The Effect of Denosumab in Elderly Patients Regarding Bone Density and Fracture Risk.

BACKGROUND: With an aging population, the importance of treating and diagnosing osteoporosis is increasing. Osteoporosis, previously known as a resorptive change primarily related to endocrinological mechanisms, is also being approached as a phenomenon of senile change. Denosumab is gaining popularity among osteoporosis medications due to its ability to increase bone mineral density (BMD) and the economic benefit arising from the 6-month cycle. In line with previous literature, this study aimed to examine the BMD-augmenting effect of denosumab through which it reduces fracture risk in individuals aged over 80 years. METHODS: We reviewed patients who received denosumab between 2018 and 2022 with a minimum clinical observation period of 12 months. BMD was measured every 12 months, and patients were classified per their period of denosumab use. Fracture risk was evaluated using the fracture risk assessment tool (FRAX) and fracture incidence during the observation period were assessed. RESULTS: Among 155 patients, a significant increase in BMD was observed at 3 sites: the lumbar spine, femoral neck, and total hip (p<0.001, p<0.001, and p=0.001, respectively). The patients were divided according to the length of clinical follow-up they received, and similar results were found in all subgroups. Fracture risk assessment was performed using FRAX and the incidence of fracture events during follow-up. FRAX significantly decreased in all subgroups except those who received 24 months of follow-up (p=0.003, p=0.41, p=0.001 in the 12, 24, and ≥36 months groups, respectively). CONCLUSIONS: Denosumab use resulted in long-term BMD increase and reduced fracture risk in individuals aged 80 and above.

Regulation of the Ca2+ Channel CaV1.2 Supports Spatial Memory and Its Flexibility and LTD.

Widespread release of norepinephrine (NE) throughout the forebrain fosters learning and memory via adrenergic receptor (AR) signaling, but the molecular mechanisms are largely unknown. The ß2 AR and its downstream effectors, the trimeric stimulatory Gs-protein, adenylyl cyclase (AC), and the cAMP-dependent protein kinase A (PKA), form a unique signaling complex with the L-type Ca2+ channel (LTCC) CaV1.2. Phosphorylation of CaV1.2 by PKA on Ser1928 is required for the upregulation of Ca2+ influx on ß2 AR stimulation and long-term potentiation induced by prolonged theta-tetanus (PTT-LTP) but not LTP induced by two 1-s-long 100-Hz tetani. However, the function of Ser1928 phosphorylation in vivo is unknown. Here, we show that S1928A knock-in (KI) mice of both sexes, which lack PTT-LTP, express deficiencies during initial consolidation of spatial memory. Especially striking is the effect of this mutation on cognitive flexibility as tested by reversal learning. Mechanistically, long-term depression (LTD) has been implicated in reversal learning. It is abrogated in male and female S1928A knock-in mice and by ß2 AR antagonists and peptides that displace ß2 AR from CaV1.2. This work identifies CaV1.2 as a critical molecular locus that regulates synaptic plasticity, spatial memory and its reversal, and LTD.SIGNIFICANCE STATEMENT We show that phosphorylation of the Ca2+ channel CaV1.2 on Ser1928 is important for consolidation of spatial memory and especially its reversal, and long-term depression (LTD). Identification of Ser1928 as critical for LTD and reversal learning supports the model that LTD underlies flexibility of reference memory.

α1-Adrenergic receptor-PKC-Pyk2-Src signaling boosts L-type Ca2+ channel CaV1.2 activity and long-term potentiation in rodents.

The cellular mechanisms mediating norepinephrine (NE) functions in brain to result in behaviors are unknown. We identified the L-type Ca2+ channel (LTCC) CaV1.2 as a principal target for Gq-coupled α1-adrenergic receptors (ARs). α1AR signaling increased LTCC activity in hippocampal neurons. This regulation required protein kinase C (PKC)-mediated activation of the tyrosine kinases Pyk2 and, downstream, Src. Pyk2 and Src were associated with CaV1.2. In model neuroendocrine PC12 cells, stimulation of PKC induced tyrosine phosphorylation of CaV1.2, a modification abrogated by inhibition of Pyk2 and Src. Upregulation of LTCC activity by α1AR and formation of a signaling complex with PKC, Pyk2, and Src suggests that CaV1.2 is a central conduit for signaling by NE. Indeed, a form of hippocampal long-term potentiation (LTP) in young mice requires both the LTCC and α1AR stimulation. Inhibition of Pyk2 and Src blocked this LTP, indicating that enhancement of CaV1.2 activity via α1AR-Pyk2-Src signaling regulates synaptic strength.

Sensitive label-free imaging of brain samples using FxClear-based tissue clearing technique.

Optical clearing has emerged as a powerful tool for volume imaging. Although volume imaging with immunostaining have been successful in many protocols, yet obtaining homogeneously stained thick samples remains challenging. Here, we propose a method for label-free imaging of brain slices by enhancing the regional heterogeneity of the optical properties using the tissue clearing principle. We used FxClear, a method for delipidation of brain tissue, to retain a larger proportion of lipids at the white matter (WM). Furthermore, the embedding media affected the contrasts for the lipid-rich or extracellular matrix-rich areas, depending on their chemical properties. Thus, we tailored clearing conditions for the enhancement of the refractive indices (RIs) differences between gray and WM, or several pathological features. RI differences can be imaged using conventional light microscopy or optical coherence tomography. We propose that our protocol is simple, reliable, and flexible for label-free imaging, easily implementable to routine histology laboratory.

Distinct Mechanisms of Over-Representation of Landmarks and Rewards in the Hippocampus.

In the hippocampus, locations associated with salient features are represented by a disproportionately large number of neurons, but the cellular and molecular mechanisms underlying this over-representation remain elusive. Using longitudinal calcium imaging in mice learning to navigate in virtual reality, we find that the over-representation of reward and landmark locations are mediated by persistent and separable subsets of neurons, with distinct time courses of emergence and differing underlying molecular mechanisms. Strikingly, we find that in mice lacking Shank2, an autism spectrum disorder (ASD)-linked gene encoding an excitatory postsynaptic scaffold protein, the learning-induced over-representation of landmarks was absent whereas the over-representation of rewards was substantially increased, as was goal-directed behavior. These findings demonstrate that multiple hippocampal coding processes for unique types of salient features are distinguished by a Shank2-dependent mechanism and suggest that abnormally distorted hippocampal salience mapping may underlie cognitive and behavioral abnormalities in a subset of ASDs.

Deep phenotyping of cardiac function in heart transplant patients using cardiovascular system models.

KEY POINTS: Right heart catheterization data from clinical records of heart transplant patients are used to identify patient-specific models of the cardiovascular system. These patient-specific cardiovascular models represent a snapshot of cardiovascular function at a given post-transplant recovery time point. This approach is used to describe cardiac function in 10 heart transplant patients, five of which had multiple right heart catheterizations allowing an assessment of cardiac function over time. These patient-specific models are used to predict cardiovascular function in the form of right and left ventricular pressure-volume loops and ventricular power, an important metric in the clinical assessment of cardiac function. Outcomes for the longitudinally tracked patients show that our approach was able to identify the one patient from the group of five that exhibited post-transplant cardiovascular complications. ABSTRACT: Heart transplant patients are followed with periodic right heart catheterizations (RHCs) to identify post-transplant complications and guide treatment. Post-transplant positive outcomes are associated with a steady reduction of right ventricular and pulmonary arterial pressures, toward normal levels of right-side pressure (about 20 mmHg) measured by RHC. This study shows that more information about patient progression is obtained by combining standard RHC measures with mechanistic computational cardiovascular system models. The purpose of this study is twofold: to understand how cardiovascular system models can be used to represent a patient's cardiovascular state, and to use these models to track post-transplant recovery and outcome. To obtain reliable parameter estimates comparable within and across datasets, we use sensitivity analysis, parameter subset selection, and optimization to determine patient-specific mechanistic parameters that can be reliably extracted from the RHC data. Patient-specific models are identified for 10 patients from their first post-transplant RHC, and longitudinal analysis is carried out for five patients. Results of the sensitivity analysis and subset selection show that we can reliably estimate seven non-measurable quantities; namely, ventricular diastolic relaxation, systemic resistance, pulmonary venous elastance, pulmonary resistance, pulmonary arterial elastance, pulmonary valve resistance and systemic arterial elastance. Changes in parameters and predicted cardiovascular function post-transplant are used to evaluate the cardiovascular state during recovery of five patients. Of these five patients, only one showed inconsistent trends during recovery in ventricular pressure-volume relationships and power output. At the four-year post-transplant time point this patient exhibited biventricular failure along with graft dysfunction while the remaining four exhibited no cardiovascular complications.

MUL1 E3 ligase regulates the antitumor effects of metformin in chemoresistant ovarian cancer cells via AKT degradation.

Chemoresistance is one of most critical clinical problems encountered when treating patients with ovarian cancer, due to the fact that the disease is usually diagnosed at advanced stages. Metformin is used as a first­line drug for the treatment of type 2 diabetes; however, drug repositioning studies have revealed its antitumor effects, mainly mediated through AMP­activated protein kinase (AMPK) activation and AKT/mammalian target of rapamycin (mTOR) pathway inhibition in various types of cancer, including drug­resistant cancer cells. The current study revealed that the novel antitumor mechanism of metformin is mediated by regulation of mitochondrial E3 ubiquitin protein ligase 1 (MUL1) expression that negatively regulates AKT. The results demonstrated that metformin decreased the expression of AKT protein levels via MUL1 E3 ligase. In addition, metformin increased both mRNA and protein levels of MUL1 and promoted degradation of AKT in a proteasome­dependent manner. Silencing MUL1 expression suppressed the metformin­mediated AKT degradation and its downstream effects. Cell cycle analysis and a clonogenic assay demonstrated that knockdown of MUL1 significantly diminished the antitumor effects of metformin. Together, these data indicate that MUL1 regulates metformin­mediated AKT degradation and the antitumor effects of metformin in chemoresistant ovarian cancer cell lines.

Role of Palmitoylation of Postsynaptic Proteins in Promoting Synaptic Plasticity.

Many postsynaptic proteins undergo palmitoylation, the reversible attachment of the fatty acid palmitate to cysteine residues, which influences trafficking, localization, and protein interaction dynamics. Both palmitoylation by palmitoyl acyl transferases (PAT) and depalmitoylation by palmitoyl-protein thioesterases (PPT) is regulated in an activity-dependent, localized fashion. Recently, palmitoylation has received attention for its pivotal contribution to various forms of synaptic plasticity, the dynamic modulation of synaptic strength in response to neuronal activity. For instance, palmitoylation and depalmitoylation of the central postsynaptic scaffold protein postsynaptic density-95 (PSD-95) is important for synaptic plasticity. Here, we provide a comprehensive review of studies linking palmitoylation of postsynaptic proteins to synaptic plasticity.

SemGen: a tool for semantics-based annotation and composition of biosimulation models.

SUMMARY: As the number and complexity of biosimulation models grows, so do demands for tools that can help users understand models and compose more comprehensive and accurate systems from existing models. SemGen is a tool for semantics-based annotation and composition of biosimulation models designed to address this demand. A key SemGen capability is to decompose and then integrate models across existing model exchange formats including SBML and CellML. To support this capability, we use semantic annotations to explicitly capture the underlying biological and physical meanings of the entities and processes that are modeled. SemGen leverages annotations to expose a model's biological and computational architecture and to help automate model composition. AVAILABILITY AND IMPLEMENTATION: SemGen is freely available at https://github.com/SemBioProcess/SemGen. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

Autophosphorylation of F-actin binding domain of CaMKIIß is required for fear learning.

CaMKII is a pivotal kinase that plays essential roles in synaptic plasticity. Apart from its signaling function, the structural function of CaMKII is becoming clear. CaMKII - F-actin interaction stabilizes actin cytoskeleton in a dendritic spine. A transient autophosphorylation at the F-actin binding region during LTP releases CaMKII from F-actin and opens a brief time-window of actin reorganization. However, the physiological relevance of this finding in learning and memory was not presented. Using a knock-in (KI) mouse carrying phosphoblock mutations in the actin-binding domain of CaMKIIß, we demonstrate that proper regulation of CaMKII - F-actin interaction is important for fear conditioning memory tasks. The KI mice show poor performance in contextual and cued versions of fear conditioning test. These results suggest the importance of CaMKII - F-actin interactions in learning and memory.

Less Invasive Anterior Iliac Approach and Compression Osteosynthesis for the Treatment of High Anterior Column Fractures of the Acetabulum.

BACKGROUND: Displaced anterior column fractures have increasingly been treated surgically by the ilioinguinal approach and fixation with lag screws and a buttress plate on the pelvic brim. However, a major disadvantage of the ilioinguinal approach is possible damage to the neurovascular bundle and the lymphatic structures in the intermediate part of the approach. This study aims to present a novel surgical technique of the less invasive anterior iliac approach and compression osteosynthesis for high anterior column fractures of the acetabulum. METHODS: In this retrospective case series, 19 patients treated operatively for isolated high anterior column fractures using the less invasive anterior iliac approach and compression osteosynthesis were included. Patient demographics, the cause of injury, associated injuries, time to surgical reconstruction, and operation time were collected from the medical records. The quality of reduction was assessed by postoperative standard radiographic views and computed tomography scans and graded according to Matta's criteria. Clinical and radiographic grades were assessed according to Matta's criteria at the last follow-up. RESULTS: This less invasive surgical technique was successful for reduction and fixation in all high anterior column fractures and provided sufficient stability to allow immediate mobilization of the patients after surgery. Twelve fractures were combined with the quadrilateral plate fracture and seven fractures did not involve the quadrilateral plate. According to Matta's criteria, anatomical reduction was obtained in 17 patients and imperfect reduction in two patients. Clinical results were excellent in 17 patients and good in two patients. Radiographic results were excellent in 17 patients and good in two patients. Ten patients had neurapraxia of the lateral femoral cutaneous nerve related to the approach, which was resolved completely in seven. One patient had deep vein thrombosis. CONCLUSIONS: Our less invasive surgical technique of the anterior iliac approach and compression osteosynthesis is a useful addition to the existing techniques in the treatment of high anterior column fractures of the acetabulum. Despite being a limited approach and fixation, this technique provides sufficient exposure for reducing and fixing the fracture and adequate stability to allow immediate mobilization of the patient after surgery.

Comparison of the expression of cluster of differentiation (CD)39 and CD73 between propofol- and sevoflurane-based anaesthesia during open heart surgery.

High expression of cluster of differentiation (CD)39 and CD73 has cardio-protective effects. We hypothesised that the expression of CD39 and CD73 would differ between propofol- and volatile anaesthetic-based anaesthesia in patients undergoing open heart surgery (OHS). The objective of this prospective randomized trial was to compare the changes in CD39 and CD73 levels in CD4+ T cells between propofol- and sevoflurane-based anaesthesia during OHS. The study randomly allocated 156 patients undergoing OHS to a propofol or sevoflurane group. Blood was obtained preoperatively and up to 48 hours after weaning from cardiopulmonary bypass (CPB). The expression levels of CD39 and CD73 in circulating CD4+ T cells, serum cytokines and other laboratory parameters were analysed. The primary outcome was the expression of CD39 and CD73 on CD4+ T cells. Demographic data and perioperative haemodynamic changes did not show significant differences between the two groups. The expression of CD39 and CD73 in the sevoflurane group was significantly lower than in the propofol group (P < 0.001). Other laboratory findings including cardiac enzymes and cytokine levels, did not show significant intergroup differences. Propofol attenuated the decrease in CD39 and CD73 in circulating CD4+ T cells compared to sevoflurane-based anaesthesia during OHS.

Inflammatory mediators ATP and S100A12 activate the NLRP3 inflammasome to induce MUC5AC production in airway epithelial cells.

Danger-associated molecular patterns (DAMPs) play a proinflammatory role in the pathogenesis of airway obstructive diseases such as severe asthma and chronic obstructive pulmonary disease. The NLRP3 inflammasome is a cytosolic multiprotein platform that activates the caspase-1 pathway in response to inflammatory stimuli such as DAMPs. ATP and S100 proteins are newly identified DAMPs that accumulate in inflamed airways. We previously demonstrated that S100A8, S100A9, and S100A12 induce production and secretion of MUC5AC, a major mucin in the conducting airway mucosa. The purpose of this study was to determine the involvement of NLRP3 inflammasome in, and the contribution of ATP to, S100 protein-induced MUC5AC production by NCI-H292 mucoepidermoid carcinoma cells. Stimulation with either S100A12 or ATP led to MUC5AC production at comparable levels. Simultaneous treatment with both stimuli resulted in additive increases in NLRP3, active caspase-1, IL-1ß, NLRP3/caspase-1 colocalization, and MUC5AC. NLRP3 siRNA or inhibitors of NF-κB, NLRP3 inflammasome oligomerization, or caspase-1 nearly completely inhibited ATP- and S100A12-mediated MUC5AC production. Furthermore, S100A12-as well as ATP-mediated MUC5AC production was almost equally blunted by both nonspecific and specific antagonists of the purinergic receptor P2X7, a principal receptor mediating NLRP3 inflammasome activation by ATP. Thus, these two danger signals contribute to MUC5AC production in airway epithelial cells through overlapping signaling pathways for NLRP3 inflammasome activation.

Packing of metalized polymer nanofibers for aneurysm embolization.

Aneurysmal subarachnoid hemorrhage (SAH) is the extravasation of blood into the subarachnoid space and is fatal in most cases. Platinum coils have been used to fill the hemorrhage site and prevent the extravasation of blood. Here we explored the use of Pt-coated polymer nanofibers (NF) to prevent blood extravasation and were able to achieve improved results in vitro. The polymer nanofibers were produced via electrospinning and were subsequently electroplated with Pt, resulting in metalized nanofibers. These nanofibers were installed within a microfluidic channel, and the resulting reduction in the permeability was evaluated using a fluid similar to blood. Based on the obtained results, these newly developed nanofibers are expected to decrease the operation cost for SAH, owing to their reduced size and low material cost. Furthermore, it is expected that these nanofibers will be used in a smaller amount during SAH operation while having the same preventive effect. This should reduce the operational risk associated with the multiple steps required to place the Pt coils at the SAH site. Finally, the underlying hydrodynamic mechanism responsible for the reduced permeability of the synthesized nanofibers is described.

α-Actinin Anchors PSD-95 at Postsynaptic Sites.

Despite the central role PSD-95 plays in anchoring postsynaptic AMPARs, how PSD-95 itself is tethered to postsynaptic sites is not well understood. Here we show that the F-actin binding protein α-actinin binds to the very N terminus of PSD-95. Knockdown (KD) of α-actinin phenocopies KD of PSD-95. Mutating lysine at position 10 or lysine at position 11 of PSD-95 to glutamate, or glutamate at position 53 or glutamate and aspartate at positions 213 and 217 of α-actinin, respectively, to lysine impairs, in parallel, PSD-95 binding to α-actinin and postsynaptic localization of PSD-95 and AMPARs. These experiments identify α-actinin as a critical PSD-95 anchor tethering the AMPAR-PSD-95 complex to postsynaptic sites.

Isoflurane's Effect on Intraoperative Systolic Left Ventricular Performance in Cardiac Valve Surgery Patients.

BACKGROUND: Isoflurane, a common anesthetic for cardiac surgery, reduced myocardial contractility in many experimental studies, few studies have determined isoflurane's direct impact on the left ventricular (LV) contractile function during cardiac surgery. We determined whether isoflurane dose-dependently reduces the peak systolic velocity of the lateral mitral annulus in tissue Doppler imaging (S') in patients undergoing cardiac surgery. METHODS: During isoflurane-supplemented remifentanil-based anesthesia for patients undergoing cardiac surgery with preoperative LV ejection fraction greater than 50% (n = 20), we analyzed the changes of S' at each isoflurane dose increment (1.0, 1.5, and 2.0 minimum alveolar concentration [MAC]: T1, T2, and T3, respectively) with a fixed remifentanil dosage (1.0 µg/min/kg) by using transesophageal echocardiography. RESULTS: Mean S' values (95% confidence interval [CI]) at T1, T2, and T3 were 10.5 (8.8-12.2), 9.5 (8.3-10.8), and 8.4 (7.3-9.5) cm/s, respectively (P < 0.001 in multivariate analysis of variance test). Their mean differences at T1 vs. T2, T2 vs. T3, and T1 vs. T3 were -1.0 (-1.6, -0.3), -1.1 (-1.7, -0.6), and -2.1 (-3.1, -1.1) cm/s, respectively. Phenylephrine infusion rates were significantly increased (0.26, 0.22, and 0.47 µg/kg/min at T1, T2, and T3, respectively, P < 0.001). CONCLUSION: Isoflurane increments (1.0-2.0 MAC) dose-dependently reduced LV systolic long-axis performance during cardiac surgeries with a preserved preoperative systolic function.

Ursolic Acid Induces Apoptosis in Colorectal Cancer Cells Partially via Upregulation of MicroRNA-4500 and Inhibition of JAK2/STAT3 Phosphorylation.

Though ursolic acid (UA) isolated from Oldenlandia diffusa was known to exhibit anti-cancer, anti-inflammatory, and anti-obesity effects, the underlying antitumor mechanism of ursolic acid was not fully understood to date. Thus, in the present study, the apoptotic mechanism of ursolic acid was elucidated in HCT116 and HT29 colorectal cancer cells in association with STAT3 and microRNA-4500 (miR-4500) by MTT assay, Terminal deoxynucleotidyl transferase-dT-mediated dUTP nick end labelling (TUNEL) assay, cell cycle analysis, immunofluorescence, and Western blotting. Ursolic acid significantly exerted cytotoxicity, increased TUNEL positive cells and sub-G1 apoptotic portion, induced cleavage of poly (adenosine diphosphate-ribose) polymerase (PARP) and caspase 3 in HCT116 and HT29 cells. Of note, ursolic acid attenuated the expression of anti-apoptotic proteins such as Janus kinase 2 (JAK2) and signal transducer and activator of transcription 3 (STAT3) and also blocked nuclear translocation of STAT3 in colorectal cancer cells. Notably, ursolic acid increased the expression level of miR-4500 in HCT116 cells by qRT-PCR analysis and conversely miR-4500 inhibitor reversed cytotoxic, anti-proliferative, and apoptotic effects by increasing TUNEL positive cells, PARP cleavage and inhibiting p-STAT3 in ursolic acid treated colorectal cancer cells. Overall, our findings provide evidence that usolic acid induces apoptosis in colorectal cancer cells partially via upregulation of miR-4500 and inhibition of STAT3 phosphorylation as a potent anti-cancer agent for colorectal cancer therapy.

Arctiin regulates collagen type 1α chain 1 mRNA expression in human dermal fibroblasts via the miR­378b­SIRT6 axis.

Arctiin, a lignin isolated from Arctium lappa, exhibits a variety of biological effects, including anti­viral, anti­inflammatory, and anti­proliferative actions, in mammalian cells. In a previous study, arctiin was demonstrated to induce procollagen type I synthesis and exhibited protective effects against ultraviolet B (UVB) radiation in normal human dermal fibroblasts (nHDFs). However, the underlying molecular mechanism of arctiin­mediated collagen synthesis remains unknown. In the present study, the mechanism for increased expression of collagen type 1α 1 chain (COL1A1) mRNA in arctiin­induced nHDFs was identified. The expression of microRNA­378b (miR­378b), downregulated by arctiin, was correlated with the expression of sirtuin­6 (SIRT6) mRNA, a regulator of COL1A1 mRNA. Furthermore, it was revealed that arctiin protected the UVB radiation­mediated decrease in COL1A1 mRNA expression, through the miR­378b/SIRT6 signaling pathway. In conclusion, these results suggest that arctiin regulates COL1A1 through the miR­378b­SIRT6 axis.

MicroRNA­378b regulates α­1­type 1 collagen expression via sirtuin 6 interference.

Ultraviolet (UV) light mediates skin aging and induces destruction of the dermis by modulating the expression levels of extracellular matrix­associated genes, including collagen and matrix metalloproteinases. Sirtuin 6 (SIRT6), a member of the sirtuin family of proteins, regulates collagen metabolism and is an established anti­aging protein. However, the exact underlying mechanism by which SIRT6 expression is regulated in dermal fibroblasts during the aging process is unclear. The present study demonstrated that expression of microRNA­378b (miR­378b) is induced in UVB­exposed human dermal fibroblasts (HDFs), and this was inversely associated with the mRNA expression levels of α­1­type 1 collagen (COL1A1). In addition, knockdown of miR­378b enhanced the mRNA expression levels of COL1A1 in HDFs. A target analysis for miR­378b was performed, and the results revealed that SIRT6, a regulator of COL1A1, contains a target sequence for miR­378b in its 3'untranslated region. Notably, the present study demonstrated that an miR­378b mimic and inhibitor may directly regulate SIRT6 expression in HDFs. In conclusion, the present study suggested that miR­378b represses the mRNA expression levels of COL1A1 via interference with SIRT6 in HDFs, and may contribute to the underlying molecular mechanism by which UVB inhibits collagen I in dermal fibroblasts.

Terminally Differentiating Eosinophils Express Neutrophil Primary Granule Proteins as well as Eosinophil-specific Granule Proteins in a Temporal Manner.

Neutrophils and eosinophils, 2 prominent granulocytes, are commonly derived from myelocytic progenitors through successive stages in the bone marrow. Our previous genome-wide transcriptomic data unexpectedly showed that genes encoding a multitude of neutrophil primary granule proteins (NPGPs) were markedly downregulated during the end period of eosinophilic terminal differentiation when cord blood (CB) cluster of differentiation (CD) 34+ cells were induced to differentiate toward the eosinophil lineage during a 24-day culture period. Accordingly, this study aimed to examine whether NPGP genes were expressed on the way to eosinophil terminal differentiation stage and to compare their expression kinetics with that of genes encoding eosinophil-specific granule proteins (ESGPs). Transcripts of all NPGP genes examined, including proteinase 3, myeloperoxidase, cathepsin G (CTSG), and neutrophil elastase, reached a peak at day 12 and sharply declined thereafter, while transcript of ESGP genes including major basic protein 1 (MBP1) attained maximum expression at days 18 or 24. Growth factor independent 1 (GFI1) and CCAAT/enhancer-binding protein α (C/EBPA), transactivators for the NPGP genes, were expressed immediately before the NPGP genes, whereas expression of C/EBPA, GATA1, and GATA2 kinetically paralleled that of eosinophil granule protein genes. The expression kinetics of NPGPs and ESGPs were duplicated upon differentiation of the eosinophilic leukemia cell line (EoL-1) immature eosinophilic cells. Importantly, confocal image analysis showed that CTSG was strongly coexpressed with MBP1 in differentiating CB eosinophils at days 12 and 18 and became barely detectable at day 24 and beyond. Our results suggest for the first time the presence of an immature stage where eosinophils coexpress NPGPs and ESGPs before final maturation.