Neuroprotective-Neurorestorative Effects Induced by Progesterone on Global Cerebral Ischemia: A Narrative Review.

Progesterone (P4) is a neuroactive hormone having pleiotropic effects, supporting its pharmacological potential to treat global (cardiac-arrest-related) cerebral ischemia, a condition associated with an elevated risk of dementia. This review examines the current biochemical, morphological, and functional evidence showing the neuroprotective/neurorestorative effects of P4 against global cerebral ischemia (GCI). Experimental findings show that P4 may counteract pathophysiological mechanisms and/or regulate endogenous mechanisms of plasticity induced by GCI. According to this, P4 treatment consistently improves the performance of cognitive functions, such as learning and memory, impaired by GCI. This functional recovery is related to the significant morphological preservation of brain structures vulnerable to ischemia when the hormone is administered before and/or after a moderate ischemic episode; and with long-term adaptive plastic restoration processes of altered brain morphology when treatment is given after an episode of severe ischemia. The insights presented here may be a guide for future basic research, including the study of P4 administration schemes that focus on promoting its post-ischemia neurorestorative effect. Furthermore, considering that functional recovery is a desired endpoint of pharmacological strategies in the clinic, they could support the study of P4 treatment for decreasing dementia in patients who have suffered an episode of GCI.

"They Go Hand in Hand": Perspectives on the Relationship Between the Core Values of Family Medicine and Abortion Provision Among Family Physicians Who Do Not Oppose Abortion.

INTRODUCTION: Most family physicians do not provide abortion care, despite an apparent alignment between the defined values of family medicine and provision of abortion in primary care. This study seeks to understand how family physicians themselves perceive the relationship between their specialty's values and abortion provision. METHODS: We conducted in-depth interviews in 2019 with 56 family physicians who do not oppose abortion in the United States. We employed a deductive-inductive content analysis approach with memos to identify key themes. This analysis focuses on participants' beliefs in the core values of family medicine and how those values relate to abortion in family medicine. RESULTS: Participants identified and described six values of the specialty they prioritized, which included relationships, care across the lifespan, whole-person care, nonjudgmental care, meeting community needs, and social justice. Family physicians in the study overwhelmingly believed that abortion aligned with family medicine values, regardless of whether they themselves provided abortion care. CONCLUSIONS: Providing abortion care in primary care settings gives family physicians an opportunity to provide comprehensive care while improving access to meet community needs. As abortion care becomes increasingly restricted in the United States, family physicians can manifest the values of family medicine through integrating abortion care into their practices in states where abortion remains legal.

Amyloid ß, Lipid Metabolism, Basal Cholinergic System, and Therapeutics in Alzheimer's Disease.

The presence of insoluble aggregates of amyloid ß (Aß) in the form of neuritic plaques (NPs) is one of the main features that define Alzheimer's disease. Studies have suggested that the accumulation of these peptides in the brain significantly contributes to extensive neuronal loss. Furthermore, the content and distribution of cholesterol in the membrane have been shown to have an important effect on the production and subsequent accumulation of Aß peptides in the plasma membrane, contributing to dysfunction and neuronal death. The monomeric forms of these membrane-bound peptides undergo several conformational changes, ranging from oligomeric forms to beta-sheet structures, each presenting different levels of toxicity. Aß peptides can be internalized by particular receptors and trigger changes from Tau phosphorylation to alterations in cognitive function, through dysfunction of the cholinergic system. The goal of this review is to summarize the current knowledge on the role of lipids in Alzheimer's disease and their relationship with the basal cholinergic system, as well as potential disease-modifying therapies.

The Impairment of Blood-Brain Barrier in Alzheimer's Disease: Challenges and Opportunities with Stem Cells.

Alzheimer's disease (AD) is the most common neurodegenerative disorder and its prevalence is increasing. Nowadays, very few drugs effectively reduce AD symptoms and thus, a better understanding of its pathophysiology is vital to design new effective schemes. Presymptomatic neuronal damage caused by the accumulation of Amyloid ß peptide and Tau protein abnormalities remains a challenge, despite recent efforts in drug development. Importantly, therapeutic targets, biomarkers, and diagnostic techniques have emerged to detect and treat AD. Of note, the compromised blood-brain barrier (BBB) and peripheral inflammation in AD are becoming more evident, being harmful factors that contribute to the development of the disease. Perspectives from different pre-clinical and clinical studies link peripheral inflammation with the onset and progression of AD. This review aims to analyze the main factors and the contribution of impaired BBB in AD development. Additionally, we describe the potential therapeutic strategies using stem cells for AD treatment.

Serum anti-neural immunoreactivity in patients with fibromyalgia. Preliminary study.

INTRODUCTION: Fibromyalgia (FM) is a non-degenerative syndrome characterized by generalized, chronic musculoskeletal pain, as well as mood, memory and sleep disorders. OBJECTIVE: To search for serum anti-neural antibodies (ANeuA) in patients with FM (FMP) in order to rule out autoimmune etiology. METHODS: The Fibromyalgia Impact Questionnaire (FIQ) and Beck's depression inventory (BDI) were applied. Immunoreactivity and the target recognized on the sera from FMPs and healthy subjects were analyzed by indirect immunofluorescence and Western blot. RESULTS: Both FIQ and BDI values were significantly altered in FMPs in comparison with those of controls (FIQ, 70 ± 25 vs. 12 ± 12, p < 0.0001; BDI, 17 ± 11 vs. 4 ± 3, p < 0.0002). Only five out of 15 FMP sera had ANeuA specifically directed against neurons from the medial vestibular nucleus of the brainstem. This immunoreactivity was not detected in the sera from the 14 controls. ANeuA recognized a 45 kDa protein. CONCLUSIONS: 30% of FMPs have ANeuA that have not been described before. In future studies, it will be necessary for anti-neural immunoreactivity to be determined in a larger sample and for the role of ANeuAs in the pathophysiology of FM to be established.

INTRODUCCIÓN: La fibromialgia (FM) es un síndrome no degenerativo caracterizado por dolor musculoesquelético crónico y generalizado; así como por alteraciones anímicas, de memoria y sueño. OBJETIVO: Buscar anticuerpos antineurales (AANeu) séricos en pacientes con FM para descartar etiología autoinmune. MÉTODOS: Se aplicó el Cuestionario de Impacto en Fibromialgia (FIQ) y el Inventario de Depresión de Beck (BDI). La inmunorreactividad y el blanco reconocido por los sueros de pacientes con FM y sujetos sanos se analizó con inmunofluorescencia indirecta y Western blot. RESULTADOS: Los valores de FIQ y BDI estuvieron significativamente alterados en los pacientes con FM, en comparación con los de los controles (FIQ, 70 ± 25 versus 12 ± 12, p < 0.0001; BDI, 17 ± 11 versus 4 ± 3, p < 0.0002). Solo cinco de 15 sueros de pacientes con FM tuvieron AANeu dirigidos específicamente contra las neuronas del núcleo vestibular medio del tronco encefálico; estos no se detectaron en los 14 sueros de los controles. Los AANeu reconocieron una proteína de 45 kDa. CONCLUSIONES: El 30 % de los pacientes con FM tiene AANeu no descritos antes. Será necesario evaluar la inmunorreactividad antineural en una muestra más grande y determinar el papel de los AANeu en la fisiopatología de la FM.

Family Physicians' Barriers and Facilitators in Incorporating Medication Abortion.

PURPOSE: Medication abortion (MAB) provision by family physicians has the potential to expand abortion access. However, there are documented individual and structural barriers to provision. This study investigates how family physicians in the United States (US) navigate the barriers impeding abortion provision in primary care. METHODS: We conducted a qualitative study on the experiences of US family physicians with MAB in primary care. We recruited participants at national conferences and via professional networks. This analysis focuses on the experiences of the subset of participants who expressed interest in providing MAB. RESULTS: Forty-eight participants met inclusion criteria, with representation from all 4 regions of the US. Participants had diverse experiences related to abortion provision, training, and the environment in which they practice, with a third of participants working in states with hostile abortion policies. We categorized participants into 3 groups: (1) doctors who did not receive training and do not provide abortions (n = 11), (2) doctors who received training but do not provide abortions (n = 20), and (3) doctors who received training and currently provide abortions (n = 17). We found that training, administrative and community support, and internal motivation to overcome barriers help family physicians integrate MAB in primary care practices. Federal and state laws, absence of training, stigma around abortion provision, inaccurate or limited knowledge of institutional barriers, and administrative resistance all contributed to doctors excluding abortion provision from their scope of practice. CONCLUSION: Improving medication abortion provision by family physicians requires addressing the individual and system barriers family physicians encounter so they receive the education, training, and support to successfully integrate abortion care into clinical practice.

Inmunorreactividad antineural sérica en pacientes con fibromialgia. Estudio preliminar / Serum anti-neural immunoreactivity in patients with fibromyalgia. Preliminary study

Resumen Introducción: La fibromialgia (FM) es un síndrome no degenerativo caracterizado por dolor musculoesquelético crónico y generalizado; así como por alteraciones anímicas, de memoria y sueño. Objetivo: Buscar anticuerpos antineurales (AANeu) séricos en pacientes con FM para descartar etiología autoinmune. Métodos: Se aplicó el Cuestionario de Impacto en Fibromialgia (FIQ) y el Inventario de Depresión de Beck (BDI). La inmunorreactividad y el blanco reconocido por los sueros de pacientes con FM y sujetos sanos se analizó con inmunofluorescencia indirecta y Western blot. Resultados: Los valores de FIQ y BDI estuvieron significativamente alterados en los pacientes con FM, en comparación con los de los controles (FIQ, 70 ± 25 versus 12 ± 12, p < 0.0001; BDI, 17 ± 11 versus 4 ± 3, p < 0.0002). Solo cinco de 15 sueros de pacientes con FM tuvieron AANeu dirigidos específicamente contra las neuronas del núcleo vestibular medio del tronco encefálico; estos no se detectaron en los 14 sueros de los controles. Los AANeu reconocieron una proteína de 45 kDa. Conclusiones: El 30 % de los pacientes con FM tiene AANeu no descritos antes. Será necesario evaluar la inmunorreactividad antineural en una muestra más grande y determinar el papel de los AANeu en la fisiopatología de la FM.

Abstract Introduction: Fibromyalgia (FM) is a non-degenerative syndrome characterized by generalized, chronic musculoskeletal pain, as well as mood, memory and sleep disorders. Objective: To search for serum anti-neural antibodies (ANeuA) in patients with FM (FMP) in order to rule out autoimmune etiology. Methods: The Fibromyalgia Impact Questionnaire (FIQ) and BECK’s depression inventory (BDI) were applied. Immunorreactivity and the target recognized on the sera from FMPs and healthy subjects were analyzed by indirect immunofluorescence and Western blot. Results: Both FIQ and BDI values were significantly altered in FMPs in comparison with those of controls (FIQ, 70 ± 25 vs. 12 ± 12, p < 0.0001; BDI, 17 ± 11 vs. 4 ± 3, p < 0.0002). Only five out of 15 FMP sera had ANeuA specifically directed against neurons from the medial vestibular nucleus of the brainstem. This immunoreactivity was not detected in the sera from the 14 controls. ANeuA recognized a 45 kDa protein. Conclusions: 30% of FMPs have ANeuA that have not been described before. In future studies, it will be necessary for anti-neural immunoreactivity to be determined in a larger sample and for the role of ANeuAs in the pathophysiology of FM to be established.

Exploring the impact of mifepristone's risk evaluation and mitigation strategy (REMS) on the integration of medication abortion into US family medicine primary care clinics✰,✰✰.

OBJECTIVES: In 2000, the United States' Food and Drug Administration (FDA) approved mifepristone for medication abortion. In this article, we explore how the Risk Evaluation and Mitigation Strategy (REMS) criteria for mifepristone specifically impede family physicians' ability to provide medication abortion in primary care settings. STUDY DESIGN: We conducted 56 qualitative interviews with a national sample of family physicians across the US who were not opposed to abortion. We examined how the REMS criteria for mifepristone impact family physicians' ability to provide medication abortion. RESULTS: Of the 56 interviews conducted, 23 participants (41%) raised the REMS criteria as a barrier to providing medication abortion in primary care. These participants reported the REMS added a layer of bureaucratic complexity that made it difficult for family physicians to navigate, even when trained, to provide abortion care. These family physicians described 2 predominant ways the REMS impede their ability to provide medication abortion: (1) The REMS require substantial involvement of clinic administration, who can be unsupportive; (2) The complexity of navigating the REMS results in physicians and clinic administration in primary care viewing medication abortion as not worth the effort, since it is only a small component of services offered in primary care. CONCLUSION: Removing the REMS could simplify integration of medication abortion into primary care, which could meet patient preferences, improve access, and reduce abortion stigma. The FDA's revised REMS criteria may ease administrative burden but will likely maintain key barriers to integrating medication abortion into family physicians' practice. IMPLICATIONS: Our study highlights that the REMS criteria are barriers to family physicians' ability to integrate medication abortion into their primary care practices. The FDA's removal of in person dispensing criteria may provide some impetus for trained family physicians to integrate medication abortion into their scope of practice but the revised REMS criteria maintain key barriers to broader adoption.

[Descriptive epidemiology and frequency variations of astrocytic tumors in the National Institute of Neurology and Neurosurgery of Mexico]. / Epidemiología descriptiva y cambios en la frecuencia de tumores astrocíticos en el Instituto Nacional de Neurología y Neurocirugía de México.

OBJECTIVE: To determine distribution, localization and frequency variations of astrocytic tumors (AT) in a Mexican Institute of neurology. MATERIALS AND METHODS: Institutional registries of AT from five decades were analyzed. AT/ Surgical discharges (SD) and AT/Central Nervous System Tumors (CNST) from 1995 to 2014 were compared. RESULTS: Two thousand two hundred and eighty-seven AT (1 356 men and 931 women) were analyzed. The most common glioma was glioblastoma multiforme (GBM), found in young adults with a higher frequency to that reported in other studies. Relation of AT/SD, as well as, relation of AT/CNST was similar between 1995 and 2014. CONCLUSIONS: In general, the frequency of AT worldwide, being higher in the subgroup of young adults with GBM. There was not significant variation in the frequency of AT during the time studied.

OBJETIVO: Determinar distribución, localización y cambios de la frecuencia de tumores astrocíticos (TA) en un instituto mexicano de neurología. MATERIAL Y MÉTODOS: Se revisaron los registros institucionales de TA de cinco décadas. Se compararon las relaciones TA/egresos quirúrgicos (EQ) y TA/total de tumores del sistema nervioso central (TSNC) de 1995 a 2014. RESULTADOS: Se analizaron 2 287 TA (1 356 en hombres y 931 en mujeres). El glioma más común fue el glioblastoma multiforme (GBM), que estuvo presente en adultos jóvenes con una frecuencia mayor a la reportada en otros estudios. La relación TA/EQ y TA/TNSC fue similar entre 1995 y 2014. CONCLUSIONES: En general, la frecuencia de TA atendidos en el Instituto es similar a la reportada internacionalmente. No obstante, los casos de TA en el subgrupo de adultos jóvenes con GBM son más frecuentes (40%) que las incidencias reportadas en otros estudios (menores al 5%). No se encontró variación significativa en la frecuencia de TA durante las últimas dos décadas.

Epidemiología descriptiva y cambios en la frecuencia de tumores astrocíticos en el Instituto Nacional de Neurología y Neurocirugía de México / Descriptive epidemiology and frequency variations of astrocytic tumors in the National Institute of Neurology and Neurosurgery of Mexico

Resumen: Objetivo: Determinar distribución, localización y cambios de la frecuencia de tumores astrocíticos (TA) en un instituto mexicano de neurología. Material y métodos: Se revisaron los registros institucionales de TA de cinco décadas. Se compararon las relaciones TA/egresos quirúrgicos (EQ) y TA/total de tumores del sistema nervioso central (TSNC) de 1995 a 2014. Resultados: Se analizaron 2 287 TA (1 356 en hombres y 931 en mujeres). El glioma más común fue el glioblastoma multiforme (GBM), que estuvo presente en adultos jóvenes con una frecuencia mayor a la reportada en otros estudios. La relación TA/EQ y TA/TNSC fue similar entre 1995 y 2014. Conclusiones: En general, la frecuencia de TA atendidos en el Instituto es similar a la reportada internacionalmente. No obstante, los casos de TA en el subgrupo de adultos jóvenes con GBM son más frecuentes (40%) que las incidencias reportadas en otros estudios (menores al 5%). No se encontró variación significativa en la frecuencia de TA durante las últimas dos décadas.

Abstract: Objective: To determine distribution, localization and frequency variations of astrocytic tumors (AT) in a Mexican Institute of neurology. Materials and methods: Institutional registries of AT from five decades were analyzed. AT/Surgical discharges (SD) and AT/Central Nervous System Tumors (CNST) from 1995 to 2014 were compared. Results: Two thousand two hundred and eighty-seven AT (1 356 men and 931 women) were analyzed. The most common glioma was glioblastoma multiforme (GBM), found in young adults with a higher frequency to that reported in other studies. Relation of AT/SD, as well as, relation of AT/CNST was similar between 1995 and 2014. Conclusions: In general, the frequency of AT attended at the Institute is similar to that found worldwide, being only higher the number of GBM in younger adults. There was not significant variation in the frequency of AT during the time studied.

Historical distribution of central nervous system tumors in the Mexican National Institute of Neurology and Neurosurgery.

OBJECTIVE: To determine the frequency of central nervous system (CNS) tumors in the first fifty years of the National Institute of Neurology and Neurosurgery of Mexico Manuel Velasco Suárez (Instituto Nacional de Neurología y Neurocirugía de México, INNN) from 1965 to 2014. MATERIALS AND METHODS: A total of 16 116 institutional records of CNS tumors were analyzed. The frequency and distribution of CNS tumors were evaluated by tumor type, patient age and patient gender. The annual relationship between CNS tumors and surgical discharges (SD) over the last 20 years was estimated. RESULTS: The frequencies of most CNS tumors were consistent with those found worldwide, and the most common tumors were neuroepithelial tumors (33%), particularly astrocytic tumors (67%); meningeal tumors (26%); and pituitary tumors (20%). The incidence of pituitary tumors in these data was twice as high as that reported in other regions of the world, and the relationship between CNS tumors and SD was consistent over time (0.22-0.39). CONCLUSION: This study summarizes the largest sample of CNS tumor cases analyzed in Mexico and provides an important reference of the frequency of this tumor type in the country. This work will serve as a basis for conducting studies evaluating factors associated with the presence of CNS tumors and for identifying adequate public health interventions.

Historical distribution of central nervous system tumors in the Mexican National Institute of Neurology and Neurosurgery / Distribución histórica de neoplasias del sistema nervioso central en el Instituto Nacional de Neurología y Neurocirugía de México

Abstract Objective: To determine the frequency of central nervous system (CNS) tumors in the first fifty years of the National Institute of Neurology and Neurosurgery of Mexico Manuel Velasco Suárez (Instituto Nacional de Neurología y Neurocirugía de México, INNN) from 1965 to 2014. Materials and methods: A total of 16 116 institutional records of CNS tumors were analyzed. The frequency and distribution of CNS tumors were evaluated by tumor type, patient age and patient gender. The annual relationship between CNS tumors and surgical discharges (SD) over the last 20 years was estimated. Results: The frequencies of most CNS tumors were consistent with those found worldwide, and the most common tumors were neuroepithelial tumors (33%), particularly astrocytic tumors (67%); meningeal tumors (26%); and pituitary tumors (20%). The incidence of pituitary tumors in these data was twice as high as that reported in other regions of the world, and the relationship between CNS tumors and SD was consistent over time (0.22-0.39). Conclusion: This study summarizes the largest sample of CNS tumor cases analyzed in Mexico and provides an important reference of the frequency of this tumor type in the country. This work will serve as a basis for conducting studies evaluating factors associated with the presence of CNS tumors and for identifying adequate public health interventions.

Resumen Objetivo: Determinar la frecuencia de neoplasias del sistema nervioso central (NSNC) en los primeros 50 años del Instituto Nacional de Neurología y Neurocirugía de México (INNN). Material y métodos: Se analizaron 16 116 registros institucionales de las NSNC, atendidas en el INNN de 1965 a 2014; se estimó su frecuencia y distribución por tipo de neoplasia, edad y género, y se determinó la relación anual de NSNC y egresos quirúrgicos (EQ) en un período de 20 años. Resultados: Las frecuencias de la mayoría de NSNC fueron consistentes con las encontradas a nivel mundial. Las más frecuentes fueron las neuroepiteliales (33%), entre las cuales destacaron las astrocíticas (67%); meníngeas (26%), e hipofisiarias (20%). El número de neoplasias hipofisiarias en esta serie fue dos veces mayor al reportado en otras regiones del mundo y la relación NSNC/EQ fue similar a través del tiempo (0.22-0.39). Conclusión: Ésta es la mayor serie de casos de NSNC analizados en México y proporciona un referente importante sobre la frecuencia de este tipo de neoplasias en el país. Este trabajo servirá de base para llevar a cabo estudios de los factores asociados a la presencia de NSNC e identificar intervenciones de salud pública adecuadas.

Uso de la nanopartícula de SiO 2 -TiO 2 en el tratamiento de úlceras en pie diabético: comunicación preliminar / Using SiO 2 - TiO 2 nanoparticle in the treatment of diabetic foot ulcers: preliminary communication

Resumen Una de las complicaciones más graves de la diabetes mellitus es el pie diabético, que resulta de la suma de factores como: macroangiopatía, microangiopatía y neuropatía que disminuyen el flujo vascular y causan pequeñas lesiones que rápidamente progresan a úlceras y pueden abarcar todos los tejidos; la clasificación de Wagner1 señala cómo se puede progresar de una pequeña lesión superficial a una profunda, y que se extienda a los tejidos profundos: tendones, músculos y aún hueso, y dañar gravemente la salud, con inminencia de muerte por sepsis. El tratamiento convencional tiene buenos resultados en general, pero requiere un cuidadoso programa de atención local, protección de mayores lesiones, antibióticos, etc., y si no hay resultado, puede terminar en amputación. La utilización de nanopartículas de óxidos metálicos, que consisten de dióxido de silicio (SiO2) y dióxido de tinanio (TiO2), preparadas mediante la técnica sol-gel, pueden ofrecer una alternativa viable en el tratamiento de la úlcera diabética, debido a un mecanismo que permite mantenerla seca y, al mismo tiempo, inhibe el crecimiento de bacterias mediante un efecto bíocatalítico2. Para evaluar el uso de estas nanopartículas en el pie diabético, se realizó un protocolo de investigación en un grupo de pacientes que acuden al Centro Especializado en la Atención del Paciente Diabético "Dr. Manuel González Rivera", dependiente de la Secretaría de Salud del Distrito Federal; este protocolo fue aprobado por la Dirección de Enseñanza e Investigación de la propia Secretaría, con el número de registro 101/100/014/13. Se estudió a 62 pacientes con diversas formas de úlcera diabética y se aplicaron las nanopartículas haciendo una curación cada 48 horas, fueron evaluadas con fotografías seriadas y cultivos de la úlcera. Todos los pacientes que recibieron el tratamiento lograron la curación, con desaparición de las úlceras y cicatrización satisfactoria. Conclusión: La aplicación tópica de las nanopartículas de SiO2 y TiO2 parece ser de utilidad en el tratamiento de la úlcera diabética.

Abstract One of the most severe complications of diabetes mellitus is the diabetic foot, which is the sum of macroangiopathy, microangiopathy and neuropathy, which leads to low vascular flow, and development of lesions which rapidly progress to ulcer and may attain all tissues; the Wagner classification1 shows how a little superficial lesion may affect all tissues: tendons, muscles and even bones, to severely affect the general health and may end on death by sepsis. The conventional treatment has good results, but requires a careful program of local attention, protection from larger lesions, antibiotics, etc., and if does not have good results, may ends on foot amputation. The use of nanoparticles of metallic oxides, silicium dioxide and titanium dioxide, prepared by the sol-gel technique, may offer a viable alternative for diabetic ulcer treatment due a mechanism which allows to keep it dry and at the same time, inhibit bacterial growing through a biocatalytic effect2. To evaluate the use of these nanoparticles in diabetic foot, a research protocol was established in a group of diabetic patients who attend to the Center Specialized on Handling of the Diabetic Patient from Mexico City of Secretary of Health; this protocol was approved by the Educations and Research Direction of the Secretary of Health. 62 diabetic patient with diabetic ulcers of different degree were studied; the nanoparticles were applied every 48 hours and evaluated with photos and bacterial cultures. All patients who received the complete treatment healed their ulcers, with satisfactory healing. Conclusion: The topical application of metallic oxides nanoparticles seems to be useful in the treatment of diabetic ulcers.

TNF-α and LPA promote synergistic expression of COX-2 in human colonic myofibroblasts: role of LPA-mediated transactivation of upregulated EGFR.

BACKGROUND: Enhanced EGF receptor (EGFR) signaling is a hallmark of many human cancers, though the role of enhanced EGFR signaling within the surrounding tumor stroma has not been well studied. The myofibroblast is an important stromal cell that demonstrates enhanced EGFR expression in the setting of inflammation, though the functional relevance is not known. We recently reported that TNF-α and the G protein-coupled receptor (GPCR) agonist lysophosphatidic acid (LPA) lead to synergistic cyclo-oxygenase-2 (COX-2) expression, an enzyme strongly associated with the development of colitis-associated cancer. Here, we investigate whether EGFR signaling plays a role in the synergistic COX-2 expression induced by LPA and TNF-α. METHODS: 18Co cells, a model of human colonic myofibroblasts, were grown to confluence on 35 × 10 mm cell culture dishes and were used from passages 10-14. 18Co cells were treated with TNF-α (8.3 ng/ml) and LPA (10 µM). EGFR and COX-2 protein expression, Y1068 phosphorylation, and p42/44 MAPK phosphorylation were assessed by Western Blot, in the presence and absence of various inhibitors. RESULTS: Exposure of 18Co cells to either TNF-α or LPA alone had no effect on EGFR autophosphorylation at Y1068. However, chronic exposure to TNF-α led to upregulation of EGFR in association with sustained LPA-mediated EGFR phosphorylation at Y1068. TNF-α and LPA also led to sustained p42/44 MAPK phosphorylation and synergistic COX-2 expression, effects that were partially inhibited by the EGFR tyrosine kinase inhibitor AG1478. p42/44 MAPK phosphorylation and COX-2 expression were inhibited to the same degree by the MMP inhibitors GM6001 and BB-94, suggesting that LPA-mediated EGFR transactivation involved MMP-mediated release of EGFR ligands from the cell surface. The Src inhibitor SU6556 inhibited TNF-α/LPA-mediated EGFR phosphorylation at Y1068, p42/44 MAPK phosphorylation, and COX-2 expression in a dose-dependent fashion, suggesting an upstream role of Src in the transactivation of EGFR. CONCLUSION: Synergistic COX-2 expression induced by TNF-α and LPA involves Src/MMP-mediated transactivation of EGFR and downstream p42/44 MAPK activation in human colonic myofibroblasts. Enhanced EGFR expression induced by TNF-α promotes GPCR-mediated EGFR transactivation in colonic myofibroblasts, providing an important mechanism for stromal COX-2 over-expression that may predispose to the development of colitis-associated cancer.

TNF-α induces upregulation of EGFR expression and signaling in human colonic myofibroblasts.

The myofibroblast has recently been identified as an important mediator of tumor necrosis factor-α (TNF-α)-associated colitis and cancer, but the mechanism(s) involved remains incompletely understood. Recent evidence suggests that TNF-α is a central regulator of multiple inflammatory signaling cascades. One important target of TNF-α may be the signaling pathway downstream of the epidermal growth factor receptor (EGFR), which has been associated with many human cancers. Here, we show that long-term exposure of 18Co cells, a model of human colonic myofibroblasts, with TNF-α led to a striking increase in cell surface EGFR expression, an effect that was completely inhibited by cycloheximide. Subsequent EGFR binding by EGF and heparin binding (HB)-EGF was associated with enhanced EGFR tyrosine kinase activity, prolonged ERK activation, and a significant increase in cyclooxygenase-2 (COX-2) expression compared with 18Co cells treated with EGF and HB-EGF alone. TNF-α also increased EGFR expression and signaling in primary myofibroblasts isolated from human colon tissue. TNF-α-induced upregulation of EGFR may be a plausible mechanism to explain the exaggerated cellular responsiveness that characterizes inflammatory bowel disease and that may contribute to a microenvironment that predisposes to colitis-associated cancer through enhanced COX-2 expression.

Protein kinase D1 mediates synergistic MMP-3 expression induced by TNF-α and bradykinin in human colonic myofibroblasts.

Stromal myofibroblasts regulate extracellular matrix components through the secretion of matrix metalloproteinases such as MMP-3. Both myofibroblasts and MMP-3 have been implicated in colonic inflammation and cancer but the regulatory signaling mechanism(s) are unknown. Exposure of the human colonic myofibroblast cell line 18Co to TNF-α and bradykinin induced synergistic MMP-3 mRNA and protein expression, which were blocked by the preferential PKC inhibitors GF109203X and Go6983 and by the MEK inhibitor U0126. Transfection with siRNA targeting PKD1, a known downstream target of both bradykinin and PKC, completely inhibited MMP-3 mRNA and protein expression. Our results imply that TNF-α and bradykinin amplify MMP-3 expression at a transcriptional level through a signaling cascade involving PKC, PKD1, and MEK. PKD1 plays a critical role in the expression of MMP-3 in human colonic myofibroblasts, and may contribute to the pathophysiology underlying colitis-associated cancer.

TNF-α potentiates lysophosphatidic acid-induced COX-2 expression via PKD in human colonic myofibroblasts.

The myofibroblast (MFB) has recently been identified as an important mediator of tumor necrosis factor-α (TNF-α)-associated colitis and cancer, but the mechanism(s) involved remains incompletely understood. Here, we show that treatment of 18Co cells, a model of human colonic MFBs, with TNF-α and lysophosphatidic acid (LPA) induced striking synergistic cyclooxygenase-2 (COX-2) protein expression and production of PGE(2). This effect was prevented by the LPA(1) receptor antagonist Ki16425, the G(iα)-specific inhibitor pertussis toxin, and by the preferential protein kinase (PK) C inhibitors GF109203X and Go6983. As a known downstream target of LPA and PKC, we tested whether PKD, recently implicated in the regulation of COX-2 expression in MFB, was involved in this response. TNF-α, while having no detectable effect on the activation of PKD when added alone, augmented PKD activation stimulated by LPA, as measured by PKD autophosphorylation at Ser(910). LPA-induced PKD activation was also inhibited by Ki16425, pertussis toxin, GF109203X, and Go6983. Transfection of 18Co cells with short interfering RNA targeting PKD completely inhibited the synergistic increase in COX-2 protein, demonstrating a critical role of PKD in this response. Our results imply that cross talk between TNF-α and LPA results in the amplification of COX-2 protein expression via a conserved PKD-dependent signaling pathway that appears to involve the LPA(1) receptor and the G protein G(iα). PKD plays a critical role in the expression of COX-2 in human colonic MFBs and may contribute to an inflammatory microenvironment that promotes tumor growth.