Mutations in the proline-rich transmembrane protein 2 (PRRT2) are associated with paroxysmal kinesigenic dyskinesia (PKD) and several other paroxysmal neurological diseases, but the PRRT2 function and pathogenic mechanisms remain largely obscure. Here we show that PRRT2 is a presynaptic protein that interacts with components of the SNARE complex and downregulates its formation. Loss-of-function mutant mice showed PKD-like phenotypes triggered by generalized seizures, hyperthermia, or optogenetic stimulation of the cerebellum. Mutant mice with specific PRRT2 deletion in cerebellar granule cells (GCs) recapitulate the behavioral phenotypes seen in Prrt2-null mice. Furthermore, recording made in cerebellar slices showed that optogenetic stimulation of GCs results in transient elevation followed by suppression of Purkinje cell firing. The anticonvulsant drug carbamazepine used in PKD treatment also relieved PKD-like behaviors in mutant mice. Together, our findings identify PRRT2 as a novel regulator of the SNARE complex and provide a circuit mechanism underlying the PRRT2-related behaviors.
Autophagy plays an important role in Alzheimer's disease (AD). It has been reported that autophagic flux is altered in patients with AD, and application of the autophagy enhancer rapamycin may alleviate the cognitive impairment and amyloid-β (Aβ) neuropathology in transgenic animal model of AD. Since rapamycin is also an immune suppressor, there is a concern that long-term use of rapamycin may bring severe unwanted side effects. The aim of this study is to test if carbamazepine (CBZ), an anti-epileptic drug that has a potent autophagy enhancement effect, has anti-AD effects in APP(swe)/PS1(deltaE9) transgenic mice model of AD. We found that APP(swe)/PS1(deltaE9) mice display increased autophagic activity accompanied by decreased mTOR activity. After three months treatment with CBZ in the APP(swe)/PS1(deltaE9) mice, we demonstrated that the spatial learning and memory deficits in these mice are significantly alleviated. We also documented that the cerebral amyloid plaque burden and Aβ42 levels in these mice are significantly reduced. Furthermore, we showed that CBZ significantly enhances the autophagic flux in the APP(swe)/PS1(deltaE9) mice which is unlikely via mTOR-dependent autophagy pathway. These data suggest that long-term CBZ treatment may have a protective effect in AD mouse model possibly through enhancing the autophagic flux.
The glycogen synthase kinase-3β (GSK3β) pathway plays a central role in Alzheimer's disease (AD) and its deregulation accounts for many of the pathological hallmarks of AD. Lithium, which modulates GSK3β activity, has been shown to reduce amyloid production and tau phosphorylation in pre-pathological AD mouse models. In this study, we investigated the effects of chronic LiCl treatment in aged double transgenic mice (AβPPSwe/PS1A246E). We found that chronic lithium treatment decreased the γ-cleavage of amyloid-β protein precursor, further reduced amyloid-β production and senile plaque formation, accompanied by the improvement in spatial learning and memory abilities. Because autophagy may play an important role in the pathology of AD, we also assessed the autophagy activity and found that the chronic lithium treatment attenuated the autophagy activation in this AD mouse model. Our results suggest that prolonged lithium treatment, even during the later stages of AD, could be an effective therapeutics.
Human epidermal growth factor receptor 2 (HER2) protein overexpression or gene amplification is an important predictive biomarker for identifying patients with breast cancer, who may benefit from HER2-targeted therapy. However, little is known about the molecular landscape and efficacy of HER2-targeted therapy in patients with HER2-mutated metastatic breast cancer. We analysed the HER2 mutation features of 1184 patients with invasive breast cancer. In addition, a single-arm, prospective, phase-II study (NCT03412383) of pyrotinib was conducted in patient with metastatic HER2 amplification-negative, mutation-positive breast cancer. Peripheral blood was collected from each patient and circulating tumour DNA (ctDNA) sequencing was performed using a 1021 gene panel. HER2 mutations were detected in 8.9% (105/1184) of patients. The HER2 amplification-positive patients had a higher mutation frequency than the HER2 amplification-negative patients (19.5% vs. 4.8%, P < 0.001). A multivariate Cox regression analysis indicated that patients with HER2 mutations had a shorter progression-free survival (PFS) than HER2 wild-type patients (median PFS 4.7 months vs. 11.0 months, hazard ratio 2.65, 95% confidence interval 1.25–5.65, P = 0.011). Ten HER2 amplification-negative, mutation-positive patients who received pyrotinib monotherapy were ultimately included in the efficacy analysis. The median PFS was 4.9 months. The objective response rate (complete response + partial response) was 40.0% and the clinical benefit rate (complete response + partial response + stable disease over 24 weeks) was 60%. In conclusion, a HER2 gene mutation analysis is potentially useful to identify biomarkers of trastuzumab resistance in HER2 amplification-positive patients. Patients with HER2-mutated, non-amplified metastatic breast cancers may benefit from pyrotinib.
We made a genetic diagnosis in 61.8% of families and identified 33 mutations. SPAST mutations are the most common in Chinese AD-HSP followed by ATL1. Our findings broaden the genetic spectrum and improve the diagnosis of HSP.
Inflammation plays a crucial role in the occurrence and development of renal fibrosis, which ultimately results in end-stage renal disease (ESRD). There is new focus on lymphangiogenesis in the field of inflammation. Recent studies have revealed the association between lymphangiogenesis and renal fibrosis, but the source of lymphatic endothelial cells (LECs) is not clear. It has also been reported that macrophages are involved in lymphangiogenesis through direct and indirect mechanisms in other tissues. We hypothesized that there was a close relationship between macrophages and lymphatic endothelial progenitor cells in renal fibrosis. In this study, we demonstrated that lymphangiogenesis occurred in a renal fibrosis model and was positively correlated with the degree of fibrosis and macrophage infiltration. Compared to resting (M0) macrophages and alternatively activated (M2) macrophages, classically activated (M1) macrophages predominantly transdifferentiated into LECs in vivo and in vitro. VEGF-C further increased M1 macrophage polarization and transdifferentiation into LECs by activating VEGFR3. It was suggested that VEGF-C/VEGFR3 pathway activation downregulated macrophage autophagy and subsequently regulated macrophage phenotype. The induction of autophagy in macrophages by rapamycin decreased M1 macrophage polarization and differentiation into LECs. These results suggested that M1 macrophages promoted lymphangiogenesis and contributed to newly formed lymphatic vessels in the renal fibrosis microenvironment, and VEGF-C/VEGFR3 signaling promoted macrophage M1 polarization by suppressing macrophage autophagy and then increased the transdifferentiation of M1 macrophages into LECs.
BackgroundAlthough the relationship between a history of kidney stones and chronic kidney disease (CKD) has been explored in many studies, it is still far from being well understood. Thus, we conducted a meta-analysis of studies comparing rates of CKD in patients with a history of kidney stones.MethodsPubMed, EMBASE, and the reference lists of relevant articles were searched to identify observational studies related to the topic. A random-effects model was used to combine the study-specific risk estimates. We explored the potential heterogeneity by subgroup analyses and meta-regression analyses.ResultsSeven studies were included in this meta-analysis. Pooled results suggested that a history of kidney stones was associated with an increased adjusted risk estimate for CKD [risk ratio (RR), 1.47 95% confidence interval (CI) [1.23–1.76])], with significant heterogeneity among these studies (I2 = 93.6%, P < 0.001). The observed positive association was observed in most of the subgroup analyses, whereas the association was not significant among studies from Asian countries, the mean age ≥50 years and male patients.ConclusionA history of kidney stones is associated with increased risk of CKD. Future investigations are encouraged to reveal the underlying mechanisms in the connection between kidney stones and CKD, which may point the way to more effective preventive and therapeutic measures.
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