Atf4 protects islet ß-cell identity and function under acute glucose-induced stress but promotes ß-cell failure in the presence of free fatty acid.

Glucolipotoxicity, caused by combined hyperglycemia and hyperlipidemia, results in ß-cell failure and type 2 diabetes (T2D) via cellular stress-related mechanisms. Activating transcription factor 4 (Atf4) is an essential effector of stress response. We show here that Atf4 expression in ß-cells is dispensable for glucose homeostasis in young mice, but it is required for ß-cell function during aging and under obesity-related metabolic stress. Henceforth, aged Atf4- deficient ß-cells display compromised secretory function under acute hyperglycemia. In contrast, they are resistant to acute free fatty acid-induced loss-of identity and dysfunction. At molecular level, Atf4 -deficient ß-cells down-regulate genes involved in protein translation, reducing ß-cell identity gene products under high glucose. They also upregulate several genes involved in lipid metabolism or signaling, likely contributing to their resistance to free fatty acid-induced dysfunction. These results suggest that Atf4 activation is required for ß-cell identity and function under high glucose, but this paradoxically induces ß-cell failure in the presence of high levels of free fatty acids. Different branches of Atf4 activity could be manipulated for protecting ß-cells from metabolic stress-induced failure. Highlights: Atf4 is dispensable in ß-cells in young miceAtf4 protects ß-cells under high glucoseAtf4 exacerbate fatty acid-induced ß-cell defectsAtf4 activates translation but depresses lipid-metabolism.

Reduced risk of overt hepatic encephalopathy and death after transjugular intrahepatic portosystemic shunt in patients with hepatic venovenous communications.

PURPOSE: Hepatic venovenous communications (HVVC) is detectable in more than one-third of cirrhotic patients, where portal hypertension (PHT) tends to present more severely. We aimed to explore the prognostic implications of HVVC in patients with sinusoidal PHT treated by transjugular intrahepatic portosystemic shunt (TIPS). METHOD: The multicenter data of patients (2020-2022) undergoing balloon-occluded hepatic venography during TIPS were retrospectively analyzed. Pre-TIPS total bile acids (TBA) levels in portal, hepatic and peripheral veins were compared between groups. The primary endpoint was the development of overt hepatic encephalopathy (HE) within one year after TIPS. RESULTS: 183 patients were eligible and classified by the presence (n = 69, 37.7 %) or absence (n = 114, 62.3 %) of HVVC. The agreement between wedged hepatic venous pressure and portal venous pressure was poor in HVVC group (intraclass correlation coefficients [ICC]: 0.141, difference: 13.4 mmHg, p < 0.001), but almost perfect in non-HVVC group (ICC: 0.877, difference: 0.4 mmHg, p = 0.152). At baseline, patients with HVVC had lower Model for end-stage liver disease scores (p < 0.001), blood ammonia levels (p < 0.001), TBA concentrations in the hepatic (p = 0.011) and peripheral veins (p = 0.049) rather than in the portal veins (p = 0.516), and a higher portosystemic pressure gradient (p = 0.035), suggesting more effective intrahepatic perfusion in this group. Within 1-year post-TIPS, HVVC group had a lower incidence of overt HE (11.7 % vs. 30.5 %, p = 0.004, HR: 0.34, 95 % CI: 0.16-0.74, absolute risk difference [ARD]: -17.4) and an improved liver transplantation-free survival rate (97.1 % vs. 86.8 %, p = 0.021, HR: 0.16, 95 % CI: 0.05-0.91, ARD: -10.3). CONCLUSIONS: For patients with sinusoidal PHT treated by TIPS, the presence of HVVC was associated with a reduced risk of overt HE and a potential survival benefit.

Inducible Fgf13 ablation alleviates cardiac fibrosis via regulation of microtubule stability.

Fibroblast growth factor (FGF) isoform 13, a distinct type of FGF, boasts significant potential for therapeutic intervention in cardiovascular dysfunctions. However, its impact on regulating fibrosis remains unexplored. This study aims to elucidate the role and mechanism of FGF13 on cardiac fibrosis. Here, we show that following transverse aortic constriction (TAC) surgery, interstitial fibrosis and collagen content increase in mice, along with reduced ejection fraction and fractional shortening, augmented heart mass. However, following Fgf13 deletion, interstitial fibrosis is decreased, ejection fraction and fractional shortening are increased, and heart mass is decreased, compared with those in the TAC group. Mechanistically, incubation of cardiac fibroblasts with transforming growth factor ß (TGFß) increases the expressions of types I and III collagen proteins, as well as α-smooth muscle actin (α-SMA) proteins, and enhances fibroblast proliferation and migration. In the absence of Fgf13, the expressions of these proteins are decreased, and fibroblast proliferation and migration are suppressed, compared with those in the TGFß-stimulated group. Overexpression of FGF13, but not FGF13 mutants defective in microtubule binding and stabilization, rescues the decrease in collagen and α-SMA protein and weakens the proliferation and migration function of the Fgf13 knockdown group. Furthermore, Fgf13 knockdown decreases ROCK protein expression via microtubule disruption. Collectively, cardiac Fgf13 knockdown protects the heart from fibrosis in response to haemodynamic stress by modulating microtubule stabilization and ROCK signaling pathway.

An Ionic Assisted Enhancement Strategy Enabled High Performance Flexible Pressure-Temperature Dual Sensor.

Flexible pressure sensors with a broad range and high sensitivity are greatly desired yet challenging to build. Herein, we have successfully fabricated a pressure-temperature dual sensor via an ionic assisted charge enhancement strategy. Benefiting from the immobilization effect for [EMIM+] [TFSI-] ion pairs and charge transfer between ionic liquid (IL) and HFMO (H10Fe3Mo21O51), the formed IL-HFMO-TPU pressure sensor shows a high sensitivity of 25.35 kPa-1 and broad sensing range (∼10 MPa), respectively. Furthermore, the sensor device exhibits high durability and stability (5000 cycles@1 MPa). The IL-HFMO-TPU sensor also shows the merit of good temperature sensing properties. Attributed to these superior properties, the proposed sensor device could detect pressure in an ultrawide sensing range (from Pa to MPa), including breathe and biophysical signal monitoring etc. The proposed ionic assisted enhancement approach is a generic strategy for constructing high performance flexible pressure-temperature dual sensor.

FGF13 deficiency ameliorates calcium signaling abnormality in heart failure by regulating microtubule stability.

Calcium signaling abnormality in cardiomyocytes, as a key mechanism, is closely associated with developing heart failure. Fibroblast growth factor 13 (FGF13) demonstrates important regulatory roles in the heart, but its association with cardiac calcium signaling in heart failure remains unknown. This study aimed to investigate the role and mechanism of FGF13 on calcium mishandling in heart failure. Mice underwent transaortic constriction to establish a heart failure model, which showed decreased ejection fraction, fractional shortening, and contractility. FGF13 deficiency alleviated cardiac dysfunction. Heart failure reduces calcium transients in cardiomyocytes, which were alleviated by FGF13 deficiency. Meanwhile, FGF13 deficiency restored decreased Cav1.2 and Serca2α expression and activity in heart failure. Furthermore, FGF13 interacted with microtubules in the heart, and FGF13 deficiency inhibited the increase of microtubule stability during heart failure. Finally, in isoproterenol-stimulated FGF13 knockdown neonatal rat ventricular myocytes (NRVMs), wildtype FGF13 overexpression, but not FGF13 mutant, which lost the binding site of microtubules, promoted calcium transient abnormality aggravation and Cav1.2 downregulation compared with FGF13 knockdown group. Generally, FGF13 deficiency improves abnormal calcium signaling by inhibiting the increased microtubule stability in heart failure, indicating the important role of FGF13 in cardiac calcium homeostasis and providing new avenues for heart failure prevention and treatment.

High-sensitivity, ultrawide linear range, antibacterial textile pressure sensor based on chitosan/MXene hierarchical architecture.

It is still a great challenge for the flexible piezoresistive pressure sensors to simultaneously achieve wide linearity and high sensitivity. Herein, we propose a high-performance textile pressure sensor based on chitosan (CTS)/MXene fiber. The hierarchical "point to line" architecture enables the pressure sensor with high sensitivity of 1.16 kPa-1 over an ultrawide linear range of 1.5 MPa. Furthermore, the CTS/MXene pressure sensor possesses a low fatigue over 1000 loading/unloading cycles under 1.5 MPa pressure load, attributed to the strong chemical bonding between CTS fiber and MXene and excellent mechanical stability. Besides, the proposed sensor shows good antibacterial effect benefiting from the strong interaction between polycationic structure of CTS/MXene and the predominantly anionic components of bacteria surface. The sensor is also applied to detect real-time human action, an overall classification accuracy of 98.61% based on deep neural network-convolutional neural network (CNN) for six human actions is realized.

Endocrine islet ß-cell subtypes with differential function are derived from biochemically distinct embryonic endocrine islet progenitors that are regulated by maternal nutrients.

Endocrine islet b cells comprise heterogenous cell subsets. Yet when/how these subsets are produced and how stable they are remain unknown. Addressing these questions is important for preventing/curing diabetes, because lower numbers of b cells with better secretory function is a high risk of this disease. Using combinatorial cell lineage tracing, scRNA-seq, and DNA methylation analysis, we show here that embryonic islet progenitors with distinct gene expression and DNA methylation produce b-cell subtypes of different function and viability in adult mice. The subtype with better function is enriched for genes involved in vesicular production/trafficking, stress response, and Ca2+-secretion coupling, which further correspond to differential DNA methylation in putative enhancers of these genes. Maternal overnutrition, a major diabetes risk factor, reduces the proportion of endocrine progenitors of the b-cell subtype with better-function via deregulating DNA methyl transferase 3a. Intriguingly, the gene signature that defines mouse b-cell subtypes can reliably divide human cells into two sub-populations while the proportion of b cells with better-function is reduced in diabetic donors. The implication of these results is that modulating DNA methylation in islet progenitors using maternal food supplements can be explored to improve b-cell function in the prevention and therapy of diabetes.

Endovascular management of sinistral portal hypertension-related variceal hemorrhage: a multicenter retrospective study.

PURPOSE: This study aimed to assess the safety and efficacy of endovascular managements, including splenic vein recanalization (SVR), partial splenic embolization (PSE), and percutaneous transsplenic gastric varices embolization combined with PSE (PSE+GVE), for management of SPH-related variceal hemorrhage (VH). METHODS: A total of 61 patients with SPH-related VH from three hospitals were enrolled and classified into three groups: the SVR group (Group 1, n=24), the PSE+GVE group (Group 2, n=17), and the PSE group (Group 3, n=20). Baseline characteristics and clinical outcomes were compared among the groups. RESULTS: The technical success rates for transhepatic and transsplenic SVR were 27.8% and 34.6%, respectively. No major complications were observed during any of the procedures. The median follow-up period was 53.2 months. The 2-year GI rebleeding rates for Group 1, 2, and 3 were 0%, 5.9%, and 35%, respectively. Groups 1 and 2 have a lower GI rebleeding rate (p = 0.002, p = 0.048, respectively) and better results of the degree of GV (p = 0.003, p = 0.044, respectively) compared to Group 3. No significant differences were found in 2-year GI rebleeding rates and the degree of GV between Group 1 and 2 (p = 0.415, p = 0.352, respectively). CONCLUSION: SVR, PSE+GVE, and PSE seem safe and effective for management of SPH-related VH. SVR appears to be the superior treatment option. Transsplenic access may further increase the SVR success rate. PSE+GVE seems to have comparable outcomes in GV control and GI rebleeding rates compared to SVR, while superior to PSE.

Preparation of Whole-mount Mouse Islets on Vascular Extracellular Matrix for Live Islet Cell Microscopy.

Pancreatic islet ß cells preferentially secrete insulin toward the plasma membrane, making contact with the capillary extracellular matrix (ECM). Isolated islets separated from the exocrine acinar cells are the best system for cell biology studies of primary ß cells, whereas isolated islets lose their capillary network during ex vivo culture. Providing the appropriate extracellular signaling by attaching islets to vascular ECM-coated surfaces can restore the polarized insulin secretion toward the ECM. The guided secretion toward ECM-coated glass coverslips provides a good model for recording insulin secretion in real time to study its regulation. Additionally, ß cells attached to the ECM-coated coverslips are suitable for confocal live imaging of subcellular components including adhesion molecules, cytoskeleton, and ion channels. This procedure is also compatible for total internal reflection fluorescence (TIRF) microscopy, which provides optimal signal-to-noise ratio and high spatial precision of structures close to the plasma membrane. In this article, we describe the optimized protocol for vascular ECM-coating of glass coverslips and the process of attachment of isolated mouse islets on the coverslip. This preparation is compatible with any high-resolution microscopy of live primary ß cells. Key features • Optimized coating procedure to attach isolated islets, compatible for both confocal and TIRF microscopy. • The ECM-coated glass coverslip functions as the artificial capillary surface to guide secretion toward the coated surface for optimal imaging of secretion events. • Shows the process of islets attachment to the ECM-coated surface in a 6-day ex vivo culture.

Dysfunctional APPL1-Mediated Epigenetic Regulation in Diabetic Vascular Injury.

BACKGROUND: APN (adiponectin) and APPL1 (adaptor protein, phosphotyrosine interacting with PH domain and leucine zipper 1) are potent vasculoprotective molecules, and their deficiency (eg, hypoadiponectinemia) contributes to diabetic vascular complications. However, the molecular mechanisms that govern their vasculoprotective genes as well as their alteration by diabetes remain unknown. METHODS: Diabetic medium-cultured rat aortic endothelial cells, mouse aortic endothelial cells from high-fat-diet animals, and diabetic human aortic endothelial cells were used for molecular/cellular investigations. The in vivo concept-prove demonstration was conducted using diabetic vascular injury and diabetic hindlimb ischemia models. RESULTS: In vivo animal experiments showed that APN replenishment caused APPL1 nuclear translocation, resulting in an interaction with HDAC (histone deacetylase) 2, which inhibited HDAC2 activity and increased H3Kac27 levels. Based on transcriptionome pathway-specific real-time polymerase chain reaction profiling and bioinformatics analysis, Angpt1 (angiopoietin 1), Ocln (occludin), and Cav1 (caveolin 1) were found to be the top 3 vasculoprotective genes suppressed by diabetes and rescued by APN in an APPL1-dependent manner. APN reverses diabetes-induced inhibition of Cav1 interaction with APPL1. APN-induced Cav1 expression was not affected by Angpt1 or Ocln deficiency, whereas APN-induced APPL1 nuclear translocation or upregulation of Angpt1/Ocln expression was abolished in the absence of Cav1 both in vivo and in vitro, suggesting Cav1 is upstream molecule of Angpt1/Ocln in response to APN administration. Chromatin immunoprecipitation-qPCR (quantitative polymerase chain reaction) demonstrated that APN caused significant enrichment of H3K27ac in Angpt1 and Ocln promoter region, an effect blocked by APPL1/Cav1 knockdown or HDAC2 overexpression. The protective effects of APN on the vascular system were attenuated by overexpression of HDAC2 and abolished by knocking out APPL1 or Cav1. The double knockdown of ANGPT1/OCLN blunted APN vascular protection both in vitro and in vivo. Furthermore, in diabetic human endothelial cells, HDAC2 activity is increased, H3 acetylation is decreased, and ANGPT1/OCLN expression is reduced, suggesting that the findings have important translational implications. CONCLUSIONS: Hypoadiponectinemia and dysregulation of APPL1-mediated epigenetic regulation are novel mechanisms leading to diabetes-induced suppression of vasculoprotective gene expression. Diabetes-induced pathological vascular remodeling may be prevented by interventions promoting APPL1 nuclear translocation and inhibiting HDAC2.

Positive association between alkaline phosphatase and arteriosclerosis: a cross-sectional study.

AIMS: Serum alkaline phosphatase (ALP) is known to be associated with cardiovascular events and cerebral arteriosclerosis. However, the link between ALP and early arteriosclerosis remains unclear. This study investigated the relationship between ALP and early arteriosclerosis assessed by brachial-ankle pulse wave velocity (Ba-PWV). METHODS: This retrospective analysis included 5011 participants who underwent health examinations, including ALP and Ba-PWV measurement, at the Second Hospital of Hebei Medical University from 2012 to 2017. Regression analysis, smoothing function analysis in the generalized additive model (GAM), threshold effect analysis, and subgroup analyses were performed. RESULTS: Multivariate regression analysis identified a significantly positive association between serum ALP and arteriosclerosis [odds ratio (OR) = 1.008, 95% confidence interval (CI) 1.004-1.011, P  < 0.001]. Smoothing function analysis indicated a two-stage association between ALP and arteriosclerosis. Furthermore, threshold effect analysis determined an inflection point at 135 U/l, below which the relationship was linearly positive and above which the risk of arteriosclerosis did not increase prominently with increasing ALP (OR = 1.009, 95% CI: 1.005-1.013, P  < 0.001; OR = 0.976, 95% CI: 0.952-1.002, P  = 0.068). However, ALP was not associated with arteriosclerosis only in participants with diabetes (OR = 0.996, 95% CI: 0.979-1.014, P  = 0.690). A positive association between Ba-PWV and arteriosclerosis was observed for both the arteriosclerosis and nonarteriosclerosis groups ( ß â€Š= 9.10, 95% CI: 4.67-13.54, P  < 0.001; ß â€Š= 8.02, 95% CI: 5.67-10.37, P  < 0.001). CONCLUSION: In this study, the serum ALP level was positively associated with early arteriosclerosis, with a saturation effect beyond ALP = 135 U/l. However, the positive association between ALP and arteriosclerosis was unclear in adults with diabetes.

Glucose-stimulated KIF5B-driven microtubule sliding organizes microtubule networks in pancreatic beta cells.

In pancreatic islet beta cells, molecular motors use cytoskeletal polymers microtubules as tracks for intracellular transport of insulin secretory granules. Beta-cell microtubule network has a complex architecture and is non-directional, which provide insulin granules at the cell periphery for rapid secretion response, yet to avoid over-secretion and subsequent hypoglycemia. We have previously characterized a peripheral sub-membrane microtubule array, which is critical for withdrawal of excessive insulin granules from the secretion sites. Microtubules in beta cells originate at the Golgi in the cell interior, and how the peripheral array is formed is unknown. Using real-time imaging and photo-kinetics approaches in clonal mouse pancreatic beta cells MIN6, we now demonstrate that kinesin KIF5B, a motor protein with a capacity to transport microtubules as cargos, slides existing microtubules to the cell periphery and aligns them to each other along the plasma membrane. Moreover, like many physiological beta-cell features, microtubule sliding is facilitated by a high glucose stimulus. These new data, together with our previous report that in high glucose sub-membrane MT array is destabilized to allow for robust secretion, indicate that MT sliding is another integral part of glucose-triggered microtubule remodeling, likely replacing destabilized peripheral microtubules to prevent their loss over time and beta-cell malfunction.

Attack of angina pectoris with low back pain alone: a case report.

A man in his late 60s with a history of angina pectoris developed low back pain during cardiac catheterization. During this episode of back pain, ST segment elevations were noted on the electrocardiogram. The patient reported relief of the pain immediately after implantation of two drug-eluting stents, and the ST segments on the electrocardiogram normalized. The probable mechanisms of low back pain during cardiac catheterization in this patient are briefly outlined.

Heteropolyacids: An Ultrasensitive Ionic Volume-Enhanced Raman Scattering Platform.

Surface-enhanced Raman scattering (SERS) is regarded as the most direct and powerful tool to identify chemical fingerprints. However, current SERS substrate materials still face some critical challenges, including low molecular utilization efficiency and low selectivity. Herein, a novel oxygen vacancy heteropolyacid─H10Fe3Mo21O51 (HFMO)─is developed as a high-performance volume-enhanced Raman scattering (VERS)-active platform. Due to its merit of water solubility, HFMO forms a special coordination bond with the probe molecule at the molecular level, which allows its enhancing ability to be comparable to that of noble metals. An enhancement factor of 1.26 × 109 and a very low detection limit of 10-13 M for rhodamine 6G were obtained. A robust O-N coordination bond was formed between the anion of HFMO and the probe molecule, resulting in a special electron transfer path (Mo-O-N) with high selectivity, which is verified using X-ray photoelectron spectroscopy analysis and density functional theory calculations. That is to say, the proposed HFMO platform has excellent VERS enhancing effect, specifically for the molecules containing the imino group (e.g., methyl blue, detection limit: 10-11 M), offering the merits of high reproducibility and uniformity, high-temperature resistance, long-time laser irradiation, and strong acid resistance. Such an initial effort on the ionic type VERS platform may enable the further development of highly sensitive, highly selective, and water-soluble VERS technology.

Association of red blood cell distribution width-to-albumin ratio with mortality in patients undergoing transcatheter aortic valve replacement.

BACKGROUND: Frailty is associated with poor prognosis in patients undergoing transcatheter aortic valve replacement (TAVR). The red blood cell distribution width (RDW)-to-albumin ratio (RAR) reflects key components of frailty. This study aimed to evaluate the relationship between RAR and all-cause mortality in patients undergoing TAVR. METHODS: The data were extracted from the Medical Information Mart for Intensive Care IV database. The RAR was computed by dividing the RDW by the albumin. The primary outcome was all-cause mortality within 1-year following TAVR. The association between RAR and the primary outcome was evaluated using the Kaplan-Meier survival curves, restricted cubic spline (RCS), and Cox proportional hazard regression models. RESULTS: A total of 760 patients (52.9% male) with a median age of 84.0 years were assessed. The Kaplan-Meier survival curves showed that patients with higher RAR had higher mortality (log-rank P < 0.001). After adjustment for potential confounders, we found that a 1 unit increase in RAR was associated with a 46% increase in 1-year mortality (HR = 1.46, 95% CI:1.22-1.75, P < 0.001). According to the RAR tertiles, high RAR (RAR > 4.0) compared with the low RAR group (RAR < 3.5) significantly increased the risk of 1-year mortality (HR = 2.21, 95% CI: 1.23-3.95, P = 0.008). The RCS regression model revealed a continuous linear relationship between RAR and all-cause mortality. No significant interaction was observed in the subgroup analysis. CONCLUSION: The RAR is independently associated with all-cause mortality in patients treated with TAVR. The higher the RAR, the higher the mortality. This simple indicator may be helpful for risk stratification of TAVR patients.

Different hydration methods for the prevention of contrast-induced nephropathy in patients with elective percutaneous coronary intervention: a retrospective study.

BACKGROUND: Hydration is currently the main measure to prevent contrast-induced nephropathy (CIN). We aimed to compare the preventive effect of preprocedure and postprocedure hydration on CIN in patients with coronary heart disease undergoing elective percutaneous coronary intervention (PCI). METHODS: A retrospective study included 198 cases of postprocedure hydration and 396 cases of preprocedure hydration using propensity score matching. The incidence of CIN 48 h after PCI and adverse events within 30 days after contrast media exposure were compared between the two groups. Logistic regression analysis was used to analyse the risk factors for CIN. RESULTS: The incidence of CIN in the postprocedure hydration group was 3.54%, while that in the preprocedure hydration group was 4.8%. There was no significant difference between the two groups (p = 0.478). Multivariate logistic regression analysis showed that diabetes mellitus, baseline BNP and cystatin C levels, and contrast agent dosage were independent risk factors for CIN. There was no significant difference in the incidence of major adverse events between the two groups (3.03% vs. 2.02%, p = 0.830). CONCLUSIONS: Postprocedure hydration is equally effective compared to preoperative hydration in the prevention of CIN in patients with coronary heart disease undergoing elective PCI.

Matters arising: Insufficient evidence that pancreatic ß cells are derived from adult ductal Neurog3-expressing progenitors.

Understanding the origin of pancreatic ß cells has profound implications for regenerative therapies in diabetes. For over a century, it was widely held that adult pancreatic duct cells act as endocrine progenitors, but lineage-tracing experiments challenged this dogma. Gribben et al. recently used two existing lineage-tracing models and single-cell RNA sequencing to conclude that adult pancreatic ducts contain endocrine progenitors that differentiate to insulin-expressing ß cells at a physiologically important rate. We now offer an alternative interpretation of these experiments. Our data indicate that the two Cre lines that were used directly label adult islet somatostatin-producing ∂ cells, which precludes their use to assess whether ß cells originate from duct cells. Furthermore, many labeled ∂ cells, which have an elongated neuron-like shape, were likely misclassified as ß cells because insulin-somatostatin coimmunolocalizations were not used. We conclude that most evidence so far indicates that endocrine and exocrine lineage borders are rarely crossed in the adult pancreas.

CAMSAP2 localizes to the Golgi in islet ß-cells and facilitates Golgi-ER trafficking.

Glucose stimulation induces the remodeling of microtubules, which potentiates insulin secretion in pancreatic ß-cells. CAMSAP2 binds to microtubule minus ends to stabilize microtubules in several cultured clonal cells. Here, we report that the knockdown of CAMSAP2 in primary ß-cells reduces total insulin content and attenuates GSIS without affecting the releasability of insulin vesicles. Surprisingly, CAMSAP2 knockdown does not change microtubule stability. Unlike in cultured insulinoma cells, CAMSAP2 in primary ß-cells predominantly localizes to the Golgi apparatus instead of microtubule minus ends. This novel localization is specific to primary ß- but not α-cells and is independent of microtubule binding. Consistent with its specific localization at the Golgi, CAMSAP2 promotes efficient Golgi-ER trafficking in primary ß-cells. Moreover, primary ß-cells and insulinoma cells likely express different CAMSAP2 isoforms. We propose that a novel CAMSAP2 isoform in primary ß-cells has a non-canonical function, which promotes Golgi-ER trafficking to support efficient production of insulin and secretion.

A new alternative technique for the guidance of transjugular intrahepatic portosystemic shunt creation using DSA overlay reference.

BACKGROUND: Portal vein puncture (PVP) is a critical step during transjugular intrahepatic portosystemic shunt (TIPS) and correlates to several complications. Techniques guiding PVP are needed. PURPOSE: To evaluate the safety, feasibility, and efficiency of digital subtraction angiography (DSA) overlay reference during TIPS creation and compare it with transhepatic portal vein (THPV) guiding. MATERIAL AND METHODS: The clinical records of 185 patients at three medical centers who underwent TIPS placement were reviewed. Portal vein access was guided by THPV guiding in 120 cases and DSA overlay reference in 60 cases. The number of punctures, portal vein entry time, procedural adverse events, technical and hemodynamic success rate were analyzed to compare the safety, feasibility, and efficiency of the two methods. RESULTS: The median numbers of punctures in group 1 and group 2 were 2 (1-4) and 2 (1-5), respectively (P = 0.094). There was no statistical difference between two groups in needle passes. The median portal vein entry time of group 1 was 12 min (8-16 min) and 13 min (8-16 min) in group 2. No significant difference was found in the PVP time (P = 0.802). Arterioportal fistula formation occurred in 15 patients in group 1; two patients in group 2 had hepatic artery injury. The patients in group 2 had lower rates of procedural adverse events (P = 0.047). Median dose area product of G1 was lower than G2 statistically (P<0.001). There was no significant difference in total fluoroscopy time (P = 0.856). CONCLUSION: DSA overlay reference has lower procedural adverse events rates compared with THPV guiding TIPS. It seems to be a safe and effective method for guiding PVP.

St18 specifies globus pallidus projection neuron identity in MGE lineage.

The medial ganglionic eminence (MGE) produces both locally-projecting interneurons, which migrate long distances to structures such as the cortex as well as projection neurons that occupy subcortical nuclei. Little is known about what regulates the migratory behavior and axonal projections of these two broad classes of neurons. We find that St18 regulates the migration and morphology of MGE neurons in vitro. Further, genetic loss-of-function of St18 in mice reveals a reduction in projection neurons of the globus pallidus pars externa. St18 functions by influencing cell fate in MGE lineages as we observe a large expansion of nascent cortical interneurons at the expense of putative GPe neurons in St18 null embryos. Downstream of St18, we identified Cbx7, a component of Polycomb repressor complex 1, and find that it is essential for projection neuron-like migration but not morphology. Thus, we identify St18 as a key regulator of projection neuron vs. interneuron identity.