Purpose of review Galectin interactions with glycoproteins and glycolipids modulate a variety of cellular responses that are now increasingly explored to better understand neuroinflammation processes and eventually find new therapeutic opportunities for neurological diseases. Recent findings Gal-1 confirmed its indirect neuroprotective roles through anti-inflammatory properties whereas Gal-3 remains elusive, showing anti-inflammatory or pro-inflammatory roles depending on damaging conditions and genetic background of mice models. Interestingly, microglial intracellular rather than extracellular overexpression of Gal-3 arose as contributing to the pathogenesis of Huntington disease, involving NLRP3 inflammasome activation and inhibition of autophagic removal of damaged endolysosomes. Decreasing Gal-3 expression had favorable effects upon disease symptoms. Gal-3 expanded its role in this endolysosomal surveillance system originally involving Gal-8 and Gal-9, which protect cells against neuropathogenic proteins and becomes impaired or even detrimental under neurodegenerative conditions. Also, Gal-1, Gal-3 and Gal-4, together with changes in glycan structures define the outcome of neuroinflammation and remyelination processes. Gal-8 emerged as a new neuroprotector factor, which added to its immunosuppressive role and presence in human cerebrospinal fluid (CSF) may generate a neuroprotective environment in the brain. Summary Galectins modulate neuroinflammation and neurodegenerative processes contributing to microglia polarization, immunosurveillance and neuroprotection through extracellular and intracellular interactions with particular and dynamic patterns of glycans, suggesting potential therapeutic targets.
Background Cognitive dysfunction (CD) is common among patients with the autoimmune disease systemic lupus erythematosus (SLE). Anti-ribosomal P autoantibodies associate with this dysfunction and have neuropathogenic effects that are mediated by cross-reacting with neuronal surface P antigen (NSPA) protein. Elucidating the function of NSPA can then reveal CD pathogenic mechanisms and treatment opportunities. In the brain, NSPA somehow contributes to glutamatergic NMDA receptor (NMDAR) activity in synaptic plasticity and memory. Here we analyze the consequences of NSPA absence in KO mice considering its structural features shared with E3 ubiquitin ligases and the crucial role of ubiquitination in synaptic plasticity. Results Electrophysiological studies revealed a decreased long-term potentiation in CA3-CA1 and medial perforant pathway-dentate gyrus (MPP-DG) hippocampal circuits, reflecting glutamatergic synaptic plasticity impairment in NSPA-KO mice. The hippocampal dentate gyrus of these mice showed a lower number of Arc-positive cells indicative of decreased synaptic activity and also showed proliferation defects of neural progenitors underlying less adult neurogenesis. All this translates into poor spatial and recognition memory when NSPA is absent. A cell-based assay demonstrated ubiquitination of NSPA as a property of RBR-type E3 ligases, while biochemical analysis of synaptic regions disclosed the tyrosine phosphatase PTPMEG as a potential substrate. Mice lacking NSPA have increased levels of PTPMEG due to its reduced ubiquitination and proteasomal degradation, which correlated with lower levels of GluN2A and GluN2B NMDAR subunits only at postsynaptic densities (PSDs), indicating selective trafficking of these proteins out of PSDs. As both GluN2A and GluN2B interact with PTPMEG, tyrosine (Tyr) dephosphorylation likely drives their endocytic removal from the PSD. Actually, immunoblot analysis showed reduced phosphorylation of the GluN2B endocytic signal Tyr1472 in NSPA-KO mice. Conclusions NSPA contributes to hippocampal plasticity and memory processes ensuring appropriate levels of adult neurogenesis and PSD-located NMDAR. PTPMEG qualifies as NSPA ubiquitination substrate that regulates Tyr phosphorylation-dependent NMDAR stability at PSDs. The NSPA/PTPMEG pathway emerges as a new regulator of glutamatergic transmission and plasticity and may provide mechanistic clues and therapeutic opportunities for anti-P-mediated pathogenicity in SLE, a still unmet need.
Hypertension is traditionally considered a disease in which elevated blood pressure contributes to inflammation and activation of the immune system, leading to cardiovascular injury and end-organ damage. Here, we discuss the effects of aldosterone on the immune system and aldosterone's contribution to vascular pathogenesis. Studies in human have suggested a broader role for aldosterone, beyond elevating blood pressure. Recent clinical data support the notion that aldosterone can directly alter the function of the immune system and cause vascular-damaging inflammation. Clinical observations have been reproduced in experimental models of hypertension, further supporting the idea that an aberrant immune response contributes to the onset of hypertension. Such studies have shown that myeloid cells are required to induce the disease and IL-17-producing CD4(+) T cells may contribute to maintaining aldosterone-mediated hypertension. In addition, regulatory T cells diminish the inflammatory damage caused by aldosterone during hypertension. This is a very active area of research that could lead to new therapeutic targets for treating hypertension.
Purpose of reviewThe aim of this study was to present a new regulation system in the hippocampus constituted by the neuronal surface P antigen (NSPA) and the tyrosine phosphatase PTPMEG/PTPN4, which provides mechanistic and therapeutic possibilities for cognitive dysfunction driven by antiribosomal P protein autoantibodies in patients with systemic lupus erythematosus (SLE).Recent findingsMice models lacking the function of NSPA as an E3 ubiquitin ligase show impaired glutamatergic synaptic plasticity, decreased levels of NMDAR at the postsynaptic density in hippocampus and memory deficits. The levels of PTPMEG/PTPN4 are increased due to lower ubiquitination and proteasomal degradation, resulting in dephosphorylation of tyrosines that control endocytosis in GluN2 NMDAR subunits. Adult hippocampal neurogenesis (AHN) that normally contributes to memory processes is also defective in the absence of NSPA.SummaryNSPA function is crucial in memory processes controlling the stability of NMDAR at PSD through the ubiquitination of PTPMEG/PTPN4 and also through AHN. As anti-P autoantibodies reproduce the impairments of glutamatergic transmission, plasticity and memory performance seen in the absence of NSPA, it might be expected to perturb the NSPA/PTPMEG/PTPN4 pathway leading to hypofunction of NMDAR. This neuropathogenic mechanism contrasts with that of anti-NMDAR antibodies also involved in lupus cognitive dysfunction. Testing this hypothesis might open new therapeutic possibilities for cognitive dysfunction in SLE patients bearing anti-P autoantibodies.
Seventy-five percent of colorectal cancers are sporadic, 20% have a family component (first or second-degree relatives with CRC) and 5% have a hereditary predisposition with a Mendelian pattern. The epidemiological evolution in the recent years in Chile has a worrisome evolution and the treatment costs of advanced stages are a burden for the healthcare system. We herein highlight the main Chilean medical and scientific contributions on the pathogenesis, early diagnosis, and treatment of CRC, which lead to its better understanding, and therefore better management, based on local evidence.
Hypertension (arterial blood pressure ≥ 140/90 mmHg) is a risk factor for cardiovascular diseases, with the greatest burden of attributable deaths in Chile, having a national prevalence of 27.6%. In 2018, the implementation of HEARTS begun in primary health care centers of the Public Health System, with the aim of achieving increase in control rates, by raising the proportion of hypertensive individuals who meet blood pressure goals (< 140/90 mmHg for individuals 15–79 years old and of 150/90 mmHg for individuals 80 years and older), and thus contributing to reduce cardiovascular morbidity and mortality associated with this condition. This is a descriptive study that follows average treatment and control rates from the Public Health System between 2017–2021 obtained from health centers statistics reports during HEARTS implementation. Treatment and control rates remained at 57% and 39% respectively between 2017-2019. Between 2020 and 2021, in the context of the SARS-CoV-2 pandemic, treatment and control rates decreased very significantly, reaching 46% and 26%, respectively, in December 2021, even though the number of centers reporting the implementation of HEARTS increased from 227 to 387 in this same period. Prior to the pandemic, during the last quarter of 2019, a decrease in cardiovascular health controls was already observed as a result of social protests. In light of the results, the technical pillars of the HEARTS Initiative have an important role in helping to recover the population control rates reached in 2019 and increasing the speed to achieve better hypertension control rates.
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