DOI 10.1007/s10517-017-3727-9
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Bulletin of Experimental Biology and Medicine, Vol. 163, No. 1, May, 2017
GENERAL PATHOLOGY AND PATHOPHYSIOLOGY Psychopharmacological Effects of JNK Inhibitor in Posthypoxic Encephalopathy and Mechanisms of Their Development G. N. Zyuz’kov1,2, N. I. Suslov1, T. N. Povet’eva1, Yu. V. Nesterova1, O. G. Afanas’eva1, E. V. Udut1, L. A. Miroshnichenko1, E. V. Simanina1, T. Yu. Polyakova1, L. A. Stavrova1, A. V. Chaikovskii1, P. V. Kul’pin1, V. V. Udut1,2, A. M. Dygai1, and V. V. Zhdanov1
Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 163, No. 1, pp. 23-27, January, 2017 Original article submitted June 7, 2016 Psychopharmacological effects of JNK inhibitor were studied using a mouse model of posthypoxic encephalopathy. The preparation exhibited a pronounced cerebroprotective effect manifested in normalization of orientation and exploratory behavior and conditioned responses in posthypoxic mice. These effects were accompanied by marked elevation of neural stem cell content in the paraventricular region of the brain. Key Words: regenerative medicine; cerebroprotective pharmacology; JNK; neural stem cells; hypoxia Popular paradigm of pharmacological protection of the brain based on functional modulation of mature cells that remained intact in the nervous tissue under pathological conditions is sometimes untenable and available drugs fail not only to restore the morphofunctional integrity of the brain, but even prevent the progredient course of pathological process in the nervous tissue [1,2,6]. In this context, the development of principally new approaches to the therapy of CNS diseases seems to be a promising way [2,3,12]. Basing on the peculiarities of intracellular signaling in various progenitor cells revealed by us we proposed a new avenue to treat a number of diseases “Strategy of Pharmacological Control of Intracellular Signal Transduction in Regeneratively Competent Cells” [4,5,11,14]. This pharmacological strategy focuses on E. D. Goldberg Research Institute of Pharmacology and Regenerative Medicine, Tomsk National Research Medical Center, Russian Academy of Sciences; 2Laboratory for Physical Processes Modeling in Biology and Medicine, National Research Tomsk State University, Tomsk, Russia. Address for correspondence:
[email protected]. G. N. Zyuz’kov
individual intracellular signal molecules implicated in the realization of growth potential of diverse progenitor elements or microenvironmental cells mediating accelerated course of reparative processes [8-10,12]. It is important that we also revealed a unique role of JNK (as compared to mature cell elements) in the life of mesenchymal progenitor cells, which inhibits the cell cycle progression [13]. Thus, studies of physiological role of JNK-mediated signaling in cerebral neural stem cells and promising therapeutic potential of JNK activity modulators in the treatment of CNS diseases is of undisputable importance. Our aim was to examine the effect of JNK inhibitor on psychoneurological status of experimental animals with modeled posthypoxic encephalopathy and to study in situ the state of cerebral neural stem cells in these animals.
1
MATERIALS AND METHODS The study was carried out on certified conventional (1st category) male outbred mice (n=56) weighing 20-
0007-4888/17/16310018 © 2017 Springer Science+Business Media New York
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G. N. Zyuz’kov, N. I. Suslov, et al.
25 g obtained from the Department of Experimental Biological Models, E. D. Goldberg Research Institute of Pharmacology and Regenerative Medicine. For modeling posthypoxic encephalopathy, the mice were placed in a 500-ml sealed chamber (2 sessions with 10-min interval) until termination of generalized convulsions and/or visually established respiratory arrest for 10-15 sec [2,15]. A selective JNK inhibitor (SP600125; InvivoGen) was daily injected subcutaneously (11 mg/kg in 0.2 ml solvent) over 7 days, the first dose being administered in 1 day after hypoxia. The control mice received equal volume of the solvent according to the same scheme.
The psychopharmacological effects of the inhibitor were assessed using functional tests. On posthypoxic days 7, 14, and 21, orientation and exploratory behavior in an open field was recorded during the first minute and two subsequent minutes separately. On days 14 and 21, retention of conditioned passive avoidance response (CPAR) trained on posthypoxic day 3 was tested [2,7,15]. To study the mechanisms underlying the development of cerebroprotective effects, the content of neural progenitor cells in the brain was determined on postischemic days 3 and 7. To this end, the nervous tissue was isolated from the paraventricular region of the cerebral
TABLE 1. Effect of JNK Inhibitor on Orientation and Exploratory Behavior in Open Field in Mice with Modeled Posthypoxic Encephalopathy (arb. units; m±SEM) Group
Total LA
Horizontal LA
Vertical LA
Holes explored
Holes sniffed
Grooming
Locomotion asymmetry index, %
7.8±1.6
4.2±0.2
0.2±0.2
0.8±0.7
2.0±0.6
0±0
30.6±4.7
12.3±1.5*
8.2±0.6*
0.2±0.2
1.8±0.5
1.8±0.8
0±0
44.3±6.1
5.3±1.2
2.8±1.0
0±0
0±0
0.7±0.5
0±0
40.6±4.3
0.5±0.3
3.3±1.1
6.3±1.5
0.8±0.3
35.8±3.6
Day 7 of the experiment 1st minute of open-field testing Intact animals Control (PE) Experiment (PE+JNK inhibitor)
+
+
2nd-3rd minutes of open-field testing Intact animals
21.0±3.4
9.3±2.8
Control (PE)
36.5±4.0* 19.7±3.8*
1.2±0.8
7.0±1.6
6.0±1.5
1.0±0.3
44.9±4.1
Experiment (PE+JNK inhibitor)
17.5±4.4
7.8±1.2
0.7±0.2
3.8±1.1
2.7±1.7
1.2±0.2
39.9±2.6
Intact animals
3.5±0.6
1.2±0.6
0.7±0.7
0.8±0.3
0.7±0.5
0.25±0.13
23.3±1.6
Control (PE)
0.7±0.3*
0.3±0.2*
0±0
0±0
0.2±0.2
0.2±0.2
33.3±2.1*
Experiment (PE+JNK inhibitor)
4.8±1.6
2.2±0.4
0±0
1.5±0.3
1.2±0.8
0±0
27.4±1.8+
Day 14 of the experiment 1st minute of open-field testing
+
+
2nd-3rd minutes of open-field testing Intact animals
14.8±2.3
6.8±1.7
1.2±0.6
2.5±1.0
2.5±0.9
0.8±0.3
34.6±3.0
Control (PE)
19.3±3.2
11.8±1.4*
0.7±0.3
1.3±0.6
3.7±1.1
1.0±0.3
60.3±4.9*
Experiment (PE+JNK inhibitor)
16.5±2.8
8.3±2.0
0.3±0.3
2.7±0.7
3.3±0.4
1.15±0.3
38.0±3.8+
6.2±1.2
2.2±0.8
0±0
1.3±1.0
1.5±0.6
0±0
31.6±2.7
13.7±1.7*
9.5±1.8*
0±0
1.2±0.5
2.3±0.8
0±0
66.7±3.7*
9.8±1.3
4.7±1.1
0.2±0.2
1.3±0.3
0.8±0.5
0.3±0.2
33.9±5.3+
Intact animals
18.8±2.3
5.5±1.4
0±0
4.5±1.0
6.7±14
1.0±0.4
25.0±2.3
Control (PE)
20.3±2.0
10.3±2.4*
0.2±0.2
3.3±1.5
4.3±1.5
0.7±0.2
42.7±3.1*
Experiment (PE+JNK inhibitor)
15.3±2.7
5.7±1.7
0±0
3.8±1.2
2.5±0.8
1.3±0.4
26.6±3.7+
+
Day 21 of the experiment 1st minute of open-field testing Intact animals Control (PE) Experiment (PE+JNK inhibitor)
+
2nd-3rd minutes of open-field testing
+
Note. Here and in Table 2: PE is posthypoxic excephalpathy. p
