Background Transcranial focused ultrasound (TFUS) is an emerging neuromodulation tool for temporarily altering brain activity and probing network functioning. The effects of TFUS on the default mode ...network (DMN) are unknown. Objective The study examined the effects of transcranial focused ultrasound (TFUS) on the functional connectivity of the default mode network (DMN), specifically by targeting the posterior cingulate cortex (PCC). Additionally, we investigated the subjective effects of TFUS on mood, mindfulness, and self-related processing. Methods The study employed a randomized, single-blind design involving 30 healthy subjects. Participants were randomly assigned to either the active TFUS group or the sham TFUS group. Resting-state functional magnetic resonance imaging (rs-fMRI) scans were conducted before and after the TFUS application. To measure subjective effects, the Toronto Mindfulness Scale, the Visual Analog Mood Scale, and the Amsterdam Resting State Questionnaire were administered at baseline and 30 min after sonication. The Self Scale and an unstructured interview were also administered 30 min after sonication. Results The active TFUS group exhibited significant reductions in functional connectivity along the midline of the DMN, while the sham TFUS group showed no changes. The active TFUS group demonstrated increased state mindfulness, reduced Global Vigor, and temporary alterations in the sense of ego, sense of time, and recollection of memories. The sham TFUS group showed an increase in state mindfulness, too, with no other subjective effects. Conclusions TFUS targeted at the PCC can alter DMN connectivity and cause changes in subjective experience. These findings support the potential of TFUS to serve both as a research tool and as a potential therapeutic intervention.
Skin fibrotic remodeling is a major feature in human atopic dermatitis (AD). Inflammation and tissue fibrosis are common consequences of Th2 responses. Elevated IL-13 and thymic stromal lymphopoietin ...(TSLP) have been found in the AD skin lesions. Fibrocytes can be recruited to inflamed tissues to promote wound healing and fibrosis. Dermal transgenic expression of IL-13 causes an AD-like phenotype with fibrosis and increased TSLP. However, the role of TSLP in fibrotic remodeling is unknown. In this study, we investigated the role of TSLP and fibrocytes in the generation of IL-13-induced skin fibrosis. In AD lesion, cessation of IL-13 transgene expression resulted in reduced skin inflammation but with no effect on further progression of fibrosis. This was accompanied by markedly increased CD34(+)/procollagen 1(+) fibrocytes. Furthermore, fibrocytes express TSLP receptor (TSLPR), and TSLP directly promotes PBMC-derived fibrocytes to produce collagen. Neutralization of TSLP or genetic deletion of TSLPR in IL-13 transgenic mice resulted in a significant reduction in fibrocytes and in skin fibrosis. Furthermore, reduction of fibrosis by depletion of TSLP was independent of IL-13. Interestingly, the number of fibrocytes was highly increased in the skin samples of AD patients. These data indicate that the progression of skin fibrosis in IL-13-induced AD occurs via TSLP/TSLPR-dependent but IL-13-independent novel mechanisms by promoting fibrocyte functions.
Beta-amyloid precursor protein (APP) has been reported to play a role in the outgrowth of neurites from cultured neurons. Both cell-surface APP and its soluble, ectodomain cleavage product ...(APPs-alpha) have been implicated in regulating the length and branching of neurites in a variety of assays, but the mechanism by which APP performs this function is not understood.
Here, we report that APP is required for proper neurite outgrowth in a cell autonomous manner, both in vitro and in vivo. Neurons that lack APP undergo elongation of their longest neurite. Deletion of APLP1 or APLP2, homologues of APP, likewise stimulates neurite lengthening. Intriguingly, wild-type neurons exposed to APPs-alpha, the principal cleavage product of APP, also undergo neurite elongation. However, APPs-alpha is unable to stimulate neurite elongation in the absence of cellular APP expression. The outgrowth-enhancing effects of both APPs-alpha and the deletion of APP are inhibited by blocking antibodies to Integrin beta1 (Itgbeta1). Moreover, full length APP interacts biochemically with Itgbeta1, and APPs-alpha can interfere with this binding.
Our findings indicate that APPs-alpha regulates the function of APP in neurite outgrowth via the novel mechanism of competing with the binding of APP to Itgbeta1.
Synapses are asymmetric cellular adhesions that are critical for nervous system development and function, but the mechanisms that induce their formation are not well understood. We have previously ...identified thrombospondin as an astrocyte-secreted protein that promotes central nervous system (CNS) synaptogenesis. Here, we identify the neuronal thrombospondin receptor involved in CNS synapse formation as α2δ-1, the receptor for the anti-epileptic and analgesic drug gabapentin. We show that the VWF-A domain of α2δ-1 interacts with the epidermal growth factor-like repeats common to all thrombospondins. α2δ-1 overexpression increases synaptogenesis in vitro and in vivo and is required postsynaptically for thrombospondin- and astrocyte-induced synapse formation in vitro. Gabapentin antagonizes thrombospondin binding to α2δ-1 and powerfully inhibits excitatory synapse formation in vitro and in vivo. These findings identify α2δ-1 as a receptor involved in excitatory synapse formation and suggest that gabapentin may function therapeutically by blocking new synapse formation.
Primary congenital glaucoma (PCG) is a devastating eye disease and an important cause of childhood blindness worldwide. In PCG, defects in the anterior chamber aqueous humor outflow structures of the ...eye result in elevated intraocular pressure (IOP); however, the genes and molecular mechanisms involved in the etiology of these defects have not been fully characterized. Previously, we observed PCG-like phenotypes in transgenic mice that lack functional angiopoietin-TEK signaling. Herein, we identified rare TEK variants in 10 of 189 unrelated PCG families and demonstrated that each mutation results in haploinsufficiency due to protein loss of function. Multiple cellular mechanisms were responsible for the loss of protein function resulting from individual TEK variants, including an absence of normal protein production, protein aggregate formation, enhanced proteasomal degradation, altered subcellular localization, and reduced responsiveness to ligand stimulation. Further, in mice, hemizygosity for Tek led to the formation of severely hypomorphic Schlemm's canal and trabecular meshwork, as well as elevated IOP, demonstrating that anterior chamber vascular development is sensitive to Tek gene dosage and the resulting decrease in angiopoietin-TEK signaling. Collectively, these results identify TEK mutations in patients with PCG that likely underlie disease and are transmitted in an autosomal dominant pattern with variable expressivity.
Plant cells undergo two types of cell cycles-the mitotic cycle in which DNA replication is coupled to mitosis, and the endocycle in which DNA replication occurs in the absence of cell division. To ...investigate DNA replication programs in these two types of cell cycles, we pulse labeled intact root tips of maize (Zea mays) with 5-ethynyl-2'-deoxyuridine (EdU) and used flow sorting of nuclei to examine DNA replication timing (RT) during the transition from a mitotic cycle to an endocycle. Comparison of the sequence-based RT profiles showed that most regions of the maize genome replicate at the same time during S phase in mitotic and endocycling cells, despite the need to replicate twice as much DNA in the endocycle and the fact that endocycling is typically associated with cell differentiation. However, regions collectively corresponding to 2% of the genome displayed significant changes in timing between the two types of cell cycles. The majority of these regions are small with a median size of 135 kb, shift to a later RT in the endocycle, and are enriched for genes expressed in the root tip. We found larger regions that shifted RT in centromeres of seven of the ten maize chromosomes. These regions covered the majority of the previously defined functional centromere, which ranged between 1 and 2 Mb in size in the reference genome. They replicate mainly during mid S phase in mitotic cells but primarily in late S phase of the endocycle. In contrast, the immediately adjacent pericentromere sequences are primarily late replicating in both cell cycles. Analysis of CENH3 enrichment levels in 8C vs 2C nuclei suggested that there is only a partial replacement of CENH3 nucleosomes after endocycle replication is complete. The shift to later replication of centromeres and possible reduction in CENH3 enrichment after endocycle replication is consistent with a hypothesis that centromeres are inactivated when their function is no longer needed.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Mitochondrial dysfunction is associated with many human diseases. Mitochondrial damage is exacerbated by inadequate protein quality control and often further contributes to pathogenesis. The ...maintenance of mitochondrial functions requires a delicate balance of continuous protein synthesis and degradation, i.e. protein turnover. To understand mitochondrial protein dynamics in vivo, we designed a metabolic heavy water (2H2O) labeling strategy customized to examine individual protein turnover in the mitochondria in a systematic fashion. Mice were fed with 2H2O at a minimal level (<5% body water) without physiological impacts. Mitochondrial proteins were analyzed from 9 mice at each of the 13 time points between 0 and 90 days (d) of labeling. A novel multiparameter fitting approach computationally determined the normalized peak areas of peptide mass isotopomers at initial and steady-state time points and permitted the protein half-life to be determined without plateau-level 2H incorporation. We characterized the turnover rates of 458 proteins in mouse cardiac and hepatic mitochondria and found median turnover rates of 0.0402 d−1 and 0.163 d−1, respectively, corresponding to median half-lives of 17.2 d and 4.26 d. Mitochondria in the heart and those in the liver exhibited distinct turnover kinetics, with limited synchronization within functional clusters. We observed considerable interprotein differences in turnover rates in both organs, with half-lives spanning from hours to months (∼60 d). Our proteomics platform demonstrates the first large-scale analysis of mitochondrial protein turnover rates in vivo, with potential applications in translational research.
Additive manufacturing (AM) also commonly known as 3D printing is an advanced technique for manufacturing complex three-dimensional (3D) parts by depositing raw material layer by layer. Various ...sub-categories of additive manufacturing exist including directed energy deposition (DED), powder bed fusion (PBF), and fused deposition modeling (FDM). FDM has gained widespread adoption as a popular method for manufacturing 3D parts, even for heavy-duty industrial applications. However, challenges remain, particularly regarding part quality. Print parameters such as print speed, nozzle temperature, and flow rate can significantly impact the final product's quality. To address this, implementing a closed-loop quality control system is essential. This system consistently monitors part surface quality during printing and adjusts print parameters upon defect detection. In this study, we propose a simple yet effective image analysis-based closed-loop control system, utilizing serial communication and Python v3.12, a widely accessible software platform. The system's accuracy and robustness are evaluated, demonstrating its effectiveness in ensuring FDM-printed part quality. Notably, this control system offers superior speed in restoring part quality to normal upon defect detection and is easily implementable on commercially available FDM 3D printers, fostering decentralized quality manufacturing.
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