Microtubules are a vital component of the cell’s cytoskeleton and their organization is crucial for healthy cell functioning. The use of label-free SH imaging of microtubules remains limited, as sensitive detection is required and the true molecular origin and main determinants required to generate SH from microtubules are not fully understood. Using advanced correlative imaging techniques, we identified the determinants of the microtubule-dependent SH signal. Microtubule polarity, number and organization determine SH signal intensity in biological samples. At the molecular level, we show that the GTP-bound tubulin dimer conformation is fundamental for microtubules to generate detectable SH signals. We show that SH imaging can be used to study the effects of microtubule-targeting drugs and proteins and to detect changes in tubulin conformations during neuronal maturation. Our data provide a means to interpret and use SH imaging to monitor changes in the microtubule network in a label-free manner.

Butyrate is a bioactive molecule produced by the intestinal flora and plays a major role in a variety of inflammatory diseases. Increasing evidence indicates that butyrate can regulate the occurrence and development of atherosclerosis. Coincidentally, it reduces hyperlipidemia and hyperglycemia, which are major risk factors of atherosclerosis. However, the mechanism by which butyrate regulates the development of atherosclerosis remains unclear. In this article, we review the effect of butyrate treatment on atherosclerosis with a focus on the mechanisms of butyrate-mediated modulation of several atherosclerotic processes. These include the improvement of monocyte-endothelial interactions, macrophage lipid accumulation, smooth muscle cell proliferation and migration, and lymphocyte differentiation and function. The existing research indicates that butyrate treatment may be a potentially effective strategy for the prevention of atherosclerosis. Identity and underlying mechanisms of the molecular pathways of these interactions should be explored in the future to counter atherosclerosis effectively.