Systemic coagulopathy promotes host lethality in a new Drosophila tumor model.

Malignant tumors trigger a complex network of inflammatory and wound repair responses, prompting Dvorak's characterization of tumors as "wounds that never heal." Some of these responses lead to profound defects in blood clotting, such as disseminated intravascular coagulopathy (DIC), which correlate with poor prognoses. Here, we demonstrate that a new tumor model in Drosophila provokes phenotypes that resemble coagulopathies observed in patients.

Restoration of Immune Privilege in Human Dermal Papillae Controlling Epithelial-Mesenchymal Interactions in Hair Formation.

Background: Hair follicles are among a handful of organs that exhibit immune privilege. Dysfunction of the hair follicle immune system underlies the development of inflammatory diseases, such as alopecia areata.

Methods: Quantitative reverse transcription PCR and immunostaining was used to confirm the expression of major histocompatibility complex class I in human dermal papilla cells.

Tumour-host interactions through the lens of Drosophila.

There is a large gap between the deep understanding of mechanisms driving tumour growth and the reasons why patients ultimately die of cancer. It is now appreciated that interactions between the tumour and surrounding non-tumour (sometimes referred to as host) cells play critical roles in mortality as well as tumour progression, but much remains unknown about the underlying molecular mechanisms, especially those that act beyond the tumour microenvironment. Drosophila has a track record of high-impact discoveries about cell-autonomous growth regulation, and is well suited to now probe mysteries of tumour - host interactions.

Wound Regeneration Deficit in Rats Correlates with Low Morphogenetic Potential and Distinct Transcriptome Profile of Epidermis.

Large excisional wounds in mice prominently regenerate new hair follicles (HFs) and fat, yet humans are deficient for this regenerative behavior. Currently, wound-induced regeneration remains a clinically desirable, but only partially understood phenomenon. We show that large excisional wounds in rats across seven strains fail to regenerate new HFs.

Regeneration of fat cells from myofibroblasts during wound healing.

Although regeneration through the reprogramming of one cell lineage to another occurs in fish and amphibians, it has not been observed in mammals. We discovered in the mouse that during wound healing, adipocytes regenerate from myofibroblasts, a cell type thought to be differentiated and nonadipogenic. Myofibroblast reprogramming required neogenic hair follicles, which triggered bone morphogenetic protein (BMP) signaling and then activation of adipocyte transcription factors expressed during development.

A Guide to Studying Human Hair Follicle Cycling In Vivo.

Hair follicles (HFs) undergo lifelong cyclical transformations, progressing through stages of rapid growth (anagen), regression (catagen), and relative "quiescence" (telogen). Given that HF cycling abnormalities underlie many human hair growth disorders, the accurate classification of individual cycle stages within skin biopsies is clinically important and essential for hair research. For preclinical human hair research purposes, human scalp skin can be xenografted onto immunocompromised mice to study human HF cycling and manipulate long-lasting anagen in vivo.

Principles and mechanisms of regeneration in the mouse model for wound-induced hair follicle neogenesis.

Wound induced hair follicle neogenesis (WIHN) describes a regenerative phenomenon in adult mammalian skin, wherein fully functional hair follicles regenerate in the center of large excisional wounds. Originally described in rats, rabbits, sheep, and humans in 1940-60, the WIHN phenomenon was reinvestigated in mice only recently. The process of hair regeneration largely duplicates the morphological and signaling features of normal embryonic hair development.

Light-emitting hair follicles: studying skin regeneration with in vivo imaging.

Cutting-edge imaging technologies and new luminescent and fluorescent genetic tools now make it possible to study hair regeneration in vivo in real time at the microscopic single-cell level and at the macroscopic level of hair follicle populations. These technologies also allow for noninvasive assessment of the skin's clinically relevant homeostatic parameters, such as oxidative stress levels and pH.