Retinal dysfunction in Huntington's disease mouse models concurs with local gliosis and microglia activation

Huntington's disease (HD) is caused by an aberrant expansion of CAG repeats in the HTT gene that mainly affects basal ganglia. Although striatal dysfunction has been widely studied in HD mouse models, other brain areas can also be relevant to the pathology. In this sense, we have special interest on the retina as this is the most exposed part of the central nervous system that enable health monitoring of patients using noninvasive techniques. To establish the retina as an appropriate tissue for HD studies, we need to correlate the retinal alterations with those in the inner brain, i.e., striatum. We confirmed the malfunction of the transgenic R6/1 retinas, which underwent a rearrangement of their transcriptome as extensive as in the striatum. Although tissue-enriched genes were downregulated in both areas, a neuroinflammation signature was only clearly induced in the R6/1 retina in which the observed glial activation was reminiscent of the situation in HD patient's brains. The retinal neuroinflammation was confirmed in the slow progressive knock-in zQ175 strain. Overall, these results demonstrated the suitability of the mouse retina as a research model for HD and its associated glial activation.

Neuroimaging and serum biomarkers of neurodegeneration and neuroplasticity in Parkinson's disease patients treated by intermittent theta-burst stimulation over the bilateral primary motor area: a randomized, double-blind, sham-controlled, crossover trial study

Background and objectives

Intermittent theta-burst stimulation (iTBS) is a patterned form of excitatory transcranial magnetic stimulation that has yielded encouraging results as an adjunctive therapeutic option to alleviate the emergence of clinical deficits in Parkinson's disease (PD) patients. Although it has been demonstrated that iTBS influences dopamine-dependent corticostriatal plasticity, little research has examined the neurobiological mechanisms underlying iTBS-induced clinical enhancement. Here, our primary goal is to verify whether iTBS bilaterally delivered over the primary motor cortex (M1) is effective as an add-on treatment at reducing scores for both motor functional impairment and nonmotor symptoms in PD. We hypothesize that these clinical improvements following bilateral M1-iTBS could be driven by endogenous dopamine release, which may rebalance cortical excitability and restore compensatory striatal volume changes, resulting in increased striato-cortico-cerebellar functional connectivity and positively impacting neuroglia and neuroplasticity.

Methods

A total of 24 PD patients will be assessed in a randomized, double-blind, sham-controlled crossover study involving the application of iTBS over the bilateral M1 (M1 iTBS). Patients on medication will be randomly assigned to receive real iTBS or control (sham) stimulation and will undergo 5 consecutive sessions (5 days) of iTBS over the bilateral M1 separated by a 3-month washout period. Motor evaluation will be performed at different follow-up visits along with a comprehensive neurocognitive assessment; evaluation of M1 excitability; combined structural magnetic resonance imaging (MRI), resting-state electroencephalography and functional MRI; and serum biomarker quantification of neuroaxonal damage, astrocytic reactivity, and neural plasticity prior to and after iTBS.

Discussion

The findings of this study will help to clarify the efficiency of M1 iTBS for the treatment of PD and further provide specific neurobiological insights into improvements in motor and nonmotor symptoms in these patients. This novel project aims to yield more detailed structural and functional brain evaluations than previous studies while using a noninvasive approach, with the potential to identify prognostic neuroprotective biomarkers and elucidate the structural and functional mechanisms of M1 iTBS-induced plasticity in the cortico-basal ganglia circuitry. Our approach may significantly optimize neuromodulation paradigms to ensure state-of-the-art and scalable rehabilitative treatment to alleviate motor and nonmotor symptoms of PD.

Adult kidney explants is a physiologic model for studying diabetic nephropathy

Inflammatory processes play a central role in the pathogenesis of diabetic nephropathy (DN) in the early stages of the disease. In vitro approach using cell lines help to understand the mechanisms involves and allow the molecular and biochemical processes. Adult kidney (AK) explants remain an essential instrument for advancing our understanding of the molecular and cellular regulation of signalling pathways from an organotipic view with physiological system interaction integrated. AK explants from T1DM animal model (BB rat) are obtained by slicing central kidney area preserving the organ's cytoarchitecture and reproduce the classical events detected during the DN in an in vivo model such as inflammation, epithelial-mesenchymal transition (EMT) processes by the modulation of a-SMA and e-Cadherin among others which have been determined by qRT-PCR, western-blot and immunohistochemistry. In this regard, AK explants reproduce the signalling pathways involve in DN progression (proinflammatory NFkB and inflammasome complex). This work demonstrates AK explants is a physiological experimental approach for studying the development and progression of DN. Furthermore, the inflammatory processes in AK explants under a diabetic environment and/or BB rats could be modulated by potential treatments for DN.

IL-1β Implications in Type 1 Diabetes Mellitus Progression: Systematic Review and Meta-Analysis

During Type 1 Diabetes Mellitus (T1DM) progression, there is chronic and low-grade inflammation that could be related to the evolution of the disease. We carried out a systematic review and meta-analysis to evaluate whether peripheral levels of pro-inflammatory markers such as interleukin-1 beta (IL-1β) is significantly different among patients with or without T1DM, in gender, management of the T1DM, detection in several biological fluids, study design, age range, and glycated hemoglobin. We searched PubMed, Embase, Web of Science, and Scopus databases, and 26 relevant studies (2186 with T1DM, 2047 controls) were included. We evaluated the studies’ quality using the Newcastle−Ottawa scale. Meta-analyses were conducted, and heterogeneity and publication bias were examined. Compared with controls, IL-1β determined by immunoassays (pooled standardized mean difference (SMD): 2.45, 95% CI = 1.73 to 3.17; p < 0.001) was significantly elevated in T1DM. The compared IL-1β levels in patients <18 years (SMD = 2.81, 95% CI = 1.88−3.74) was significantly elevated. The hemoglobin-glycated (Hbg) levels in patients <18 years were compared (Hbg > 7: SMD = 5.43, 95% CI = 3.31−7.56; p = 0.001). Compared with the study design, IL-1β evaluated by ELISA (pooled SMD = 3.29, 95% CI = 2.27 to 4.30, p < 0.001) was significantly elevated in T1DM patients. IL-1β remained significantly higher in patients with a worse management of T1DM and in the early stage of T1DM. IL-1β levels determine the inflammatory environment during T1DM.

Cortical Thickness and Serum NfL Explain Cognitive Dysfunction in Newly Diagnosed Patients With Multiple Sclerosis

Background and Objectives

To determine the relative importance of global or regional MRI and blood markers of neurodegeneration and neuroaxonal injury in predicting cognitive performance for recently diagnosed patients with multiple sclerosis (MS).

Methods

Thirty-five newly diagnosed patients with relapsing-remitting MS (RRMS) and 23 healthy controls (HCs) simultaneously completed a full clinical and neuropsychological assessment, structural brain MRI, and serum neurofilament light chain (sNfL) level test. Linear regression analyses were performed to determine which global or regional measures of gray matter (GM) atrophy and cortical thickness (CT), in combination with sNfL levels and clinical scores, are most strongly related to neuropsychological impairment.

Results

Compared with HCs, patients with MS showed bilateral thalamic GM atrophy (left, p = 0.033; right, p = 0.047) and diminished CT, particularly in the right superior and transverse temporal gyri (p = 0.045; p = 0.037). Regional atrophy failed to add predictive variance, whereas anxiety symptoms, sNfL, and global CT were the best predictors (R² = 0.404; p < 0.001) of cognitive outcomes, with temporal thickness accounting for greater variance in cognitive deficits than global CT.

Discussion

Thalamic GM atrophy and thinning in temporal regions represent a distinctive MRI trait in the early stages of MS. Although sNfL levels alone do not clearly differentiate HCs and patients with RRMS, in combination with global and regional CT, sNfL levels can better explain the presence of underlying cognitive deficits. Hence, cortical thinning and sNfL increases can be considered 2 parallel neurodegenerative markers in the pathogenesis of progression in newly diagnosed patients with MS.

Anti-Inflammatory (M2) Response Is Induced by a sp2-Iminosugar Glycolipid Sulfoxide in Diabetic Retinopathy

Diabetic retinopathy (DR) is one of the most common complications of Diabetes Mellitus (DM) and is directly associated with inflammatory processes. Currently, neuro-inflammation is considered an early event in DR and proceeds via microglia polarization. A hallmark of DR is the presence of retinal reactive gliosis. Here we report the beneficial effect of (S_S,1R)-1-docecylsulfiny-5N,6O-oxomethylidenenojirimycin ((Ss)-DS-ONJ), a member of the sp²-iminosugar glycolipid (sp²-IGL) family, by decreasing iNOS and inflammasome activation in Bv.2 microglial cells exposed to pro-inflammatory stimuli. Moreover, pretreatment with (Ss)-DS-ONJ increased Heme-oxygenase (HO)-1 as well as interleukin 10 (IL10) expression in LPS-stimulated microglial cells, thereby promoting M2 (anti-inflammatory) response by the induction of Arginase-1. The results strongly suggest that this is the likely molecular mechanism involved in the anti-inflammatory effects of (S_S)-DS-ONJ in microglia. (S_S)-DS-ONJ further reduced gliosis in retinal explants from type 1 diabetic BB rats, which is consistent with the enhanced M2 response. In conclusion, targeting microglia polarization dynamics in M2 status by compounds with anti-inflammatory activities offers promising therapeutic interventions at early stages of DR.