Melatonin protects rats from radiotherapy-induced small intestine toxicity

Radiotherapy-induced gut toxicity is among the most prevalent dose-limiting toxicities following radiotherapy. Prevention of radiation enteropathy requires protection of the small intestine. However, despite the prevalence and burden of this pathology, there are currently no effective treatments for radiotherapy-induced gut toxicity, and this pathology remains unclear. The present study aimed to investigate the changes induced in the rat small intestine after external irradiation of the tongue, and to explore the potential radio-protective effects of melatonin gel. Male Wistar rats were subjected to irradiation of their tongues with an X-Ray YXLON Y.Tu 320-D03 irradiator, receiving a dose of 7.5 Gy/day for 5 days. For 21 days post-irradiation, rats were treated with 45 mg/day melatonin gel or vehicle, by local application into their mouths. Our results showed that mitochondrial oxidative stress, bioenergetic impairment, and subsequent NLRP3 inflammasome activation were involved in the development of radiotherapy-induced gut toxicity. Oral treatment with melatonin gel had a protective effect in the small intestine, which was associated with mitochondrial protection and, consequently, with a reduced inflammatory response, blunting the NF-κB/NLRP3 inflammasome signaling activation. Thus, rats treated with melatonin gel showed reduced intestinal apoptosis, relieving mucosal dysfunction and facilitating intestinal mucosa recovery. Our findings suggest that oral treatment with melatonin gel may be a potential preventive therapy for radiotherapy-induced gut toxicity in cancer patients.This study was partially supported by grant no. SAF2009-14037 from the Spanish Ministry of Economy and Competitivity (MINECO), GREIB.PT_2010_04 from the CEIBiotic Program of the University of Granada, Spain, and CTS-101 from the Consejería de Innovación, Ciencia y Empresa, Junta de Andalucía, Spain

(−)-Epigallocatechin-3-Gallate Diminishes Intra-and Extracellular Amyloid-Induced Cytotoxic Effects on Cholinergic-like Neurons from Familial Alzheimer’s Disease PSEN1 E280A

Alzheimer’s disease (AD) is a complex neurodegenerative disease characterized by functional disruption, death of cholinergic neurons (ChNs) because of intracellular and extracellular Aβ aggregates, and hyperphosphorylation of protein TAU (p-TAU). To date, there are no efficient therapies against AD. Therefore, new therapies for its treatment are in need. The goal of this investigation was to evaluate the effect of the polyphenol epigallocatechin-3-gallate (EGCG) on cholinergic-like neurons (ChLNs) bearing the mutation E280A in PRESENILIN 1 (PSEN1 E280A). To this aim, wild-type (WT) and PSEN1 E280A ChLNs were exposed to EGCG (5–50 μM) for 4 days. Untreated or treated neurons were assessed for biochemical and functional analysis. We found that EGCG (50 μM) significantly inhibited the aggregation of (i)sAPPβf, blocked p-TAU, increased ∆Ψm, decreased oxidation of DJ-1 at residue Cys106-SH, and inhibited the activation of transcription factor c-JUN and P53, PUMA, and CASPASE-3 in mutant ChLNs compared to WT. Although EGCG did not reduce (e)Aβ42, the polyphenol reversed Ca2+ influx dysregulation as a response to acetylcholine (ACh) stimuli in PSEN1 E280A ChLNs, inhibited the activation of transcription factor NF-κB, and reduced the secretion of pro-inflammatory IL-6 in wild-type astrocyte-like cells (ALCs) when exposed to mutant ChLNs culture supernatant. Taken together, our findings suggest that the EGCG might be a promising therapeutic approach for the treatment of FAD

Cholinergic-like neurons carrying PSEN1 E280A mutation from familial Alzheimer's disease reveal intraneuronal sAPPβ fragments accumulation, hyperphosphorylation of TAU, oxidative stress, apoptosis and Ca2+ dysregulation: Therapeutic implications.

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by progressive memory loss and cognitive disturbance as a consequence of the loss of cholinergic neurons in the brain, neuritic plaques and hyperphosphorylation of TAU protein. Although the underlying mechanisms leading to these events are unclear, mutations in presenilin 1 (PSEN1), e.g., E280A (PSEN1 E280A), are causative factors for autosomal dominant early-onset familial AD (FAD). Despite advances in the understanding of the physiopathology of AD, there are no efficient therapies to date. Limitations in culturing brain-derived live neurons might explain the limited effectiveness of AD research. Here, we show that mesenchymal stromal (stem) cells (MSCs) can be used to model FAD, providing novel opportunities to study cellular mechanisms and to establish therapeutic strategies. Indeed, we cultured MSCs with the FAD mutation PSEN1 E280A and wild-type (WT) PSEN1 from umbilical cords and characterized the transdifferentiation of these cells into cholinergic-like neurons (ChLNs). PSEN1 E280A ChLNs but not WT PSEN1 ChLNs exhibited increased intracellular soluble amyloid precursor protein (sAPPf) fragments and extracellular Aβ42 peptide and TAU phosphorylation (at residues Ser202/Thr205), recapitulating the molecular pathogenesis of FAD caused by mutant PSEN1. Furthermore, PSEN1 E280A ChLNs presented oxidative stress (OS) as evidenced by the oxidation of DJ-1Cys106-SH into DJ-1Cys106-SO3 and the detection of DCF-positive cells and apoptosis markers such as activated pro-apoptosis proteins p53, c-JUN, PUMA and CASPASE-3 and the concomitant loss of the mitochondrial membrane potential and DNA fragmentation. Additionally, mutant ChLNs displayed Ca2+ flux dysregulation and deficient acetylcholinesterase (AChE) activity compared to control ChLNs. Interestingly, the inhibitor JNK SP600125 almost completely blocked TAU phosphorylation. Our findings demonstrate that FAD MSC-derived cholinergic neurons with the PSEN1 E280A mutation provide important clues for the identification of targetable pathological molecules

Integrating Behavioral Health Care into HIV/AIDS Care Clinics in Puerto Rico

People living with HIV/AIDS (PLWHA) are more likely to have mental health needs than the general population. Integrating behavioral health services in the primary care scenario has the potential to improve the physical and psychological well-being of PLWHA. However, this integration requires addressing fundamental issues, such as clinicians training, the development of new administrative processes, and addressing infrastructure issues. We describe the Primary Care Psychology Program (PCPP) in Puerto Rico created to address the mental health needs of PLWHA. PCPP provides care in a multidisciplinary and collaborative manner that focuses on HIV, uses behavioral measures to drive clinical decisions, and provides evidence-based treatments. In addition, the article presents preliminary findings from a retrospective chart review that evidenced improvements of CD4 counts, viral load, and depressive symptoms among PLWHA. We conclude that the primary care behavioral health model has the potential to address the complexities in HIV-care and improve the quality of life among PLWHA in Puerto Rico.Las personas que viven con VIH/SIDA (PVVS) pueden experimentar mayores necesidades de salud mental en comparación con la población general. La integración de servicios de salud conductual en cuidado primario tiene el potencial de mejorar el bienestar psicológico y físico de las PVVS. La integración de estos servicios requiere atender retos fundamentales, como la necesidad de adquirir conocimiento nuevo, desarrollo de procesos administrativos, y atender asuntos de infraestructura. En este artículo describimos el Programa de Psicología de Cuidado Primario (PPCP) desarrollado en Puerto Rico con el objetivo de atender las necesidades de salud mental de las PVVS. El PPCP sigue un modelo de cuidado integrado completo que provee atención multidisciplinaria desde una orientación colaborativa enfocada en el VIH, hace uso de instrumentos específicos al VIH que informan las decisiones clínicas, y provee tratamientos basados en evidencia. Se presentan resultados preliminares de una revisión de expediente retrospectiva en donde se evidencia mejoría en CD4, carga viral y síntomas de depresión entre PVVS. El modelo de cuidado integrado de salud conductual en cuidado primario presenta el potencial de atender las complejidades en el cuidado del VIH y mejorar la calidad de vidade las PVVS en Puerto Rico

Immunohistochemical staining of Ki-67 and ZO-1.

<p>Immunohistochemical staining of the proliferation marker Ki-67 (A) and of the tight junctions protein zonula occludens 1 (ZO-1) (C) in rat small intestine from non-irradiated rats (control) and irradiated rats treated with vehicle (IR) or melatonin gel (IR + aMT). The right panels show details at higher magnification. Scale bar = 100 μm and 50 μm in the left and right panels, respectively. (B, D) Quantification of the staining in A and C; n = 4 per group. Data are expressed as mean ± s.e.m. ***<i>P</i> < 0.001 vs. control and ###<i>P</i> < 0.001 vs. IR.</p

The molecular pathway involved in small intestine damage induced by external radiation, which is inhibited by melatonin gel.

<p>Radiation administered to the tongue induced small intestine damage, activating several molecular pathways. Melatonin gel protected mitochondria and inhibited the NF-κB and NLRP3 inflammasome pathways, reducing inflammation and apoptosis, relieving mucosal dysfunction, and facilitating intestinal mucosa recovery.</p

NLRP3 inflammasome pathway.

<p>Western blot (WB) analysis and densitometric quantification of NLRP3 (A, D), pro-caspase 1 (B, D), and caspase 1 (C, D) in small intestine from non-irradiated (control) and irradiated rats treated with vehicle (IR) or melatonin gel (IR + aMT); n = 6 per group. Data are expressed as mean ± s.e.m. **<i>P</i> < 0.01, ***<i>P</i> < 0.001 vs. control; and ##<i>P</i> < 0.01, ###<i>P</i> < 0.001 vs. IR.</p

Electron microscopy (EM) analysis.

<p>EM images of mitochondria of small intestine cells from non-irradiated rats (control) and irradiated rats treated with vehicle (IR) or melatonin gel (IR + aMT); n = 4 per group. Swollen and less dense mitochondria are indicated by black arrows. Normal mitochondria are indicated by white arrows. Degenerated and shorted villi are indicated by black arrows. Right panels show details at higher magnification. Scale bar = 2 μm and 500 nm in the left and right panels, respectively.</p

Melatonin levels.

<p>HPLC analysis of the melatonin content of the small intestine from non-irradiated rats (control) and irradiated rats treated with vehicle (IR) or melatonin gel (IR + aMT); n = 6 per group. Data are expressed as mean ± s.e.m. ***<i>P</i> < 0.001 vs. control and ###<i>P</i> < 0.001 vs. IR.</p