GIRK2 potassium channels expressed by the AgRP neurons decrease adiposity and body weight in mice.

It is well known that the neuropeptide Y (NPY)/agouti-related peptide (AgRP) neurons increase appetite and decrease thermogenesis. Previous studies demonstrated that optogenetic and/or chemogenetic manipulations of NPY/AgRP neuronal activity alter food intake and/or energy expenditure (EE). However, little is known about intrinsic molecules regulating NPY/AgRP neuronal excitability to affect long-term metabolic function. Here, we found that the G protein-gated inwardly rectifying K+ (GIRK) channels are key to stabilize NPY/AgRP neurons and that NPY/AgRP neuron-selective deletion of the GIRK2 subunit results in a persistently increased excitability of the NPY/AgRP neurons. Interestingly, increased body weight and adiposity observed in the NPY/AgRP neuron-selective GIRK2 knockout mice were due to decreased sympathetic activity and EE, while food intake remained unchanged. The conditional knockout mice also showed compromised adaptation to coldness. In summary, our study identified GIRK2 as a key determinant of NPY/AgRP neuronal excitability and driver of EE in physiological and stress conditions.

Current Status of Anti-Reflux Surgery as a Treatment for GERD.

Anti-reflux surgery (ARS) is an efficient treatment option for gastroesophageal reflux disease (GERD). Despite growing evidence of the efficacy and safety of ARS, medications including proton pump inhibitors (PPIs) remain the most commonly administered treatments for GERD. Meanwhile, ARS can be an effective treatment option for patients who need medications continuously or for those who are refractory to PPI treatment, if proper candidates are selected. However, in practice, ARS is often regarded as a last resort for patients who are unresponsive to PPIs. Accumulating ARS-related studies indicate that surgery is equivalent to or better than medical treatment for controlling typical and atypical GERD symptoms. Furthermore, because of overall reduced medication expenses, ARS may be more cost-effective than PPI. Patients are selected for ARS based on endoscopic findings, esophageal acid exposure time, and PPI responsiveness. Although there is limited evidence, ARS may be expanded to include patients with normal acid exposure, such as those with reflux hypersensitivity. Additionally, other factors such as age, body mass index, and comorbidities are known to affect ARS outcomes; and such factors should be considered. Nissen fundoplication or partial fundoplication including Dor fundoplication and Toupet fundoplication can be chosen, depending on whether the patient prioritizes symptom improvement or minimizing postoperative symptoms such as dysphagia. Furthermore, efforts to reduce and manage postoperative complications and create awareness of the long-term efficacy and safety of the ARS are recommended, as well as adequate training programs for new surgeons.

Trends in laparoscopic anti-reflux surgery: a Korea nationwide study.

BACKGROUND: In 2014, the results derived from the nationwide data of the Korean Anti-reflux Surgery Study (KARS) demonstrated short-term feasibility and safety of anti-reflux surgery. This study aimed to update the longer-term safety and feasibility of laparoscopic anti-reflux surgery up to 1-year follow-up with the KARS nationwide cohort. METHODS: The data of 310 patients with GERD who received anti-reflux surgery up to 2018 were analyzed. Baseline patient characteristics, postoperative symptom resolution, and postoperative complications were evaluated at postoperative 3 months and 1 year using the questionnaire designed by KARS. We divided the patients into two groups according to the operation period (up to and after 2014) to identify changes in the trends of the characteristics of surgical patients and operative qualities. RESULTS: The typical preoperative symptoms were present in 275 patients (91.7%), and atypical symptoms were present in 208 patients (71.0%). Ninety-seven (35.5%) and 124 patients (46.1%) had inadequate PPI responses and hiatal hernia, respectively. At postoperative 1 year, typical and atypical symptoms were either completely or partially controlled in 90.3% and 73.5.0% of patients, respectively. Moderate-to-severe dysphagia, inability to belch, gas bloating, and flatulence at postoperative 1 year were identified in 23.5%, 29.4%, 23.2%, and 22.0% of patients, respectively. The number of surgical patients continuously increased from 2011 to 2018 in Korea. The proportion of patients with hiatal hernia and comorbidities increased (p < 0.01, p = 0.053), and the operation time decreased significantly (p < 0.01) in the late period (2015-2018) as compared with the early period (2011-2014). Symptom control and complication rate were equivalent between the two periods. CONCLUSIONS: Anti-reflux surgery was effective with > 90% of typical symptom resolution and posed a comparable postoperative complication rate with those in Western studies with mid-term to long-term follow-up. This result supports the feasibility and safety of anti-reflux surgery as a treatment for GERD in the Korean population.

Specification and spatial arrangement of cells in the germline stem cell niche of the Drosophila ovary depend on the Maf transcription factor Traffic jam.

Germline stem cells in the Drosophila ovary are maintained by a somatic niche. The niche is structurally and functionally complex and contains four cell types, the escort, cap, and terminal filament cells and the newly identified transition cell. We find that the large Maf transcription factor Traffic jam (Tj) is essential for determining niche cell fates and architecture, enabling each niche in the ovary to support a normal complement of 2-3 germline stem cells. In particular, we focused on the question of how cap cells form. Cap cells express Tj and are considered the key component of a mature germline stem cell niche. We conclude that Tj controls the specification of cap cells, as the complete loss of Tj function caused the development of additional terminal filament cells at the expense of cap cells, and terminal filament cells developed cap cell characteristics when induced to express Tj. Further, we propose that Tj controls the morphogenetic behavior of cap cells as they adopted the shape and spatial organization of terminal filament cells but otherwise appeared to retain their fate when Tj expression was only partially reduced. Our data indicate that Tj contributes to the establishment of germline stem cells by promoting the cap cell fate, and controls the stem cell-carrying capacity of the niche by regulating niche architecture. Analysis of the interactions between Tj and the Notch (N) pathway indicates that Tj and N have distinct functions in the cap cell specification program. We propose that formation of cap cells depends on the combined activities of Tj and the N pathway, with Tj promoting the cap cell fate by blocking the terminal filament cell fate, and N supporting cap cells by preventing the escort cell fate and/or controlling the number of cap cell precursors.

Deep response to a combination of mTOR inhibitor temsirolimus and dual immunotherapy of nivolumab/ipilimumab in poorly differentiated thyroid carcinoma with PTEN mutation: a case report and literature review.

Treating advanced thyroid cancer presents challenges due to its resistance to various treatment modalities, thereby limiting therapeutic options. To our knowledge, this study is the first to report the efficacy of temsirolimus in conjunction with dual immunotherapy of nivolumab/ipilimumab to treat heavily treated advanced PDTC. A 50-year-old female initially presented with a rapidly enlarging mass on her right neck. Subsequent diagnosis revealed poorly differentiated thyroid carcinoma, leading to a total thyroidectomy followed by post-operative radioablation therapy. After four years, an examination for persistent cough revealed a recurrence of the disease within multiple mediastinal nodes. Genetic analysis of blood samples uncovered somatic mutations in the tumor, specifically involving PTEN and TP53. The disease progressed despite palliative radiation, lenvatinib, and nivolumab/ipilimumab therapy. Consequently, temsirolimus, functioning as an mTOR inhibitor, was introduced as an adjunct to the nivolumab/ipilimumab regimen. This combination approach yielded remarkable clinical improvement and disease control for a duration of approximately six months. Temsirolimus likely suppressed the aberrantly activated PI3K/AKT/mTOR signaling pathway, facilitated by the PTEN genetic alteration, thus engendering an effective treatment response. This synergy between targeted agents and immunotherapy presents a promising therapeutic strategy for advanced PDTC patients with limited treatment alternatives. In previous clinical trials, mTOR inhibitors have demonstrated the ability to maintain stable disease (SD) in 65% to 74% for advanced thyroid cancer patients, including those with PDTC. When combined with other targeted therapies, the observed SD or partial response rates range from 80% to 97%. Many of these trials primarily involved differentiated thyroid carcinoma, with diverse genetic mutations. Thyroid cancer patients with alterations in the PI3K/mTOR/Akt appeared to benefit most from mTOR inhibitors. However, no clear association between the efficacy of mTOR inhibitors and specific histologies or genetic mutations has been established. Future studies are warranted to elucidate these associations.

Trends, Sociodemographic and Hospital-Level Factors Associated with Palliative Care Utilization Among Metastatic Prostate Cancer Patients.

Background: Several factors are reported to be associated with palliative care utilization among patients with various cancers, but literature is lacking on metastatic prostate cancer (MPC) specific factors. Early integration of palliative care in management of MPC patients could increase their quality of life and overall outcomes. Methods: Retrospective longitudinal analyses were conducted using the National Inpatient Sample (NIS) data (2010 - 2019). Prevalence trends in palliative care utilization were assessed, and sociodemographic and hospital-level factors associated with palliative care utilization in MPC patients were examined. Results: The overall prevalence of palliative care utilization was 13.1% with an increasing trend from 8490 to 15,231 per 100,000 MPC admissions (p-trend <.001). MPC patients aged 65 years and above had similar odds of receiving palliative care compared to younger patients. Relative to non-Hispanic Whites, other racial groups had similar likelihood to utilize palliative care services. Patients in higher median household national income quartiles had greater odds of utilizing palliative care relative to those in the first income quartile. Patients on Medicaid, private insurance and other insurance types had greater odds of palliative care use in comparison to those on Medicare. Other factors identified were hospital region, location and teaching status, patient disposition, admission type, length of stay, and number of comorbidities. Conclusion: Our findings underscore the significance of enhanced government policies and institutional support in improving palliative care use among hospitalized MPC patients. Health systems must be proactive in addressing barriers to optimization of palliative care utilization in this population.

Redefining Clinical Hyperprogression: The Incidence, Clinical Implications, and Risk Factors of Hyperprogression in Non-Small Cell Lung Cancer Treated with Immunotherapy.

INTRODUCTION: Immune checkpoint inhibitors (ICIs) may be associated with hyperprogressive disease (HPD). However, there is currently no standardized definition of HPD, with its risk factors and clinical implications remaining unclear. We investigated HPD in lung cancer patients undergoing immunotherapy, aiming to redefine HPD, identify risk factors, and assess its impact on survival. METHODS: Clinical and radiologic data from 121 non-small cell lung cancer (NSCLC) patients with 136 immunotherapy cases were reviewed retrospectively. Three HPD definitions (Champiat et al., HPDc; Saâda-Bouzid et al., HPDs; and Ferrara et al., HPDf) were employed. Additionally, all new measurable lesions on the post-treatment CT scan were incorporated in measuring the sum of longest diameters (SLD) to define modified HPD (mHPD). RESULTS: Among the 121 patients, 4 (3.3%) had HPDc, 11 (9.1%) had HPDs, and none had HPDf. Adding all new measurable lesions increased HPD incidence by 5%-10% across definitions. Multivariate analysis revealed significantly lower progression-free survival (PFS) and overall survival (OS) for patients with HPDc (HR 5.25, P = .001; HR 3.75, P = .015) and HPDs (HR 3.74, P < .001; HR 3.46, P < .001) compared to those without. Patients with mHPD showed similarly poor survival outcomes as HPD patients. Liver metastasis at diagnosis was associated with HPDs, and a high tumor burden correlated with HPDc. CONCLUSIONS: The incidence and risk factors of HPD varied with different definitions, but mHPD identified more cases with poor outcomes. This comprehensive approach may enhance the identification of at-risk patients and lead to a better understanding of HPD in lung cancer during immunotherapy.

Personalized, tumor-informed, circulating tumor DNA assay for detecting minimal residual disease in non-small cell lung cancer patients receiving curative treatments.

BACKGROUND: Circulating tumor DNA (ctDNA) has emerged as a prognostic and predictive biomarker for detection of minimal residual disease (MRD), monitoring treatment response, and early detection of recurrence in cancer patients. In this study, we explored the utility of ctDNA-based MRD detection to predict recurrence in a real-world cohort of primarily early-stage non-small cell lung cancer (NSCLC) patients treated with curative intent. METHODS: Longitudinal plasma samples were collected post curative-intent treatment from 36 patients with stage I-IV NSCLC. A personalized, tumor-informed assay was used to detect and quantify ctDNA in plasma samples. RESULTS: Of the 24 patients with plasma samples available during the MRD window (within 6 months of curative surgery and before adjuvant therapy), ctDNA was detectable in two patients. Patients with ctDNA-positivity during the MRD window were 15 times more likely to recur compared to ctDNA-negative patients (HR: 15.0, 95% CI: 1.0-253.0, p = 0.010). At any time post-curative intent treatment, ctDNA-positivity was associated with significantly poorer recurrence-free survival compared to persistently ctDNA-negative patients (p < 0.0001). CONCLUSION: Our real-world data indicate that longitudinal, personalized, tumor-informed ctDNA monitoring is a valuable tool in patients with NSCLC receiving curative treatment to identify patients at high risk for recurrence.

Melanocortin-4 receptors activate sympathetic preganglionic neurons and elevate blood pressure via TRPV1.

Melanocortin-4 receptors (MC4Rs) expressed by the central nervous system are essential regulators of energy homeostasis, and Mc4r mutation is the most common cause of human monogenic obesity. Notably, patients with obesity carrying Mc4r mutations are protected against obesity-induced hypertension, and MC4R agonists elevate blood pressure (BP). Although increased sympathetic tone by MC4Rs is suggested to underlie this phenotype, the detailed mechanisms remain unclear. Here, we investigate how MC4Rs regulate the sympathetic preganglionic neurons and find that MC4Rs activate these neurons via the protein kinase A-dependent activation of the transient receptor potential vanilloid 1 (TRPV1) channel. Importantly, we demonstrate that the inhibition of TRPV1 prevents MC4R-induced elevation of BP but does not affect MC4R-induced anorexia. We further show that TRPV1 is responsible for MC4R-dependent activation of the sympathetic preganglionic neurons by high-fat diet. Together, our results provide insight into how MC4Rs regulate sympathetic function.

Delineating a serotonin 1B receptor circuit for appetite suppression in mice.

Triptans are a class of commonly prescribed antimigraine drugs. Here, we report a previously unrecognized role for them to suppress appetite in mice. In particular, frovatriptan treatment reduces food intake and body weight in diet-induced obese mice. Moreover, the anorectic effect depends on the serotonin (5-HT) 1B receptor (Htr1b). By ablating Htr1b in four different brain regions, we demonstrate that Htr1b engages in spatiotemporally segregated neural pathways to regulate postnatal growth and food intake. Moreover, Htr1b in AgRP neurons in the arcuate nucleus of the hypothalamus (ARH) contributes to the hypophagic effects of HTR1B agonists. To further study the anorexigenic Htr1b circuit, we generated Htr1b-Cre mice. We find that ARH Htr1b neurons bidirectionally regulate food intake in vivo. Furthermore, single-nucleus RNA sequencing analyses revealed that Htr1b marks a subset of AgRP neurons. Finally, we used an intersectional approach to specifically target these neurons (Htr1bAgRP neurons). We show that they regulate food intake, in part, through a Htr1bAgRP→PVH circuit.

Association of HLA class I homozygosity with unfavorable clinical outcomes in patients with non-small cell lung cancer treated with chemo-immunotherapy or immunotherapy as first-line therapy.

BACKGROUND: Homozygosity at HLA-I locus has been reported to be an unfavorable predictive biomarker of second-line or beyond immunotherapy in patients with different types of cancer. The linkage between HLA-I zygosity and survival in NSCLC patients treated with first-line immunotherapy with or without chemotherapy has not been reported. METHODS: Next generation sequencing with HLA genotyping was performed on patients with advanced NSCLC treated with immune checkpoint inhibitors with or without chemotherapy as first-line (N = 29). Progression free survival was compared between HLA-I homozygous (defined as homozygosity in at least one locus A, B, or C) and heterozygous patients. Kaplan-Meier curves were built, and log-rank test was used. RESULTS: Among 29 enrollees, 25 patients (86.2%) were HLA-I heterozygous and four patients (13.8%) were HLA-I homozygous. Treatment response was not available in five patients with HLA-I heterozygosity. Among 20 patients with HLA-I heterozygosity, five patients (20.0%) had partial response, 10 patients (50.0%) had stable disease, two patients (8.0%) had non-complete response/non-progressive disease, and three patients (12.0%) had progressive disease. Among four patients with HLA-I heterozygosity, one patient (25.0%) had partial response, one patient (25.0%) had stable disease, and two patients (50.0%) had progressive disease. The median progression free survival was not reached in heterozygous group and was 2.97 months in homozygous group (Log-rank p = 0.68). CONCLUSIONS: We observed a trend toward an inverse association between HLA-I homozygosity and survival outcomes in patients with NSCLC treated with first-line therapy in conjunction with immunotherapy. Further prospective studies to validate aforementioned relationship are warranted.

Generation of caudal-type serotonin neurons and hindbrain-fate organoids from hPSCs.

Serotonin (5-HT) neurons, the major components of the raphe nuclei, arise from ventral hindbrain progenitors. Based on anatomical location and axonal projection, 5-HT neurons are coarsely divided into rostral and caudal groups. Here, we propose a novel strategy to generate hindbrain 5-HT neurons from human pluripotent stem cells (hPSCs), which involves the formation of ventral-type neural progenitor cells and stimulation of the hindbrain 5-HT neural development. A caudalizing agent, retinoid acid, was used to direct the cells into the hindbrain cell fate. Approximately 30%-40% of hPSCs successfully developed into 5-HT-expressing neurons using our protocol, with the majority acquiring a caudal rhombomere identity (r5-8). We further modified our monolayer differentiation system to generate 5-HT neuron-enriched hindbrain-like organoids. We also suggest downstream applications of our 5-HT monolayer and organoid cultures to study neuronal response to gut microbiota. Our methodology could become a powerful tool for future studies related to 5-HT neurotransmission.

Blood transfusions may adversely affect survival outcomes of patients with lung cancer: a systematic review and meta-analysis.

BACKGROUND: Despite common use in clinical practice, the impact of blood transfusions on prognosis among patients with lung cancer remains unclear. The purpose of the current study is to perform an updated systematic review and meta-analysis to evaluate the influence of blood transfusions on survival outcomes of lung cancer patients. METHODS: We searched PubMed, Embase, Cochrane Library, and Ovid MEDLINE for publications illustrating the association between blood transfusions and prognosis among people with lung cancer from inception to November 2019. Overall survival (OS) and disease-free survival (DFS) were the outcomes of interest. Pooled hazard ratios (HRs) with 95% confidence intervals (CIs) were computed using the random-effects model. Study heterogeneity was evaluated with the I2 test. Publication bias was explored via funnel plot and trim-and-fill analyses. RESULTS: We included 23 cohort studies with 12,175 patients (3,027 cases and 9,148 controls) for meta-analysis. Among these records, 22 studies investigated the effect of perioperative transfusions, while one examined that of transfusions during chemotherapy. Two studies suggested the possible dose-dependent effect in accordance with the number of transfused units. In pooled analyses, blood transfusions deleteriously influenced both OS (HR=1.35, 95% CI: 1.14-1.61, P<0.001, I2=0%) and DFS (HR=1.46, 95% CI: 1.15-1.86, P=0.001, I2=0%) of people with lung cancer. No evidence of significant publication bias was detected in funnel plot and trim-and-fill analyses (OS: HR=1.26, 95% CI: 1.07-1.49, P=0.006; DFS: HR=1.35, 95% CI: 1.08-1.69, P=0.008). CONCLUSIONS: Blood transfusions were associated with decreased survival of patients with lung cancer.

Postoperative nutritional outcomes and quality of life-related complications of proximal versus total gastrectomy for upper-third early gastric cancer: a meta-analysis.

Although proximal gastrectomy (PG) provides superior nutritional outcomes over total gastrectomy (TG) in upper-third early gastric cancer (EGC), surgeons are reluctant to perform PG due to the high rate of postoperative reflux. This meta-analysis aimed to comprehensively compare operative outcomes, nutritional outcomes, and quality of life-related complications between TG and PG performed with esophagogastrostomy (EG), jejunal interposition, or double-tract reconstruction (DTR) to reduce reflux after PG. After searching PubMed, Embase, Medline, and Web of Science databases, 25 studies comparing PG with TG in upper-third EGC published up to October 2020 were identified. PG with DTR was similar to TG regarding operative outcomes. Patients who underwent PG with DTR had less weight reduction (weighted mean difference [WMD] 4.29; 95% confidence interval [0.51-8.07]), reduced hemoglobin loss (WMD 5.74; [2.56-8.93]), and reduced vitamin B12 supplementation requirement (odds ratio [OR] 0.06; [0.00-0.89]) compared to patients who underwent TG. PG with EG caused more reflux (OR 5.18; [2.03-13.24]) and anastomotic stenosis (OR 3.94; [2.40-6.46]) than TG. However, PG with DTR was similar to TG regarding quality of life-related complications including reflux, anastomotic stenosis, and leakage. Hence, PG with DTR can be recommended for patients with upper-third EGC considering its superior postoperative nutritional outcomes.

Laparoscopic total gastrectomy as a valid procedure to treat gastric cancer option both in early and advanced stage: A systematic review and meta-analysis.

Although laparoscopic total gastrectomy (LTG) compared to open total gastrectomy (OTG) has been widely used for advanced gastric cancer patients, its oncologic validity is yet to be proven. We performed systemic review and meta-analysis to compare LTG versus OTG for early and advanced stages of gastric cancer. Short- and long-term outcomes of both procedures were analyzed using original studies collected by searching Google Scholar, Medline, PubMed, Embase, and Cochrane library in accordance with the PRISMA guidelines. To analyze procedures more precisely, we categorized studies into advanced gastric cancer (AGC) and early gastric cancer (EGC) groups and matched lymph node (LN) dissection, and metastasis ratio. Nineteen studies with a total of 3943 patients were included. LTG required more operative time and had less dissected LNs, indicating a favorable quality of OTG. However, LTG was superior with less blood loss, a shorter postoperative hospital stay, and lower postoperative complication rates. The 5-year survival rate was similar in both groups in which extent of LN dissection and lymph node metastasis ratio were controlled. Although more LNs were removed in OTG, the discrepancy had an insignificant impact on the survival rate. To the best of our knowledge, this study is the first to employ quantitative synthesis in evaluation of long-term oncologic validity of LTG and OTG in AGC, with LN dissection and N stage controlled setting. Non-inferiority of LTG on oncologic outcome and superiority of LTG on perioperative outcome lead to a conclusion that LTG has potential as a valid treatment modality in AGC.

Myosin II promotes the anisotropic loss of the apical domain during Drosophila neuroblast ingression.

Epithelial-mesenchymal transitions play key roles in development and cancer and entail the loss of epithelial polarity and cell adhesion. In this study, we use quantitative live imaging of ingressing neuroblasts (NBs) in Drosophila melanogaster embryos to assess apical domain loss and junctional disassembly. Ingression is independent of the Snail family of transcriptional repressors and down-regulation of Drosophila E-cadherin (DEcad) transcription. Instead, the posttranscriptionally regulated decrease in DEcad coincides with the reduction of cell contact length and depends on tension anisotropy between NBs and their neighbors. A major driver of apical constriction and junctional disassembly are periodic pulses of junctional and medial myosin II that result in progressively stronger cortical contractions during ingression. Effective contractions require the molecular coupling between myosin and junctions and apical relaxation of neighboring cells. Moreover, planar polarization of myosin leads to the loss of anterior-posterior junctions before the loss of dorsal-ventral junctions. We conclude that planar-polarized dynamic actomyosin networks drive apical constriction and the anisotropic loss of cell contacts during NB ingression.

Leptin and insulin engage specific PI3K subunits in hypothalamic SF1 neurons.

OBJECTIVE: The ventromedial hypothalamic nucleus (VMH) regulates energy balance and glucose homeostasis. Leptin and insulin exert metabolic effects via their cognate receptors expressed by the steroidogenic factor 1 (SF1) neurons within the VMH. However, detailed cellular mechanisms involved in the regulation of these neurons by leptin and insulin remain to be identified. METHODS: We utilized genetically-modified mouse models and performed patch-clamp electrophysiology experiments to resolve this issue. RESULTS: We identified distinct populations of leptin-activated and leptin-inhibited SF1 neurons. In contrast, insulin uniformly inhibited SF1 neurons. Notably, we found that leptin-activated, leptin-inhibited, and insulin-inhibited SF1 neurons are distinct subpopulations within the VMH. Leptin depolarization of SF1 neuron also required the PI3K p110ß catalytic subunit. This effect was mediated by the putative transient receptor potential C (TRPC) channel. On the other hand, hyperpolarizing responses of SF1 neurons by leptin and insulin required either of the p110α or p110ß catalytic subunits, and were mediated by the putative ATP-sensitive K(+) (KATP) channel. CONCLUSIONS: Our results demonstrate that specific PI3K catalytic subunits are responsible for the acute effects of leptin and insulin on VMH SF1 neurons, and provide insights into the cellular mechanisms of leptin and insulin action on VMH SF1 neurons that regulate energy balance and glucose homeostasis.

Polymer Thin Films with Tunable Acetylcholine-like Functionality Enable Long-Term Culture of Primary Hippocampal Neurons.

In vitro culture systems for primary neurons have served as useful tools for neuroscience research. However, conventional in vitro culture methods are still plagued by challenging problems with respect to applications to neurodegenerative disease models or neuron-based biosensors and neural chips, which commonly require long-term culture of neural cells. These impediments highlight the necessity of developing a platform capable of sustaining neural activity over months. Here, we designed a series of polymeric bilayers composed of poly(glycidyl methacrylate) (pGMA) and poly(2-(dimethylamino)ethyl methacrylate) (pDMAEMA), designated pGMA:pDMAEMA, using initiated chemical vapor deposition (iCVD). Harnessing the surface-growing characteristics of iCVD polymer films, we were able to precisely engraft acetylcholine-like functionalities (tertiary amine and quaternary ammonium) onto cell culture plates. Notably, pGD3, a pGMA:pDMAEMA preparation with the highest surface composition of quaternary ammonium, fostered the most rapid outgrowth of neural cells. Clear contrasts in neural growth and survival between pGD3 and poly-l-lysine (PLL)-coated surfaces became apparent after 30 days in vitro (DIV). Moreover, brain-derived neurotrophic factor level continuously accumulated in pGD3-cultured neurons, reaching a 3-fold increase at 50 DIV. Electrophysiological measurements at 30 DIV revealed that the pGD3 surface not only promoted healthy maturation of hippocampal neurons but also enhanced the function of hippocampal ionotropic glutamate receptors in response to synaptic glutamate release. Neurons cultured long-term on pGD3 also maintained their characteristic depolarization-induced Ca2+ influx functions. Furthermore, primary hippocampal neurons cultured on pGD3 showed long-term survival in a stable state up to 90 days-far longer than neurons on conventional PLL-coated surfaces. Taken together, our findings indicate that a polymer thin film with optimal acetylcholine-like functionality enables a long-term culture and survival of primary neurons.

Islet-like organoids derived from human pluripotent stem cells efficiently function in the glucose responsiveness in vitro and in vivo.

Insulin secretion is elaborately modulated in pancreatic ß cells within islets of three-dimensional (3D) structures. Using human pluripotent stem cells (hPSCs) to develop islet-like structures with insulin-producing ß cells for the treatment of diabetes is challenging. Here, we report that pancreatic islet-like clusters derived from hESCs are functionally capable of glucose-responsive insulin secretion as well as therapeutic effects. Pancreatic hormone-expressing endocrine cells (ECs) were differentiated from hESCs using a step-wise protocol. The hESC-derived ECs expressed pancreatic endocrine hormones, such as insulin, somatostatin, and pancreatic polypeptide. Notably, dissociated ECs autonomously aggregated to form islet-like, 3D structures of consistent sizes (100-150 µm in diameter). These EC clusters (ECCs) enhanced insulin secretion in response to glucose stimulus and potassium channel inhibition in vitro. Furthermore, ß cell-deficient mice transplanted with ECCs survived for more than 40 d while retaining a normal blood glucose level to some extent. The expression of pancreatic endocrine hormones was observed in tissues transplanted with ECCs. In addition, ECCs could be generated from human induced pluripotent stem cells. These results suggest that hPSC-derived, islet-like clusters may be alternative therapeutic cell sources for treating diabetes.

Gas adsorption properties of highly porous metal-organic frameworks containing functionalized naphthalene dicarboxylate linkers.

Three functionalized metal-organic frameworks (MOFs), MOF-205-NH2, MOF-205-NO2, and MOF-205-OBn, formulated as Zn4O(BTB)4/3(L), where BTB is benzene-1,3,5-tribenzoate and L is 1-aminonaphthalene-3,7-dicarboxylate (NDC-NH2), 1-nitronaphthalene-3,7-dicarboxylate (NDC-NO2) or 1,5-dibenzyloxy-2,6-naphthalenedicarboxylate (NDC-(OBn)2), were synthesized and their gas (H2, CO2, or CH4) adsorption properties were compared to those of the un-functionalized, parent MOF-205. Ordered structural models for MOF-205 and its derivatives were built based on the crystal structures and were subsequently used for predicting porosity properties. Although the Brunauer-Emmett-Teller (BET) surface areas of the three MOF-205 derivatives were reduced (MOF-205, 4460; MOF-205-NH2, 4330; MOF-205-NO2, 3980; MOF-205-OBn, 3470 m(2) g(-1)), all three derivatives were shown to have enhanced H2 adsorption capacities at 77 K and CO2 uptakes at 253, 273, and 298 K respectively at 1 bar in comparison with MOF-205. The results indicate the following trend in H2 adsorption: MOF-205 < MOF-205-NO2 < MOF-205-NH2 < MOF-205-OBn. MOF-205-OBn showed good ideal adsorbed solution theory (IAST) selectivity values of 6.5 for CO2/N2 (15/85 in v/v) and 2.7 for CO2/CH4 (50/50 in v/v) at 298 K. Despite the large reduction (-22%) in the surface area, MOF-205-OBn displayed comparable total volumetric CO2 (at 48 bar) and CH4 (at 35 bar) storage capacities with those of MOF-205 at 298 K: MOF-205-OBn, 305 (CO2) and 112 (CH4) cm(3) cm(-3), and for MOF-205, 307 (CO2) and 120 (CH4) cm(3) cm(-3), respectively.