Intrastriatal Injection of Autologous Blood or Clostridial Collagenase as Murine Models of Intracerebral Hemorrhage

Summary

Preclinical models of intracerebral hemorrhage are utilized to mimic certain aspects of clinical disease. Thus, mechanisms of injury and potential therapeutic strategies may be explored. In this protocol, two models of intracerebral hemorrhage are described, intrastriatal (basal ganglia) injections of autologous blood or collagenase.

Abstract

Intracerebral hemorrhage (ICH) is a common form of cerebrovascular disease and is associated with significant morbidity and mortality. Lack of effective treatment and failure of large clinical trials aimed at hemostasis and clot removal demonstrate the need for further mechanism-driven investigation of ICH. This research may be performed through the framework provided by preclinical models. Two murine models in popular use include intrastriatal (basal ganglia) injection of either autologous whole blood or clostridial collagenase. Since, each model represents distinctly different pathophysiological features related to ICH, use of a particular model may be selected based on what aspect of the disease is to be studied. For example, autologous blood injection most accurately represents the brain's response to the presence of intraparenchymal blood, and may most closely replicate lobar hemorrhage. Clostridial collagenase injection most accurately represents the small vessel rupture and hematoma evolution characteristic of deep hemorrhages. Thus, each model results in different hematoma formation, neuroinflammatory response, cerebral edema development, and neurobehavioral outcomes. Robustness of a purported therapeutic intervention can be best assessed using both models. In this protocol, induction of ICH using both models, immediate post-operative demonstration of injury, and early post-operative care techniques are demonstrated. Both models result in reproducible injuries, hematoma volumes, and neurobehavioral deficits. Because of the heterogeneity of human ICH, multiple preclinical models are needed to thoroughly explore pathophysiologic mechanisms and test potential therapeutic strategies.

Introduction

Intracerebral hemorrhage (ICH) is a relatively common form of cerebrovascular disease with approximately 40–50% of afflicted patients dying within 30 days ¹. Unfortunately, little improvement has been made in the mortality rate over the last 20 years ². Reports from the National Institutes of Health ³ and guidelines from the American Heart Association ⁴ stressed the importance of developing clinically relevant models of ICH to extend the understanding of pathophysiology and develop targets for new therapeutic approaches.

Several models exist to mimic human ICH ⁵. As understanding ....

Protocol

Ethics Statement: This protocol has been approved by the Duke University Institutional Animal Care and Use Committee and follows all the guidelines for the ethical use of animals.

1. Preparation of Equipment

1. Autoclave the surgical tools prior to surgery.
2. Disinfect the stereotactic apparatus with 70% ethanol.
3. Turn on water bath and keep water temperature at 42 °C.
4. Dissolve Type IV-S clostridial collagenase in normal saline at a concentration of 0.075 U per 0.4 µl.

2. Collagenase Injection Model

1. Weigh the mouse.
2. Anesthetize the mouse i....

Results

Due to differences in hematoma formation (Figure 1), ipsilateral turning is shown immediately after wake up for autologous blood injected mice and within 2 - 4 hr after collagenase injection, as hematoma expansion occurs (Figure 2). Absence of ipsilateral turning should raise concern for absence of significant injury. On the first post injury day, mice in both models should demonstrate significant neurological deficits (Figure 3). At 24 hr after injection, ipsilateral he.......

Discussion

Despite emerging preclinical research and resultant large clinical trials for promising therapeutics ^15-18, there are no pharmacological interventions demonstrated to improve outcome in ICH, and care remains largely supportive. Lists of possible therapies may be generated by high throughput technologies, such as transcriptomic and proteomic work. While these technologies continue to advance our knowledge of potential therapeutic targets, forward and backward translation of promising targets may be best examine.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Stereotactic frame	Stoelting Co.	51603
Probe holder with corner clamp	Stoelting Co.	51631
Mini grinder	Power Glide	Model 60100002
0.5 μl syringe	Microliter	86259	25 G needle
5 μl syringe	Microliter	7637-01
30 G microliter syringe	Microliter	7762-03
Syringe pump	KD Scientific	Model 100
Heat therapy water pump	Gaymar Industries, Inc.	Model# TP650
Circulating waterbed	CMS Tool & Die, Inc.
Rodent ventilator	Harvard Apparatus	Model 683
Isoflurane vaporizer	Drager	Vapor 19.1
Air flowmeter	Cole Parmer	Model PMR1-010295
Induction chamber			Self made
Otoscope	Welch Allyn	22820
Intravenous catheter	Becton-Dickinson	381534	20 G, 1.16 inch Insyte-W
Isoflurane	Baxter Healthcare Corporation	NDC10019-360-69
Collagenase Type IV-S	Sigma	C1889
Polyethylene tubing PE10	Becton-Dickinson	427401
27 G 1 1/4 inch needle	Becton-Dickinson	305136
Surgical scissors	Miltex	21-539
Forceps	Miltex	17-307
Needle holder	Boboz	RS-7840
Monofilament suture	Ethicon	8698	Size 5-0
Indicating controller	YSI	73ATD