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Endocrine Reviews Nov 2023Pregnancy-associated plasma protein-A (PAPP-A) was first identified in the early 1970s as a placental protein of unknown function, present at high concentrations in the... (Review)
Review
Pregnancy-associated plasma protein-A (PAPP-A) was first identified in the early 1970s as a placental protein of unknown function, present at high concentrations in the circulation of pregnant women. In the mid-to-late 1990s, PAPP-A was discovered to be a metzincin metalloproteinase, expressed by many nonplacental cells, that regulates local insulin-like growth factor (IGF) activity through cleavage of high-affinity IGF binding proteins (IGFBPs), in particular IGFBP-4. With PAPP-A as a cell surface-associated enzyme, the reduced affinity of the cleavage fragments results in increased IGF available to bind and activate IGF receptors in the pericellular environment. This proteolytic regulation of IGF activity is important, since the IGFs promote proliferation, differentiation, migration, and survival in various normal and cancer cells. Thus, there has been a steady growth in investigation of PAPP-A structure and function outside of pregnancy. This review provides historical perspective on the discovery of PAPP-A and its structure and cellular function, highlights key studies of the first 50 years in PAPP-A research, and introduces new findings from recent years.
Topics: Pregnancy; Humans; Female; Pregnancy-Associated Plasma Protein-A; Placenta; Metalloproteases; Cell Differentiation; Insulin-Like Growth Factor I
PubMed: 37267421
DOI: 10.1210/endrev/bnad017 -
Journal of Hazardous Materials Jan 2024Macrophages are essential for the maintenance of endothelial cell function. However, the potential impact and mechanisms of crosstalk between macrophages and endothelial...
Macrophages are essential for the maintenance of endothelial cell function. However, the potential impact and mechanisms of crosstalk between macrophages and endothelial cells during silicosis progression remain unexplored. To fill this knowledge gap, a mouse model of silicosis was established. Single cell sequencing, spatial transcriptome sequencing, western blotting, immunofluorescence staining, tube-forming and wound healing assays were used to explore the effects of silicon dioxide on macrophage-endothelial interactions. To investigate the mechanism of macrophage-mediated fibrosis, MMP12 was specifically inactivated using siRNA and pharmacological approaches, and macrophages were depleted using disodium chlorophosphite liposomes. Compared to the normal saline group, the silica dust group showed altered macrophage-endothelial interactions. Matrix metalloproteinase family member MMP12 was identified as a key mediator of the altered function of macrophage-endothelial interactions after silica exposure, which was accompanied by pro-inflammatory macrophage activation and fibrotic progression. By using ablation strategies, macrophage-derived MMP12 was shown to mediate endothelial cell dysfunction by accumulating on the extracellular matrix. During the inflammatory phase of silicosis, MMP12 secreted by pro-inflammatory macrophages caused decreased endothelial cell viability, reduced migration, decreased trans-endothelial resistance and increased permeability; while during the fibrotic phase, macrophage-derived MMP12 sustained endothelial cell injury through accumulation on the extracellular matrix.
Topics: Animals; Mice; Matrix Metalloproteinase 12; Endothelial Cells; Fibrosis; Macrophages; Silicosis; Silicon Dioxide
PubMed: 37816293
DOI: 10.1016/j.jhazmat.2023.132733 -
Medicine Jul 2023Studies in the 1920s found that botulinum neurotoxin type A (BoNT/A) inhibited the activity of motor and parasympathetic nerve endings, confirmed several decades later...
Studies in the 1920s found that botulinum neurotoxin type A (BoNT/A) inhibited the activity of motor and parasympathetic nerve endings, confirmed several decades later to be due to decreased acetylcholine release. The 1970s were marked by studies of cellular mechanisms aided by use of neutralizing antibodies as pharmacologic tools: BoNT/A disappeared from accessibility to neutralizing antibodies within minutes, although it took several hours for onset of muscle weakness. The multi-step mechanism was experimentally confirmed and is now recognized to consist broadly of binding to nerve terminals, internalization, and lysis or cleavage of a protein (SNAP-25: synaptosomal associated protein-25 kDa) that is part of the SNARE (Soluble NSF Attachment protein REceptor) complex needed for synaptic vesicle docking and fusion. Clinical use of the BoNT/A product onabotulinumtoxinA was based on its ability to reduce muscle contractions via inhibition of acetylcholine from motor terminals. Sensory mechanisms of onabotulinumtoxinA have now been identified, supporting its successful treatment of chronic migraine and urgency in overactive bladder. Exploration into migraine mechanisms led to anatomical studies documenting pain fibers that send axons through sutures of the skull to outside the head-a potential route by which extracranial injections could affect intracranial processes. Several clinical studies have also identified benefits of onabotulinumtoxinA in major depression, which have been attributed to central responses induced by feedback from facial muscle and skin movement. Overall, the history of BoNT/A is distinguished by basic science studies that stimulated clinical use and, conversely, clinical observations that spurred basic research into novel mechanisms of action.
Topics: Humans; Botulinum Toxins, Type A; Acetylcholine; Urinary Bladder, Overactive; Migraine Disorders; Muscle Contraction
PubMed: 37499078
DOI: 10.1097/MD.0000000000032372 -
Journal of the American Society of... Jul 2023Although gene expression changes have been characterized in human diabetic kidney disease (DKD), unbiased tissue proteomics information for this condition is lacking....
SIGNIFICANCE STATEMENT
Although gene expression changes have been characterized in human diabetic kidney disease (DKD), unbiased tissue proteomics information for this condition is lacking. The authors conducted an unbiased aptamer-based proteomic analysis of samples from patients with DKD and healthy controls, identifying proteins with levels that associate with kidney function (eGFR) or fibrosis, after adjusting for key covariates. Overall, tissue gene expression only modestly correlated with tissue protein levels. Kidney protein and RNA levels of matrix metalloproteinase 7 (MMP7) strongly correlated with fibrosis and with eGFR. Single-cell RNA sequencing indicated that kidney tubule cells are an important source of MMP7. Furthermore, plasma MMP7 levels predicted future kidney function decline. These findings identify kidney tissue MMP7 as a biomarker of fibrosis and blood MMP7 as a biomarker for future kidney function decline.
BACKGROUND
Diabetic kidney disease (DKD) is responsible for close to half of all ESKD cases. Although unbiased gene expression changes have been extensively characterized in human kidney tissue samples, unbiased protein-level information is not available.
METHODS
We collected human kidney samples from 23 individuals with DKD and ten healthy controls, gathered associated clinical and demographics information, and implemented histologic analysis. We performed unbiased proteomics using the SomaScan platform and quantified the level of 1305 proteins and analyzed gene expression levels by bulk RNA and single-cell RNA sequencing (scRNA-seq). We validated protein levels in a separate cohort of kidney tissue samples as well as in 11,030 blood samples.
RESULTS
Globally, human kidney transcript and protein levels showed only modest correlation. Our analysis identified 14 proteins with kidney tissue levels that correlated with eGFR and found that the levels of 152 proteins correlated with interstitial fibrosis. Of the identified proteins, matrix metalloprotease 7 (MMP7) showed the strongest association with both fibrosis and eGFR. The correlation between tissue MMP7 protein expression and kidney function was validated in external datasets. The levels of MMP7 RNA correlated with fibrosis in the primary and validation datasets. Findings from scRNA-seq pointed to proximal tubules, connecting tubules, and principal cells as likely cellular sources of increased tissue MMP7 expression. Furthermore, plasma MMP7 levels correlated not only with kidney function but also associated with prospective kidney function decline.
CONCLUSIONS
Our findings, which underscore the value of human kidney tissue proteomics analysis, identify kidney tissue MMP7 as a diagnostic marker of kidney fibrosis and blood MMP7 as a biomarker for future kidney function decline.
Topics: Humans; Matrix Metalloproteinase 7; Diabetic Nephropathies; Proteomics; Kidney; Biomarkers; Fibrosis; RNA
PubMed: 37022120
DOI: 10.1681/ASN.0000000000000141 -
Circulation Research Sep 2023The locus was genome-wide significantly associated with coronary artery disease. Lack of the ECM (extracellular matrix) protease ADAMTS-7 (A disintegrin and...
BACKGROUND
The locus was genome-wide significantly associated with coronary artery disease. Lack of the ECM (extracellular matrix) protease ADAMTS-7 (A disintegrin and metalloproteinase-7) was shown to reduce atherosclerotic plaque formation. Here, we sought to identify molecular mechanisms and downstream targets of ADAMTS-7 mediating the risk of atherosclerosis.
METHODS
Targets of ADAMTS-7 were identified by high-resolution mass spectrometry of atherosclerotic plaques from Apoe and ApoeAdamts7 mice. ECM proteins were identified using solubility profiling. Putative targets were validated using immunofluorescence, in vitro degradation assays, coimmunoprecipitation, and Förster resonance energy transfer-based protein-protein interaction assays. expression was measured in fibrous caps of human carotid artery plaques.
RESULTS
In humans, expression was higher in caps of unstable as compared to stable carotid plaques. Compared to Apoe mice, atherosclerotic aortas of Apoe mice lacking Adamts-7 (ApoeAdamts7) contained higher protein levels of Timp-1 (tissue inhibitor of metalloprotease-1). In coimmunoprecipitation experiments, the catalytic domain of ADAMTS-7 bound to TIMP-1, which was degraded in the presence of ADAMTS-7 in vitro. ADAMTS-7 reduced the inhibitory capacity of TIMP-1 at its canonical target MMP-9 (matrix metalloprotease-9). As a downstream mechanism, we investigated collagen content in plaques of Apoe and ApoeAdamts7 mice after a Western diet. Picrosirius red staining of the aortic root revealed less collagen as a readout of higher MMP-9 activity in Apoe as compared to Apoe Adamts7 mice. To facilitate high-throughput screening for ADAMTS-7 inhibitors with the aim of decreasing TIMP-1 degradation, we designed a Förster resonance energy transfer-based assay targeting the ADAMTS-7 catalytic site.
CONCLUSIONS
ADAMTS-7, which is induced in unstable atherosclerotic plaques, decreases TIMP-1 stability reducing its inhibitory effect on MMP-9, which is known to promote collagen degradation and is likewise associated with coronary artery disease. Disrupting the interaction of ADAMTS-7 and TIMP-1 might be a strategy to increase collagen content and plaque stability for the reduction of atherosclerosis-related events.
Topics: Animals; Humans; Mice; ADAMTS7 Protein; Atherosclerosis; Collagen; Coronary Artery Disease; Matrix Metalloproteinase 9; Plaque, Atherosclerotic; Tissue Inhibitor of Metalloproteinase-1; Mice, Knockout, ApoE
PubMed: 37675562
DOI: 10.1161/CIRCRESAHA.123.322737 -
Cell Aug 2023The endopeptidase ADAM10 is a critical catalyst for the regulated proteolysis of key drivers of mammalian development, physiology, and non-amyloidogenic cleavage of APP...
The endopeptidase ADAM10 is a critical catalyst for the regulated proteolysis of key drivers of mammalian development, physiology, and non-amyloidogenic cleavage of APP as the primary α-secretase. ADAM10 function requires the formation of a complex with a C8-tetraspanin protein, but how tetraspanin binding enables positioning of the enzyme active site for membrane-proximal cleavage remains unknown. We present here a cryo-EM structure of a vFab-ADAM10-Tspan15 complex, which shows that Tspan15 binding relieves ADAM10 autoinhibition and acts as a molecular measuring stick to position the enzyme active site about 20 Å from the plasma membrane for membrane-proximal substrate cleavage. Cell-based assays of N-cadherin shedding establish that the positioning of the active site by the interface between the ADAM10 catalytic domain and the bound tetraspanin influences selection of the preferred cleavage site. Together, these studies reveal the molecular mechanism underlying ADAM10 proteolysis at membrane-proximal sites and offer a roadmap for its modulation in disease.
Topics: Animals; ADAM10 Protein; Amyloid Precursor Protein Secretases; Mammals; Proteolysis; Tetraspanins; Humans
PubMed: 37516108
DOI: 10.1016/j.cell.2023.06.026 -
Journal of Cell Science Jan 2024Matrix metalloproteinases (MMPs) are a family of zinc-dependent proteinases that belong to the group of endopeptidases or matrixins. They are able to cleave a plethora... (Review)
Review
Matrix metalloproteinases (MMPs) are a family of zinc-dependent proteinases that belong to the group of endopeptidases or matrixins. They are able to cleave a plethora of substrates, including components of the extracellular matrix and cell-surface-associated proteins, as well as intracellular targets. Accordingly, MMPs play key roles in a variety of physiological and pathological processes, such as tissue homeostasis and cancer cell invasion. MMP activity is exquisitely regulated at several levels, including pro-domain removal, association with inhibitors, intracellular trafficking and transport via extracellular vesicles. Moreover, the regulation of MMP activity is currently being rediscovered for the development of respective therapies for the treatment of cancer, as well as infectious, inflammatory and neurological diseases. In this Cell Science at a Glance article and the accompanying poster, we present an overview of the current knowledge regarding the regulation of MMP activity, the intra- and extra-cellular trafficking pathways of these enzymes and their diverse groups of target proteins, as well as their impact on health and disease.
Topics: Endopeptidases; Extracellular Matrix; Extracellular Vesicles; Membrane Proteins; Matrix Metalloproteinases
PubMed: 38236162
DOI: 10.1242/jcs.261898 -
Circulation Feb 2024A better understanding of the molecular mechanism of aortic valve development and bicuspid aortic valve (BAV) formation would significantly improve and optimize the...
BACKGROUND
A better understanding of the molecular mechanism of aortic valve development and bicuspid aortic valve (BAV) formation would significantly improve and optimize the therapeutic strategy for BAV treatment. Over the past decade, the genes involved in aortic valve development and BAV formation have been increasingly recognized. On the other hand, (a disintegrin and metalloproteinase with thrombospondin motifs) gene family members have been reported to be able to modulate cardiovascular development and diseases. The present study aimed to further investigate the roles of ADAMTS family members in aortic valve development and BAV formation.
METHODS
Morpholino-based family gene-targeted screening for zebrafish heart outflow tract phenotypes combined with DNA sequencing in a 304 cohort BAV patient registry study was initially carried out to identify potentially related genes. Both gene-specific fluorescence in situ hybridization assay and genetic tracing experiments were performed to evaluate the expression pattern in the aortic valve. Accordingly, related genetic mouse models (both knockout and knockin) were generated using the CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/clustered regularly interspaced short palindromic repeat-associated 9) method to further study the roles of family genes. The lineage-tracing technique was used again to evaluate how the cellular activity of specific progenitor cells was regulated by genes. Bulk RNA sequencing was used to investigate the signaling pathways involved. Inducible pluripotent stem cells derived from both BAV patients and genetic mouse tissue were used to study the molecular mechanism of ADAMTS. Immunohistochemistry was performed to examine the phenotype of cardiac valve anomalies, especially in the extracellular matrix components.
RESULTS
genes targeting and phenotype screening in zebrafish and targeted DNA sequencing on a cohort of patients with BAV identified (a disintegrin and metalloproteinase with thrombospondin motifs 16) as a BAV-causing gene and found the p. H357Q variant in an inherited BAV family. Both in situ hybridization and genetic tracing studies described a unique spatiotemporal pattern of ADAMTS16 expression during aortic valve development. and mouse models both exhibited a right coronary cusp-noncoronary cusp fusion-type BAV phenotype, with progressive aortic valve thickening associated with raphe formation (fusion of the commissure). Further, ADAMTS16 deficiency in Tie2 lineage cells recapitulated the BAV phenotype. This was confirmed in lineage-tracing mouse models in which deficiency affected endothelial and second heart field cells, not the neural crest cells. Accordingly, the changes were mainly detected in the noncoronary and right coronary leaflets. Bulk RNA sequencing using inducible pluripotent stem cells-derived endothelial cells and genetic mouse embryonic heart tissue unveiled enhanced FAK (focal adhesion kinase) signaling, which was accompanied by elevated fibronectin levels. Both in vitro inducible pluripotent stem cells-derived endothelial cells culture and ex vivo embryonic outflow tract explant studies validated the altered FAK signaling.
CONCLUSIONS
Our present study identified a novel BAV-causing p. H357Q variant. ADAMTS16 deficiency led to BAV formation.
Topics: Humans; Animals; Mice; Bicuspid Aortic Valve Disease; Zebrafish; Heart Valve Diseases; Endothelial Cells; Disintegrins; In Situ Hybridization, Fluorescence; Aortic Valve; Heart Defects, Congenital; Extracellular Matrix; Thrombospondins; Metalloproteases; ADAMTS Proteins
PubMed: 38018454
DOI: 10.1161/CIRCULATIONAHA.123.065458 -
Journal of the Neurological Sciences Jan 2024Botulinum toxin (BoNT) was approved by the United States Food and Drug Administration (FDA) in 1989 for facial movement disorders and strabismus, but since that time its... (Review)
Review
Botulinum toxin (BoNT) was approved by the United States Food and Drug Administration (FDA) in 1989 for facial movement disorders and strabismus, but since that time its indications have been expanding beyond neurologic and ophthalmologic disorders. This article is a narrative review of the therapeutic use of BoNT in tremors, dystonia, sialorrhea, bladder and other autonomic symptoms, levodopa-induced dyskinesia and other problems occuring in the setting of parkinsonism. Though FDA approval is lacking for some of these indications, expert experiences have shown that BoNT is often beneficial in this group of patients.
Topics: United States; Humans; Botulinum Toxins; Parkinson Disease; Parkinsonian Disorders; Tremor; Dystonic Disorders; Botulinum Toxins, Type A
PubMed: 38056063
DOI: 10.1016/j.jns.2023.122810 -
Aesthetic Surgery Journal Aug 2023In aesthetic clinical practice, botulinum toxin type A (BoNT-A) is best known for its use as a neuromodulator for the treatment of dynamic facial lines; however, when...
Microtoxin for Improving Pore Size, Skin Laxity, Sebum Control, and Scars: A Roundtable on Integrating Intradermal Botulinum Toxin Type A Microdoses Into Clinical Practice.
BACKGROUND
In aesthetic clinical practice, botulinum toxin type A (BoNT-A) is best known for its use as a neuromodulator for the treatment of dynamic facial lines; however, when injected intradermally as microdroplets, BoNT-A can improve skin quality and overall skin appearance.
OBJECTIVES
To discuss key aspects of microtoxin use in clinical practice and provide expert guidance on utilization.
METHODS
As part of a continuing medical education lecture series and roundtable, the authors discussed key aspects of microtoxin patient selection, injection technique, and safety.
RESULTS
The experiences of expert faculty are shared here. Clinical experience is consistent with reported data. Microtoxin can be used to reduce pore size, sebum production, rosacea, acne, and fine lines, and to improve jawline and neck definition. Intradermal injection can also be employed for the improvement of transverse neck lines as well as for the safe prevention and management of scars and keloids.
CONCLUSIONS
Expanding the use of BoNT-A, a predictable, minimally invasive, and affordable treatment to address commonly encountered complaints is appealing. The authors have found that making patients aware of microtoxin as a treatment option results in an increased interest in and utilization of BoNT-A, and high satisfaction among appropriately selected patients.
Topics: Humans; Botulinum Toxins, Type A; Sebum; Skin; Injections, Intradermal; Keloid
PubMed: 36857534
DOI: 10.1093/asj/sjad044