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1.
Front Vet Sci ; 11: 1398961, 2024.
Article in English | MEDLINE | ID: mdl-38978631

ABSTRACT

The present study evaluated the effects of omega-3 (ω-3) fatty acid-rich linseed supplementation on the reproductive performance, endocrine profile, and biochemical profile of ewes reared in subtropical climates. Forty-eight acyclic and clinically healthy Marwari sheep, aged 1.5-2.5 years with no parity, were divided into four groups (n = n = 12 in each). Ewes in the control group (group I) were fed only a basal feed, whereas ewes in the treatment groups II, III, and IV were fed the basal diet along with 10%, 15%, and 20% linseed, respectively, daily on a dry matter basis. The experiment was conducted during the typical breeding season (October-November) of the sheep. The estrus induction rate was significantly higher (p < 0.05) in all treatment groups than in the control group. The estrus induction interval was significantly lower (p < 0.05) in group III. The conception rate in group I was significantly lower (p < 0.05). In addition, ewes in the control group had a significantly lower (p < 0.05) lambing rate than all treatment groups. Serum progesterone concentrations differed significantly (p < 0.05) between the control and the treatment groups on days 15, 30, 45, and 60 of supplementation. On treatment days 15 and 30, the serum estrogen concentrations were significantly higher (p < 0.05) in all treatment groups compared to that in group I. In all treatment groups, monounsaturated fatty acid (MUFA) decreased significantly (p < 0.05), whereas polyunsaturated fatty acid (PUFA) increased significantly (p < 0.05) from day 15 onward. In conclusion, by providing 15% dietary linseed supplementation to ewes, their reproductive performance can be improved in subtropical climates. Future studies are recommended to further elucidate the role of linseed supplementation in sheep reproduction in subtropical climates.

2.
Catheter Cardiovasc Interv ; 103(1): 51-60, 2024 01.
Article in English | MEDLINE | ID: mdl-37994226

ABSTRACT

BACKGROUND: Among the two stent strategies, contemporary evidence favors double kissing crush technique (DKC) for complex unprotected distal left main bifurcation (UdLMB) lesions. However one of the major challenges to these lesions is side branch (SB) restenosis. AIMS: Our aim was to identify optical coherence tomographic (OCT) characteristics that may predict SB restenosis (SBR) after UdLMB angioplasty using DKC technique. METHODS: This was a single-center, retrospective study that included 60 patients with complex UdLMB disease, who underwent OCT-guided angioplasty using DKC technique. Angiographic follow-up was performed in all patients at 1 year to identify patients with SBR. Patients with SBR group were compared with patients without SBR (NSBR group) for OCT parameters during index procedure. RESULTS: Twelve (20%) patients developed SBR at 1-year follow-up. The SBR group had longer SB lesion (18.8 ± 3.2 vs. 15.3 ± 3.7 mm, p = 0.004) and neo-metallic carinal length (2.1 vs. 0.1 mm, p < 0.001) when compared to the NSBR group. Longer neo-metallic carinal length was associated with the absence of the dumbbell sign, presence of hanging stent struts across the SB ostium on OCT of final MB pullback. On multivariate regression analysis, SB distal reference diameter (DRD) and SB stent expansion were identified as independent predictors of SBR with SB-DRD of ≤2.8 mm (area under curve-0.73, sensitivity-83.3%, and specificity-62.5%) and SB stent expansion of ≤89% (area under curve-0.88, sensitivity-83.3%, and specificity- 81.2%) as the best cut off values to predict SBR. CONCLUSIONS: SB DRD and SB stent expansion are the OCT predictors of future SBR after UdLMB angioplasty using DKC technique.


Subject(s)
Angioplasty, Balloon, Coronary , Coronary Artery Disease , Drug-Eluting Stents , Heart Valve Diseases , Humans , Angioplasty, Balloon, Coronary/adverse effects , Angioplasty, Balloon, Coronary/methods , Retrospective Studies , Tomography, Optical Coherence , Treatment Outcome , Coronary Artery Disease/therapy , Coronary Artery Disease/surgery , Stents , Constriction, Pathologic , Coronary Angiography/methods
3.
Catheter Cardiovasc Interv ; 102(3): 495-498, 2023 09.
Article in English | MEDLINE | ID: mdl-37464986

ABSTRACT

A 49-year-old male presented with class III exertional angina, 1 year after angioplasty of the left anterior descending artery (LAD) and right coronary artery. Coronary angiogram revealed 90% in-stent restenosis (ISR) in mid-LAD with angiographic impression of stent fracture. Optical coherence tomographic evaluation of mid-LAD ISR showed a distinct 3 mm long "eclipse sign" indicating embolized, broken guiding catheter tip as a cause of ISR, which was confirmed on reviewing 1-year-old angiographic images. This was managed with "cut and fix technique" using cutting balloon and another drug-eluting stent. Optical coherence tomographic at 9 months showed well endothelialized stent with a thin layer of neo-intimal hyperplasia over the sandwiched broken guiding tip.


Subject(s)
Coronary Restenosis , Drug-Eluting Stents , Male , Humans , Middle Aged , Infant , Drug-Eluting Stents/adverse effects , Treatment Outcome , Stents/adverse effects , Coronary Angiography/adverse effects , Catheters/adverse effects , Coronary Restenosis/etiology , Tomography, Optical Coherence/methods
4.
Med J Armed Forces India ; 78(4): 387-393, 2022 Oct.
Article in English | MEDLINE | ID: mdl-36267505

ABSTRACT

Backrground: Transcatheter aortic valve replacement (TAVR) has become an accepted modality of treatment in intermediate and high surgical risk patients of symptomatic severe calcific aortic stenosis (AS). We herein report Indian data of 84 intermediate and high-risk patients who underwent TAVR at two Armed Forces cardiac centres. Methods: Most of the patients underwent TAVR in cardiac catheterization lab by percutaneous transfemoral approach, under conscious sedation. Patients were followed up and echocardiographic parameters were assessed after six months of procedure. Results: Total of 84 intermediate and high-risk patients underwent TAVR between Jan 2017 and June 2021. Mean age of population was 71.5 ± 8.4 years; 28.5% of patients had bicuspid aortic valve and Mean STS score was 6.34 ± 2.08. Majority (92.8%) patients underwent the procedure under conscious sedation. Self-expanding valves were used in 72.6% and balloon expandable in 27.4% of patients. Predilatation was done in 64% patients while 13% cases underwent post dilatation. Procedural mortality was 2.3%. Rate of permanent pacemaker implantation was 4.9%. Ischemic stroke occurred in 1.1% of patents. There was no case of severe paravalvular leak. Emergency surgical aortic valve replacement was done in 2.4% patients. Procedural success in this study was 97.6%. All-cause mortality was 9.5% at 6 months. Conclusions: TAVR is an effective treatment modality in intermediate and high-risk Indian patients with severe aortic stenosis. Patients with bicuspid or previous bio prosthetic aortic valves also have a good outcome post TAVR.

5.
Med J Armed Forces India ; 78(4): 463-468, 2022 Oct.
Article in English | MEDLINE | ID: mdl-36267507

ABSTRACT

Background: Heart Failure with reduced Ejection Fraction (HFrEF) is a common disorder affecting a large population. Iron deficiency (ID) with and without anaemia is an important variable which is often underreported and under treated in clinical practice, which contributes to patient symptoms. The present study was undertaken to study the prevalence and Spectrum of Iron Deficiency in patients of HFrEF. Methods: This is a single-centre observational study. All patients with a clinical diagnosis of HFrEF presenting to the hospital were studied. Ejection Fraction (EF) was assessed on Echo and ID was diagnosed on basis of serum ferritin <100 micro g/dl or serum ferritin 100-300 micro g/dl with low Transferrin Saturation (TSAT) (< 20%). Results: We have studied a total of 204 patients with a predominantly male population (73%) and a mean age of 62.88 years. Most of our patients were in mid-level functional class (mean 2.48 ± 0.50) and had low EF (mean 29.56 ± 6.52). Out of 204 patients, 88.7% patients had ID with 83% patients having absolute ID. Of the total patients with HF, 70% had anaemia. Amongst those with anaemia 93% had ID, and even without anaemia, 68% had absolute or functional ID, underlying the importance of evaluating iron status in all patients of HF irrespective of their haemoglobin levels. Conclusion: This study highlights the burden of iron deficiency in heart failure patients in the Indian population and opens the way for large scale studies for better characterization of iron deficiency as well as therapeutic trials in the management of heart failure patients.

6.
Thromb Res ; 215: 5-13, 2022 07.
Article in English | MEDLINE | ID: mdl-35580466

ABSTRACT

BACKGROUND: DNA methylation regulates gene expression by inhibiting transcription factor binding to promoter and regulatory regions. Acute hypoxia during altitude exposure is associated with decreased natural anticoagulants and morbid thrombotic events. Thrombomodulin (TM) is a high affinity thrombin binding receptor protein, vital for vascular homeostasis. The purpose of this study is to determine gene expression regulation via methylation of TM gene in high altitude hypoxia induced deep vein thrombosis (DVT) patients. MATERIALS AND RESULTS: Percent 5-methyl cytosine analysis showed increased methylation in high altitude DVT patients (HAP) as compared to high altitude control (HAC) and seal level control (Control) subjects, while TM protein and mRNA levels were decreased in high altitude DVT patients as compared to other two groups. Bisulfite sequencing analysis indicated increased methylation in TM promoter in high altitude DVT patients compared to high altitude controls. Flow cytometry analysis showed decreased TM expression in hypoxia induced primary human umbilical vein endothelial cells (HUVECs). Treatment with specific DNA methyltransferase (DNMT) inhibitor-decitabine during hypoxia, restored TM expression. in vitro global methylation assay showed increased methylation in hypoxia group. Specific concentration of decitabine in hypoxia decreased global methylation showing a direct correlation between DNMTs and methylation. Selective dose of decitabine restored TM levels in HUVECs. DNMT1 and DNMT3B proteins showed to mediate the overall expression of TM. CONCLUSION: TM emerged as a potential candidate for methylation in high altitude DVT patients, regulated by hypoxia-induced epigenetic mechanism. Hypoxia culminates in methylation of DNA sequences in the promoter region of TM gene and increased the expression of DNMT1 and DNMT3B per se in primary HUVECs. Critical DNA methylation events were found to be compromised in high altitude DVT patients.


Subject(s)
DNA Methylation , Thrombomodulin/genetics , Venous Thrombosis , Altitude , Decitabine/administration & dosage , Human Umbilical Vein Endothelial Cells , Humans , Hypoxia/metabolism , Promoter Regions, Genetic , Venous Thrombosis/genetics
8.
Lancet Reg Health Southeast Asia ; 3: 100016, 2022 Aug.
Article in English | MEDLINE | ID: mdl-37384264

ABSTRACT

Background: Previous literature suggests that thrombosis is more common in lowlanders sojourning at high altitude (HA) compared to near-sea-level. Though the pathophysiology is partly understood, little is known of its epidemiology. To elucidate this, an observational prospective longitudinal study was conducted in healthy soldiers sojourning for months at HA. Methods: A total of 960 healthy male subjects were screened in the plains, of which 750 ascended, to altitudes above 15,000ft (4,472m). Clinical examination, haemogram, coagulogram, markers of inflammation and endothelial dysfunction, were studied at three time points during ascent and descent. The diagnosis of thrombosis was confirmed radiologically in all cases where a thrombotic event was suspected clinically. Subjects developing thrombosis at HA were labelled as Index Cases (ICs) and compared to a nested cohort of the healthy subjects (comparison group,(CG)) matched for altitude of stay. Findings: Twelve and three subjects, developed venous (incidence: 5,926/105 person-years) and arterial (incidence: 1,482/105 person-years) thrombosis at HA, respectively. The ICs had enhanced coagulation (FVIIa: p<0.001; FXa: p<0.001) and decreased levels of natural anticoagulants (thrombomodulin, p=0.016; tissue factor pathway inhibitor [TFPI]: p<0.001) and a trend to dampened fibrinolysis (tissue plasminogen activator tPA; p=0.078) compared to CG. ICs also exhibited statistically significant increase in the levels of endothelial dysfunction and inflammation markers (vascular cell adhesion molecule-1[VCAM-1], intercellular adhesion molecule-1 [ICAM-1], vascular endothelial growth factor receptor 3 [VEGFR-3], P-Selectin, CD40 ligand, soluble C-reactive protein and myeloperoxidase: p<0.001). Interpretation: The incidence of thrombosis in healthy subjects at HA was higher than that reported in literature at near sea-level. This was associated with inflammation, endothelial dysfunction, a prothrombotic state and dampened fibrinolysis. Funding: Research grants from the Armed Forces Medical Research Committee, Office of the Director General of Armed Forces Medical Services (DGAFMS) & Defence Research and Development Organization (DRDO), Ministry of Defence, India.

9.
Thromb Haemost ; 121(11): 1497-1511, 2021 11.
Article in English | MEDLINE | ID: mdl-33580494

ABSTRACT

BACKGROUND: The pathophysiology of deep vein thrombosis (DVT) is considered as multifactorial, where thrombus formation is an interplay of genetic and acquired risk factors. Little is known about the expression profile and roles of long noncoding RNAs (lncRNAs) in human subjects developing DVT at high altitude. METHODS: Using RNAseQ, we compared peripheral blood mRNA and lncRNA expression profile in human high-altitude DVT (HA-DVT) patients with high-altitude control subjects. We used DESeq to identify differentially expressed (DE) genes. We annotated the lncRNAs using NONCODE 3.0 database. In silico putative lncRNA-miRNA association study unravels the endogenous miRNA sponge associated with our candidate lncRNAs. These findings were validated by small-interfering RNA (siRNA) knockdown assay of the candidate lncRNAs conducted in primary endothelial cells. RESULTS: We identified 1,524 DE mRNAs and 973 DE lncRNAs. Co-expressed protein-coding gene analysis resulted in a list of 722 co-expressed protein-coding genes with a Pearson correlation coefficients >0.7. The functional annotation of co-expressed genes and putative proteins revealed their involvement in the hypoxia, immune response, and coagulation cascade. Through its miRNA response elements to compete for miR-143 and miR-15, lncRNA-LINC00659 and UXT-AS1 regulate the expression of prothrombotic genes. Furthermore, in vitro RNA interference (siRNA) simultaneously suppressed lncRNAs and target gene mRNA level. CONCLUSION: This transcriptome profile describes novel potential mechanisms of interaction between lncRNAs, the coding genes, miRNAs, and regulatory transcription factors that define the thrombotic signature and may be used in establishing lncRNAs as a biomarker in HA-DVT.


Subject(s)
Altitude , Gene Expression Profiling , RNA, Long Noncoding/genetics , Transcriptome , Venous Thrombosis/genetics , Adult , Cell Hypoxia , Cells, Cultured , Databases, Genetic , Endothelial Cells/metabolism , Gene Regulatory Networks , Humans , Male , MicroRNAs/genetics , MicroRNAs/metabolism , RNA, Long Noncoding/blood , RNA-Seq , Venous Thrombosis/blood , Venous Thrombosis/diagnosis
10.
Blood Adv ; 3(22): 3713-3723, 2019 11 26.
Article in English | MEDLINE | ID: mdl-31765479

ABSTRACT

High-altitude (HA) hypoxia exposure is believed to induce venous thromboembolism (VTE) in otherwise healthy individuals, although this needs to be fully established. The present study aims to ascertain the role of HA exposure in aggravating any predisposition toward VTE and to explore whether the etiology of HA-induced VTE is different from that of VTE closer to sea level. We compared manifestation-matched male VTE patients from HA (HAPs) and VTE patients from the plains closer to sea level (SLPs) for 54 parameters, including coagulation-related, fibrinolytic, and thrombophilic variables, as well as markers for stress and inflammatory response and platelet and endothelial activation. Our results established an association between HA hypoxia and VTE in alterations of primarily hemostatic variables. Approximately 96% of HAPs presented with ≥10 altered parameters out of 54 studied compared with 7% of SLPs. Elevated platelet count, von Willebrand factor, and clotting factors and altered coagulation exhibited significant associations with VTE events and altitude exposure (all P < .05). Additionally, most VTEs at HA were associated with younger age groups, unlike those on the plains. A receiver operator characteristic curve analysis revealed differences between HAPs and SLPs for CD40 ligand (area under the curve [AUC], 0.90; 95% confidence interval [CI], 0.84-0.96]), P-selectin (0.79; 0.70-0.88), platelet factor-4 (0.90; 0.84-0.96), intracellular adhesion molecule-1 (0.86; 0.79-0.93), vascular cell adhesion molecule-1 (0.97; 0.95-0.99), vascular endothelial growth factor (0.87; 0.8-0.94), FLT4 (0.94; 0.89-0.99), and Toll-like receptor-2 (0.98; 0.96-1.0) (all P < .05). In conclusion, this study suggests that HA exposure perturbs the molecules associated with vascular integrity and contributes to the early onset of VTE.


Subject(s)
Altitude , Environmental Exposure/adverse effects , Venous Thromboembolism/etiology , Venous Thromboembolism/metabolism , Adult , Biomarkers , Blood Coagulation , Blood Coagulation Tests , Blood Platelets/metabolism , Endothelial Cells/metabolism , Hemostasis , Humans , Male , Middle Aged , ROC Curve , Risk Assessment , Risk Factors , Venous Thromboembolism/diagnosis
12.
Thromb Haemost ; 118(7): 1279-1295, 2018 Jul.
Article in English | MEDLINE | ID: mdl-29864786

ABSTRACT

Venous thromboembolism (VTE), a multi-factorial disease, is the third most common cardiovascular disease. Established genetic and acquired risk factors are responsible for the onset of VTE. High altitude (HA) also poses as an additional risk factor, predisposing individuals to VTE; however, its molecular mechanism remains elusive. This study aimed to identify genes/pathways associated with the pathophysiology of deep vein thrombosis (DVT) at HA. Gene expression profiling of DVT patients, who developed the disease, either at sea level or at HA-DVT locations, resulted in differential expression of 378 and 875 genes, respectively. Gene expression profiles were subjected to bioinformatic analysis, followed by technical and biological validation of selected genes using quantitative reverse transcription-polymerase chain reaction. Both gene ontology and pathway analysis showed enrichment of genes involved in haemostasis and platelet activation in HA-DVT patients with the most relevant pathway being 'response to hypoxia'. Thus, given the environmental condition the differential expression of hypoxia-responsive genes (angiogenin, ribonuclease, RNase A family, 5; early growth response 1; lamin A; matrix metallopeptidase 14 [membrane-inserted]; neurofibromin 1; PDZ and LIM domain 1; procollagen-lysine 1, 2-oxoglutarate 5-dioxygenase 1; solute carrier family 6 [neurotransmitter transporter, serotonin], member 4; solute carrier family 9 [sodium/hydrogen exchanger], member 1; and TEK tyrosine kinase, endothelial) in HA-DVT could be a determining factor to understand the pathophysiology of DVT at HA.


Subject(s)
Altitude , Blood Coagulation Disorders/genetics , Blood Coagulation/genetics , Gene-Environment Interaction , Hypoxia/genetics , Venous Thrombosis/genetics , Adult , Blood Coagulation Disorders/blood , Blood Coagulation Disorders/diagnosis , Case-Control Studies , Gene Expression Profiling/methods , Gene Regulatory Networks , Genetic Predisposition to Disease , Genome-Wide Association Study , Humans , Hypoxia/complications , Hypoxia/diagnosis , Male , Phenotype , Risk Assessment , Risk Factors , Transcriptome , Venous Thrombosis/blood , Venous Thrombosis/diagnosis
13.
BMJ Case Rep ; 20172017 Dec 01.
Article in English | MEDLINE | ID: mdl-29196310

ABSTRACT

Spontaneous retroperitoneal haematoma (SRH) can be a life-threatening emergency presenting with hypovolaemic shock. SRH has been rarely reported with May-Thurner syndrome (MTS) where it occurs due to rupture of the iliac vein or venous collaterals. We report a case of MTS that presented with deep venous thrombosis of the left lower limb complicated by bilateral pulmonary embolism (PE) and a large pelvic haematoma. The simultaneous occurrence of a large pelvic haematoma and PE offered a therapeutic challenge. Successful endovascular management of the case is discussed in this report.


Subject(s)
Hematoma/complications , Hematoma/surgery , Lower Extremity/blood supply , Peritoneum/blood supply , Pulmonary Embolism/etiology , Thrombolytic Therapy/instrumentation , Aftercare , Computed Tomography Angiography/methods , Diagnosis, Differential , Endovascular Procedures/methods , Factor Xa Inhibitors/therapeutic use , Female , Hematoma/drug therapy , Hematoma/pathology , Humans , Lower Extremity/diagnostic imaging , Lower Extremity/pathology , Magnetic Resonance Imaging/methods , Middle Aged , Peritoneum/diagnostic imaging , Peritoneum/pathology , Pulmonary Embolism/diagnostic imaging , Pyrazoles/administration & dosage , Pyrazoles/therapeutic use , Pyridones/administration & dosage , Pyridones/therapeutic use , Stents/standards , Treatment Outcome , Ultrasonography/methods , Ultrasonography, Doppler/methods , Venous Thrombosis/etiology
14.
Proc Natl Acad Sci U S A ; 114(18): 4763-4768, 2017 05 02.
Article in English | MEDLINE | ID: mdl-28420787

ABSTRACT

Venous thromboembolism (VTE), caused by altered hemostasis, remains the third most common cause of mortality among all cardiovascular conditions. In addition to established genetic and acquired risk factors, low-oxygen environments also predispose otherwise healthy individuals to VTE. Although disease etiology appears to entail perturbation of hemostasis pathways, the key molecular determinants during immediate early response remain elusive. Using an established model of venous thrombosis, we here show that systemic hypoxia accelerates thromboembolic events, functionally stimulated by the activation of nucleotide binding domain, leucine-rich-containing family, pyrin domain containing 3 (NLRP3) inflammasome complex and increased IL-1ß secretion. Interestingly, we also show that the expression of NLRP3 is mediated by hypoxia-inducible factor 1-alpha (HIF-1α) during these conditions. The pharmacological inhibition of caspase-1, in vivo knockdown of NLRP3, or HIF-1α other than IL-1ß-neutralizing antibodies attenuated inflammasome activation and curtailed thrombosis under hypoxic conditions. We extend the significance of these preclinical findings by studying modulation of this pathway in patients with altitude-induced venous thrombosis. Our results demonstrate distinctive, increased expression of NLRP3, caspase-1, and IL-1ß in individuals with clinically established venous thrombosis. We therefore propose that an early proinflammatory state in the venous milieu, orchestrated by the HIF-induced NLRP3 inflammasome complex, is a key determinant of acute thrombotic events during hypoxic conditions.


Subject(s)
Hypoxia/metabolism , Inflammasomes/metabolism , NLR Family, Pyrin Domain-Containing 3 Protein/biosynthesis , Venous Thrombosis/metabolism , Animals , Caspase 1/biosynthesis , Disease Models, Animal , Female , Gene Expression Regulation , Humans , Hypoxia/pathology , Hypoxia-Inducible Factor 1, alpha Subunit/biosynthesis , Interleukin-1beta/biosynthesis , Male , Rats , Rats, Sprague-Dawley , Venous Thrombosis/pathology
15.
BMJ Case Rep ; 20162016 Mar 04.
Article in English | MEDLINE | ID: mdl-26944369

ABSTRACT

Invasive aspergillosis is a severe fungal infection that primarily affects immunocompromised patients. We report a case of invasive aspergillosis presenting as a febrile respiratory infection with a cardiac mass in an immunocompetent patient. Excision of the intracardiac mass followed by histopathological examination confirmed the diagnosis. The patient was managed with voriconazole, to which he responded well. Rare occurrence of an intracardiac mass with systemic aspergillosis in an immunocompetent host is discussed in this case report.


Subject(s)
Aspergillosis/diagnosis , Heart Diseases/diagnostic imaging , Heart Diseases/microbiology , Administration, Intravenous , Antifungal Agents/administration & dosage , Aspergillosis/drug therapy , Aspergillosis/microbiology , Aspergillosis/surgery , Aspergillus fumigatus/isolation & purification , Diagnosis, Differential , Echocardiography/methods , Heart Diseases/drug therapy , Heart Diseases/immunology , Humans , Immunocompetence , Male , Respiratory Tract Infections/diagnosis , Respiratory Tract Infections/immunology , Respiratory Tract Infections/microbiology , Treatment Outcome , Voriconazole/administration & dosage , Young Adult
16.
Blood ; 123(8): 1250-60, 2014 Feb 20.
Article in English | MEDLINE | ID: mdl-24297866

ABSTRACT

Oxygen-compromised environments, such as high altitude, air travel, and sports, and pathological conditions, such as solid tumors, have been suggested to be prothrombotic. Despite the indispensable role of platelets in thrombus formation, the studies linking hypoxia, platelet reactivity, and thrombus formation are limited. In the present study, platelet proteome/reactivity was analyzed to elucidate the acute hypoxia-induced prothrombotic phenotype. Rats exposed to acute simulated hypoxia (282 torr/8% oxygen) demonstrated a decreased bleeding propensity and increased platelet reactivity. Proteomic analysis of hypoxic platelets revealed 27 differentially expressed proteins, including those involved in coagulation. Among these proteins, calpain small subunit 1, a 28-kDa regulatory component for calpain function, was significantly upregulated under hypoxic conditions. Moreover, intraplatelet Ca(2+) level and platelet calpain activity were also found to be in accordance with calpain small subunit 1 expression. The inhibition of calpain activity demonstrated reversal of hypoxia-induced platelet hyperreactivity. The prothrombotic role for calpain was further confirmed by an in vivo model of hypoxia-induced thrombosis. Interestingly, patients who developed thrombosis while at extreme altitude had elevated plasma calpain activities and increased soluble P-selectin level. In summary, this study suggests that augmented calpain activity is associated with increased incidence of thrombosis under hypoxic environments.


Subject(s)
Blood Platelets/metabolism , Calpain/metabolism , Hypoxia/metabolism , Thrombosis/metabolism , Adult , Altitude Sickness/metabolism , Animals , Calpain/genetics , Disease Models, Animal , Enzyme Activation/physiology , Humans , Male , Platelet Activation/physiology , Proteome/metabolism , Rats , Rats, Sprague-Dawley , Thrombophilia/metabolism
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