Sympathetic neurons express and secrete MMP-2 and MT1-MMP to control nerve sprouting via pro-NGF conversion

Expression profile of genes related to pregnancy maintenance in Dromedary Camel during the first trimester

So far, few signals involved in embryo-maternal dialogue have been identified in pregnant she-camel. Our objective was to investigate expression profiles of genes relevant to uterine extracellular matrix remodeling (ITGB4, SLCO2A1, FOS, and JUN), uterine tissue vascularization, and placental formation (VEGFA, PGF, and PDGFA), embryonic growth and development (IGF1 and PTEN), plus cell death of uterine tissue (BCL2) in early pregnant versus non-pregnant she-camels. Forty genital tracts (20 pregnant and 20 non-pregnant) and blood samples were collected from abattoirs. Total RNA was extracted from uterine tissues and qRT-PCR was conducted for candidate genes. Serum concentrations of progesterone (P4) and estradiol17-β (E2) were measured. Expression of ITGB4, FOS, and PGF genes increased (P < 0.001) in the right uterine horn of pregnant versus non-pregnant she-camels. Moreover, JUN, SLCO2A1, VEGFA, and PTEN mRNAs were up-regulated (P < 0.001) in various segments of uterine tissues in pregnant groups. The PDGFA transcript was over-expressed (P < 0.001) in both uterine horns of pregnant groups. Additionally, IGF1 was higher (P < 0.001) in the right horn and the uterine body of pregnant groups, and expression of BCL2 was increased (P < 0.001) in the pregnant uterine body. Moreover, serum concentrations of P4 were higher (P < 0.001) and E2 lower (P < 0.05) in pregnant she-camels. Taken together, the fine-tuning of genes related to implantation, matrix formation, vascularization, and placental formation is highly required for successful pregnancy in she-camels.

Emerging roles of MT-MMPs in embryonic development

Membrane-type matrix metalloproteinases (MT-MMPs) are cell membrane-tethered proteinases that belong to the family of the MMPs. Apart from their roles in degradation of the extracellular milieu, MT-MMPs are able to activate through proteolytic processing at the cell surface distinct molecules such as receptors, growth factors, cytokines, adhesion molecules, and other pericellular proteins. Although most of the information regarding these enzymes comes from cancer studies, our current knowledge about their contribution in distinct developmental processes occurring in the embryo is limited. In this review, we want to summarize the involvement of MT-MMPs in distinct processes during embryonic morphogenesis, including cell migration and proliferation, epithelial-mesenchymal transition, cell polarity and branching, axon growth and navigation, synapse formation, and angiogenesis. We also considered information about MT-MMP functions from studies assessed in pathological conditions and compared these data with those relevant for embryonic development.

New Insights Into the Role of β-NGF/TrKA System in the Endometrium of Alpacas During Early Pregnancy

One striking reproductive feature in South American camelids is that more than 90% of gestations are established in the left uterine horn (LUH). This phenomenon could be related to a differential vascular irrigation of the LUH. An increase of vascularization in llama endometrium was observed after systemic administration of Beta Nerve Growth Factor (β-NGF), a neurotrophin present in the uterus and placenta of various mammals that is involved in pregnancy development. We hypothesized that the β-NGF signaling pathway is related to embryo implantation in the LUH in camelids. The aim of this study was to characterize the spatial expression of β-NGF and its high-affinity receptor, TrKA, between LUH and right uterine horn (RUH) of non-pregnant (NP) and early pregnant alpacas (15 and 30 days of gestation, 15 and 30P, respectively). In addition, β-NGF, TrKA, and Vascular Endothelium Growth Factor A (VEGFA) temporal gene expression patterns and counting of blood vessels were evaluated among groups. The β-NGF and TrKA were localized in the luminal, glandular, and vascular epithelium of the alpaca uterus and in the embryonic membranes of the 30-days-old conceptus. β-NGF and TrKA immunosignal were stronger in 15P females than that of NP and 30P. In addition, TrKA signal was higher in the LUH luminal epithelium of NP and 15P alpacas than that of NP-RUH and 15P-RUH. β-NGF mRNA relative abundance was higher in the 30P-RUH than that of NP-RUH; whereas TrKA mRNA abundance only differed between 15P-RUH and NP-LUH. VEGFA mRNA relative abundance was higher in NP females compared to the LUH of 15P and 30P alpacas, and lower to their right counterparts. The number of vessels per field was higher in 15P than that of 30P. A positive correlation was observed between the number of vessels per field and β-NGF immunosignal in 15P-LUH. In contrast, the area occupied by vessels was higher in 30P alpacas than of NP and 15P females. The changes of β-NGF/TrKA expression pattern in the peri-implantation endometria between LUH and RUH and their localization in the extraembryonic membranes support the implication of the neurotrophin during implantation and pregnancy development in South American Camelids.

A HPV16-related prognostic indicator for head and neck squamous cell carcinoma

Background

The human papillomavirus (HPV) is emerging as an important risk factor in head and neck squamous cell carcinoma (HNSCC) patients. This has been observed particularly in the case of HPV16. The HPV16+ HNSCC subtype has distinct pathological, clinical, molecular, and prognostic characteristics. This study aimed to identify potential microRNAs (miRNAs) and their roles in HPV16+ HNSCC progression.

Method

miRNA, mRNA and the clinical data of 519 HNSCC and 44 HNSCC-negative samples were obtained from The Cancer Genome Atlas (TCGA) database. Differentially expressed miRNAs (DEMs) in HPV16-related HNSCC tissues with prognostic value were selected. DEM levels were assessed based on clinicopathological parameters and overall survival (OS). Target genes were also predicted and functional analysis based on Gene Set Enrichment Analysis (GSEA) were then performed.

Results

In HPV16+ HNSCC tissues, miR-99a-3p and miR-4746-5p were significantly upregulated. In contrast, miR-411-5p was shown to be downregulated. miR-99a-3p^highmiR-411-5p^lowmiR-4746-5p^high expression could estimate improved OS and low frequent perineural invasion (PNI). Predicted target genes were enriched in cell growth, neuroepithelial cell differentiation, MAPK and FoxO signaling pathways. Epithelial mesenchymal transition (EMT) gene set and invasion related genes were downregulated in miR-99a-3p^highmiR-411-5p^lowmiR-4746-5p^high HNSCC patients.

Conclusion

miR-99a-3p, miR-411-5p and miR-4746-5p might participate in HPV16+ HNSCC progression through EMT related pathways and affect prognosis.

Effect of mating on mRNA and protein expression of beta nerve growth factor and its receptor, TrKA, in the oviduct of llama (Lama glama)

Copulation produces different stimuli in the female reproductive tract in camelids, which lead to ovulation. Expression of β-nerve growth factor (β-NGF) and its specific receptor, tropomyosin receptor kinase A (TrKA), was studied comparing the oviductal microenvironment of mated and nonmated llamas. β-NGF and TrKA were expressed in the llama ampulla, isthmus, and utero-tubal-junction (UTJ), and they were mainly colocalized in the apical region of the oviductal mucosa. A TrKA immunosignal was also found in muscle cells and blood vessels, with the highest mark in UTJ muscle cells of copulated females. Both β-NGF and TrKA transcripts were expressed in the three oviductal segments. Relative TrKA abundance did not differ between mated and nonmated females, but relative β-NGF abundance was higher in the UTJ of copulated females (p < .05). β-NGF might not be secreted into the oviductal fluid (OF) since the protein was not found in the OF of mated or nonmated females. Therefore, it can be concluded that the llama oviduct expresses the β-NGF/TrKA system and that an increase in β-NGF gene expression in the UTJ 24 h after copulation along with an increase in TrKA protein expression may indicate an important role in the gamete transport and fertilization process in llamas.

Electrical stimulation accelerates neurite regeneration in axotomized dorsal root ganglion neurons by increasing MMP-2 expression

Electrical stimulation (ES) can be useful for promoting the regeneration of injured axons, but the mechanism underlying its positive effects is largely unknown. The current study aimed to investigate whether ES could enhance the regeneration of injured neurites in dorsal root ganglion explants and regulate the MMP-2 expression level, which is correlated with regeneration. Significantly increased neurite regeneration and MMP-2 expression was observed in the ES group compared with the sham group. However, an MMP inhibitor significantly decreased this ES-induced neurite regeneration. Our data suggest that the positive effect of ES on neurite regeneration could likely be mediated by an increase in MMP-2 expression, thereby promoting the regeneration of injured neurites.

The Nucleus Accumbens: Mechanisms of Addiction across Drug Classes Reflect the Importance of Glutamate Homeostasis

The nucleus accumbens is a major input structure of the basal ganglia and integrates information from cortical and limbic structures to mediate goal-directed behaviors. Chronic exposure to several classes of drugs of abuse disrupts plasticity in this region, allowing drug-associated cues to engender a pathologic motivation for drug seeking. A number of alterations in glutamatergic transmission occur within the nucleus accumbens after withdrawal from chronic drug exposure. These drug-induced neuroadaptations serve as the molecular basis for relapse vulnerability. In this review, we focus on the role that glutamate signal transduction in the nucleus accumbens plays in addiction-related behaviors. First, we explore the nucleus accumbens, including the cell types and neuronal populations present as well as afferent and efferent connections. Next we discuss rodent models of addiction and assess the viability of these models for testing candidate pharmacotherapies for the prevention of relapse. Then we provide a review of the literature describing how synaptic plasticity in the accumbens is altered after exposure to drugs of abuse and withdrawal and also how pharmacological manipulation of glutamate systems in the accumbens can inhibit drug seeking in the laboratory setting. Finally, we examine results from clinical trials in which pharmacotherapies designed to manipulate glutamate systems have been effective in treating relapse in human patients. Further elucidation of how drugs of abuse alter glutamatergic plasticity within the accumbens will be necessary for the development of new therapeutics for the treatment of addiction across all classes of addictive substances.

Electrical stimulation inhibits cytosine arabinoside-induced neuronal death by preventing apoptosis in dorsal root ganglion neurons

The current study aimed to investigate whether electrical stimulation could prevent apoptotic neuronal cell death during treatment with cytosine arabinoside (ara-C). From in-vitro experiments, the effects of electrical stimulation were assessed on neurite fragmentation and neuronal cell death in ara-C-treated dorsal root ganglion (DRG) explants. Ara-C treatment increased neurite fragmentation and neuronal cell death in DRG explants and activated caspase-3 by cleaving it, which could induce apoptosis. Electrical stimulation can significantly reduce neurite fragmentation and neuronal cell death compared with nonelectrically stimulated groups. Furthermore, electrical stimulation inhibited caspase-3 activation and reduced apoptotic neuronal death in DRG explants. It was suggested that the neuroprotective effect of electrical stimulation is likely mediated by the inhibition of caspase-3 activation and therefore the inhibition of apoptosis following ara-C treatment.

Differential temporal expression of matrix metalloproteinases following sciatic nerve crush

We previously performed transcriptome sequencing and found that genes for matrix metalloproteinases (MMPs), such as MMP7 and 12, seem to be highly upregulated following peripheral nerve injury, and may be involved in nerve repair. In the present study, we systematically determined the expression levels of MMPs and their regulators at 1, 4, 7 and 14 days after sciatic nerve crush injury. The number of differentially expressed genes was elevated at 4 and 7 days after injury, but decreased at 14 days after injury. Among the differentially expressed genes, those most up-regulated showed fold changes of more than 214, while those most down-regulated exhibited fold changes of more than 2−10. Gene sequencing showed that, at all time points after injury, a variety of MMP genes in the “Inhibition of MMPs” pathway were up-regulated, and their inhibitor genes were down-regulated. Expression of key up- and down-regulated genes was verified by quantitative real-time polymerase chain reaction analysis and found to be consistent with transcriptome sequencing. These results suggest that MMP-related genes are strongly involved in the process of peripheral nerve regeneration.

Cell adhesion and invasion mechanisms that guide developing axons

Axon extension, guidance and tissue invasion share many similarities to normal cell migration and cancer cell metastasis. Proper cell and growth cone migration requires tightly regulated adhesion complex assembly and detachment from the extracellular matrix (ECM). In addition, many cell types actively remodel the ECM using matrix metalloproteases (MMPs) to control tissue invasion and cell dispersal. Targeting and activating MMPs is a tightly regulated process, that when dysregulated, can lead to cancer cell metastasis. Interestingly, new evidence suggests that growth cones express similar cellular and molecular machinery as migrating cells to clutch retrograde actin flow on ECM proteins and target matrix degradation, which may be used to facilitate axon pathfinding through the basal lamina and across tissues.

Chronic mild stress influences nerve growth factor through a matrix metalloproteinase-dependent mechanism

Stress is generally a beneficial experience that motivates an organism to action to overcome the stressful challenge. In particular situations, when stress becomes chronic might be harmful and devastating. The hypothalamus is a critical coordinator of stress and the metabolic response; therefore, disruptions in this structure may be a significant cause of the hormonal and metabolic disturbances observed in depression. Chronic stress induces adverse changes in the morphology of neural cells that are often associated with a deficiency of neurotrophic factors (NTFs); additionally, many studies indicate that insufficient NTF synthesis may participate in the pathogenesis of depression. The aim of the present study was to determine the expression of the nerve growth factor (NGF) in the hypothalamus of male rats subjected to chronic mild stress (CMS) or to prenatal stress (PS) and to PS in combination with an acute stress event (AS). It has been found that chronic mild stress, but not prenatal stress, acute stress or a combination of PS with AS, decreased the concentration of the mature form of NGF (m-NGF) in the rat hypothalamus. A discrepancy between an increase in the Ngf mRNA and a decrease in the m-NGF levels suggested that chronic mild stress inhibited NGF maturation or enhanced the degradation of this factor. We have shown that NGF degradation in the hypothalamus of rats subjected to chronic mild stress is matrix metalloproteinase-dependent and related to an increase in the active forms of some metalloproteinases (MMP), including MMP2, MMP3, MMP9 and MMP13, while the NGF maturation process does not seem to be changed. We suggested that activated MMP2 and MMP9 potently cleave the mature but not the pro- form of NGF into biologically inactive products, which is the reason for m-NGF decomposition. In turn, the enhanced expression of Ngf in the hypothalamus of these rats is an attempt to overcome the reduced levels of m-NGF. Additionally, the decreased level of m-NGF together with the increased level of pro-NGF can decrease TrkA-mediated neuronal survival signalling and enhance the action of pro-NGF on the p75(NTR) receptor, respectively, to evoke pro-apoptotic signalling. This hypothesis is supported by elevated levels of the caspase-3 mRNA in the hypothalamus of rats subjected to chronic mild stress.

The tetrapartite synapse: Extracellular matrix remodeling contributes to corticoaccumbens plasticity underlying drug addiction

Synaptic plasticity has long been known to involve three key elements of neuropil, the presynapse, the postsynapse and adjacent glia. Here we review the role of the extracellular matrix in synaptic plasticity as a necessary component forming the tetrapartite synapse. We describe the role of matrix metalloproteinases as enzymes sculpting extracellular proteins and thereby creating an extracellular signaling domain required for synaptic plasticity. Specifically we focus on the role of the tetrapartite synapse in mediating the effects of addictive drugs at cortico-striatal synapses, and conclude that the extracellular signaling domain and its regulation by matrix metalloproteinases is critical for developing and expressing drug seeking behaviors.

The biology of neurotrophins: cardiovascular function

This chapter addresses the role of neurotrophins in the development of the heart, blood vessels, and neural circuits that control cardiovascular function, as well as the role of neurotrophins in the mature cardiovascular system. The cardiovascular system includes the heart and vasculature whose functions are tightly controlled by the nervous system. Neurons, cardiomyocytes, endothelial cells, vascular smooth muscle cells, and pericytes are all targets for neurotrophin action during development. Neurotrophin expression continues throughout life, and several common pathologies that impact cardiovascular function involve changes in the expression or activity of neurotrophins. These include atherosclerosis, hypertension, diabetes, acute myocardial infarction, and heart failure. In many of these conditions, altered expression of neurotrophins and/or neurotrophin receptors has direct effects on vascular endothelial and smooth muscle cells in addition to effects on nerves that modulate vascular resistance and cardiac function. This chapter summarizes the effects of neurotrophins in cardiovascular physiology and pathophysiology.

Matrix metalloproteinase-2 and -9 as promising benefactors in development, plasticity and repair of the nervous system

It has been 50 years since Gross and Lapiere discovered collagenolytic activity during tadpole tail metamorphosis, which was later on revealed as MMP-1, the founding member of the matrix metalloproteinases (MMPs). Currently, MMPs constitute a large group of endoproteases that are not only able to cleave all protein components of the extracellular matrix, but also to activate or inactivate many other signaling molecules, such as receptors, adhesion molecules and growth factors. Elevated MMP levels are associated with an increasing number of injuries and disorders, such as cancer, inflammation and auto-immune diseases. Yet, MMP upregulation has also been implicated in many physiological functions such as embryonic development, wound healing and angiogenesis and therefore, these proteinases are considered to be crucial mediators in many biological processes. Over the past decennia, MMP research has gained considerable attention in several pathologies, most prominently in the field of cancer metastasis, and more recent investigations also focus on the nervous system, with a striking emphasis on the gelatinases, MMP-2 and MMP-9. Unfortunately, the contribution of these gelatinases to neuropathological disorders, like multiple sclerosis and Alzheimer's disease, has overshadowed their potential as modulators of fundamental nervous system functions. Within this review, we wish to highlight the currently known or suggested actions of MMP-2 and MMP-9 in the developing and adult nervous system and their potential to improve repair or regeneration after nervous system injury.

Carotenoid compositions of coloured tomato cultivars and contribution to antioxidant activities and protection against H(2)O(2)-induced cell death in H9c2

The carotenoid compositions, antioxidant activities and the potential cardio-protective role of 13 tomato cultivars with distinct colour were studied. Colour coordinates were evaluated by colorimeter and the carotenoid compositions were analysed by UPLC. Red tomatoes had the highest total carotenoid contents (TCC) and antioxidant activities, followed by purple, orange, pink and yellow ones. The TCC were 120.5-278.0 μg/gDW, and the antioxidant activities were 21.32-40.07 μmolTE/gDW (PCL), 64.42-89.98% (DPPH) and 10.47-13.76 μmolTE/g DW (ORAC), respectively. The lipophilic extracts were also found to prevent cell death in a cell-based model system using cardiac H9c2 cells and H(2)O(2), via attenuation of the caspase-3 and matrix metalloproteinase-2 activities. The extracts of different tomatoes showed strong but different antioxidant activities. Roles of total and individual carotenoids in the antioxidant activities were studied and lycopene showed the highest correlation. Results of this study can be used to guide the development of new tomato cultivars and functional foods, and benefit the consumers.

Lectican proteoglycans, their cleaving metalloproteinases, and plasticity in the central nervous system extracellular microenvironment

The extracellular matrix (ECM) in the central nervous system actively orchestrates and modulates changes in neural structure and function in response to experience, after injury, during disease, and with changes in neuronal activity. A component of the multi-protein, ECM aggregate in brain, the chondroitin sulfate (CS)-bearing proteoglycans (PGs) known as lecticans, inhibit neurite outgrowth, alter dendritic spine shape, elicit closure of critical period plasticity, and block target reinnervation and functional recovery after injury as the major component of a glial scar. While removal of the CS chains from lecticans with chondroitinase ABC improves plasticity, proteolytic cleavage of the lectican core protein may change the conformation of the matrix aggregate and also modulate neural plasticity. This review centers on the roles of the lecticans and the endogenous metalloproteinase families that proteolytically cleave lectican core proteins, the matrix metalloproteinases (MMPs) and a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTSs), in neural plasticity. These extracellular metalloproteinases modulate structural neural plasticity-including changes in neurite outgrowth and dendritic spine remodeling-and synaptic plasticity. Some of these actions have been demonstrated to occur via cleavage of the PG core protein. Other actions of the proteases include cleavage of non-matrix substrate proteins, whereas still other actions may occur directly at the cell surface without proteolytic cleavage. The data convincingly demonstrate that metalloproteinases modulate physiological and pathophysiological neural plasticity.

Neural functions of matrix metalloproteinases: plasticity, neurogenesis, and disease

The brain changes in response to experience and altered environment. To do that, the nervous system often remodels the structures of neuronal circuits. This structural plasticity of the neuronal circuits appears to be controlled not only by intrinsic factors, but also by extrinsic mechanisms including modification of the extracellular matrix. Recent studies employing a range of animal models implicate that matrix metalloproteinases regulate multiple aspects of the neuronal development and remodeling in the brain. This paper aims to summarize recent advances of our knowledge on the neuronal functions of matrix metalloproteinases and discuss how they might relate in neuronal disease.

Toward an integrative analysis of the tumor microenvironment in ovarian epithelial carcinoma

Ovarian epithelial carcinomas are heterogeneous malignancies exhibiting great diversity in histological phenotypes as well as genetic and epigenetic aberrations. A general early event in tumorigenesis is regional dissemination into the peritoneal cavity. Initial spread to the peritoneum is made possible by cooperative signaling between a wide array of molecules constituting the tissue microenvironment in the coelomic epithelium. Changes in the activity of key microenvironmental components not constitutively expressed in normal tissue, including several disclosed adhesion molecules, growth factors, proteases, and G-protein coupled receptors (GPCRs), coordinate the transition. Remodeling of the extracellular matrix (ECM) and subsequent cell surface interactions enable transformation by promoting chromosomal instability (CIN) and stimulating several common signal transduction cascades to prepare the tissue for harboring and facilitating growth, angiogenesis and metastasis of the developing tumor.

Post-treatment with amphetamine enhances reinnervation of the ipsilateral side cortex in stroke rats

Amphetamine (AM) treatment has been shown to alter behavioral recovery after ischemia caused by embolism, permanent unilateral occlusion of the common carotid and middle cerebral arteries, or unilateral sensorimotor cortex ablation in rats. However, the behavioral results are inconsistent possibly due to difficulty controlling the size of the lesion before treatment. There is also evidence that AM promotes neuroregeneration in the cortex contralateral to the infarction; however, the effects of AM in the ipsilateral cortex remain unclear. The purpose of this study was to employ T2-weighted imaging (T2WI) to establish controlled criteria for AM treatment and to examine neuroregenerative effects in both cortices after stroke. Adult rats were anesthetized, and the right middle cerebral artery was ligated for 90 min to generate lesions in the ipsilateral cortex. Animals were separated into two equal treatment groups (AM or saline) according to the size of infarction, measured by T2WI at 2days after stroke. AM or saline was administered to stroke rats every third day starting on day 3 for 4weeks. AM treatment significantly reduced neurological deficits, as measured by body asymmetry and Bederson's score. T2WI and diffusion tensor imaging (DTI) were used to examine the size of infarction and axonal reinnervation, respectively, before and following treatment on days 2, 10 and 25 after stroke. AM treatment reduced the volume of tissue loss on days 10 and 25. A significant increase in fractional anisotropy ratio was found in the ipsilateral cortex after repeated AM administration, suggesting a possible increase in axonal outgrowth in the lesioned side cortex. Western analysis indicated that AM significantly increased the expression of synaptophysin ipsilaterally and neurofilament bilaterally. AM also enhanced matrix metalloproteinase (MMP) enzymatic activity, determined by MMP zymography in the lesioned side cortex. qRT-PCR was used to examine the expression of trophic factors after the 1st and 2nd doses of AM or saline injection. The expression of BDNF, but not BMP7 or CART, was significantly enhanced by AM in the lesioned side cortex. In conclusion, post-stroke treatment with AM facilitates behavioral recovery, which is associated with an increase in fractional anisotropy activity, enhanced fiber growth in tractography, synaptogenesis, upregulation of BDNF, and MMP activity mainly in the lesioned cortex. Our data suggest that the ipsilateral cortex may be the major target of action in stroke brain after AM treatment.