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PloS One 2022In Duchenne muscular dystrophy (DMD), a lack of functional dystrophin leads to myofiber instability and progressive muscle damage that results in fibrosis. While...
In Duchenne muscular dystrophy (DMD), a lack of functional dystrophin leads to myofiber instability and progressive muscle damage that results in fibrosis. While fibrosis is primarily characterized by an accumulation of extracellular matrix (ECM) components, there are changes in ECM architecture during fibrosis that relate more closely to functional muscle stiffness. One of these architectural changes in dystrophic muscle is collagen cross-linking, which has been shown to increase the passive muscle stiffness in models of fibrosis including the mdx mouse, a model of DMD. We tested whether the intraperitoneal injections of beta-aminopropionitrile (BAPN), an inhibitor of the cross-linking enzyme lysyl oxidase, would reduce collagen cross-linking and passive stiffness in young and adult mdx mice compared to saline-injected controls. We found no significant differences between BAPN treated and saline treated mice in collagen cross-linking and stiffness parameters. However, we observed that while collagen cross-linking and passive stiffness scaled positively in dystrophic muscles, collagen fiber alignment scaled with passive stiffness distinctly between muscles. We also observed that the dystrophic diaphragm showed the most dramatic fibrosis in terms of collagen content, cross-linking, and stiffness. Overall, we show that while BAPN was not effective at reducing collagen cross-linking, the positive association between collagen cross-linking and stiffness in dystrophic muscles still show cross-linking as a viable target for reducing passive muscle stiffness in DMD or other fibrotic muscle conditions.
Topics: Animals; Mice; Aminopropionitrile; Collagen; Disease Models, Animal; Fibrosis; Mice, Inbred mdx; Muscle, Skeletal; Muscular Dystrophy, Duchenne; Protein-Lysine 6-Oxidase
PubMed: 36302059
DOI: 10.1371/journal.pone.0271776 -
Cells Oct 2022Aortic dissection (AD) is a lethal aortic pathology without effective medical treatments since the underlying pathological mechanisms responsible for AD remain elusive....
Aortic dissection (AD) is a lethal aortic pathology without effective medical treatments since the underlying pathological mechanisms responsible for AD remain elusive. Matrix metalloproteinase-8 (MMP8) has been previously identified as a key player in atherosclerosis and arterial remodeling. However, the functional role of MMP8 in AD remains largely unknown. Here, we report that an increased level of MMP8 was observed in 3-aminopropionitrile fumarate (BAPN)-induced murine AD. AD incidence and aortic elastin fragmentation were markedly reduced in MMP8-knockout mice. Importantly, pharmacologic inhibition of MMP8 significantly reduced the AD incidence and aortic elastin fragmentation. We observed less inflammatory cell accumulation, a lower level of aortic inflammation, and decreased smooth muscle cell (SMC) apoptosis in MMP8-knockout mice. In line with our previous observation that MMP8 cleaves Ang I to generate Ang II, BAPN-treated MMP8-knockout mice had increased levels of Ang I, but decreased levels of Ang II and lower blood pressure. Additionally, we observed a decreased expression level of vascular cell adhesion molecule-1 (VCAM1) and a reduced level of reactive oxygen species (ROS) in MMP8-knockout aortas. Mechanistically, our data show that the Ang II/VCAM1 signal axis is responsible for MMP8-mediated inflammatory cell invasion and transendothelial migration, while MMP8-mediated SMC inflammation and apoptosis are attributed to Ang II/ROS signaling. Finally, we observed higher levels of aortic and serum MMP8 in patients with AD. We therefore provide new insights into the molecular mechanisms underlying AD and identify MMP8 as a potential therapeutic target for this life-threatening aortic disease.
Topics: Animals; Mice; Aminopropionitrile; Aortic Dissection; Angiotensin II; Disease Models, Animal; Elastin; Inflammation; Matrix Metalloproteinase 8; Mice, Knockout; Reactive Oxygen Species; Vascular Cell Adhesion Molecule-1; Humans
PubMed: 36291087
DOI: 10.3390/cells11203218 -
Cardiovascular Therapeutics 2022The nacht domain, leucine-rich repeat, and pyrin domain-containing protein 3 (NLRP3) inflammasome is upregulated in human abdominal aortic aneurysm (AAA), but its...
BACKGROUND AND AIMS
The nacht domain, leucine-rich repeat, and pyrin domain-containing protein 3 (NLRP3) inflammasome is upregulated in human abdominal aortic aneurysm (AAA), but its pathogenic role is unclear. The aims of this study were firstly to examine whether the inflammasome was upregulated in a mouse model of AAA and secondly to test whether the inflammasome inhibitor colchicine limited AAA growth.
METHODS
AAA was induced in eight-week-old male C57BL6/J mice with topical application of elastase to the infrarenal aorta and oral 3-aminopropionitrile (E-BAPN). For aim one, inflammasome activation, abdominal aortic diameter, and rupture were compared between mice with AAA and sham controls. For aim two, 3 weeks after AAA induction, mice were randomly allocated to receive colchicine ( = 28, 0.2 mg/kg/d) or vehicle control ( = 29). The primary outcome was the rate of maximum aortic diameter increase measured by ultrasound over 13 weeks.
RESULTS
There was upregulation of NLRP3 markers interleukin- (IL-) 1 (median, IQR; 15.67, 7.11-22.60 pg/mg protein versus 6.87, 4.54-11.60 pg/mg protein, = .048) and caspase-1 (109, 83-155 relative luminosity units (RLU) versus 45, 38-65 RLU, < .001) in AAA samples compared to controls. Aortic diameter increase over 80 days (mean difference, MD, 4.3 mm, 95% CI 3.3, 5.3, < .001) was significantly greater in mice in which aneurysms were induced compared to sham controls. Colchicine did not significantly limit aortic diameter increase over 80 days (MD -0.1 mm, 95% CI -1.1, 0.86, = .922).
CONCLUSIONS
The inflammasome was activated in this mouse model of AAA; however, daily oral administration of colchicine did not limit AAA growth.
Topics: Animals; Male; Mice; Aminopropionitrile; Aortic Aneurysm, Abdominal; Caspases; Colchicine; Disease Models, Animal; Inflammasomes; Leucine; Mice, Inbred C57BL; NLR Family, Pyrin Domain-Containing 3 Protein; Pancreatic Elastase
PubMed: 36262119
DOI: 10.1155/2022/5299370 -
International Journal of Molecular... Sep 2022The five lysyl-oxidase genes share similar enzymatic activities and contribute to tumor progression. We have knocked out the five lysyl-oxidase genes in MDA-MB-231...
The five lysyl-oxidase genes share similar enzymatic activities and contribute to tumor progression. We have knocked out the five lysyl-oxidase genes in MDA-MB-231 breast cancer cells using CRISPR/Cas9 in order to identify genes that are regulated by LOX but not by other lysyl-oxidases and in order to study such genes in more mechanistic detail in the future. Re-expression of the full-length cDNA encoding LOX identified four genes whose expression was downregulated in the knock-out cells and rescued following LOX re-expression but not re-expression of other lysyl-oxidases. These were the AGR2, STOX2, DNAJB11 and DNAJC3 genes. AGR2 and STOX2 were previously identified as promoters of tumor progression. In addition, we identified several genes that were not downregulated in the knock-out cells but were strongly upregulated following LOX or LOXL3 re-expression. Some of these, such as the DERL3 gene, also promote tumor progression. There was very little proteolytic processing of the re-expressed LOX pro-enzyme in the MDA-MB-231 cells, while in the HEK293 cells, the LOX pro-enzyme was efficiently cleaved. We introduced point mutations into the known BMP-1 and ADAMTS2/14 cleavage sites of LOX. The BMP-1 mutant was secreted but not cleaved, while the LOX double mutant dmutLOX was not cleaved or secreted. However, even in the presence of the irreversible LOX inhibitor β-aminoproprionitrile (BAPN), these point-mutated LOX variants induced the expression of these genes, suggesting that the LOX pro-enzyme has hitherto unrecognized biological functions.
Topics: Amino Acid Oxidoreductases; Aminopropionitrile; DNA, Complementary; HEK293 Cells; Humans; Mucoproteins; Neoplasms; Oncogene Proteins; Protein-Lysine 6-Oxidase
PubMed: 36232621
DOI: 10.3390/ijms231911322 -
BMC Cardiovascular Disorders Oct 2022The incidence and mortality of aortic dissection (AD) are increasing. In pathological studies, macrophages, T lymphocytes and dendritic cells were found in the tunica...
BACKGROUND
The incidence and mortality of aortic dissection (AD) are increasing. In pathological studies, macrophages, T lymphocytes and dendritic cells were found in the tunica media of the aorta. Acetaldehyde dehydrogenase 2 (ALDH) gene polymorphisms are associated with a high incidence of hypertension in Asian populations. However, there is no clear evidence of the relationship between ALDH and aortic dissection in Asians. The aim of this study was to investigate the incidence of aortic dissection in different ALDH genotypes and explore changes in the vasculature.
MATERIALS AND METHODS
Three-week-old male mice were administered freshly prepared β-aminopropionitrile solution dissolved in drinking water (1 g/kg/d) for 28 days to induce TAD. An animal ultrasound imaging system was used to observe the formation of arterial dissection and changes in cardiac function. Subsequently, mice were euthanized by cervical dislocation. The aortas were fixed for HE staining and EVG staining to observe aortic elastic fiber tears and pseudoluma formation under a microscope.
RESULTS
Knockout of ALDH mitigated β-aminopropionitrile-induced TAD formation in animal studies. Ultrasound results showed that ALDH knockout reduced the degree of ascending aortic widening and the incidence of aortic dissection rupture. Pathological sections of multiple aortic segments showed that the protective effect of ALDH knockout was observed in not only the ascending aorta but also the aortic arch and descending aorta. The expression levels of genes related to NK CD56bright cells, Th17 cells, T cells and T helper cells were decreased in ALDH knockout mice treated with β-aminopropionitrile for 28 days.
CONCLUSION
ALDH knockout protects against aortic dissection by altering the inflammatory response and immune response and protecting elastic fibers.
Topics: Aldehyde Dehydrogenase, Mitochondrial; Aminopropionitrile; Aortic Dissection; Animals; Aortic Aneurysm, Thoracic; Aortic Rupture; Disease Models, Animal; Drinking Water; Male; Mice; Mice, Inbred C57BL; Mice, Knockout
PubMed: 36229771
DOI: 10.1186/s12872-022-02874-5 -
Acta Pharmaceutica Sinica. B Sep 2022Recent insights collectively suggest the important roles of lysyl oxidase (LysOX) in the pathological processes of several acute and chronic neurological diseases, but...
Recent insights collectively suggest the important roles of lysyl oxidase (LysOX) in the pathological processes of several acute and chronic neurological diseases, but the molecular regulatory mechanisms remain elusive. Herein, we explore the regulatory role of LysOX in the seizure-induced ferroptotic cell death of neurons. Mechanistically, LysOX promotes ferroptosis-associated lipid peroxidation in neurons activating extracellular regulated protein kinase (ERK)-dependent 5-lipoxygenase (Alox5) signaling. In addition, overexpression of LysOX adeno-associated viral vector (AAV)-based gene transfer enhances ferroptosis sensitivity and aggravates seizure-induced hippocampal damage. Our studies show that pharmacological inhibition of LysOX with -aminopropionitrile (BAPN) significantly blocks seizure-induced ferroptosis and thereby alleviates neuronal damage, while the BAPN-associated cardiotoxicity and neurotoxicity could further be reduced through encapsulation with bioresponsive amorphous calcium carbonate-based nanocarriers. These findings unveil a previously unrecognized LysOX-ERK-Alox5 pathway for ferroptosis regulation during seizure-induced neuronal damage. Suppressing this pathway may yield therapeutic implications for restoring seizure-induced neuronal injury.
PubMed: 36176900
DOI: 10.1016/j.apsb.2022.04.017 -
Cureus Aug 2022Lathyriasis or lathyrism is a form of upper motor neuron disease caused by the dietary intake of grass pea (). It is an irreversible crippling disease with poor...
Lathyriasis or lathyrism is a form of upper motor neuron disease caused by the dietary intake of grass pea (). It is an irreversible crippling disease with poor outcomes. The possible pathogenesis is attributed to a toxin present in the legume, i.e., BOAA (beta-n-oxalyl amino L-alanine). Lathyrism can also be associated with vascular involvement resulting in angiolathyrism, which is mediated by a toxin β-aminopropionitrile, and bony involvement resulting in osteolathyrism characterized by bone growth impairment. A 12-year-old male child presented to us with chronic myalgia and a gradual decline in the power in the bilateral lower limbs, both in extension and flexion, followed by an inability to walk. On examination, he had spastic paraparesis with brisk deep tendon reflexes and positive Babinski sign with sustained bilateral ankle clonus suggestive of upper motor neuron lesion. Doppler studies of the bilateral lower limb suggested deep vein thrombosis of the right posterior tibial vein. His electrophysiological studies and neuroimaging were otherwise normal. We found deep vein thrombosis and bony exostosis, which have never been reported in the existing literature. This could be a new form of angiolathyrism and osteolathyrism we are reporting here. A review of dietary history revealed consumption of grass pea over the past few years daily, following which diagnosis of neurolathyrism was considered. A review of the literature does not suggest any specific treatment for this crippling disease and the treatment largely remains supportive. The child was provided vitamin C, gabapentin, and perampanel for neuromuscular pain, and low molecular weight heparin for deep vein thrombosis. Physiotherapy was initiated and surgical excision was planned by the orthopedic team for the exostotic lesion. The diagnosis of lathyrism should strongly be suspected if there is a history of consumption of grass pea. Public health education, improvement in the socio-economic condition, and strict prohibition of the sale and consumption of grass pea can root out the problem of lathyrism.
PubMed: 36108319
DOI: 10.7759/cureus.27720 -
Arteriosclerosis, Thrombosis, and... Oct 2022Cross-linking of lysine residues in elastic and collagen fibers is a vital process in aortic development. Inhibition of lysyl oxidase by BAPN (β-aminopropionitrile)...
BACKGROUND
Cross-linking of lysine residues in elastic and collagen fibers is a vital process in aortic development. Inhibition of lysyl oxidase by BAPN (β-aminopropionitrile) leads to thoracic aortopathies in mice. Although the renin-angiotensin system contributes to several types of thoracic aortopathies, it remains unclear whether inhibition of the renin-angiotensin system protects against aortopathy caused by the impairment of elastic fiber/collagen crosslinking.
METHODS
BAPN (0.5% wt/vol) was started in drinking water to induce aortopathies in male C57BL/6J mice at 4 weeks of age for 4 weeks. Five approaches were used to investigate the impact of the renin-angiotensin system. Bulk RNA sequencing was performed to explore potential molecular mechanisms of BAPN-induced thoracic aortopathies.
RESULTS
Losartan increased plasma renin concentrations significantly, compared with vehicle-infused mice, indicating effective angiotensin II type 1 receptor inhibition. However, losartan did not suppress BAPN-induced aortic rupture and dilatation. Since losartan is a surmountable inhibitor of the renin-angiotensin system, irbesartan, an insurmountable inhibitor, was also tested. Although increased plasma renin concentrations indicated effective inhibition, irbesartan did not ameliorate aortic rupture and dilatation in BAPN-administered mice. Thus, BAPN-induced thoracic aortopathies were refractory to angiotensin II type 1 receptor blockade. Next, we inhibited angiotensin II production by pharmacological or genetic depletion of AGT (angiotensinogen), the unique precursor of angiotensin II. However, neither suppressed BAPN-induced thoracic aortic rupture and dilatation. Aortic RNA sequencing revealed molecular changes during BAPN administration that were distinct from other types of aortopathies in which angiotensin II type 1 receptor inhibition protects against aneurysm formation.
CONCLUSIONS
Inhibition of either angiotensin II action or production of the renin-angiotensin system does not attenuate BAPN-induced thoracic aortopathies in mice.
Topics: Aminopropionitrile; Angiotensin II; Angiotensinogen; Animals; Aortic Aneurysm, Thoracic; Aortic Rupture; Dilatation, Pathologic; Disease Models, Animal; Irbesartan; Losartan; Lysine; Male; Mice; Mice, Inbred C57BL; Protein-Lysine 6-Oxidase; Receptor, Angiotensin, Type 1; Renin; Renin-Angiotensin System
PubMed: 36004642
DOI: 10.1161/ATVBAHA.122.317712 -
International Journal of Biological... 2022A variety of programmed cell death types have been shown to participate in the loss of smooth muscle cells (SMCs) during the development of aortic dissection (AD), but...
A variety of programmed cell death types have been shown to participate in the loss of smooth muscle cells (SMCs) during the development of aortic dissection (AD), but it is still largely unclear whether ferroptosis is involved in the development of AD. In the present study, we found that the expression of key ferroptosis regulatory proteins, solute carrier family 7 member 11 (SLC7A11), ferroptosis suppressor protein 1 (FSP1) and glutathione peroxidase 4 (GPX4) were downregulated in aortas of Stanford type A AD (TAAD) patients, and liproxstatin-1, a specific inhibitor of ferroptosis, obviously abolished the β-aminopropionitrile (BAPN)-induced development and rupture of AD in mice. Furthermore, the expression of methyltransferase-like 3 (METTL3), a major methyltransferase of RNA mA, was remarkably upregulated in the aortas of TAAD patients, and the protein levels of METTL3 were negatively correlated with SLC7A11 and FSP1 levels in human aortas. Overexpression of METTL3 in human aortic SMCs (HASMCs) inhibited, while METTL3 knockdown promoted SLC7A11 and FSP1 expression. More importantly, overexpression of METTL3 facilitated imidazole ketone erastin- and cystine deprivation-induced ferroptosis, while knockdown of METTL3 repressed ferroptosis of HASMCs. Overexpression of either SLC7A11 or FSP1 largely abrogated the effect of METTL3 on HASMC ferroptosis. Therefore, we have revealed that ferroptosis is a critical cause of AD in both humans and mice and that METTL3 promotes ferroptosis of HASMCs by inhibiting the expression of SLC7A11 and FSP1. Thus, targeting ferroptosis or mA RNA methylation is a potential novel strategy for the treatment of AD.
Topics: Aortic Dissection; Animals; Ferroptosis; Humans; Methyltransferases; Mice; Myocytes, Smooth Muscle; RNA
PubMed: 35844806
DOI: 10.7150/ijbs.72528 -
Translational Andrology and Urology May 2022The mechanisms of the microenergy acoustic pulse (MAP) therapy on restoring structure and function of pelvic floor muscles (PFM) after simulated birth injury are not...
BACKGROUND
The mechanisms of the microenergy acoustic pulse (MAP) therapy on restoring structure and function of pelvic floor muscles (PFM) after simulated birth injury are not well understood.
METHODS
A total 24 female Sprague-Dawley rats were randomly grouped into sham control (sham), vaginal balloon dilation and ovariectomy (VBDO), VBDO + β-aminopropionitrile (BAPN, an irreversible LOX inhibitor), and VBDO + BAPN and treated with MAP (n=6 in each group). The MAP therapy was administered 2 times per week for 4 weeks with 1-week washout, the functional and histological studies were conducted in all 24 rats. The viscoelastic behavior of the PFM, including iliococcygeus (IC) and pubococcygeus (PC), was examined with a biomechanical assay. The structure of the PFM was assessed by immunofluorescence and Masson's trichrome staining.
RESULTS
The leak point pressure (LPP) assay demonstrated that the MAP therapy group had higher LPPs compared to that of VBDO and BAPN groups. In the sham group, the muscular stiffness (K) of IC muscle was significantly higher than that of PC muscle while the pelvic floor muscle rebound activity (MRA) of PC muscle was stronger than that of IC muscle (291.26±45.33 and 241.18±14.23 N/cm, respectively). Both VBDO and BAPN decreased the MRA and increased the K in both IC and PC. Histologic examination revealed increased fibrous tissue (collagen) and degeneration of muscle fibers in both VBDO and BAPN groups. MAP therapy significantly reduced the collagen content and improved the architecture of muscle fibers.
CONCLUSIONS
MAP appears to restore the structure and function of PFM by regenerating muscular fibers and improving biomechanical properties in an animal model of simulated birth injury.
PubMed: 35693721
DOI: 10.21037/tau-22-30