Particularly interesting potential spermidine target gene is POP3, which belongs to the highly conserved popeye domain-containing family, and has been implicated in cell adherence and migration. Although these microarray results could not be further validated since all available HF samples and sections had been consumed for the analyses reported here, our preliminary data provide new leads to previously unsuspected spermidine target genes in human tissue physiology. An intriguing chance observation of our study was the finding that spermidine clearly up-regulated transcription of K77 in the HFs of two female patients. Since this keratin has previously been claimed to be exclusively expressed in eccrine glands, we are now LY2157299 following this lead up on the gene and protein level in order to obtain deeper insights into the unexpected and enigmatic functions that K77 may have in human HF biology, and why expression of this gene is so spermidine-sensitive. In summary, our study provides the first evidence that spermidine directly impacts on the growth, cycling, keratin expression and epithelial progenitor functions of human HFs. Due to its anagen-prolonging effects, spermidine deserves rigorous clinical testing as a candidate anti-hair loss agent. It could become an adjuvant therapy for hair loss disorders associated with premature catagen induction, leading to telogen effluvium, and/ or reduced hair shaft production. Moreover, we show that the complex regulatory role of polyamines in human epithelial biology in situ extends far beyond the mere stimulation of proliferation. Our study also documents that, to further dissect the full range of polyamine functions in normal human tissue physiology, human HF organ culture offers a highly instructive, clinically relevant research tool. Elucidation of the genetic factors involved in schizophrenia is one of the major challenges in current neurobiology. LRRTM1 is an emerging candidate gene for schizophrenia. A three-marker haplotype upstream of LRRTM1 on 2p12 is associated with schizophrenia/schizoaffective disorder when inherited paternally. In biological terms, LRRTM1 and Lrrtm1 encode a single-membrane-spanning transmembrane protein with a leucinerich repeat domain in its N-terminal side, and they are predominantly expressed in the nervous systems of humans and mice, respectively. Tagged-rat Lrrtm1 protein is localized in the excitatory synapses of cultured hippocampal neurons and shows synaptogenic activity in neuron/fibroblast coculture assay. Furthermore, the distribution of vesicular glutamate transporter is altered in Lrrtm1�C/�C mice. These results raise the possibility that Lrrtm1 is essential for higher brain function inmammals, but this possibility has not been Fingolimod addressed to date.