, 51 ICF and 5 amphophilic hepatocellular adenomas, and 3 out of 5 hepatocellular carcinomas showed a weak IRS-1 expression. The results suggest a close association of IRS-1 over-expression with the glycogenotic hepatocellular phenotype. The modulation and enhancement of tumour progression by DHEA is associated with a shift from glycogenosis to amphophilia and basophilia, and a down-regulation of IRS-1 expression.

Adenoma, Liver Cell↗

Defense and repair mechanisms in the airway epithelium exposed to oxidative stress: effects of analogues of retinoic acid.

A model of rabbit tracheal epithelial (RTE) cells in vitro was developed in order to investigate the effects, on the airway epithelium, of reactive oxygen species (ROS) generated by H2O2 in association or not in association with Fe2+. The immediate consequence of a 24 h exposure of RTE cells to an oxidative stress was an increase in catalase activity whereas superoxide dismutase activity was not modified. A latter consequence of a chronic ROS insult was the induction of a repair mechanism which led to squamous metaplasia (SM). SM is characterized by a stratification of the epithelium, the expression of the cytokeratin 13 and the appearance of cells with cross-linked envelopes. Reversible modifications between mucociliary and squamous phenotype are modulated by retinoids. The action of retinoids is selective: metaplasia is inhibited by agonists of RAR alpha and beta receptors and not by an agonist of RAR gamma receptors.

Animals↗

Clinical features of hypertrophic cardiomyopathy caused by mutation of a "hot spot" in the alpha-tropomyosin gene.

OBJECTIVES: We studied the clinical and genetic features of familial hypertrophic cardiomyopathy (FHC) caused by an Asp175Asn mutation in the alpha-tropomyosin gene in affected subjects from three unrelated families. BACKGROUND: Correlation of genotype and phenotype has provided important information in FHC caused by beta-cardiac myosin and cardiac troponin T mutations. Comparable analyses of hypertrophic cardiomyopathy caused by alpha-tropomyosin mutations have been hampered by the rarity of these genetic defects. METHODS: The haplotypes of three kindreds with FHC due to an alpha-tropomyosin gene mutation, Asp175Asn, were analyzed. The cardiac histopathologic findings of this mutation are reported. Distribution of left ventricular hypertrophy in affected members was assessed by two-dimensional echocardiography, and patient survival rates were compared. RESULTS: Genetic studies defined unique haplotypes in the three families, demonstrating that independent mutations caused the disease in each. The Asp175Asn mutation caused cardiac histopathologic findings of myocyte hypertrophy, disarray and replacement fibrosis. The severity and distribution of left ventricular hypertrophy varied considerably in affected members from the three families (mean maximal wall thickness +/- SD: 24 +/- 4.5 mm in anterior septum of Family DT; 15 +/- 2.7 mm in anterior septum and free wall of Family DB; 18 +/- 2.1 mm in posterior septum of Family MI), but survival was comparable and favorable. CONCLUSIONS: Nucleotide residue 579 in the alpha-tropomyosin gene may have increased susceptibility to mutation. On cardiac histopathologic study, defects in this sarcomere thin filament component are indistinguishable from other genetic etiologies of hypertrophic cardiomyopathy. The Asp175Asn mutation can elicit different morphologic responses, suggesting that the hypertrophic phenotype is modulated not by genetic etiologic factors alone. In contrast, prognosis reflected genotype; near normal life expectancy is found in hypertrophic cardiomyopathy caused by the alpha-tropomyosin mutation Asp175Asn.

Adolescent↗

Vir90, a virulence-activated gene coding for a Bordetella pertussis iron-regulated outer membrane protein.

Bordetella pertussis undergoes phenotypic changes modulated by the bvgAS locus, which regulates the expression of many genes related to virulence and immunogenicity. We previously reported the N-terminal sequence of a 90 kDa bvg-regulated outer membrane protein (OMP) of B. pertussis (SWISS-PROT accession No. p81549), a novel potential virulence factor that we named Vir90. The open reading frames (ORFs) which potentially code for Vir90 in B. pertussis, B. parapertussis and B. bronchiseptica were identified by computer analysis of the genomic sequences available for the three Bordetella species. Nucleotide sequence analysis of the vir90 upstream region revealed the presence of a putative promoter, a BvgA binding site and a putative Fur binding site. The B. pertussis Vir90 protein showed significant homology with ferrisiderophore receptors from Gram-negative bacteria. An antiserum raised against Vir90His recombinant protein recognized the 90-kDa protein in immunoblots of OMPs from these three virulent Bordetella species. The accumulation of the Vir90 protein increased 4-fold under low iron growth conditions. Therefore, the vir90 gene is expressed in the tested species and its expression is regulated positively by the BvgAS system and negatively under high iron concentration, likely by Fur.

Amino Acid Sequence↗

Modifier genes and protective alleles in humans and mice.

Interest in modifier genes is growing rapidly because of their ability to modulate the phenotype of individuals with monogenic and multigenic traits and diseases. A neglected class of modifiers is protective alleles that can suppress disease in otherwise susceptible individuals. Together these modifier genes and protective alleles provide important glimpses into the molecular and cellular basis for the functional networks that provide robustness and homeostasis in complex biological systems.

Animals↗

Theragnostic imaging for radiation oncology: dose-painting by numbers.

Theragnostic imaging for radiation oncology is the use of molecular and functional imaging to prescribe the distribution of radiation in four dimensions-the three dimensions of space plus time-of radiotherapy alone or combined with other treatment modalities in an individual patient. Several new imaging targets for positron-emission tomography, single-photon-emission CT, and magnetic resonance spectroscopy allow variations in microenvironmental or cellular phenotypes that modulate the effect of radiation to be mapped in three dimensions. Dose-painting by numbers is a strategy by which the dose distribution delivered by inverse planned intensity-modulated radiotherapy is prescribed in four dimensions. This approach will revolutionise the way that radiotherapy is prescribed and planned and, at least in theory, will improve the therapeutic outcome in terms of local tumour control and side-effects to unaffected tissue.

Diagnostic Imaging↗

Hyperactivation of protein kinase B and ERK have discrete effects on survival, proliferation, and cytokine expression in Nf1-deficient myeloid cells.

The Nf1 tumor suppressor encodes a GTPase-activating protein for Ras. Previous work has implicated hyperactive Ras in the aberrant growth of Nf1-deficient cells; however, there are limited data on which effectors modulate specific phenotypes. To address this, we generated myeloid cell lines by infecting fetal liver cells with a retrovirus encoding a truncated allele of c-Myb. Granulocyte-macrophage colony stimulating factor (GM-CSF) promoted the survival of wild-type Myb cells in a dose-dependent manner. By contrast, Nf1-deficient myeloid cells deprived of growth factors, were resistant to apoptosis due to hyperactivation of the phosphoinositide-3-OH kinase/protein kinase B cascade. Nf1(-/-) cells also demonstrated growth factor-independent proliferation and upregulation of GM-CSF mRNA production that were dependent upon Raf/MEK/ERK signaling. These data link specific Ras effectors with discrete cellular phenotypes in Nf1-deficient cells.

Animals↗

The sum is greater than the FGFR1 partner.

Cancer-associated chromosomal translocations create chimeric oncoproteins that contribute to aberrant growth by dominant or dominant negative mechanisms. Interestingly, genes such as MLL, RARA, and EWS are fused to multiple partners. This molecular promiscuity can provide important functional information, as specific translocations may be associated with discrete clinical and molecular features. In this issue of Cancer Cell, use a murine retroviral transduction/transplantation system to analyze two FGFR1 fusions found in hematologic malignancies. Their results show that these chromosomal rearrangements play a central role in pathogenesis, underscore the role of partner genes in modulating disease phenotypes, and uncover potential therapeutic targets.

Bone Marrow↗