Kevin John Mills

Epidermal changes associated with symptomatic resolution of dandruff: biomarkers of scalp health

Background  Dandruff is a common scalp condition characterized by flakes, pruritus and sometimes mild erythema. These symptoms reflect underlying histopathologic and biochemical events that must be reversed if treatment is to be effective.

Dandruff/seborrhoeic dermatitis is characterized by an inflammatory genomic signature and possible immune dysfunction: transcriptional analysis of the condition and treatment effects of zinc pyrithione

Background  Dandruff/seborrhoeic dermatitis is a common scalp condition that is characterized by flakes, pruritus and sometimes mild erythema. These symptoms reflect tissue level events that are poorly understood at the molecular level.

Population level rhythms in human skin: implications for circadian medicine

Skin is the largest organ in the body and serves important barrier, regulatory, and sensory functions. Like other tissues, skin is subject to temporal fluctuations in physiological responses under both homeostatic and stressed states. To gain insight into these fluctuations, we investigated the role of the circadian clock in the transcriptional regulation of epidermis using a hybrid experimental design, where a limited set of human subjects (n=20) were sampled throughout the 24 h cycle and a larger population (n=219) were sampled once. By looking at pairwise correlations of core clock genes in 298 skin samples, we found a robust circadian oscillator in skin at the population level. Encouraged by this, we used CYCLOPS to reconstruct the temporal order of all samples and identified hundreds of rhythmically-expressed genes at the population level in human skin. We compared these results with published time-series skin data from mouse and show strong concordance in circadian phase across species for both transcripts and pathways. Further, like blood, skin is readily accessible and a potential source of biomarkers. Using ZeitZeiger, we identified a biomarker set for human skin that is capable of reporting circadian phase to within 3 h from a single sample. In summary, we show rhythms in human skin that persist at the population scale and a path to develop robust single-sample circadian biomarkers. One Sentence Summary Human epidermis shows strong circadian rhythms at the population scale and provides a better source for developing robust, single-sample circadian phase biomarkers than human blood.

Analysis of gene expression profiles of multiple skin diseases identifies a conserved signature of disrupted homeostasis

Triggers of skin disease pathogenesis vary, but events associated with the elicitation of a lesion share many features in common. Our objective was to examine gene expression patterns in skin disease to develop a molecular signature of disruption of cutaneous homeostasis. Gene expression data from common inflammatory skin diseases (eg psoriasis, atopic dermatitis, seborrhoeic dermatitis and acne) and a novel statistical algorithm were used to define a unifying molecular signature referred to as the “unhealthy skin signature” (USS). Using a pattern‐matching algorithm, analysis of public data repositories revealed that the USS is found in diverse epithelial diseases. Studies of milder disruptions of epidermal homeostasis have also shown that these conditions converge, to varying degrees, on the USS and that the degree of convergence is related directly to the severity of homeostatic disruption. The USS contains genes that had no prior published association with skin, but that play important roles in many different disease processes, supporting the importance of the USS to homeostasis. Finally, we show through pattern matching that the USS can be used to discover new potential dermatologic therapeutics. The USS provides a new means to further interrogate epithelial homeostasis and potentially develop novel therapeutics with efficacy across a spectrum of skin conditions.