Toll-like Receptor 4 Signaling is Critical for the Adaptive Cellular Stress Response Effects Induced by Intermittent Fasting in the Mouse Brain.

Among different kinds of dietary energy restriction, intermittent fasting (IF) has been considered a dietary regimen which causes a mild stress to the organism. IF can stimulate proteins and signaling pathways related to cell stress that can culminate in the increase of the body resistance to severe stress conditions. Energy intake reduction induced by IF can induce modulation of receptors, kinases, and phosphatases, which in turn can modulate the activation of transcription factors such as NF-E2-related factor 2 (NRF2) and cAMP response element-binding (CREB) which regulate the transcription of genes related to the translation of proteins such as growth factors: brain-derived neurotrophic factor (BDNF), chaperone proteins: heat shock proteins (HSP), and so on. It has been shown that toll-like receptors (TLRs) are important molecules in innate immune response which are present not only in the periphery but also in neurons and glial cells. In central nervous system, TLRs can exert functions related to set up responses to infection, as well as influence neural progenitor cell proliferation and differentiation, being involved in cognitive parameters such as learning and memory. Little is known about the involvement of TLR4 on the beneficial effects induced by IF protocol. The present work investigated the effects of IF on memory and on the signaling mechanisms associated with NRF2 and CREB in Tlr4 knockout mice. The results suggest that TLR4 participates in the modulatory effects of IF on oxidative stress levels, on the transcription factors CREB and NRF2, and on BDNF and HSP90 expressions in hippocampus.

Metastasis of renal clear-cell carcinoma to the oral mucosa, an atypical location

The majority of cases of metastatic tumors involve the mandible and some the maxilla but they are considerably lesscommon in intraoral soft tissues. In addition, the primary tumor is known in the majority of cases; although in onethirdof such cases, metastasis is the first clinical manifestation. The most common primary tumors metastasizingto the mouth are lung carcinoma in men and breast carcinoma in women. An oral metastasis implies a serious prognosis,as in the majority of patients there is multiple organ involvement at the time of diagnosis. We present the caseof a 52-year old patient with renal pathology who came to the emergency room due to a rapidly increasing gingivaltumor. With the provisional clinical diagnosis of a pyogenic granuloma,the tumor was excised. Subsequent anatomopathologicalanalysis revealed a tumor metastasis compatible with clear-cell carcinoma, and its renal originwas confirmed by means of immunohistochemical techniques (AU)