scholarly journals Prx2 (Peroxiredoxin 2) as a Cause of Hydrocephalus After Intraventricular Hemorrhage

Stroke ◽  
2020 ◽  
Vol 51 (5) ◽  
pp. 1578-1586 ◽  
Author(s):  
Xiaoxiao Tan ◽  
Jingyin Chen ◽  
Richard F. Keep ◽  
Guohua Xi ◽  
Ya Hua

Background and Purpose— Our recent study demonstrated that release of Prx2 (peroxiredoxin 2) from red blood cells (RBCs) is involved in the inflammatory response and brain injury after intracerebral hemorrhage. The current study investigated the role of extracellular Prx2 in hydrocephalus development after experimental intraventricular hemorrhage. Methods— There were 4 parts in this study. First, Sprague-Dawley rats received an intraventricular injection of lysed RBC or saline and were euthanized at 1 hour for Prx2 measurements. Second, rats received an intraventricular injection of Prx2, deactivated Prx2, or saline. Third, lysed RBC was coinjected with conoidin A, a Prx2 inhibitor, or vehicle. Fourth, rats received Prx2 injection and were treated with minocycline or saline (i.p.). The effects of Prx2 and the inhibitors were examined using magnetic resonance imaging assessing ventriculomegaly, histology assessing ventricular wall damage, and immunohistochemistry to assess inflammation, particularly at the choroid plexus. Results— Intraventricular injection of lysed RBC resulted in increased brain Prx2 and hydrocephalus. Intraventricular injection of Prx2 alone caused hydrocephalus, ventricular wall damage, activation of choroid plexus epiplexus cells (macrophages), and an accumulation of neutrophils. Conoidin A attenuated lysed RBC-induced injury. Systemic minocycline treatment reduced the epiplexus cell activation and hydrocephalus induced by Prx2. Conclusions— Prx2 contributed to the intraventricular hemorrhage-induced hydrocephalus, probably by inducing inflammatory responses in choroid plexus and ventricular wall damage.

2013 ◽  
Vol 34 (3) ◽  
pp. 489-494 ◽  
Author(s):  
Feng Gao ◽  
Fuyi Liu ◽  
Zhi Chen ◽  
Ya Hua ◽  
Richard F Keep ◽  
...  

Previous studies demonstrated that thrombin is an important factor in brain injury after intracerebral hemorrhage. This study investigated the effect of thrombin on hydrocephalus development in a rat intraventricular hemorrhage (IVH) model. There were three parts in this study. First, male Sprague–Dawley rats had an injection of 200  μL saline, autologous blood or heparinized blood, into the right lateral ventricle. Second, rats had an injection of 50  μL saline or 3U thrombin into the right lateral ventricle. Third, rats had an injection of thrombin (3U) with a protease-activated receptor-1 (PAR-1) antagonist, SCH79797 (0.15 nmol), or vehicle into the right lateral ventricle. Lateral ventricle volumes were measured by magnetic resonance imaging and the brains were used for immunohistochemistry and western blot analyses. Intraventricular injection of autologous blood induced hydrocephalus from day 1 to 28. Heparinized blood injection resulted in less hydrocephalus at all time points compared with blood injection alone ( P<0.05). Intraventricular injection of thrombin caused significant hydrocephalus, ventricular wall damage, and periventricular blood–brain barrier disruption. Thrombin-induced hydrocephalus was reduced by co-injection of the PAR-1 antagonist SCH79797 ( P<0.05). In conclusion, thrombin contributes to hydrocephalus development after IVH and thrombin-induced hydrocephalus is through PAR-1.


2014 ◽  
Vol 34 (6) ◽  
pp. 1070-1075 ◽  
Author(s):  
Chao Gao ◽  
Hanjian Du ◽  
Ya Hua ◽  
Richard F Keep ◽  
Jennifer Strahle ◽  
...  

Thrombin and iron are two major players in intracerebral hemorrhage-induced brain injury and our recent study found that thrombin contributes to hydrocephalus development in a rat model of intraventricular hemorrhage (IVH). This study investigated the role of red blood cell (RBC) lysis and iron in hydrocephalus after IVH. There were three parts to this study. First, male Sprague-Dawley rats received an injection of saline, packed, or lysed RBCs into the right lateral ventricle. Second, rats had an intraventricular injection of iron or saline. Third, the rats received intraventricular injection of lysed RBCs mixed with deferoxamine (0.5 mg in 5 μL saline) or saline. All rats underwent magnetic resonance imaging at 24 hours and were then euthanized for brain edema measurement, western blot analysis, or brain histology. We found that intraventricular injection of lysed RBCs, but not packed RBCs, resulted in ventricular enlargement and marked increases in brain heme oxygenase-1 and ferritin at 24 hours. Intraventricular injection of iron also resulted in ventricular enlargement and ventricular wall damage 24 hours later. Coinjection of deferoxamine reduced lysed RBC-induced ventricular enlargement ( P<0.01). These results suggest that iron, a degradation product of hemoglobin, has an important role in hydrocephalus development after IVH.


Biomolecules ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 654
Author(s):  
Ting Chen ◽  
Xiaoxiao Tan ◽  
Fan Xia ◽  
Ya Hua ◽  
Richard F. Keep ◽  
...  

The choroid plexus (CP) is the primary source of cerebrospinal fluid in the central nervous system. Recent evidence indicates that inflammatory pathways at the CP may be involved in hydrocephalus development. Peroxiredoxin 2 (Prx2) is a major component of red blood cells. Extracellular Prx2 is proinflammatory, and its release after red blood cell lysis may contribute to hydrocephalus after intraventricular hemorrhage. This study aimed to identify alterations in CP macrophages and dendritic cells following intracerebroventricular Prx2 injection and investigate the relationship between macrophages/dendritic cells and hydrocephalus. There were two parts to this study. In the first part, adult male Sprague–Dawley rats received an intracerebroventricular injection of Prx2 or saline. In the second part, Prx2 was co-injected with clodronate liposomes or control liposomes. All animals were euthanized at 24 h after magnetic resonance imaging. Immunohistochemistry was used to evaluate macrophages in CP, magnetic resonance imaging to quantify hydrocephalus, and histology to assess ventricular wall damage. The intracerebroventricular injection of Prx2 not only increased the OX-6 positive cells, but it also altered their location in the CP and immunophenotype. Co-injecting clodronate liposomes with Prx2 decreased the number of macrophages and simultaneously attenuated Prx2-induced hydrocephalus and ventricular wall damage. These results suggest that CP macrophages play an essential role in CP inflammation-induced hydrocephalus. These macrophages may be a potential therapeutic target in post-hemorrhagic hydrocephalus.


Author(s):  
MANOBHARATHI VENGAIMARAN ◽  
KALAIYARASI DHAMODHARAN ◽  
MIRUNALINI SANKARAN

Objective: The central motive of this study is to explore the therapeutic impact of Diosgenin encapsulated Chitosan nanoparticles (DG@CS-NP) on mammary carcinogenesis in female Sprague Dawley rats via modulating hormonal status, cell proliferation, inflammatory responses, and Apoptosis. Methods: 7,12-dimethylbenz(a)anthracene (DMBA) was administered subcutaneously near the mammary gland (25 mg/kg b. wt) to provoke mammary tumor in female Sprague Dawley rats. Following the progress of a tumor, DMBA-induced tumor-bearing rats were medicated orally with 5 mg/kg b. wt of DG@CS-NP. Consequently, the expression of ER, PR, PCNA, Cyclin D1, NF-κB, TNF-α, Bcl-2, Caspases-3, and p53 in experimental rats were revealed via architectural immunohistochemistry. Further, Diosgenin interactions with these proteins were evidently confirmed by molecular docking analysis. Results: As a result, we noticed diminished levels of ER, PR, PCNA, Cyclin D1, NF-κB, TNF-α, and Bcl-2 expressions in DG@CS-NP medicated rats as well as with elevated levels of Caspases-3 and p53 expressions. In DMBA rats, the expressions were vice versa. Additionally, molecular docking analyses support these outcomes by highlighting the strong interaction between Diosgenin and breast cancer targets. Conclusion: These reports prove that DG@CS-NP imposes its therapeutic impact by hormonal adjustments, downregulating proteins involved in inflammation and cellular proliferation, and thereby promotes apoptosis by impeding apoptotic inhibitors.


1994 ◽  
Vol 267 (3) ◽  
pp. L256-L262 ◽  
Author(s):  
H. Sakakibara ◽  
K. Shima ◽  
S. I. Said

In view of the evidence that vasoactive intestinal peptide (VIP) may modulate acute inflammatory injury in the lung, we investigated the presence and characteristics of VIP receptors on alveolar macrophages (AMs). We examined the binding of monoiodinated [Tyr(125I)10]-labeled VIP (125I-VIP) to rat AMs (> 96% pure), obtained from Sprague-Dawley rats by bronchoalveolar lavage (BAL). At 23 degrees C, the interaction of 125I-VIP with AMs was rapid, reversible, saturable, and linearly proportional to the number of cells. At equilibrium, the binding was competitively inhibited by 10(-11)-10(-6) M of native peptide [half-maximal inhibition (IC50) = 0.53 +/- 0.34 nM, n = 8], with evidence for two classes of binding sites: one with a high affinity (Kd = 0.20 +/- 0.09 nM) and a low capacity (1,190 +/- 640 sites/cell) and another with a low affinity (Kd = 43.2 +/- 13.8 nM) and a high capacity (51,700 +/- 14,000 sites/cell). VIP-related peptides inhibited the binding with the order of potency: VIP > peptide histidine isoleucine > helodermin >> secretin; glucagon was ineffective. In the presence of 3-isobutyl-1-methylxanthine, VIP dose dependently stimulated adenosine 3',5'-cyclic monophosphate accumulation in intact AMs, with maximal stimulation (6.3 times basal level) at 1 nM, and half-maximal accumulation at 0.23 +/- 0.11 nM VIP (Kd for high-affinity sites). For determination of the mass of the VIP receptor, 125I-VIP was covalently bound to AMs with the cross-linking agent dithiobis succinimidyl propionate. Autoradiographic studies after sodium dodecyl sulfate/polyacrylamide gel electrophoresis of solubilized affinity-labeled cells revealed a single major band of M(r) 76,400. We conclude that VIP binds to specific receptors on rat AMs that are coupled to adenylate cyclase, through which VIP may modulate inflammatory responses within the lung.


1979 ◽  
Vol 80 (3) ◽  
pp. 662-673 ◽  
Author(s):  
B van Deurs ◽  
J K Koehler

The tight junctions of the choroid plexus epithelium of rats were studied by freeze-fracture. In glutaraldehyde-fixed material, the junctions exhibited rows of aligned particles and short bars on P-faces, the E-faces showing grooves bearing relatively many particles. A particulate nature of the junctional strands could be established by using unfixed material. The mean values of junctional strands from the lateral, third, and fourth ventricles of Lewis rats were 7.5 +/- 2.6, 7.4 +/- 2.2, and 7.5 +/- 2.4; and of Sprague-Dawley rats 7.7 +/- 3.4, 7.4 +/- 2.3, and 7.3 +/- 1.6. Examination of complementary replicas (of fixed tissue) showed that discomtinuities are present in the junctional strands: 42.2 +/- 4.6% of the length of measured P-face ridges were discontinuities, and the total amount of complementary particles in E-face grooves constituted 17.8 +/- 4.4% of the total length of the grooves, thus approximately 25% of the junctional strands can be considered to be discontinuous. The average width of the discontinuities, when corrected for complementary particles in E-face grooves, was 7.7 +/- 4.5 nm. In control experiments with a "tighter" tight junction (small intestine), complementary replicas revealed that the junctional fibrils are rather continuous and that the very few particles in E-face grooves mostly filled out discontinuities in the P-face ridges. Approximately 5% of the strands were found to be discontinuous. These data support the notion that the presence of pores in the junctional strands of the choroid plexus epithelium may explain the high transepithelial conductance in a "leaky" epithelium having a high number of junctional strands. However, loss of junctional material during fracturing is also considered as an alternative explanation of the present results.


2009 ◽  
Vol 111 (6) ◽  
pp. 1356-1364 ◽  
Author(s):  
Tuomas O. Lilius ◽  
Pekka V. Rauhala ◽  
Oleg Kambur ◽  
Eija A. Kalso

Background Opioid analgesics are effective in relieving chronic pain, but they have serious adverse effects, including development of tolerance and dependence. Ibudilast, an inhibitor of glial activation and cyclic nucleotide phosphodiesterases, has shown potential in the treatment of neuropathic pain and opioid withdrawal. Because glial cell activation could also be involved in the development of opioid tolerance in rats, the authors studied the antinociceptive effects of ibudilast and morphine in different models of coadministration. Methods Antinociception was assessed using male Sprague- Dawley rats in hot plate and tail-flick tests. The effects of ibudilast on acute morphine-induced antinociception, induction of morphine tolerance, and established morphine tolerance were studied. Results Systemic ibudilast produced modest dose-related antinociception and decreased locomotor activity at the studied doses of 2.5-22.5 mg/kg. The highest tested dose of 22.5 mg/kg produced 52% of the maximum possible effect in the tail-flick test. It had an additive antinociceptive effect when combined with systemic morphine. Coadministration of ibudilast with morphine did not attenuate the development of morphine tolerance. However, in morphine-tolerant rats, ibudilast partly restored morphine-induced antinociception. Conclusions Ibudilast produces modest antinociception, and it is effective in restoring but not in preventing morphine tolerance. The mechanisms of the effects of ibudilast should be better understood before it is considered for clinical use.


2013 ◽  
Vol 2013 ◽  
pp. 1-14 ◽  
Author(s):  
Duan-Yong Liu ◽  
Chun-Shui Pan ◽  
Yu-Ying Liu ◽  
Xiao-Hong Wei ◽  
Chang-Man Zhou ◽  
...  

Huang Qi Jian Zhong Pellet (HQJZ) is a famous Chinese medicine formula for treatment of various gastrointestinal tract diseases. This study investigated the role of HQJZ in 2,4,6-trinitrobenzene sulfonic acid- (TNBS-) induced colitis and its underlying mechanism. Colonic mucosal injury was induced by TNBS in the Sprague-Dawley rats. In the HQJZ treatment group, HQJZ was administered (2 g/kg) for 14 days starting from day 1 after TNBS infusion. Colonic mucosal injury occurred obviously 1 day after TNBS challenge and did not recover distinctively until day 15, including an increase in macro- and microscopic scores, a colonic weight index, a decrease in colonic length, a number of functional capillaries, and blood flow. Inverted intravital microscopy and ELISA showed colonic microcirculatory disturbances and inflammatory responses after TNBS stimulation, respectively. TNBS decreased occludin, RhoA, and ROCK-I, while increasing Rac-1, PAK-1, and phosphorylated myosin light chain. In addition, ATP content and ATP5D expression in colonic mucosa decreased after TNBS challenge. Impressively, treatment with HQJZ significantly attenuated all of the alterations evoked by TNBS, promoting the recovery of colonic injury. The present study demonstrated HQJZ as a multitargeting management for colonic mucosal injury, which set in motion mechanisms involving improvement of energy metabolism.


1990 ◽  
Vol 258 (6) ◽  
pp. F1538-F1546 ◽  
Author(s):  
C. E. Johanson ◽  
V. A. Murphy

Agents that inhibit or stimulate Na+ transport were tested for their effects on the ionic composition and volume of the in vivo choroid plexus (CP) epithelium. Ketamine-anesthetized adult Sprague-Dawley rats treated 1 h with acetazolamide or insulin were analyzed for choroid cell [Na+]i, [HCO3-]i, and pHi (dimethadione method); for transmembrane Na+ and H+ gradients; and for the kinetics of penetration of 22Na from plasma to plexus epithelium to CSF. Acetazolamide (25 mg/kg) reduced [Na+]i by 5-10 mmol/l and substantially elevated [HCO3-]i and pHi; the concurrent 22Na uptake by the in vivo choroid plexus and CSF, as quantified by the transfer coefficient, Kin (ml.g-1.h-1), was curtailed by 55-60%. Such effects on Na+ transport and distribution are likely secondary to the alkalinization of pHi induced by carbonic anhydrase inhibition. Conversely, insulin (3 U/kg ip) stimulated Na+ transport, i.e., manifested as enhanced uptake of 22Na from plasma to choroid cell and increased [Na+]i. For various treatments altering the basolateral membrane H+ gradient, the regression analysis of the 22Na Kin vs. log [H+]i/[H+]ISF (where ISF is interstitial fluid) was significant at P less than 0.01. This is consistent with effects mediated by Na(+)-H+ exchange. K+ and Cl- redistribution phenomena were coincident with altered Na+ transport, as choroidal cells retained K+, Cl-, and H2O after acetazolamide but lost K+, Cl-, and H2O with insulin treatment. A model is presented relating alterations in CP Na+ transport, KCl content, and cell volume. Overall, the findings encourage the postulate for effects of these drugs on Na+ transport basolaterally, either indirectly by attenuating [H+]i/[H+]ISF (acetazolamide) or directly by accelerating Na+ transport (insulin).


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