50 research outputs found
Neurodevelopment Genes in Lampreys Reveal Trends for Forebrain Evolution in Craniates
The forebrain is the brain region which has undergone the most dramatic changes through vertebrate evolution. Analyses conducted in lampreys are essential to gain insight into the broad ancestral characteristics of the forebrain at the dawn of vertebrates, and to understand the molecular basis for the diversifications that have taken place in cyclostomes and gnathostomes following their splitting. Here, we report the embryonic expression patterns of 43 lamprey genes, coding for transcription factors or signaling molecules known to be involved in cell proliferation, stemcellness, neurogenesis, patterning and regionalization in the developing forebrain. Systematic expression patterns comparisons with model organisms highlight conservations likely to reflect shared features present in the vertebrate ancestors. They also point to changes in signaling systems –pathways which control the growth and patterning of the neuroepithelium-, which may have been crucial in the evolution of forebrain anatomy at the origin of vertebrates
Loss of angiotensin II receptor expression in dopamine neurons in Parkinson’s disease correlates with pathological progression and is accompanied by increases in Nox4- and 8-OH guanosine-related nucleic acid oxidation and caspase-3 activation
Endothelin-1 induces LIMK2-mediated programmed necrotic neuronal death independent of NOS activity
Gi/o-protein coupled receptors in the aging brain
Cells translate extracellular signals to regulate processes such as differentiation, metabolism and proliferation, via transmembranar receptors. G protein-coupled receptors (GPCRs) belong to the largest family of transmembrane receptors, with over 800 members in the human species. Given the variety of key physiological functions regulated by GPCRs, these are main targets of existing drugs. During normal aging, alterations in the expression and activity of GPCRs have been observed. The central nervous system (CNS) is particularly affected by these alterations, which results in decreased brain functions, impaired neuroregeneration, and increased vulnerability to neuropathologies, such as Alzheimer's and Parkinson diseases. GPCRs signal via heterotrimeric G proteins, such as Go, the most abundant heterotrimeric G protein in CNS. We here review age-induced effects of GPCR signaling via the Gi/o subfamily at the CNS. During the aging process, a reduction in protein density is observed for almost half of the Gi/o-coupled GPCRs, particularly in age-vulnerable regions such as the frontal cortex, hippocampus, substantia nigra and striatum. Gi/o levels also tend to decrease with aging, particularly in regions such as the frontal cortex. Alterations in the expression and activity of GPCRs and coupled G proteins result from altered proteostasis, peroxidation of membranar lipids and age-associated neuronal degeneration and death, and have impact on aging hallmarks and age-related neuropathologies. Further, due to oligomerization of GPCRs at the membrane and their cooperative signaling, down-regulation of a specific Gi/o-coupled GPCR may affect signaling and drug targeting of other types/subtypes of GPCRs with which it dimerizes. Gi/o-coupled GPCRs receptorsomes are thus the focus of more effective therapeutic drugs aiming to prevent or revert the decline in brain functions and increased risk of neuropathologies at advanced ages.This work was supported by Fundação para a Ciência e
Tecnologia, Centro 2020 and Portugal 2020, the COMPETE
program, QREN, and the European Union (FEDER program)
via the GoBack project (PTDC/CVT-CVT/32261/2017),
the pAGE program (Centro-01-0145-FEDER-000003), and
Institute for Biomedicine iBiMED (UID/BIM/04501/2013;
UID/BIM/04501/2019).publishe
Climatic trends, risk perceptions and coping strategies of smallholder cattle farmers in some villages of Bhutan
Climate change and variability is a global issue, and it affects the small subsistence farmers of Himalayan developing countries like Bhutan. We used a set of semi-structure questionnaire to interview the farmers to understand and analyze local perceptions and reactive responses adapted to climate uncertainties in some villages of Bhutan. Farmers were aware of climate change, and radio and television were identified as the main sources of climate change/global warming related information. In general, farmers have observed rainfall anomalies and prolong dry seasons for the past decades and these were the main threats to their livestock farming. Increased diseases and parasites incidence were also observed, which may be related rising in temperature. Households faced an increasing water shortage and insufficient forage supply that attributed to poor cattle health and cattle production. Farmers are using different coping strategies to adapt to change; these are the plantation of supplementary forage resources, providing concentrated high protein feed and practicing forest grazing. However, we found that adaptation to climate change by Bhutanese farmers' was influenced by socio-economic and political dynamics