Ribosome-Associated Vesicles promote activity-dependent local translation.

Local protein synthesis in axons and dendrites underpins synaptic plasticity. However, the composition of the protein synthesis machinery in distal neuronal processes and the mechanisms for its activity-driven deployment to local translation sites remain unclear. Here, we employed cryo-electron tomography, volume electron microscopy, and live-cell imaging to identify Ribosome-Associated Vesicles (RAVs) as a dynamic platform for moving ribosomes to distal processes. Stimulation via chemically-induced long-term potentiation causes RAV accumulation in distal sites to drive local translation. We also demonstrate activity-driven changes in RAV generation and dynamics in vivo, identifying tubular ER shaping proteins in RAV biogenesis. Together, our work identifies a mechanism for ribosomal delivery to distal sites in neurons to promote activity-dependent local translation.

Photothermal Excitation of Neurons Using MXene: Cellular Stress and Phototoxicity Evaluation.

Understanding the communication of individual neurons necessitates precise control of neural activity. Photothermal modulation is a remote and non-genetic technique to control neural activity with high spatiotemporal resolution. The local heat release by photothermally active nanomaterial will change the membrane properties of the interfaced neurons during light illumination. Recently, it is demonstrated that the two-dimensional Ti3 C2 Tx MXene is an outstanding candidate to photothermally excite neurons with low incident energy. However, the safety of using Ti3 C2 Tx for neural modulation is unknown. Here, the biosafety of Ti3 C2 Tx -based photothermal modulation is thoroughly investigated, including assessments of plasma membrane integrity, mitochondrial stress, and oxidative stress. It is demonstrated that culturing neurons on 25 µg cm-2 Ti3 C2 Tx films and illuminating them with laser pulses (635 nm) with different incident energies (2-10 µJ per pulse) and different pulse frequencies (1 pulse, 1 Hz, and 10 Hz) neither damage the cell membrane, induce cellular stress, nor generate oxidative stress. The threshold energy to cause damage (i.e., 14 µJ per pulse) exceeded the incident energy for neural excitation (<10 µJ per pulse). This multi-assay safety evaluation provides crucial insights for guiding the establishment of light conditions and protocols in the clinical translation of photothermal modulation.

The mRNA levels of TGF-ß Type II receptor splice variants in monocytes are associated with disease activity in patients with rheumatoid arthritis.

OBJECTIVES: In rheumatoid arthritis (RA) patients, TGF-ß exerts a singular effect on lymphocytes, macrophages, and polymorphonuclear leukocytes. Moreover, evidences indicate that TGF-ß1 stimulation affects the expression levels of TGF-ß receptors. Therefore, we analysed in different leukocyte subpopulations, whether the mRNA abundance of TGFBR2 splice variants might be related to RA. METHODS: We isolated different leukocyte subpopulations from peripheral blood from 9 healthy control volunteers and 9 RA patients, matched by gender and age (cohort 1), and 8 additional RA patients (cohort 2). Then we quantified, by RT-qPCR, the mRNA relative abundance of TGFBR2 splice variants (namely TGFBR2A and TGFBR2B) in PMNs, and PBMCs (monocytes and non-monocytes). We first checked whether the TGFBR2-splice variant mRNA profile could be associated with any particular blood cell type both, in healthy control volunteers and in RA patients. In addition, PBMC and PMN mRNA levels were correlated, using Spearman's rank-order correlation test, with clinical and biochemical determinations of RA patients. RESULTS: We have shown that TGFBR2 exhibits an alternative splicing pattern in different subpopulations of human leucocytes from healthy controls, and the lack of it in the same cell type from RA samples. Furthermore, our study yields initial evidence that TGFBR2 mRNA expression levels in monocytes might mirror RA disease activity. CONCLUSIONS: mRNA abundance of TGFBR2 splice variants in monocytes shows changes linked to RA disease activity.

Percepción de la AR en una población fuera del ámbito sanitario / Perception of RA in a population outside health services

Objetivos: El acceso temprano a la población de pacientes con artritis reumatoidea (AR) a la asistencia especializada es un predictor de buen pronóstico. Sin embargo, la demora en la consulta es una constante; fueron identificados factores tales como los vinculados al paciente, el médico generalista o al sistema de salud. El objeto del estudio fue el de explorar la percepción de la población fuera del ámbito asistencial en un escenario potencial de sintomatología compatible con AR. Material y métodos: Se realizó un muestreo aleatorio de 1073 individuos mayores de 18 años, se realizó en la vía pública de los partidos de Quilmes y Berazategui. La encuesta fue efectuada por voluntarias entrenadas a tal fin las que indagaron acerca de a qué profesional consultaría si tuviera dolor e inflamación de los nudillos y muñecas de ambas manos, si cree padecer estos síntomas y si conoce la diferencia entre artritis y artrosis. Resultados: Frente a la posibilidad de padecer síntomas que remedan AR, la población encuestada eligió a los siguientes especialistas: traumatólogo (61%), clínico (17%), reumatólogo (15%), otros (7%). Un tercio de los encuestados refirió padecer esos síntomas y la mayoría (61%) referían no conocer la diferencia entre artritis y artrosis. Quienes más eligieron al reumatólogo como opción (56%) fueron del sexo femenino de entre 51 y 80 años y que conocían la diferencia entre AR y OA. Conclusiones: La ausencia relativa del reumatólogo en la preferencia de la población encuestada, así como la confusión respecto de la presencia de sintomatología compatible con la enfermedad o de la diferencia entre artritis y artrosis señalan la necesidad de ejecutar campañas de concientización pública dirigidas a la reafirmación de la especialidad frente a la patología articular inflamatoria.

Objectives: Early access to specialized care is a predictor of goodprognosis in patients recently diagnosed rheumatoid arthritis (RA).However, the delay in the consultation is a constant; they wereidentified factors such as those related to the patient, the generalpractitioner or the health system. The purpose of the study wasto explore the perception of the population outside the healthcaresetting in a potential scenario of symptoms compatible with RA.Material and methods: A random sample of 1073 individualsaged 18 and over was conducted. It was held in public matches ofQuilmes and Berazategui. The survey was conducted by volunteerstrained for this purpose which were asked which professional (interms of specialty) would consult if they had pain and swellingof the knuckles and wrists of both hands, and "if you know thedifference between arthritis and osteoarthritis".Results: Facing the possibility of having symptoms that mimic RA,the population surveyed chose the following specialists: orthopedicsurgeons (61%), clinicians (17%), rheumatologists (15%), others(7%). A third of respondents have referred these symptoms and most(61%) reported not knowing the difference between arthritis andosteoarthritis. People who chose rheumatologist an option (56%)were female between 51 and 80 years and knew the differencebetween RA and OA.Conclusions: The relative absence of rheumatologist in thepreference of the surveyed population, as well as confusion aboutthe presence of symptoms compatible with the disease or thedifference between arthritis and osteoarthritis indicate the needto implement public awareness campaigns aimed at reaffirmingspecialty against inflammatory joint disease.