Methods in molecular biology
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Normal and tumor stem cells are present in rare quantities in tissues and this has historically represented a major hurdle to in-depth investigations of their biology. In the case of the mammary gland, the relative promiscuity of the immunophenotypical markers described in several studies for the isolation of human and mouse mammary stem cells limits their usefulness, in particular when highly purified mammary stem cell fractions are required for an in-depth molecular and functional characterization (Stingl et al. Nature 439:993-997, 2006; Shackleton et al. ⋯ Cell 138:1083-1095, 2009). Following mammosphere dissociation, the differential degree of PKH26 epifluorescence displayed by stem cells compared to precursor cells is exploited for their purification by FACS sorting. As a result, the scarcely represented PKH26-labeled mammary stem cells are purified to near homogeneity and can be used for further molecular and biological studies.
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The field of psychoneuroimmunology (PNI) aims to uncover the processes and consequences of nervous, immune, and endocrine system relationships. Behavior is a consequence of such interactions and manifests from a complex interweave of factors including immune-to-neural and neural-to-immune communication. Often the signaling molecules involved during a particular episode of neuroimmune activation are not known but behavioral response provides evidence that bioactives such as neurotransmitters and cytokines are perturbed. ⋯ Immunobehaviors include lethargy, loss of appetite, and disinterest in social activity and the surrounding environment. In addition, neuroimmune activation can precipitate feelings of depression and anxiety while negatively impacting cognitive function and physical activity. Provided is a detailed overview of behavioral tests frequently used to examine neuroimmune activation in mice with a special emphasis on preexperimental conditions that can confound or prevent successful immunobehavioral experimentation.
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Spinal cord injury-induced pain is a common clinical problem affecting adversely the quality of daily lives of spinal cord injured patients. Management with current pain medications can only lead to partial pain relief in some spinal cord injured patients, which is usually associated with unfavorable side effects. ⋯ We describe here the generation of a spinal cord contusion injury model that mimics the etiology and phenotypes of chronic pain states in spinal cord injured patients. Therefore, this model can be a useful tool for studying spinal cord injury mechanisms, functional recovery, research, and development of new medications for better functional and symptomatic improvements, including pain management.
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The spared nerve injury (SNI) model mimics human neuropathic pain related to peripheral nerve injury and is based upon an invasive but simple surgical procedure. Since its first description in 2000, it has displayed a remarkable development. ⋯ Besides, variants of the SNI model have been developed in rats, mice and neonatal/young rodents, resulting in several possible angles of analysis. Therefore, the purpose of this chapter is to provide a detailed guidance regarding the SNI model and its variants, highlighting its surgical and behavioural testing specificities.
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Protocols for high-resolution respirometry (HRR) of intact cells, permeabilized cells, and permeabilized muscle fibers offer sensitive diagnostic tests of integrated mitochondrial function using standard cell culture techniques and small needle biopsies of muscle. Multiple substrate-uncoupler-inhibitor titration (SUIT) protocols for analysis of oxidative phosphorylation improve our understanding of mitochondrial respiratory control and the pathophysiology of mitochondrial diseases. Respiratory states are defined in functional terms to account for the network of metabolic interactions in complex SUIT protocols with stepwise modulation of coupling and substrate control. ⋯ Substrate control with electron entry separately through Complex I (pyruvate + malate or glutamate + malate) or Complex II (succinate + rotenone) restricts ETS capacity and artificially enhances flux control upstream of the Q-cycle, providing diagnostic information on specific branches of the ETS. Oxygen levels are maintained above air saturation in protocols with permeabilized muscle fibers to avoid experimental oxygen limitation of respiration. Standardized two-point calibration of the polarographic oxygen sensor (static sensor calibration), calibration of the sensor response time (dynamic sensor calibration), and evaluation of instrumental background oxygen flux (systemic flux compensation) provide the unique experimental basis for high accuracy of quantitative results and quality control in HRR.