Three Cases of Lymphocytic Infiltration of the Eyelid

Lymphocytic infiltration of the skin (LIS), first reported by Jessner and Kanof in 1953, is a disease of unknown etiology characterized by erythematous papules and plaques on the head, neck, and upper back and histopathological findings of a normal epidermis with underlying lymphocytic infiltration of the reticular dermis without mucin deposition. A 69-year-old man and a 21-year-old woman presented with edematous indurative erythema of the left upper eyelid. Lymphocytic infiltration of the dermis with CD4+ T cell predominance was noted on biopsy. A 68-year-old man presented with a four-year history of recurrent edematous indurative erythema of the right upper eyelid that extended up to the right cheek. Predominantly dermal infiltration of CD8+ T lymphocytes was found on biopsy. We treated all three patients with 8–16 mg of methylprednisolone daily, and the erythema and induration improved. CD4+ T cells were predominant in the acute phase (patients 1 and 2), whereas CD8+ T cells were predominant in the chronic phase (patient 3). CD8+ T cells may be involved in LIS recurrence. Lymphocytic infiltration of the eyelid may be associated with isolated circumscribed, edematous, indurative, colorless lesions that are responsive to daily low-to-middle doses of oral methylprednisolone.

ANATOMICAL STUDY OF MORINGA LEAF (MORINGA OLEIFERA LAM.) UNDER IRON FERTILIZATION

The effect of different levels of nano- and mineral-Iron and their method of application on anatomical properties of the upper and lower epidermis of Moringa (Moringa oleifera Lam.) leaves was studied. Seeds of Moringa were sown in 15 kgs soil capacity pots during the growing season of 2018/2019 arranged as a factorial experiment within Completely Randomized Design, with three replicates. The factorswere a method of fertilization(soil or foliar application),three levels i.e. 0,180 and 360mg.l-1 of each of mineral and nano-Iron. The total number of experimental units was 2×3×3×3 for method, nano-Iron, mineral-Iron, and replicates respectively.The application method caused an increase in the mean dimensions of normal epidermis cells, stomatoes, and hairs.These traits were increased as Iron levels increased. Where 360 mg.l-1 of both types of Iron gave the highest dimensions. Soil application gave higher values of epidermis dimensions than that obtained from the foliar application. The number of stomatoesincreased with increasing the level of Iron. The number of normal epidermis cells was conversely proportioned with their volume.

Trichohyalin-like 1 protein plays a crucial role in proliferation and anti-apoptosis of normal human keratinocytes and squamous cell carcinoma cells

Epidermal differentiation is a complex process that requires the regulated and sequential expression of various genes. Most fused-type S100 proteins are expressed in the granular layer and it is hypothesized that these proteins may be associated with cornification and barrier formation. We previously identified a member of the fused-type S100 proteins, Trichohyalin-like 1 (TCHHL1) protein. TCHHL1 is distributed in the basal layer of the normal epidermis. Furthermore, the expression is markedly increased in cancerous/non-cancerous skin samples with the hyperproliferation of keratinocytes. We herein examined the role of TCHHL1 in normal human keratinocytes (NHKs) and squamous cell carcinoma (SCC). The knockdown of TCHHL1 by transfection with TCHHL1 siRNA significantly inhibited proliferation and induced the early apoptosis of NHKs. In TCHHL1-knockdown NHKs, the level of extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation was markedly decreased. In addition, the slight inhibition of v-akt murine thymoma viral oncogene homolog (AKT) phosphorylation and upregulation of forkhead box-containing protein O1(FOXO1), B-cell lymphoma2 (BCL2) and Bcl2-like protein 11 (BCL2L11) was observed. Skin-equivalent models built by TCHHL1-knockdown NHKs showed a markedly hypoplastic epidermis. These findings highlight that TCHHL1 plays an important role in homeostasis of the normal epidermis. TCHHL1 was expressed in the growing cells of cutaneous SCC; therefore, we next examined an association with the cell growth in HSC-1 cells (a human SCC line). In HSC-1 cells, the knockdown of TCHHL1 also suppressed cell proliferation and induced apoptosis. These cells showed an inhibition of phosphorylation of ERK1/2, AKT and signal transducers and activator of transcription 3, and the significant upregulation of FOXO1, BCL2, and BCL2L11. Accordingly, TCHHL1 is associated with survival of cutaneous SCC. In addition, we hypothesize that TCHHL1 may be a novel therapeutic target in cutaneous SCC.

Keratin 17 is induced in prurigo nodularis lesions

Prurigo nodularis (PN) is a highly pruritic chronic inflammatory dermatosis with unknown pathogenesis. It is characterized by the existence of many hyperkeratotic, erosive papules and nodules, and the development of lesions may be associated with hyperproliferation and aberrant differentiation of keratinocytes. Keratin 17 (K17) is overexpressed selectively in human proliferative skin diseases, promoting keratinocyte proliferation not found in normal epidermis. In this study, we investigated the mRNA levels and protein levels of K17 in lesional and perilesional skin using quantitative real-time polymerase chain reaction and western blot. We demonstrate that K17 is induced in lesional and perilesional skin in PN. The mRNA expression level of K17 was upregulated in PN lesions (P < 0.01), with multifold changes in the PN lesion (normalized to glyceraldehyde-3-phosphate dehydrogenase as the housekeeping gene) showing a median positive correlation with PRUNOSI (P < 0.05). The protein level of K17 was also markedly increased in PN lesions (P < 0.01). In conclusion, K17 is highly induced in PN lesions, which may contribute to the proliferation of keratinocytes and the pathogenesis of PN.

Re-epithelialization and immune cell behaviour in an ex vivo human skin model

A large body of literature is available on wound healing in humans. Nonetheless, a standardized ex vivo wound model without disruption of the dermal compartment has not been put forward with compelling justification. Here, we present a novel wound model based on application of negative pressure and its effects for epidermal regeneration and immune cell behaviour. Importantly, the basement membrane remained intact after blister roof removal and keratinocytes were absent in the wounded area. Upon six days of culture, the wound was covered with one to three-cell thick K14+Ki67+ keratinocyte layers, indicating that proliferation and migration were involved in wound closure. After eight to twelve days, a multi-layered epidermis was formed expressing epidermal differentiation markers (K10, filaggrin, DSG-1, CDSN). Investigations about immune cell-specific manners revealed more T cells in the blister roof epidermis compared to normal epidermis. We identified several cell populations in blister roof epidermis and suction blister fluid that are absent in normal epidermis which correlated with their decrease in the dermis, indicating a dermal efflux upon negative pressure. Together, our model recapitulates the main features of epithelial wound regeneration, and can be applied for testing wound healing therapies and investigating underlying mechanisms.

Do DLX3 and CD271 Protect Human Keratinocytes from Squamous Tumor Development?

Well-regulated epidermal homeostasis depends on the function of different classes of factors, such as transcription regulators and receptors. Alterations in this homeostatic balance may lead to the development of cutaneous squamous tumorigenesis. The homeobox transcription factor DLX3 is determinant for a p53-dependent regulation of epidermal differentiation and modulates skin carcinogenesis. The maintenance of skin homeostasis also involves the action of neurotrophins (NTs) and their receptors, Trk and CD271. While Trk receptor overexpression is a hallmark of cancer, there are conflicting data on CD271 expression and function in cutaneous SCC (cSCC). Previous studies have reported NT receptors expression in head and neck SSC (HNSCC). We show that CD271 is expressed at low levels in primary cSCC cells and the number of CD271+ cells correlates with cell cohesion in SCC spheroids. In normal epidermis, CD271 is expressed in proliferative progenitor cells and DLX3 in terminally differentiated keratinocytes. Brain-derived neurotrophic factor (BDNF) and neurotrophin 3 (NT3) increase DLX3 expression. In the absence of a functional BDNF receptor TrkB in keratinocytes, we hypothesize that the BDNF-dependent DLX3 response could be mediated via CD271. Altogether, our results support a putative CD271-DLX3 connection in keratinocytes, which might be crucial to preventing squamous skin cancer.

Diferenciación celular en el queratinocito epidérmico de caninos durante la carcinogénesis

La epidermis está expuesta a agresiones ambientales sostenidas tales como la radiación ultravioleta, los carcinógenos químicos y las infecciones virales. Como resultado, el queratinocito epidérmico tiene un riesgo aumentado de adquirir alteraciones genéticas y epigenéticas que le permitan impulsar la progresión hacia un fenotipo celular tumoral. El tipo de tumor epidérmico que se desarrolle, así como también su comportamiento biológico, será el reflejo de la actividad desregulada de distintas vías de señalización celular. En este sentido, el estudio de los mecanismos moleculares desregulados durante el proceso de carcinogénesis epidérmica en los caninos puede proporcionar dianas terapéuticas adecuadas para el desarrollo de nuevas terapias para los pacientes con neoplasias de la epidermis interfolicular (NEIF). Por lo tanto, el propósito de este estudio fue evaluar el patrón de expresión inmunohistoquímico de diferentes moléculas implicadas en procesos celulares claves (pEGFRTyr1068, pAktSer473, pS6Ser235/236, Ki-67, PTEN, YAP, β-catenina, E-cadherina, CK5 y p63) en muestras de epidermis normal, epidermis preneoplásica, papilomas cutáneos y carcinomas de células escamosas cutáneos de caninos mediante el uso de micromatrices de tejidos. Los resultados demuestran que las moléculas de señalización implicadas en la vía de señalización PI3K/Akt/mTOR se activan con frecuencia en las NEIF caninas, pero que esta activación puede ser independiente de la activación del EGFR. Además, se encontró la expresión desregulada de YAP, β-catenina y E-cadherina en la mayoría de las NEIF. Finalmente, se demuestra, mediante la evaluación conjunta de p63/CK5, que las células madre epidérmicas desempeñan un papel importante durante el proceso de carcinogénesis epidérmica. Estos hallazgos demuestran que las NEIF caninas pueden albergar alteraciones complementarias en múltiples moléculas de señalización que convergen para impulsar la adquisición de un fenotipo maligno en los queratinocitos. Esta información emergente proporciona un marco molecular adecuado para el desarrollo de nuevas terapias basadas en objetivos moleculares para los pacientes caninos con NEIF.

IL-17R–EGFR axis links wound healing to tumorigenesis in Lrig1+ stem cells

Lrig1 marks a distinct population of stem cells restricted to the upper pilosebaceous unit in normal epidermis. Here we report that IL-17A–mediated activation of EGFR plays a critical role in the expansion and migration of Lrig1+ stem cells and their progenies in response to wounding, thereby promoting wound healing and skin tumorigenesis. Lrig1-specific deletion of the IL-17R adaptor Act1 or EGFR in mice impairs wound healing and reduces tumor formation. Mechanistically, IL-17R recruits EGFR for IL-17A–mediated signaling in Lrig1+ stem cells. While TRAF4, enriched in Lrig1+ stem cells, tethers IL-17RA and EGFR, Act1 recruits c-Src for IL-17A–induced EGFR transactivation and downstream activation of ERK5, which promotes the expansion and migration of Lrig1+ stem cells. This study demonstrates that IL-17A activates the IL-17R–EGFR axis in Lrig1+ stem cells linking wound healing to tumorigenesis.