Post-transcriptional regulatory pre-complex assembly drives timely cell-state transitions during differentiation.

Complexes that control mRNA stability and translation promote timely cell-state transitions during differentiation by ensuring appropriate expression patterns of key developmental regulators. The Drosophila RNA-binding protein Brain tumor (Brat) promotes degradation of target transcripts during the maternal-to-zygotic transition in syncytial embryos and in uncommitted intermediate neural progenitors (immature INPs). We identified Ubiquitin-specific protease 5 (Usp5) as a Brat interactor essential for the degradation of Brat target mRNAs in both cell types. Usp5 promotes Brat-dedadenylase pre-complex assembly in mitotic neural stem cells (neuroblasts) by bridging Brat and the scaffolding components of deadenylase complexes lacking their catalytic subunits. The adaptor protein Miranda binds the RNA-binding domain of Brat, limiting its ability to bind target mRNAs in mitotic neuroblasts. Cortical displacement of Miranda activates Brat-mediated mRNA decay in immature INPs. We propose that the assembly of an enzymatically inactive and RNA-binding-deficient pre-complex poises mRNA degradation machineries for rapid activation driving timely developmental transitions.

Effectiveness of Activity-Based Task-Oriented Training on Upper Extremity Recovery for Adults With Stroke: A Systematic Review.

IMPORTANCE: Interventions for improving upper extremity (UE) recovery have become a priority in stroke rehabilitation because UE disability can undermine a person's capacity to perform daily activities after stroke. A better understanding of the use of activity-based task-oriented training (TOT) will inform the development of more effective UE interventions in stroke rehabilitation. OBJECTIVE: To examine the effectiveness of activity-based TOT in improving the UE recovery of adults with stroke. DATA SOURCES: CINAHL Plus, MEDLINE, and PubMed. STUDY SELECTION AND DATA COLLECTION: Inclusion criteria included quantitative studies published between June 2012 and December 2022 that reported UE recovery as an outcome, including measurements of motor function, motor performance, and performance of activities of daily living (ADLs); a sample age ≥18 yr, with stroke in all phases; and interventions that incorporated real-world daily activities. We assessed articles for inclusion, quality, and risk of bias following Cochrane methodology and Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. FINDINGS: Sixteen studies (692 participants, Level 1-4 evidence) were included. Strong to moderate evidence supported the effectiveness of activity-based TOT in UE motor function, motor performance, and ADL performance for adults with stroke. Strong evidence supported the effectiveness of hospital-based TOT, and moderate evidence supported the effectiveness of home-based TOT. CONCLUSIONS AND RELEVANCE: The results not only showed the value of activity-based TOT as an effective UE intervention in stroke rehabilitation but also supported the occupational therapy philosophy of using functional and meaningful activities in practice. Further research on home-based TOT is needed. Plain-Language Summary: This systematic review shows the effectiveness and value of using real-life activities in task-oriented training approaches for adult survivors of stroke. The authors found strong evidence for hospital-based task-oriented training interventions and moderate evidence for home-based interventions for improving upper extremity recovery. This review shows the value of upper extremity task-oriented training as an effective intervention in stroke rehabilitation. The review also supports the occupational therapy philosophy of using functional and meaningful activities in practice as well as the profession's use of evidence-based practice in stroke rehabilitation.

Low-level repressive histone marks fine-tune gene transcription in neural stem cells.

Coordinated regulation of gene activity by transcriptional and translational mechanisms poise stem cells for a timely cell-state transition during differentiation. Although important for all stemness-to-differentiation transitions, mechanistic understanding of the fine-tuning of gene transcription is lacking due to the compensatory effect of translational control. We used intermediate neural progenitor (INP) identity commitment to define the mechanisms that fine-tune stemness gene transcription in fly neural stem cells (neuroblasts). We demonstrate that the transcription factor FruitlessC (FruC) binds cis-regulatory elements of most genes uniquely transcribed in neuroblasts. Loss of fruC function alone has no effect on INP commitment but drives INP dedifferentiation when translational control is reduced. FruC negatively regulates gene expression by promoting low-level enrichment of the repressive histone mark H3K27me3 in gene cis-regulatory regions. Identical to fruC loss-of-function, reducing Polycomb Repressive Complex 2 activity increases stemness gene activity. We propose low-level H3K27me3 enrichment fine-tunes gene transcription in stem cells, a mechanism likely conserved from flies to humans.

From neurons to sperm, our bodies are formed of a range of cells tailored to perform a unique role. However, organisms also host small reservoirs of unspecialized 'stem cells' that retain the ability to become different kinds of cells. When these stem cells divide, one daughter cell remains a stem cell while the other undergoes a series of changes that allows it to mature into a specific cell type. This 'differentiation' process involves quickly switching off the stem cell programme, the set of genes that give a cell the ability to keep dividing while maintaining an unspecialized state. Failure to do so can result in the differentiating cell reverting towards its initial state and multiplying uncontrollably, which can lead to tumours and other health problems. While scientists have a good understanding of how the stem cell programme is turned off during differentiation, controlling these genes is a balancing act that starts even before division: if the program is over-active in the 'mother' stem cell, for instance, the systems that switch it off in its daughter can become overwhelmed. The mechanisms presiding over these steps are less well-understood. To address this knowledge gap, Rajan, Anhezini et al. set out to determine how stem cells present in the brains of fruit flies could control the level of activity of their own stem cell programme. RNA sequencing and other genetic analyses revealed that a protein unique to these cells, called Fruitless, was responsible for decreasing the activity of the programme. Biochemical experiments then showed that Fruitless performed this role by attaching a small amount of chemical modifications (called methyl groups) to the proteins that 'package' the DNA near genes involved in the stem cell programme. High levels of methyl groups present near a gene will switch off this sequence completely; however, the amount of methyl groups that Fruitless helped to deposit is multiple folds lower. Consequently, Fruitless 'fine-tunes' the activity of the stem cell programme instead, dampening it just enough to stop it from overpowering the 'off' mechanism that would take place later in the daughter cell. These results shed new light on how stem cells behave ­ and how our bodies stop them from proliferating uncontrollably. In the future, Rajan, Anhezini et al. hope that this work will help to understand and treat diseases caused by defective stem cell differentiation.

A wearable electrochemical fabric for cytokine monitoring.

Wearable biosensors monitoring various biomarkers in sweat provide comprehensive and prompt profiling of health states at molecular levels. Cytokines existed in sweat with trace amounts play an important role in cellular activity modulation. Unfortunately, flexible and wearable biosensors for cytokine monitoring have not yet been achieved due to the limitation of membrane-based structure and sensing strategy. Herein, we develop a novel electrochemical fabric based on aptamer-functionalized carbon nanotube/graphene fibers for real-time and in situ monitoring of IL-6, a paramount cytokine biomarker for inflammation and cancer. This fabric system possesses flexibility, anti-fatigue ability and breathability for wearable applications and can apply to different body parts in various forms. Moreover, the electrochemical fabric can track other biomarkers by replacing the coupling aptamer, serving as a universal platform for sweat analysis. This fabric-based platform holds the potential to facilitate an intelligent and personalized health monitoring approach.

Deep learning-based optical coherence tomography image analysis of human brain cancer.

Real-time intraoperative delineation of cancer and non-cancer brain tissues, especially in the eloquent cortex, is critical for thorough cancer resection, lengthening survival, and improving quality of life. Prior studies have established that thresholding optical attenuation values reveals cancer regions with high sensitivity and specificity. However, threshold of a single value disregards local information important to making more robust predictions. Hence, we propose deep convolutional neural networks (CNNs) trained on labeled OCT images and co-occurrence matrix features extracted from these images to synergize attenuation characteristics and texture features. Specifically, we adapt a deep ensemble model trained on 5,831 examples in a training dataset of 7 patients. We obtain 93.31% sensitivity and 97.04% specificity on a holdout set of 4 patients without the need for beam profile normalization using a reference phantom. The segmentation maps produced by parsing the OCT volume and tiling the outputs of our model are in excellent agreement with attenuation mapping-based methods. Our new approach for this important application has considerable implications for clinical translation.

Embedded Integration of Sb2Se3 Film by Low-Temperature Plasma-Assisted Chemical Vapor Reaction with Polycrystalline Si Transistor for High-Performance Flexible Visible-to-Near-Infrared Photodetector.

Flexible optoelectronics have garnered considerable interest for applications such as optical communication, motion capture, biosignal detection, and night vision. Transition-metal dichalcogenides are widely used as flexible photodetectors owing to their outstanding electrical and optical properties and high flexibility. Herein, a two-dimensional (2D) Sb2Se3 film-based one transistor-one resistor (1T1R) flexible photodetector with high photosensing current and detection ranges from visible to near-infrared was developed. The flexible 1T1R was fabricated using an efficient field-effect transistor platform with the 2D Sb2Se3 film directly deposited on the sensing region using a low-temperature plasma-assisted chemical vapor reaction. The photodetector could achieve a maximum Iphoto/Idark of 15,000 under white light with a power density of 26 mW/cm2, in which the photodetector showed quick rising and falling response times of 0.16 and 0.28 s, respectively. The 2D Sb2Se3 film exhibits broadband absorption in the visible and IR regions, yielding an excellent photoresponse under laser illumination with different wavelengths. To investigate the flexibility and stability of the 1T1R photodetector, the photoresponses were measured under different bending cycles and curvatures, which maintained its functions and exhibited high stability under convex and concave bending at a curvature radius of 20 mm.

Premature translation of the Drosophila zygotic genome activator Zelda is not sufficient to precociously activate gene expression.

Following fertilization, the unified germ cells rapidly transition to a totipotent embryo. Maternally deposited mRNAs encode the proteins necessary for this reprogramming as the zygotic genome remains transcriptionally quiescent during the initial stages of development. The transcription factors required to activate the zygotic genome are among these maternally deposited mRNAs and are robustly translated following fertilization. In Drosophila, the mRNA encoding Zelda, the major activator of the zygotic genome, is not translated until 1 h after fertilization. Here we demonstrate that zelda translation is repressed in the early embryo by the TRIM-NHL protein Brain tumor (BRAT). BRAT also regulates Zelda levels in the larval neuroblast lineage. In the embryo, BRAT-mediated translational repression is regulated by the Pan Gu kinase, which is triggered by egg activation. The Pan Gu kinase phosphorylates translational regulators, suggesting that Pan Gu kinase activity alleviates translational repression of zelda by BRAT and coupling translation of zelda with that of other regulators of early embryonic development. Using the premature translation of zelda in embryos lacking BRAT activity, we showed that early translation of a zygotic genome activator is not sufficient to drive precocious gene expression. Instead, Zelda-target genes showed increased expression at the time they are normally activated. We propose that transition through early development requires the integration of multiple processes, including the slowing of the nuclear division cycle and activation of the zygotic genome. These processes are coordinately controlled by Pan Gu kinase-mediated regulation of translation.

Cell-type-specific chromatin occupancy by the pioneer factor Zelda drives key developmental transitions in Drosophila.

During Drosophila embryogenesis, the essential pioneer factor Zelda defines hundreds of cis-regulatory regions and in doing so reprograms the zygotic transcriptome. While Zelda is essential later in development, it is unclear how the ability of Zelda to define cis-regulatory regions is shaped by cell-type-specific chromatin architecture. Asymmetric division of neural stem cells (neuroblasts) in the fly brain provide an excellent paradigm for investigating the cell-type-specific functions of this pioneer factor. We show that Zelda synergistically functions with Notch to maintain neuroblasts in an undifferentiated state. Zelda misexpression reprograms progenitor cells to neuroblasts, but this capacity is limited by transcriptional repressors critical for progenitor commitment. Zelda genomic occupancy in neuroblasts is reorganized as compared to the embryo, and this reorganization is correlated with differences in chromatin accessibility and cofactor availability. We propose that Zelda regulates essential transitions in the neuroblasts and embryo through a shared gene-regulatory network driven by cell-type-specific enhancers.

Regulation of Neural Stem Cell Competency and Commitment during Indirect Neurogenesis.

Indirect neurogenesis, during which neural stem cells generate neurons through intermediate progenitors, drives the evolution of lissencephalic brains to gyrencephalic brains. The mechanisms that specify intermediate progenitor identity and that regulate stem cell competency to generate intermediate progenitors remain poorly understood despite their roles in indirect neurogenesis. Well-characterized lineage hierarchy and available powerful genetic tools for manipulating gene functions make fruit fly neural stem cell (neuroblast) lineages an excellent in vivo paradigm for investigating the mechanisms that regulate neurogenesis. Type II neuroblasts in fly larval brains repeatedly undergo asymmetric divisions to generate intermediate neural progenitors (INPs) that undergo limited proliferation to increase the number of neurons generated per stem cell division. Here, we review key regulatory genes and the mechanisms by which they promote the specification and generation of INPs, safeguarding the indirect generation of neurons during fly larval brain neurogenesis. Homologs of these regulators of INPs have been shown to play important roles in regulating brain development in vertebrates. Insight into the precise regulation of intermediate progenitors will likely improve our understanding of the control of indirect neurogenesis during brain development and brain evolution.

DNAzyme-Amplified Label-Free Biosensor for the Simple and Sensitive Detection of Pyrophosphatase.

The level of pyrophosphatase (PPase) expression has been suggested as a potential biomarker of various cancers, and its prognostic value has been evaluated in patients suffering from lung cancer, colorectal cancer, and hyperthyroidism. However, the detection of PPase usually needs specific materials that require complicated, time-consuming reactions with restricted linear range and sensitivity, limiting their application in early clinical diagnosis. Herein, we developed a DNAzyme-based biosensor for the detection of PPase. In the presence of PPase, pyrophosphate (PPi) and Cu2+ ions released from the PPi-Cu2+-PPi complex induce the cleavage of the DNAzyme and the corresponding substrate. An apurinic/apyrimidinic (AP) site was elaborately designed within substrates that could encase the fluorophore 2-amino-5,6,7-trimethyl-1,8-naphthyridine (ATMND). The fluorescence of ATMND was initially quenched but restored when the DNAzyme/substrate complex was hydrolyzed with the release of ATMND. In this way, the PPase activity can be estimated by detecting the increased fluorescence of the released ATMND. Under optimized conditions, the activity of PPase could be analyzed at concentrations from 0.5 to 1000 mU, with the lowest detectable concentration being 0.5 mU. This work lays a foundation for developing a DNAzyme-amplified fluorescent biosensor with a high sensitivity, a wide linear range, and single-step operation for use as an easy diagnostic for PPase analysis.

me31B regulates stem cell homeostasis by preventing excess dedifferentiation in the Drosophila male germline.

Tissue-specific stem cells maintain tissue homeostasis by providing a continuous supply of differentiated cells throughout the life of organisms. Differentiated/differentiating cells can revert back to a stem cell identity via dedifferentiation to help maintain the stem cell pool beyond the lifetime of individual stem cells. Although dedifferentiation is important for maintaining the stem cell population, it is speculated that it underlies tumorigenesis. Therefore, this process must be tightly controlled. Here, we show that a translational regulator, me31B, plays a critical role in preventing excess dedifferentiation in the Drosophila male germline: in the absence of me31B, spermatogonia dedifferentiate into germline stem cells (GSCs) at a dramatically elevated frequency. Our results show that the excess dedifferentiation is likely due to misregulation of nos, a key regulator of germ cell identity and GSC maintenance. Taken together, our data reveal negative regulation of dedifferentiation to balance stem cell maintenance with differentiation.

The molecular landscape of neural differentiation in the developing Drosophila brain revealed by targeted scRNA-seq and multi-informatic analysis.

The Drosophila type II neuroblast lineages present an attractive model to investigate the neurogenesis and differentiation process as they adapt to a process similar to that in the human outer subventricular zone. We perform targeted single-cell mRNA sequencing in third instar larval brains to study this process of the type II NB lineage. Combining prior knowledge, in silico analyses, and in situ validation, our multi-informatic investigation describes the molecular landscape from a single developmental snapshot. 17 markers are identified to differentiate distinct maturation stages. 30 markers are identified to specify the stem cell origin and/or cell division numbers of INPs, and at least 12 neuronal subtypes are identified. To foster future discoveries, we provide annotated tables of pairwise gene-gene correlation in single cells and MiCV, a web tool for interactively analyzing scRNA-seq datasets. Taken together, these resources advance our understanding of the neural differentiation process at the molecular level.

Sequential activation of transcriptional repressors promotes progenitor commitment by silencing stem cell identity genes.

Stem cells that indirectly generate differentiated cells through intermediate progenitors drives vertebrate brain evolution. Due to a lack of lineage information, how stem cell functionality, including the competency to generate intermediate progenitors, becomes extinguished during progenitor commitment remains unclear. Type II neuroblasts in fly larval brains divide asymmetrically to generate a neuroblast and a progeny that commits to an intermediate progenitor (INP) identity. We identified Tailless (Tll) as a master regulator of type II neuroblast functional identity, including the competency to generate INPs. Successive expression of transcriptional repressors functions through Hdac3 to silence tll during INP commitment. Reducing repressor activity allows re-activation of Notch in INPs to ectopically induce tll expression driving supernumerary neuroblast formation. Knocking-down hdac3 function prevents downregulation of tll during INP commitment. We propose that continual inactivation of stem cell identity genes allows intermediate progenitors to stably commit to generating diverse differentiated cells during indirect neurogenesis.

Deep sea minerals ameliorate diabetic-induced inflammation via inhibition of TNFα signaling pathways.

It has been well-documented that the consumption of deep sea water (DSW) has beneficial effects on myocardial hypertrophy and cardiac apoptosis induced by hypercholesterolemia. However, the molecular mechanisms for the anti-inflammatory effects of DSW on diabetic cardiomyopathy are still largely unclear. The main purpose of this present study was to test the hypothesis that DSW exerts anti-inflammatory effects through the suppression of the TNF-α-mediated signaling pathways. IP injection of streptozotocin (STZ) at the dose of 65 mg/kg was used to establish a diabetes rat model. DSW mineral extracts that diluted in desalinated water were prepared in three different dosages and administered to the rats through gavages for 4 weeks. These dosages are DSW-1X (equivalent to 37 mg Mg2+ /kg/day), 2X (equivalent to 74 mg Mg2+ /kg/day) and 3X (equivalent to 111 mg Mg2+ mg/kg/day). Immunofluorescence staining and Western blot showed that the protein expression level of TNF-α was markedly higher in the STZ-induced diabetic rat hearts than in the control group. Consequently, the phosphorylation levels of the TNF-α-modulated downstream signaling molecules and P38 mitogen-activated protein kinases (MAPKs) were notably elevated in heart tissues of STZ-induced diabetes. These higher phosphorylation levels subsequently upregulated NF-κB-modulated inflammatory mediators, such as cyclooxygenase (COX)-II and inducible nitric oxide synthase (iNOS). However, treatment with DSW as well as MgSO4 , the main mineral in DSW, significantly reversed all the alterations. These findings suggest that DSW has potential as a therapeutic agent for preventing diabetes-related cardiovascular diseases.

Ultrahigh-resolution optical coherence tomography/angiography with an economic and compact supercontinuum laser.

In this study, a Q-switch pumped supercontinuum laser (QS-SCL) is used as a light source for in vivo imaging via ultrahigh-resolution optical coherence tomography and angiography (UHR-OCT/OCTA). For this purpose, an OCT system based on a spectral-domain detection scheme is constructed, and a spectrometer with a spectral range of 635 - 875 nm is designed. The effective full-width at half maximum of spectrum covers 150 nm, and the corresponding axial and transverse resolutions are 2 and 10 µm in air, respectively. The relative intensity noise of the QS-SCL and mode-locked SCL is quantitatively compared. Furthermore, a special processing algorithm is developed to eliminate the intrinsic noise of QS-SCL. This work demonstrates that QS-SCLs can effectively reduce the cost and size of UHR-OCT/OCTA instruments, making clinical applications feasible.

Deep ocean minerals inhibit IL-6 and IGFIIR hypertrophic signaling pathways to attenuate diabetes-induced hypertrophy in rat hearts.

We previously reported that deep sea water (DSW) prolongs the life span of streptozotocin (STZ)-induced diabetic rats by the compensatory augmentation of the insulin like growth factor (IGF)-I survival signaling and inhibition of apoptosis. Here, we investigated the effects of DSW on cardiac hypertrophy in diabetic rats. Cardiac hypertrophy was induced in rats by using STZ (65 mg/kg) administered via IP injection. DSW was prepared by mixing DSW mineral extracts and desalinated water. Different dosages of DSW-1X (equivalent to 37 mg Mg2+·kg-1·day-1), 2X (equivalent to 74 mg Mg2+·kg-1·day-1) and 3X (equivalent to 111 mg Mg2+·kg-1·day-1) were administered to the rats through gavage for 4 wk. Cardiac hypertrophy was evaluated by the heart weight-to-body weight ratio and the cardiac tissue cross-sectional area after hematoxylin and eosin staining. The protein levels of the cardiac hypertrophy signaling molecules were determined by Western blot. Our results showed that the suppressive effects of the DSW treatment on STZ-induced cardiac hypertrophy were comparable to those of MgSO4 administration and that the hypertrophic marker brain natriuretic peptide (BNP) was decreased by DSW. In addition, DSW attenuated both the eccentric hypertrophy signaling pathway, IL-6-MEK-STAT3, and the concentric signaling pathway, IGF-II-PKCα-CaMKII, in DM rat hearts. The cardiac hypertrophy-associated activation of extracellular signal-regulated kinase (ERK) and the upregulation of the transcription factor GATA binding protein 4 (GATA4) were also negated by treatment with DSW. The results from this study suggest that DSW could be a potential therapeutic agent for the prevention and treatment of diabetic cardiac hypertrophy.NEW & NOTEWORTHY Deep sea water, containing high levels of minerals, improve cardiac hypertrophy in diabetic rats through attenuating the eccentric signaling pathway, IL-6-MEK5-STAT3, and concentric signaling pathway, IGF2-PKCα-CaMKII. The results from this study suggest that deep sea water could be a potential therapeutic agent for the prevention and treatment of diabetic cardiac hypertrophy.

Combining DNA-stabilized silver nanocluster synthesis with exonuclease III amplification allows label-free detection of coralyne.

In this paper we describe a label-free biosensor for coralyne, prepared by combining DNA-stabilized silver nanoclusters (Ag NCs) with an exonuclease III amplification strategy. An artificial DNA probe having a polyadenine (poly-A) sequence at both the 3'- and 5'-ends was used as a probe to detect coralyne. In the absence of coralyne, the probe existed in a hairpin conformation that left both its 3'- and 5'-ends free. In the presence of coralyne, two adjacent adenine (A) bases in the poly-A sequence of the probe formed an A2 unit and then coordinated with coralyne through non-Watson-Crick base pairing. The DNA probe, having captured coralyne, was subsequently digested by exonuclease III, even though the distance between the A2 units in the A2-coralyne-A2 complex would be much larger than that found in common Watson-Crick base pairing. After digestion, the DNA probe became a single-stranded DNA (ssDNA) residue and released its captured coralyne. The liberated coralyne was then coordinated by another DNA probe having the hairpin conformation; as a result, many ssDNA residues formed after digestion. Two kinds of Ag NCs having different optical utilities were obtained: one corresponding to the hairpin conformational DNA probe and the other to the ssDNA residue. The difference in fluorescence intensity at 588 nm of these two kinds of Ag NCs reflected the concentration of coralyne. The linear range (on a logarithmic scale) for detecting coralyne spanned from 5 to 1000 nM, with an estimated detection limit of 1.83 nM.

Multilayered gene control drives timely exit from the stem cell state in uncommitted progenitors during Drosophila asymmetric neural stem cell division.

Self-renewal genes maintain stem cells in an undifferentiated state by preventing the commitment to differentiate. Robust inactivation of self-renewal gene activity following asymmetric stem cell division allows uncommitted stem cell progeny to exit from an undifferentiated state and initiate the commitment to differentiate. Nonetheless, how self-renewal gene activity at mRNA and protein levels becomes synchronously terminated in uncommitted stem cell progeny is unclear. We demonstrate that a multilayered gene regulation system terminates self-renewal gene activity at all levels in uncommitted stem cell progeny in the fly neural stem cell lineage. We found that the RNA-binding protein Brain tumor (Brat) targets the transcripts of a self-renewal gene, deadpan (dpn), for decay by recruiting the deadenylation machinery to the 3' untranslated region (UTR). Furthermore, we identified a nuclear protein, Insensible, that complements Cullin-mediated proteolysis to robustly inactivate Dpn activity by limiting the level of active Dpn through protein sequestration. The synergy between post-transcriptional and transcriptional control of self-renewal genes drives timely exit from the stem cell state in uncommitted progenitors. Our proposed multilayered gene regulation system could be broadly applicable to the control of exit from stemness in all stem cell lineages.

Noninvasive structural and microvascular anatomy of oral mucosae using handheld optical coherence tomography.

In this study, we demonstrated the feasibility of using a handheld optical coherence tomography (OCT) for in vivo visualizations of the microstructural and microvascular features of various oral mucosal types. To scan arbitrary locations of the oral mucosa, a scanning probe was developed, composed of a probe body fabricated by a 3D printer, miniaturized two-axis galvanometer, relay lenses, and reflective prism. With a 3D printing technique, the probe weight and the system volume were greatly reduced, enabling the effective improvement of imaging artifacts from unconscious motion and system complexity. Additionally, in our design, the distal end of the probe can be switched to fit various oral conditions, and the optical parameters of the probe, such as the transverse resolution, working distance, and probe length can be easily varied. The results showed that the epithelium and lamina propria layers, as well as the fungiform papilla and salivary gland, were differentiated. Moreover, various microcirculation features at different mucosal sites were identified that are potentially effective indicators for the diagnosis of premalignant lesions. The demonstrated results indicate that the developed OCT system is a promising tool for noninvasive imaging of oral mucosae.

RBPJ/CBF1 interacts with L3MBTL3/MBT1 to promote repression of Notch signaling via histone demethylase KDM1A/LSD1.

Notch signaling is an evolutionarily conserved signal transduction pathway that is essential for metazoan development. Upon ligand binding, the Notch intracellular domain (NOTCH ICD) translocates into the nucleus and forms a complex with the transcription factor RBPJ (also known as CBF1 or CSL) to activate expression of Notch target genes. In the absence of a Notch signal, RBPJ acts as a transcriptional repressor. Using a proteomic approach, we identified L3MBTL3 (also known as MBT1) as a novel RBPJ interactor. L3MBTL3 competes with NOTCH ICD for binding to RBPJ In the absence of NOTCH ICD, RBPJ recruits L3MBTL3 and the histone demethylase KDM1A (also known as LSD1) to the enhancers of Notch target genes, leading to H3K4me2 demethylation and to transcriptional repression. Importantly, in vivo analyses of the homologs of RBPJ and L3MBTL3 in Drosophila melanogaster and Caenorhabditis elegans demonstrate that the functional link between RBPJ and L3MBTL3 is evolutionarily conserved, thus identifying L3MBTL3 as a universal modulator of Notch signaling in metazoans.