AMPD2 regulates GTP synthesis and is mutated in a potentially treatable neurodegenerative brainstem disorder.

Purine biosynthesis and metabolism, conserved in all living organisms, is essential for cellular energy homeostasis and nucleic acid synthesis. The de novo synthesis of purine precursors is under tight negative feedback regulation mediated by adenosine and guanine nucleotides. We describe a distinct early-onset neurodegenerative condition resulting from mutations in the adenosine monophosphate deaminase 2 gene (AMPD2). Patients have characteristic brain imaging features of pontocerebellar hypoplasia (PCH) due to loss of brainstem and cerebellar parenchyma. We found that AMPD2 plays an evolutionary conserved role in the maintenance of cellular guanine nucleotide pools by regulating the feedback inhibition of adenosine derivatives on de novo purine synthesis. AMPD2 deficiency results in defective GTP-dependent initiation of protein translation, which can be rescued by administration of purine precursors. These data suggest AMPD2-related PCH as a potentially treatable early-onset neurodegenerative disease.

Aortic Dissection and a Previously Unreported ACTA2 Missense Variant Mutation in a Young Patient: A Case Report.

Hereditary connective tissue disease is known to cause aortic lesions at an early age. Familial aortic aneurysm/dissection is caused due to an ACTA2 mutation that affects smooth muscle structure. We present a case of a 15-year-old boy with a mild developmental disorder in whom no abnormalities were identified on previous physical examinations. The patient presented with severe left heart failure, extensive dissection from the ascending aorta to the common iliac artery, and myocardial and cerebral infarctions. He underwent an urgent Bentall surgery. Six months later, the patient underwent surgical reconstruction of the abdominal aorta from the aortic arch and returned to normal daily activities. Pathological examination demonstrated the absence of elastic fibers but presence of abundant reticular fibers and mucopolysaccharides from the tunica intima to the media. Genetic testing revealed a heterozygous missense variant of the ACTA2 gene. To the best of our knowledge, this is the first sporadic case of structurally abnormal smooth muscle organization resulting in clinical symptoms with no previously reported pathogenicity.

Clinical and molecular features of 66 patients with musculocontractural Ehlers-Danlos syndrome caused by pathogenic variants in CHST14 (mcEDS-CHST14).

BACKGROUND: Musculocontractural Ehlers-Danlos syndrome is caused by biallelic loss-of-function variants in CHST14 (mcEDS-CHST14) or DSE (mcEDS-DSE). Although 48 patients in 33 families with mcEDS-CHST14 have been reported, the spectrum of pathogenic variants, accurate prevalence of various manifestations and detailed natural history have not been systematically investigated. METHODS: We collected detailed and comprehensive clinical and molecular information regarding previously reported and newly identified patients with mcEDS-CHST14 through international collaborations. RESULTS: Sixty-six patients in 48 families (33 males/females; 0-59 years), including 18 newly reported patients, were evaluated. Japanese was the predominant ethnicity (27 families), associated with three recurrent variants. No apparent genotype-phenotype correlation was noted. Specific craniofacial (large fontanelle with delayed closure, downslanting palpebral fissures and hypertelorism), skeletal (characteristic finger morphologies, joint hypermobility, multiple congenital contractures, progressive talipes deformities and recurrent joint dislocation), cutaneous (hyperextensibility, fine/acrogeria-like/wrinkling palmar creases and bruisability) and ocular (refractive errors) features were observed in most patients (>90%). Large subcutaneous haematomas, constipation, cryptorchidism, hypotonia and motor developmental delay were also common (>80%). Median ages at the initial episode of dislocation or large subcutaneous haematoma were both 6 years. Nine patients died; their median age was 12 years. Several features, including joint and skin characteristics (hypermobility/extensibility and fragility), were significantly more frequent in patients with mcEDS-CHST14 than in eight reported patients with mcEDS-DSE. CONCLUSION: This first international collaborative study of mcEDS-CHST14 demonstrated that the subtype represents a multisystem disorder with unique set of clinical phenotypes consisting of multiple malformations and progressive fragility-related manifestations; these require lifelong, multidisciplinary healthcare approaches.

Nonsurgical treatment of cerebral ischemia associated with ACTA2 cerebral arteriopathy: a case report and literature review.

Mutations in ACTA2 gene can lead to multisystemic smooth muscle dysfunction, including cerebrovascular disease. Treatment strategies for this rare entity remain controversial, and patients are at increasing risk of neurological sequelae. We herein present the case of an 11-year-old boy previously diagnosed with an ACTA2 gene mutation who developed repetitive transient ischemic attacks and treated with bosentan, an oral endothelin receptor antagonist. Magnetic resonance imaging revealed bilateral, periventricular white matter T2 hyperintensities, and magnetic resonance angiography identified several abnormalities including fusiform dilatation in the proximal segments of internal cerebral arteries, together with followed by terminal segmental stenosis. The distal branches showed a markedly straightened course with no increase in lenticulostriate collaterals. Magnetic resonance imaging also revealed an increase in the number and size of large periventricular white matter lesions located in the left frontal lobe with the progression of ischemic symptoms. Instead of revascularization surgery, the administration of bosentan was started due to the high risk of perioperative ischemic sequelae. After bosentan initiation, the patient's repetitive episodes of cerebral ischemia ceased, and there has been no increase in the number of white matter lesions for 7 years. Bosentan might be beneficial for treating cerebral ischemia associated with ACTA2 cerebral arteriopathy by maintaining the dilatation of stenotic vessels and adequate systemic blood flow and should be considered before performing revascularization surgery.

Aortic dissection during pregnancy and puerperium: A Japanese nationwide survey.

AIM: This study aimed to characterize the incidence and clinical significance of pregnancy-related aortic dissection using a large-scale survey in Japan. METHODS: A questionnaire requesting the detailed information included in the clinical charts of pregnancy-related aortic dissection cases (without any personally identifying information) was designed between 2013 and 2017 and administered to 407 perinatal centers in Japan. The response rate was 70.5%. Seventeen cases of pregnancy-related aortic dissection were identified. RESULTS: Maternal death due to aortic dissection was observed in nine patients (56.2%) while seven survived (43.8%). Dissection occurred during the postpartum period in 10 cases (62.5%), the third trimester in 4 (25.0%), labor in 1 (6.2%), and the second trimester in 1 (6.2%). The most common underlying diseases were: Marfan syndrome (25.0%), Loeys-Dietz syndrome (6.2%), hypertension (6.2%), and Takayasu aortitis (6.2%). Stanford type A aortic dissection was associated with maternal death during both pregnancy and the postpartum period. However, deceased patients showed lower rates of pre-diagnosed connective tissue disease than did survivors. CONCLUSIONS: The mortality rate of aortic dissection that occurred during pregnancy or postnatal periods was more than 50%. Aortic dissection occurred more frequently in the postnatal period than during pregnancy, and less frequently in women previously diagnosed with connective tissue disease than in women without any medical history of aortic disorders. If symptoms suggestive of aortic dissection, such as severe back pain, are observed, even after the end of pregnancy, exhaustive diagnostic examinations should be carried out.

A Nonsense SMAD3 Mutation in a Girl with Familial Thoracic Aortic Aneurysm and Dissection without Joint Abnormality.

INTRODUCTION: Thoracic aortic aneurysms and dissections (TAAD) are rare in children and often associated with underlying genetic disorders accompanied with other systemic manifestations, including connective or osteo-articular tissue diseases. CASE PRESENTATION: We report the case of a 10-year-old girl with a novel nonsense SMAD3 mutation, p.Glu102X, who presented with familial TAAD without any signs of osteoarthritis. Histological analysis of aorta fragments from the patient with TAAD obtained during surgery revealed elastin degradation and inflammatory infiltration of T cells with dense CD31 + microvessels, which is consistent with previous findings. Interestingly, the family members with the SMAD3 mutation developed IgA nephropathy. CONCLUSION: Because the TGF-ß/Smad signalling pathway plays an important role in the primary pathogenesis of IgA nephropathy and TAAD, we presume that IgA nephropathy could be a novel clinical phenotype of SMAD3 deficiency. Further accumulation of genetically proven cases with SMAD3 deficiency is needed to more accurately characterize phenotypic variability and elucidate a wide spectrum of TGF-ß-associated disorders.

A mutation update on the LDS-associated genes TGFB2/3 and SMAD2/3.

The Loeys-Dietz syndrome (LDS) is a connective tissue disorder affecting the cardiovascular, skeletal, and ocular system. Most typically, LDS patients present with aortic aneurysms and arterial tortuosity, hypertelorism, and bifid/broad uvula or cleft palate. Initially, mutations in transforming growth factor-ß (TGF-ß) receptors (TGFBR1 and TGFBR2) were described to cause LDS, hereby leading to impaired TGF-ß signaling. More recently, TGF-ß ligands, TGFB2 and TGFB3, as well as intracellular downstream effectors of the TGF-ß pathway, SMAD2 and SMAD3, were shown to be involved in LDS. This emphasizes the role of disturbed TGF-ß signaling in LDS pathogenesis. Since most literature so far has focused on TGFBR1/2, we provide a comprehensive review on the known and some novel TGFB2/3 and SMAD2/3 mutations. For TGFB2 and SMAD3, the clinical manifestations, both of the patients previously described in the literature and our newly reported patients, are summarized in detail. This clearly indicates that LDS concerns a disorder with a broad phenotypical spectrum that is still emerging as more patients will be identified. All mutations described here are present in the corresponding Leiden Open Variant Database.

Clinical history and management recommendations of the smooth muscle dysfunction syndrome due to ACTA2 arginine 179 alterations.

PURPOSE: Smooth muscle dysfunction syndrome (SMDS) due to heterozygous ACTA2 arginine 179 alterations is characterized by patent ductus arteriosus, vasculopathy (aneurysm and occlusive lesions), pulmonary arterial hypertension, and other complications in smooth muscle-dependent organs. We sought to define the clinical history of SMDS to develop recommendations for evaluation and management. METHODS: Medical records of 33 patients with SMDS (median age 12 years) were abstracted and analyzed. RESULTS: All patients had congenital mydriasis and related pupillary abnormalities at birth and presented in infancy with a patent ductus arteriosus or aortopulmonary window. Patients had cerebrovascular disease characterized by small vessel disease (hyperintense periventricular white matter lesions; 95%), intracranial artery stenosis (77%), ischemic strokes (27%), and seizures (18%). Twelve (36%) patients had thoracic aortic aneurysm repair or dissection at median age of 14 years and aortic disease was fully penetrant by the age of 25 years. Three (9%) patients had axillary artery aneurysms complicated by thromboembolic episodes. Nine patients died between the ages of 0.5 and 32 years due to aortic, pulmonary, or stroke complications, or unknown causes. CONCLUSION: Based on these data, recommendations are provided for the surveillance and management of SMDS to help prevent early-onset life-threatening complications.

Genetics of hereditary large vessel diseases.

Recent progress in the study of hereditary large vessel diseases such as Marfan syndrome (MFS) have not only identified responsible genes but also provided better understanding of the pathophysiology and revealed possible new therapeutic targets. Genes identified for these diseases include FBN1, TGFBR1, TGFBR2, SMAD3, TGFB2, TGFB3, SKI, EFEMP2, COL3A1, FLNA, ACTA2, MYH11, MYLK and SLC2A10, as well as others. Their dysfunction disrupts the function of transforming growth factor-ß (TGF-ß) signaling pathways, as well as that of the extracellular matrix and smooth muscle contractile apparatus, resulting in progression of structural damage to large vessels, including aortic aneurysms and dissections. Notably, it has been shown that the TGF-ß signaling pathway has a key role in the pathogenesis of MFS and related disorders, which may be important for development of strategies for medical and surgical treatment of thoracic aortic aneurysms and dissections.

Genetic mutation analysis in Japanese patients with non-syndromic congenital heart disease.

Congenital heart disease (CHD) is the most common birth defect occurring in humans and some transcriptional factors have been identified as causative. However, additional mutation analysis of these genes is necessary to develop effective diagnostic and medical treatment methods. We conducted sequence analysis of the coding regions of NKX2.5, GATA4, TBX1, TBX5, TBX20, CFC1 and ZIC3 in 111 Japanese patients with non-syndromic CHD and 9 of their relatives. All patient samples were also analyzed by multiplex ligation-dependent probe amplification using probes involved in chromosome deletion related to CHD. Five novel variations of TBX5, GATA4 and TBX20 were detected in 6 of the patients, whereas none were found in 200 controls. The TBX5 variation p.Pro108Thr, located in the T-box domain, was identified in a patient with tricuspid atresia, an exon-intron boundary variation of GATA4 (IVS4+5G>A) was detected in a Tetralogy of Fallot patient and an 8p23 microdeletion was detected in one patient with atrioventricular septal defect and psychomotor delay. A total of seven non-synonymous polymorphisms were found in the patients and controls. Accumulation of novel variations of genes involving the cardiac development may be required for better understanding of CHD.

Moyamoya disease and artery tortuosity as rare phenotypes in a patient with an elastin mutation.

Sporadic and familial elastin mutations can occur in large vessel stenosis such as supravalvular aortic stenosis and narrowing of the descending aorta. However, there are very few reports regarding the arteriopathy of cerebral, pulmonary or abdominal arteries in elastin mutations. We herein report the case of a Japanese female patient presenting with multiple arteriopathy including moyamoya disease, a tortuosity of abdominal arteries and pulmonary hypertension due to peripheral pulmonary artery stenosis. This case suggests the possible progression of cerebral arteriopathy including moyamoya disease in patients with elastin mutations. © 2016 Wiley Periodicals, Inc.

Reversible cerebral vasoconstriction syndrome and posterior reversible encephalopathy syndrome in a boy with Loeys-Dietz syndrome.

Loeys-Dietz syndrome (LDS) is an autosomal dominant connective tissue disorder, caused by heterozygous mutations in TGFBR1 or TGFBR2 and characterized by vascular complications (cerebral, thoracic, and abdominal arterial aneurysms and/or dissections) and skeletal manifestations. We here report the first patient with LDS presenting with reversible cerebral vasoconstriction syndrome (RCVS), a clinico-radiological condition characterized by recurrent thunderclap headaches, with or without neurological symptoms, and reversible vasoconstriction of cerebral arteries. The patient was a 9-year-old boy with a heterozygous TGFBR2 mutation, manifesting camptodactyly, talipes equinovarus, and lamboid craniosynostosis. He complained of severe recurrent headaches 2 months after total aortic replacement for aortic root dilatation and a massive Stanford type B aortic dissection. A thoracic CT scan revealed a left subclavian artery dissection. Brain MRI and MRA detected bilateral internal carotid artery constriction along with a cortical subarachnoid hemorrhage without intracranial aneurysms. Subsequently, he developed visual disturbance and a generalized seizure associated with multiple legions of cortical and subcortical increased signals including the left posterior lobe, consistent with posterior reversible encephalopathy syndrome (PRES), a condition characterized by headaches, visual disorders, seizures, altered mentation, consciousness disturbances, focal neurological signs, and vasogenic edema predominantly in the white matter of the posterior lobe. Vasoconstriction of the internal carotid artery was undetectable 2 months later, and he was diagnosed as having RCVS. Endothelial dysfunction, associated with impaired TGF-ß signaling, might have been attributable to the development of RCVS and PRES.

AMPD1 regulates mTORC1-p70 S6 kinase axis in the control of insulin sensitivity in skeletal muscle.

BACKGROUND: Insulin resistance triggered by excess fat is a key pathogenic factor that promotes type 2 diabetes. Understanding molecular mechanisms of insulin resistance may lead to the identification of a novel therapeutic target for type 2 diabetes. AMPD1, an isoform of AMP deaminase (AMPD), is suggested to play roles in the regulation of glucose metabolism through controlling AMP-activated protein kinase (AMPK) activation. We reported that the diet-induced insulin resistance was improved in AMPD1-deficient mice compared to wild type mice. To further delineate this observation, we studied changes of insulin signaling in skeletal muscle of wild type (WT) and AMPD1-deficient mice. METHODS: Phosphorylation levels of kinases and expression levels of mTOR components were quantified by immunoblotting using protein extracts from tissues. The interaction between mTOR and Raptor was determined by immunoblotting of mTOR immunoprecipitates with anti-Raptor antibody. Gene expression was studied by quantitative PCR using RNA extracted from tissues. RESULTS: Phosphorylation levels of AMPK, Akt and p70 S6 kinase in skeletal muscle were higher in AMPD1-deficient mice compared to WT mice after high fat diet challenge, while they did not show such difference in normal chow diet. Also, no significant changes in phosphorylation levels of AMPK, Akt or p70 S6 kinase were observed in liver and white adipose tissue between WT and AMPD1-deficient mice. The expression levels of mTOR, Raptor and Rictor tended to be increased by AMPD1 deficiency compared to WT after high fat diet challenge. AMPD1 deficiency increased Raptor-bound mTOR in skeletal muscle compared to WT after high fat diet challenge. Gene expression of peroxisome proliferator-activated receptor-γ coactivator 1α and ß, downstream targets of p70 S6 kinase, in skeletal muscles was not changed significantly by AMPD1 deficiency compared to the wild type after high fat diet challenge. CONCLUSION: These data suggest that AMPD1 deficiency activates AMPK/Akt/mTORC1/p70 S6 kinase axis in skeletal muscle after high fat diet challenge, but not in normal chow diet. These changes may contribute to improve insulin resistance.

Hereditary hemorrhagic telangiectasia in Japanese patients.

To describe clinical presentations of hereditary hemorrhagic telangiectasia (HHT) patients in Japan. There were 80 patients (40 men and 40 women, age 2-78, mean 39.4 years old), who were either genetically verified or genetically not identifiable but clinically definite HHT patients. Clinical presentations of these HHT patients were analyzed retrospectively. Radiological examinations, which included at least brain magnetic resonance imaging and lung computed tomography, were performed when indicated. Seventy-eight patients had either endoglin (ENG) or activin A receptor type II-like 1 (ACVRL1) mutation. They were 53 HHT1 patients with ENG mutation in 27 families and 25 HHT2 patients with ACVRL1 mutation in 17 families. Two other female patients were clinically definite HHT, but genetic mutation could not be identified. Nosebleeds were noted in 53/53 (100%) HHT1 and 24/25 (96%) HHT2 patients. Telangiectases were observed in 34/53 (64%) HHT1 and 18/25 (72%) HHT2 patients. Pulmonary arteriovenous malformations (AVMs) were noted in 33/52 HHT1 (63%) and 5/25 HHT2 patients (20%). Brain AVMs were detected in 12/51 HHT1 (24%) and 1/25 HHT2 (4%) patients. Hepatic AVMs were noted in 7/29 (24%) HHT1 and 16/20 (80%) HHT2 patients. The number of HHT1 patients was roughly twice as many as that of HHT2 patients in Japan. Pulmonary and brain AVMs were predominantly observed in HHT1 while hepatic AVMs were detected in HHT2. It seemed that ethnicity and regionality had minimal roles in the clinical presentation of HHT.

AMPD1: a novel therapeutic target for reversing insulin resistance.

BACKGROUND: Insulin resistance is one of the hallmark manifestations of obesity and Type II diabetes and reversal of this pathogenic abnormality is an attractive target for new therapies for Type II diabetes. A recent report that metformin, a drug known to reverse insulin resistance, demonstrated in vitro the metformin can inhibit AMP deaminase (AMPD) activity. Skeletal muscle is one of the primary organs contributing to insulin resistance and that the AMPD1 gene is selectively expressed at high levels in skeletal muscle. METHODS: Recognizing the background above, we asked if genetic disruption of the AMPD1 gene might ameliorate the manifestations of insulin resistance. AMPD1 deficient homozygous mice and control mice fed normal chow diet or a high-fat diet, and blood analysis, glucose tolerance test and insulin tolerance test were performed. Also, skeletal muscle metabolism and gene expression including nucleotide levels and activation of AMP activated protein kinase (AMP kinase) were evaluated in both conditions. RESULTS: Disruption of the AMPD1 gene leads to a less severe state of insulin resistance, improved glucose tolerance and enhanced insulin clearance in mice fed a high fat diet. Given the central role of AMP kinase in insulin action, and its response to changes in AMP concentrations in the cell, we examined the skeletal muscle of the AMPD1 deficient mice and found that they have greater AMP kinase activity as evidenced by higher levels of phosphorylated AMP kinase. CONCLUSIONS: Taken together these data suggest that AMPD may be a new drug target for the reversal of insulin resistance and the treatment of Type II diabetes.

Postoperative mitral leaflet rupture in an infant with Loeys-Dietz syndrome.

This report describes an infantile case of Loeys-Dietz syndrome (LDS) with spontaneous mitral leaflet rupture. The patient was diagnosed with a type B interruption of the aortic arch. Bilateral pulmonary artery banding was performed 5 days after birth. On the 53rd day, intra-cardiac repair was performed without valvuloplasty. Although the operation was successful, mitral regurgitation deteriorated at 4 weeks after operation. On the 88th day, a mitral valvuloplasty was performed and a severely ruptured anterior leaflet was observed. Seven days after valvuloplasty, the mitral valve insufficiency again worsened and a fourth operation was performed. Two tears were observed in the anterior and posterior mitral valve leaflets, and a mitral valve replacement was required. Subsequently, the patient was diagnosed with LDS according to gene mutational status. LDS is known to have a poor prognosis with cardiovascular complications, but valve rupture has not been previously reported in other cases.

Hereditary Aortic Aneurysms and Dissections: Clinical Diagnosis and Genetic Testing.

Hereditary aortic aneurysms and dissections, such as Marfan syndrome, differ in that they occur in younger patients without generally recognized risk factors, have a predilection for the thoracic rather than the abdominal aorta, and are at risk for dissection even at smaller aortic diameters. Early diagnosis, careful follow-up, and early intervention, such as medication to reduce aortic root growth and prophylactic aortic replacement to prevent fatal aortic dissection, are essential for a better prognosis. Molecular genetic testing is extremely useful for early diagnosis. However, in actual clinical practice, the question often arises as to when and to which patient genetic testing should be offered since the outcome of the tests can have important implications for the patient and the relatives. Pre- and post-test genetic counseling is essential for early intervention to be effective. (This article is a secondary translation of Jpn J Vasc Surg 2023; 32: 261-267.).

Association between parental decisions regarding abortion and severity of fetal heart disease.

The prenatal diagnosis of fetal heart disease potentially influences parental decision-making regarding pregnancy termination. Existing literature indicates that the severity, whether in complexity or lethality, significantly influences parental decisions concerning abortion. However, questions remain as to how fetal heart disease severity impacts parental decisions, given recent advancements in postsurgical outcomes. Therefore, we investigated risk factors associated with parents' decision-making regarding abortion following a prenatal diagnosis of fetal heart disease. Our analysis included 73 (terminated: n = 37; continued: n = 36) pregnancies with a fetal heart disease diagnosed before 22 weeks of gestation. Increased gestational age at diagnosis reduced the likelihood of parents' decision on termination (Model 1: adjusted odds ratio, 0.94; 95% confidence interval 0.89-0.99; Model 2: 0.95 0.90-0.997). Critical disease (5.25; 1.09-25.19) and concurrent extracardiac or genetic abnormalities (Model 1: 4.19, 1.21-14.53; Model 2: 5.47, 1.50-19.96) increased the likelihood of choosing abortion. Notably, complex disease did not significantly influence parental decisions (0.56; 0.14-2.20). These results suggest that parental decision-making regarding abortion may be influenced by earlier gestational age at diagnosis, the lethality of heart disease, and extracardiac or genetic abnormalities, but not its complexity if prenatal diagnosis and parental counseling are provided at a cardiovascular-specialized facility.

AMP deaminase 3 plays a critical role in remote reperfusion lung injury.

Remote reperfusion lung injury following skeletal muscle ischemia and reperfusion accounts for high morbidity and mortality. AMP deaminase (AMPD), a key enzyme for nucleotide cycle, has been implicated in the regulation of this phenomenon. However, the function of Ampd2 and Ampd3 subtype has not been elucidated in remote reperfusion rodent lung injury. We utilized AMPD3 and AMPD2-deficient mice. The two types of AMPD-deficient mice and wild-type (WT) littermates were subjected to ischemia-reperfusion injury. After 3h bilateral hind-limb ischemia and reperfusion, AMPD3 mRNA, AMPD activity and inosine monophosphate (IMP) increased significantly in WT and AMPD2-deficient mice lungs, while they did not show significant alterations in AMPD3-deficient mice lungs. Genetic inactivation of Ampd3 resulted in markedly accelerated myeloperoxidase (MPO) activity along with exaggerated neutrophils infiltration and hemorrhage in the lungs compared to WT and AMPD2-deficient mice, furthermore, IMP treatment significantly attenuated MPO activity and neutrophils infiltration in WT and the two types of AMPD-deficient mice lungs after 3h reperfusion. These findings demonstrate for the first time in AMP-deficient mice models that AMPD3 plays a critical role in remote reperfusion lung injury via generation of IMP and validate the potential to use IMP into the clinical arena to attenuate remote ischemia-reperfusion lung injury.