Abstract 9: Involvement of Caveolin-1 in Vascular Remodeling and Inflammation Induced by Angiotensin II

We have recently reported that caveolin-1 (Cav1) enriched membrane microdomains in vascular smooth muscle cells (VSMC) mediate a metalloprotease ADAM17-dependent EGF receptor (EGFR) transactivation, which is linked to vascular remodeling induced by AngII. We have tested our hypothesis that Cav1, a major structural protein of caveolae, plays a critical role for development of vascular remodeling by AngII via regulation of ADAM17 and EGFR. Here, 8 week old male Cav1-/- and control Cav+/+ wild-type mice (WT) were infused with AngII (1 μg/kg/min) for 2 weeks to induce vascular remodeling and hypertension. Upon AngII infusion, histological assessments demonstrated medial hypertrophy and perivascular fibrosis of coronary and renal arteries in WT mice compared with saline-infused control mice. The AngII-infused WT mice also showed a phenotype of cardiac hypertrophy with increased HW/BW ratio (mg/g: 8.0±0.6 vs 5.7±0.7 p<0.01) compared with WT control. In contrast to AngII-infused WT mice, Cav1-/- mice with AngII showed attenuation of vascular remodeling but not cardiac hypertrophy ; HW/BW ratio (8.6±0.5 vs 6.4±0.2 p<0.05). Similar levels of AngII-induced hypertension were observed in both WT and Cav1-/- mice assessed by telemetry (MAP mmHg: 142±9 vs 154±20). In WT mice, Ang II enhanced ADAM17 expression and phospho-Tyr EGFR staining in heart and kidney vasculature. These events were attenuated in vessels from Cav1-/- mice infused with AngII. In addition, IHC analysis revealed less ER stress in heart and kidney vasculature of AngII-infused Cav1-/- mice compared with WT mice. Enhanced Cav1 and VCAM-1 expression were also observed in the aorta from AngII-infused WT mice but not in Cav1-/- aorta. These data suggest that Cav1 and presumably vascular caveolae play critical roles for vascular remodeling and inflammation via induction of ADAM17 and activation of EGFR independent of blood pressure or cardiac hypertrophy regulation.

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Abstract 279: Role of Caveolin-1 in Abdominal Aortic Aneurysm induced by Angiotensin II

Arteriosclerosis Thrombosis and Vascular Biology ◽

10.1161/atvb.33.suppl_1.a279 ◽

2013 ◽

Vol 33 (suppl_1) ◽

Author(s):

Takehiko Takayanagi ◽

Kevin Crawford ◽

Tomonori Kobayashi ◽

Victor Rizzo ◽

Satoru Eguchi

Keyword(s):

Oxidative Stress ◽

Abdominal Aortic Aneurysm ◽

Angiotensin Ii ◽

Aortic Aneurysm ◽

Egf Receptor ◽

Critical Role ◽

Membrane Microdomains ◽

Structural Protein ◽

Caveolin 1 ◽

Abdominal Aortic

Abdominal aortic aneurysm (AAA) is a significant cause of mortality for adults aged >60 years. Accumulating evidence suggests that activation of the AT1 receptor by angiotensin II (AngII) in AAA formation. While several downstream signals and target proteins have been identified in this pathway, there is a huge void in our knowledge regarding the AngII-sensitive proximal events primarily responsible for AAA formation. We recently reported that caveolae membrane microdomains in vascular smooth muscle cells (VSMC) mediate a metalloprotease ADAM17-dependent EGF receptor (EGFR) transactivation which linked to vascular remodeling induced by AngII. Given that ADAM17 expression is one of the key features in AAA, we have tested our hypothesis that caveolin-1 (Cav1), a major structural protein of caveolae, in the vasculature plays a critical role for development of AAA via its regulation on ADAM17. 8 week old male Cav1-/- mice and the control C57Bl/6 wild-type (WT) mice were co-infused with AngII and BAPN, a lysyl oxidase inhibitor, to induce AAA. We found that Cav1-/- mice did not develop AAA compared to C57Bl/6 mice in spite of hypertension assessed by telemetry in both groups. This finding suggests that the AngII signaling essential for vascular contraction remains in place in Cav1-/- mice. We found an increased expression of ADAM17 and auto-phosphorylation of EGFR in WT abdominal aortae with aneurysms that were markedly attenuated in Cav1-/- mice infused with AngII+BAPN. Furthermore, Cav1-/- mice with the infusion showed less oxidative stress and ER stress than their WT counterparts as assessed by nitrotyrosine staining and KDEL/p-eIF2a staining, respectively. In conclusion, Cav1 and presumably vascular caveolae micro-domain appear to play a critical role in the formation of AAA in mice via regulation of the ADAM17/EGFR signaling axis and subsequent induction of ER/oxidative stress.

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Abstract P223: Caveolin-1 Contributes to Vascular Remodeling and Inflammation Induced by Angiotensin Ii in vivo and in vitro

Hypertension ◽

10.1161/hyp.68.suppl_1.p223 ◽

2016 ◽

Vol 68 (suppl_1) ◽

Author(s):

Tatsuo Kawai ◽

Steven J Forrester ◽

Katherine J Elliot ◽

Takashi Obama ◽

Takehiko Takayanagi ◽

...

Keyword(s):

Angiotensin Ii ◽

Cardiac Hypertrophy ◽

Vascular Remodeling ◽

Critical Role ◽

Heart Weight ◽

Cell Protein ◽

Membrane Microdomains ◽

Ros Generation ◽

Caveolin 1 ◽

Mitochondrial Ros

We have recently reported that caveolin-1 (Cav1) enriched membrane microdomains in vascular smooth muscle cells (VSMC) mediate a metalloprotease ADAM17-dependent EGF receptor (EGFR) transactivation, which is linked to vascular remodeling but not contraction induced by angiotensin II (AngII). We have tested our hypothesis that Cav1, a major structural protein of caveolae, plays a critical role for development of vascular remodeling but not hypertension induced by AngII. 8 week old male Cav1-/- and the control Cav+/+ wild-type mice (WT: C57BL6) were infused with AngII (1 μg/kg/min) for 2 weeks to induce vascular remodeling and hypertension. Upon AngII infusion, histological assessments demonstrated medial hypertrophy and perivascular fibrosis of coronary and renal arteries in WT mice compared with sham-operated control mice. The AngII-infused WT mice also showed a phenotype of cardiac hypertrophy with increased heart weight/body weight (HW/BW) ratio (mg/g: 8.0±0.6 vs 5.7±0.7 p<0.01) compared with WT control. In contrast to AngII-infused WT mice, Cav1-/- mice with AngII infusion showed attenuation of vascular remodeling but not cardiac hypertrophy; HW/BW ratio (8.6±0.5 vs 6.4±0.2 p<0.05). Similar levels of AngII-induced hypertension were observed in both WT and Cav1-/- mice assessed by telemetry (mean arterial pressure: 142±9 vs 154±20 mmHg). In WT mice, Ang II enhanced ADAM17 expression and phospho-Tyr1068 EGFR staining in vasculatures of heart and kidney. These events were attenuated in vessels from Cav1-/- mice infused with AngII. In addition, immuno-histochemical analyses revealed less ER stress in heart and kidney of AngII-infused Cav1-/- mice compared with WT mice. Enhanced Cav1 and VCAM-1 expression were also observed in aorta from AngII-infused WT mice but not in Cav1-/- aorta. In rat VSMCs, adenoviral encoding Cav1 siRNA (100 moi) attenuated AngII-induced enhancements of total cell protein, cell volume and extracellular collagen content but not mitochondrial ROS generation. These data suggest that Cav1 and presumably vascular caveolae play critical roles for vascular remodeling and inflammation which likely involves the ADAM17/EGFR cascade independent from blood pressure or mitochondrial ROS regulation.

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Localization of Phospholipase D1 to Caveolin-enriched Membrane via Palmitoylation: Implications for Epidermal Growth Factor Signaling

Molecular Biology of the Cell ◽

10.1091/mbc.e02-02-0100 ◽

2002 ◽

Vol 13 (11) ◽

pp. 3976-3988 ◽

Cited By ~ 40

Author(s):

Jung Min Han ◽

Yong Kim ◽

Jun Sung Lee ◽

Chang Sup Lee ◽

Byoung Dae Lee ◽

...

Keyword(s):

Growth Factor ◽

Epidermal Growth Factor ◽

Egf Receptor ◽

Point Mutations ◽

Dominant Negative ◽

Growth Factor Signaling ◽

Wild Type ◽

Caveolin 1 ◽

Epidermal Growth ◽

Egf Signaling

Phospholipase D (PLD) has been suggested to mediate epidermal growth factor (EGF) signaling. However, the molecular mechanism of EGF-induced PLD activation has not yet been elucidated. We investigated the importance of the phosphorylation and compartmentalization of PLD1 in EGF signaling. EGF treatment of COS-7 cells transiently expressing PLD1 stimulated PLD1 activity and induced PLD1 phosphorylation. The EGF-induced phosphorylation of threonine147 was completely blocked and the activity of PLD1 attenuated by point mutations (S2A/T147A/S561A) of PLD1 phosphorylation sites. The expression of a dominant negative PKCα mutant by adenovirus-mediated gene transfer greatly inhibited the phosphorylation and activation of PLD1 induced by EGF in PLD1-transfected COS-7 cells. EGF-induced PLD1 phosphorylation occurred primarily in the caveolin-enriched membrane (CEM) fraction, and the kinetics of PLD1 phosphorylation in the CEM were strongly correlated with PLD1 phosphorylation in the total membrane. Interestingly, EGF-induced PLD1 phosphorylation and activation and the coimmunoprecipitation of PLD1 with caveolin-1 and the EGF receptor in the CEM were significantly attenuated in the palmitoylation-deficient C240S/C241S mutant, which did not localize to the CEM. Immunocytochemical analysis revealed that wild-type PLD1 colocalized with caveolin-1 and the EGF receptor and that phosphorylated PLD1 was localized exclusively in the plasma membrane, although some PLD1 was also detected in vesicular structures. Transfection of wild-type PLD1 but not of C240S/C241S mutant increased EGF-induced raf-1 translocation to the CEM and ERK phosphorylation. This study shows, for the first time, that EGF-induced PLD1 phosphorylation and activation occur in the CEM and that the correct localization of PLD1 to the CEM via palmitoylation is critical for EGF signaling.

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miR299a-5p promotes renal fibrosis by suppressing the antifibrotic actions of follistatin

Scientific Reports ◽

10.1038/s41598-020-80199-z ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Neel Mehta ◽

Renzhong Li ◽

Dan Zhang ◽

Asfia Soomro ◽

Juehua He ◽

...

Keyword(s):

Renal Fibrosis ◽

Mesangial Cells ◽

Matrix Proteins ◽

Membrane Microdomains ◽

Glomerular Mesangial Cells ◽

Wild Type ◽

Caveolin 1 ◽

Inhibition Studies

AbstractCaveolin-1 (cav-1), an integral protein of the membrane microdomains caveolae, is required for synthesis of matrix proteins by glomerular mesangial cells (MC). Previously, we demonstrated that the antifibrotic protein follistatin (FST) is transcriptionally upregulated in cav-1 knockout MC and that its administration is protective against renal fibrosis. Here, we screened cav-1 wild-type and knockout MC for FST-targeting microRNAs in order to identity novel antifibrotic therapeutic targets. We identified that miR299a-5p was significantly suppressed in cav-1 knockout MC, and this was associated with stabilization of the FST 3′UTR. Overexpression and inhibition studies confirmed the role of miR299a-5p in regulating FST expression. Furthermore, the profibrotic cytokine TGFβ1 was found to stimulate the expression of miR299a-5p and, in turn, downregulate FST. Through inhibition of FST, miR299a-5p overexpression augmented, while miR299a-5p inhibition diminished TGFβ1 profibrotic responses, whereas miR299a-5p overexpression re-enabled cav-1 knockout MC to respond to TGFβ1. In vivo, miR299a-5p was upregulated in the kidneys of mice with chronic kidney disease (CKD). miR299a-5p inhibition protected these mice against renal fibrosis and CKD severity. Our data demonstrate that miR299a-5p is an important post-transcriptional regulator of FST, with its upregulation an important pathogenic contributor to renal fibrosis. Thus, miR299a-5p inhibition offers a potential novel therapeutic approach for CKD.

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Critical Role of Caveolin-1 Loss/Dysfunction in Pulmonary Hypertension

Medical Sciences ◽

10.3390/medsci9040058 ◽

2021 ◽

Vol 9 (4) ◽

pp. 58

Author(s):

Rajamma Mathew

Keyword(s):

Cell Proliferation ◽

Endothelial Cells ◽

Pulmonary Hypertension ◽

Membrane Protein ◽

Critical Role ◽

High Morbidity ◽

Caveolin 1 ◽

Enhanced Expression ◽

Medial Hypertrophy

Pulmonary hypertension (PH) is a rare disease with a high morbidity and mortality rate. A number of systemic diseases and genetic mutations are known to lead to PH. The main features of PH are altered vascular relaxation responses and the activation of proliferative and anti-apoptotic pathways, resulting in pulmonary vascular remodeling, elevated pulmonary artery pressure, and right ventricular hypertrophy, ultimately leading to right heart failure and premature death. Important advances have been made in the field of pulmonary pathobiology, and several deregulated signaling pathways have been shown to be associated with PH. Clinical and experimental studies suggest that, irrespective of the underlying disease, endothelial cell disruption and/or dysfunction play a key role in the pathogenesis of PH. Endothelial caveolin-1, a cell membrane protein, interacts with and regulates several transcription factors and maintains homeostasis. Disruption of endothelial cells leads to the loss or dysfunction of endothelial caveolin-1, resulting in reciprocal activation of proliferative and inflammatory pathways, leading to cell proliferation, medial hypertrophy, and PH, which initiates PH and facilitates its progression. The disruption of endothelial cells, accompanied by the loss of endothelial caveolin-1, is accompanied by enhanced expression of caveolin-1 in smooth muscle cells (SMCs) that leads to pro-proliferative and pro-migratory responses, subsequently leading to neointima formation. The neointimal cells have low caveolin-1 and normal eNOS expression that may be responsible for promoting nitrosative and oxidative stress, furthering cell proliferation and metabolic alterations. These changes have been observed in human PH lungs and in experimental models of PH. In hypoxia-induced PH, there is no endothelial disruption, loss of endothelial caveolin-1, or enhanced expression of caveolin-1 in SMCs. Hypoxia induces alterations in membrane composition without caveolin-1 or any other membrane protein loss. However, caveolin-1 is dysfunctional, resulting in cell proliferation, medial hypertrophy, and PH. These alterations are reversible upon removal of hypoxia, provided there is no associated EC disruption. This review examined the role of caveolin-1 disruption and dysfunction in PH.

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Ectopic expression of caveolin-1 restores physiological contractile response of aged colonic smooth muscle

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00064.2007 ◽

2007 ◽

Vol 293 (1) ◽

pp. G240-G249 ◽

Cited By ~ 19

Author(s):

Sita Somara ◽

Robert R. Gilmont ◽

Jeffrery R. Martens ◽

Khalil N. Bitar

Keyword(s):

Signal Transduction ◽

Smooth Muscle ◽

Muscle Contraction ◽

Contractile Response ◽

Colonic Motility ◽

Smooth Muscle Contraction ◽

Membrane Microdomains ◽

Aged Rats ◽

Wild Type ◽

Caveolin 1

Reduced colonic motility has been observed in aged rats with a parallel reduction in acetylcholine (ACh)-induced myosin light chain (MLC20) phosphorylation. MLC20 phosphorylation during smooth muscle contraction is maintained by a coordinated signal transduction cascade requiring both PKC-α and RhoA. Caveolae are membrane microdomains that permit rapid and efficient coordination of different signal transduction cascades leading to sustained smooth muscle contraction of the colon. Here, we show that normal physiological contraction can be reinstated in aged colonic smooth muscle cells (CSMCs) upon transfection with wild-type caveolin-1 through the activation of both the RhoA/Rho kinase and PKC pathways. Our data demonstrate that impaired contraction in aging is an outcome of altered membrane translocation of PKC-α and RhoA with a concomitant reduction in the association of these molecules with the caveolae-specific protein caveolin-1, resulting in a parallel decrease in the myosin phosphatase-targeting subunit (MYPT) and CPI-17 phosphorylation. Decreased MYPT and CPI-17 phosphorylation activates MLC phosphatase activity, resulting in MLC20 dephosphorylation, which may be responsible for decreased colonic motility in aged rats. Importantly, transfection of CSMCs from aged rats with wild-type yellow fluorescent protein-caveolin-1 cDNA restored translocation of RhoA and PKC-α and phosphorylation of MYPT, CPI-17, and MLC20, thereby restoring the contractile response to levels comparable with young adult rats. Thus, we propose that caveolin-1 gene transfer may represent a promising therapeutic treatment to correct the age-related decline in colonic smooth muscle motility.

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Increased ICAM-1 and PECAM-1 Transcription Levels in the Heart of Apo-E Deficient Mice in Comparison to Wild Type (C57BL6).

Thrombosis and Haemostasis ◽

10.1055/s-0037-1615767 ◽

2001 ◽

Vol 85 (05) ◽

pp. 908-914 ◽

Cited By ~ 3

Author(s):

Kazem Zibara ◽

Kamel Chettab ◽

Brigitte McGregor ◽

Robin Poston ◽

John McGregor

Keyword(s):

Adhesion Molecules ◽

Vascular Remodeling ◽

Critical Role ◽

Vascular Lesions ◽

Chow Diet ◽

Wild Type ◽

Northern Blots ◽

Apo E ◽

Deficient Mice ◽

Gene Expression Levels

SummaryAdhesion molecules and chemoattractants are thought to play a critical role in the homing of leukocytes to sites of vascular lesions. Apo-E deficiency in mice creates an atherosclerotic model that mimics vascular lesions in man. Little is known on the effect of Apo-E deficiency on expression of adhesion molecules in the hearts of these animals. In this study, male C57BL6 and Apo-E deficient mice were fed a chow diet over periods of time (0 to 20 weeks). The transcription levels of major adhesion molecules (ICAM-1, PECAM-1), present in the heart, were followed by northern blots. Immunohistochemistry was used to localize these adhesion molecules in the heart. Results show a significant increase in gene transcription levels of ICAM-1 and PECAM-1 in Apo-E animals, but not wild type, at 16 and 20 weeks of chow diet. Such increase in levels of transcription was not observed in younger Apo-E and C57BL6 animals (0, 6 weeks of diet). ICAM-1 and PECAM-1 were strongly expressed in the endocardium and heart microvessels. In contrast, VCAM-1 was poorly stained, with only an occasional expression on the endocardium and arterioles. Enhanced gene expression levels of heart ICAM-1 and PECAM-1 observed in Apo-E deficient mice, but not in control animals, appears to induce the initial stages of an inflammatory reaction. Such observations, not previously reported, may induce heart vascular remodeling.

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Abstract 668: Inhibition of DNA Methyltransferase Inhibits the Ang II-Induced Increase in Blood Pressure, Vascular Remodeling and Target Organ Damage

Circulation ◽

10.1161/circ.116.suppl_16.ii_124 ◽

2007 ◽

Vol 116 (suppl_16) ◽

Author(s):

Methode Bacanamwo ◽

Mukaila Akinbami ◽

Dahai Wang ◽

Gary H Gibbons

Keyword(s):

Blood Pressure ◽

Cardiac Hypertrophy ◽

Vascular Remodeling ◽

Dna Methyltransferase ◽

Target Organ Damage ◽

Critical Role ◽

Organ Damage ◽

Target Organ ◽

Ang Ii ◽

Resistance Arteries

Growth signals stimulate DNA methyltransferase (DNMT) expression through extracellular signal-regulated kinases 1/2 (ERK1/2) pathway and that inhibition of ERK1/2 signaling results in repression of DNMT expression and activation of expression of some DNMT-repressed genes. Angiotensin II (Ang II) has been shown to stimulate ERK1/2 signaling in resistance arteries. We hypothesized that Ang II stimulates DNMT expression resulting in methylation and repression of antihypertensive genes such as 11β-hydroxysteroid dehydrogenase 2 (11β-HSD2) and that blocking DNMT activity may inhibit Ang II-induced hypertension, vascular remodeling, and target organ damage. C57BL/6J (C57) mice were treated with the specific DNMT inhibitor 5′-aza-2′-deoxycytidine (aza-CdR, 1 mg/kg/day) intraperitoneally for 3 consecutive days before subcutaneous Ang II infusion for 28d at a pressure dose of 0.7 mg/kg/day using Alzet osmotic minipumps. Systolic blood pressure was monitored during this period and tissues were harvested to determine vascular wall thickness, cardiac hypertrophy, and expression and methylation of 11β-HSD2 in arteries and the kidneys. Ang II infusion induced a more than 2-fold increase in DNMT1 expression (n=6, p≤ 0.05). Moreover, blocking DNMT1 activity significantly inhibited the Ang II-induced increase in systolic and diastolic blood pressure (from 102 ± 3 to138 ± 7 for saline-treated vs. 101 ± 4 to 105 ± 6 mm Hg for aza-CdR-treated mice, n=8, p≤ 0.01 for saline vs.aza-CdR in the presence of Ang II treatment). In addition, expression of 11β-HSD2 was inhibited by Ang II treatment. However, expression of 11β-HSD2 was found to be above the background observed in absence of Ang II when Ang II treatment was associated with DNMT activity blockade. Methylation-specific PCR indicated that 11β-HSD2 was methylated in the arteries and kidneys but its Ang II-dependency is still to be determined. Finally when DNMT activity was inhibited, the Ang II-induced increase cardiac hypertrophy (heart/body weight) and wall/lumen ratio in the carotid arteries were significantly inhibited (n= 8, p≤ 0.05). These results suggest that DNA methylation plays a critical role in the coordinate regulation of genes involved in the pathogenesis of hypertension and vascular remodeling.

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A Study of the Efficiency of Modern Domestic Disinfectants in the System of TB Control Activities

Agricultural science and practice ◽

10.15407/agrisp2.02.026 ◽

2015 ◽

Vol 2 (2) ◽

pp. 26-31 ◽

Cited By ~ 3

Author(s):

A. Paliy ◽

A. Zavgorodniy ◽

B. Stegniy ◽

A. Gerilovych

Keyword(s):

Molecular Genetic ◽

Critical Role ◽

Bactericidal Effect ◽

Chain Reaction ◽

Tb Control ◽

Source Of Infection ◽

Polymerase Chain ◽

And Control ◽

Chemical Groups ◽

Test Objects

Due to the absence of elaborated effi cient means for specifi c prevention of bovine tuberculosis, it is ex- tremely important to detect and eliminate the source of infection and to take veterinary and sanitary preven- tive measures. Here the critical role is attributed to disinfection, which breaks the epizootic chain due to the elimination of pathogenic microorganisms in the environment and involves the application of disinfectants of different chemical groups. Aim. To study the tuberculocidal properties of new disinfectants DZPT-2 and FAG against atypical mycobacteria Mycobacterium fortitum and a TB agent Mycobacterium bovis. Methods. The bacteriological and molecular-genetic methods were used. Results. It was determined that DZPT-2 prepara- tion has bactericidal effect on M. fortuitum when used in the concentration of 2.0 % of the active ingredient (AI) when exposed for 5–24 h, while disinfectant FAG has a bactericidal effect in the concentration of 2.0 % when exposed for 24 h. Disinfectant DZPT-2 in the concentration of 2.0 % of the AI, when exposed for 5–24 h, and FAG preparation in the concentration of 2.0 %, when exposed for 24 h, and with the norm of consump- tion rate of 1 cubic decimeter per 1 square meter disinfect the test-objects (batiste, wood, glazed tile, metal, glass), contaminated with the TB agent M. bovis. Conclusions. Disinfecting preparations of DZPT-2 in the concentration of 2.0 % of AI when exposed for 5 h and FAG in the concentration of 2.0 % when exposed for 24 h may be used in the complex of veterinary and sanitary measures to prevent and control TB of farm ani- mals. The possibility of using the polymerase chain reaction as an additional method of estimating tuberculo- cide activity of disinfectants was proven.

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