Table 2:
Assay | Type, Application or Benefit | How to | Difficulties | Reference |
---|---|---|---|---|
Cremaster (IVM) | - Most common for studying recruitment cascade - Only transillumination needed, possibly fluorescence imaging and RLOT - Administration of inflammatory stimuli possible (trauma vs. TNFα vs. fMLP vs. LPS) → local inflammation - CLP for systemic inflammation |
- Inject stimulus (e.g. TNFα intrascrotally) - Wait 2h - Anesthetize mouse - Mobilize cremaster |
- Tissue damage and flow reduction by stretching of the muscle - Bleeding |
- [128] |
Lung (IVM) | Intravital microscopy | - Anesthetize mouse, mechanical ventilation - Thoracic window preparation |
- Motion artefacts - Bleeding - Tissue damage due to thoracic window |
- [129] |
Lung inflammation | - Different disease models ((A) ventilator induced VILI vs. (B) acid induced ALI vs. (C) pneumonia) | - (A) Mechanical ventilation (VILI) - (B) Application of acid (ALI) - (C) Application of bacteria (intratracheal injection) - (C) Bacterial burden (plating of tissue samples) - (A–C) Flow cytometry of whole organ lysates and bronchoalveolar lavage for inflammatory cell recruitment |
- Inhomogeneous injection of bacteria (left vs. right lung) | - (A) ALI. [130] - (B) Bacterial pneumonia:. [11] - (C) LPS induced lung injury: [69] |
Heart (IVM) | Intravital microscopy | - Anesthetize animal - Intubation and mechanical ventilation - Preparation of thorax - Connect ECG - Positioning of suction device or imaging-holder - ECG-triggered imaging |
- Motion artefacts - Bleeding - Tissue damage |
- Heterotopic heart transplant: [43] - Tissue stabilization and acquisition gating: [131] |
Heart inflammation | - LAD occlusion - Lipotoxic cardiomyopathy |
- Anesthesia - Thorax preparation - Ligation of the LAD - Re-opening of LAD if wanted |
- Inconsistent vessel ligation | - LAD occlusion: [93] - Myocarditis: [132] - Lipotoxic cardiomyopathy: [133] - Sepsis related cardiac dysfunction: [134] - Model guidelines: [135] |
Kidney (IVM) | Intravital microscopy | - Anesthesia - Preparation of kidney - Intravital microscopy |
- Bleeding - Non-flat surface for imaging |
- [136] |
Kidney inflammation | (A) Ischemia reperfusion injury vs. (B) Sepsis related acute kidney injury vs. (C) Chronic kidney failure |
(A) - Clamping of both kidneys (B) - Uterine ligation and bacterial inoculation or - CLP (C) - 5/6 nephrectomy |
(A) - Bleeding, organ damage (B) - Inconsistent cecal puncturing or bacterial burden (C) - Inconsistent nephrectomy size |
- (A) IRI: [44] - (B) Sepsis related: Uterine ligation and bacterial inoculation:. [137] - (B) Sepsis related: CLP: [138] - (C) CKD: [124] |
Brain (IVM) | Intravital microscopy, cranial window | - Anesthesia - Disinfect and prepare skin - Thinning of skull bone with micro-drill - Multiphoton imaging |
- Tissue damage, compression artefacts - Bleeding |
- [139] |
Brain inflammation |
(A) CLP vs. (B) EAE vs. (C) Stroke |
(A) Prepare abdomen, ligate and puncture the cecum (B) Subcutaneous injection of Mog35–55 peptide in CFA with 1 mg/ml killed Mycobacterium tuberculosis H37Ra; double injection of i.v. pertussis toxin. (C) MCA electrocoagulation or small filament insertion |
(A) Inconsistent ligation and puncture (B) Scoring difficulties, incongruent resemblance of human MS disease (C) Inconsistent advancement of filament or tissue damage by electrocoagulation |
- (A) [140][91] - (B) [141] - (C) MCA electrocoagulation: [89]; Filament insertion: [142] |
Liver (IVM) | Intravital microscopy | - Anesthesia - Opening of abdominal cavity - Mobilization of liver lobe - Tissue preparation and coverslip attachment - Time lapse microscopy |
- Immobilization - Drying of liver tissue - Duration of imaging |
- [143] |
Liver inflammation | (A) Bacterial vs. (B) Sterile heat injury |
(A) CLP (compare above) or injection of bacteria (B) - Anesthesia - Opening of abdominal cavity - Mobilization of liver lobe - Heat wire injury - Time lapse microscopy |
(A) Compare above (B) Inconsistent injury size; excessive tissue damage |
-(A) MRSA infection: [76] -(B) [41] |
Intestinal inflammation | Colitis (A) Bacterial (B) Dextran sodium sulfate (DSS)-induced |
(A) Antibiotic treatment, followed by gavage of bacteria (B) 1.5 to 3.5% DSS in drinking water for 5 to 9 days |
- Motility - Inconsistent inflammation |
- (A) [144] -(B) [145, 146] |
Fetal (Yolk-sac) (IVM) | Yolk-sac vs. skin vs. skull | - Anesthesia - Prepare abdomen - Exteriorize and incise uterus - Mobilize fetus - Imaging |
- Drying - Tilted surface - Pressure onto vessels |
- [147] |
Joints | Arthritis model | - Serum separation from K/BxN mice - Injection of serum (150–250 μl) intraperitoneally on days 0 and 2 - Clinical scoring |
- Inconsistent injections - Inconsistent blood collection and serum separation from donor mice |
- [148][149] |
Skin (IVM) | Intravital microscopy |
- Anesthesia - Prepare imaging area, for example ear stage - Multiphoton microscopy |
- Movement artefacts - Pigmentation - Z-deviation |
- [150] |
Skin inflammation | (A) Bacterial vs. (B) Allergic skin inflammation |
(A) Intradermal injection in small volume (0.5 – 4 μl) into pinnae of ear or back skin of mice (B) Shave skin, tape-strip 6 times, place patch with chicken egg ovalbumin on skin; sensitization for 7 weeks, challenge on days 0 and 3 after sensitization by application of ovalbumin to shaved, tape-stripped, nonharmed skin area |
- Inconsistent stimulation - Injection of amount of bacteria imprecise or displacement of ovalbumin patch |
-(A) [151] -(B) [152] |
Atherosclerosis | ApoE knockout model | - ApoE−/− mice - High fat diet containing 21% fat (ssniff) |
- Dissimilar lipid metabolism to humans (VLDL vs. LDL) - Possible non-atherosclerosis related inflammatory effects |
- [153] |
Venous thrombosis | Flow restriction model | - Anesthesia - Median laparotomy - Placement of space holder on inferior vena cava - Application of narrowing ligature below left renal vein - Removal of space holder - Flow measurements (reduction by approx. 80% desired) |
- Injury of the vessel wall and subsequent thrombus induction due to endothelial damage - Bleeding - Complete occlusion of the vessel |
- [126] |
Systemic hypoxia | Normobaric hypoxia supply | - Expose animals to hypoxic conditions for set time periods (e.g. 4 hours) - Can be combined with other disease models (such as bacterial pneumonia) |
- Inconsistent oxygen supply - Changes in respiratory rate - Differences in gas-mixtures used for hypoxia induction |
- [50][48] |
Abbreviations Table 2: CFA: Complete Freund’s adjuvant; CLP: Cecal ligation puncture; DSS: Dextran sulfate sodium; EAE: Experimental autoimmune encephalomyelitis; LAD: Left anterior descending; MCA: Middle cerebral artery; MRSA: Methicillin resistant staphylococcus aureus; MS: Multiple sclerosis; RLOT: Reflected light oblique transillumination; VILI: Ventilator induced lung injury, ALI: acute lung injury.