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1.
Bioact Mater ; 26: 52-63, 2023 Aug.
Article in English | MEDLINE | ID: mdl-36875050

ABSTRACT

Abdominal aortic aneurysm (AAA) is a progressive aortic dilatation, causing ∼80% mortality upon rupture. Currently, there is no approved drug therapy for AAA. Surgical repairs are invasive and risky and thus not recommended to patients with small AAAs which, however, account for ∼90% of the newly diagnosed cases. It is therefore a compelling unmet clinical need to discover effective non-invasive strategies to prevent or slow down AAA progression. We contend that the first AAA drug therapy will only arise through discoveries of both effective drug targets and innovative delivery methods. There is substantial evidence that degenerative smooth muscle cells (SMCs) orchestrate AAA pathogenesis and progression. In this study, we made an exciting finding that PERK, the endoplasmic reticulum (ER) stress Protein Kinase R-like ER Kinase, is a potent driver of SMC degeneration and hence a potential therapeutic target. Indeed, local knockdown of PERK in elastase-challenged aorta significantly attenuated AAA lesions in vivo. In parallel, we also conceived a biomimetic nanocluster (NC) design uniquely tailored to AAA-targeting drug delivery. This NC demonstrated excellent AAA homing via a platelet-derived biomembrane coating; and when loaded with a selective PERK inhibitor (PERKi, GSK2656157), the NC therapy conferred remarkable benefits in both preventing aneurysm development and halting the progression of pre-existing aneurysmal lesions in two distinct rodent models of AAA. In summary, our current study not only establishes a new intervention target for mitigating SMC degeneration and aneurysmal pathogenesis, but also provides a powerful tool to facilitate the development of effective drug therapy of AAA.

2.
Klin Monbl Augenheilkd ; 240(1): 13-23, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36706766

ABSTRACT

This article aims to present the differential diagnostics of benign and malignant eyelid tumours. The most common malignant eyelid tumour is basal cell carcinoma, followed by squamous cell carcinoma. The common signs of malignity are loss of lashes, ulceration, and infiltration of the lesion. Often the clinical appearance is various and therefore only a histological analysis gives the proper diagnosis. For most tumours, surgical resection is the gold standard of therapy. The reconstruction of the defects should be performed by an experienced oculoplastic surgeon. In malignant tumours that require large safety margins, the defect can be easily very large, and the reconstruction must then be performed with advanced ophthalmic plastic reconstruction techniques.


Subject(s)
Carcinoma, Basal Cell , Eyelid Neoplasms , Plastic Surgery Procedures , Skin Neoplasms , Humans , Eyelid Neoplasms/diagnosis , Eyelid Neoplasms/surgery , Diagnosis, Differential , Skin Neoplasms/diagnosis , Skin Neoplasms/surgery , Skin Neoplasms/pathology , Carcinoma, Basal Cell/diagnosis , Carcinoma, Basal Cell/surgery
4.
Front Cardiovasc Med ; 9: 949262, 2022.
Article in English | MEDLINE | ID: mdl-36211542

ABSTRACT

Abdominal aortic aneurysm (AAA) is a prevalent vascular disease with high mortality rates upon rupture. Despite its prevalence in elderly populations, there remain limited treatment options; invasive surgical repair, while risky, is the only therapeutic intervention with proven clinical benefits. Dietary factors have long been suggested to be closely associated with AAA risks, and dietary therapies recently emerged as promising avenues to achieve non-invasive management of a wide spectrum of diseases. However, the role of dietary therapies in AAA remains elusive. In this article, we will summarize the recent clinical and pre-clinical efforts in understanding the therapeutic and mechanistic implications of various dietary patterns and therapeutic approaches in AAA.

5.
J Cell Sci ; 135(12)2022 06 15.
Article in English | MEDLINE | ID: mdl-35583107

ABSTRACT

Capping protein Arp2/3 myosin I linker (CARMIL) proteins are multi-domain scaffold proteins that regulate actin dynamics by regulating the activity of capping protein (CP). Here, we characterize CARMIL-GAP (GAP for GTPase-activating protein), a Dictyostelium CARMIL isoform that contains a ∼130 residue insert that, by homology, confers GTPase-activating properties for Rho-related GTPases. Consistent with this idea, this GAP domain binds Dictyostelium Rac1a and accelerates its rate of GTP hydrolysis. CARMIL-GAP concentrates with F-actin in phagocytic cups and at the leading edge of chemotaxing cells, and CARMIL-GAP-null cells exhibit pronounced defects in phagocytosis and chemotactic streaming. Importantly, these defects are fully rescued by expressing GFP-tagged CARMIL-GAP in CARMIL-GAP-null cells. Finally, rescue with versions of CARMIL-GAP that lack either GAP activity or the ability to regulate CP show that, although both activities contribute significantly to CARMIL-GAP function, the GAP activity plays the bigger role. Together, our results add to the growing evidence that CARMIL proteins influence actin dynamics by regulating signaling molecules as well as CP, and that the continuous cycling of the nucleotide state of Rho GTPases is often required to drive Rho-dependent biological processes.


Subject(s)
Actin Capping Proteins , Dictyostelium , Actin Capping Proteins/metabolism , Actin Cytoskeleton/metabolism , Actins/metabolism , Carrier Proteins/metabolism , Dictyostelium/genetics , Dictyostelium/metabolism , GTPase-Activating Proteins/genetics , GTPase-Activating Proteins/metabolism , Microfilament Proteins/genetics , Microfilament Proteins/metabolism
6.
Soc Psychiatry Psychiatr Epidemiol ; 57(5): 1039-1047, 2022 May.
Article in English | MEDLINE | ID: mdl-35022820

ABSTRACT

PURPOSE: Suicide among hospitality workers has recently attracted attention in the media. To date, little is known about suicide among hospitality workers in Australia. METHODS: Suicide data were obtained from the National Coronial Information System (NCIS). Occupational suicide rates were calculated using the Australian Bureau of Statistics population-level data from the 2011 census. Negative binomial regression, univariate logistic regression, and multivariate logistic regression were used to estimate the association between suicide and employment as a hospitality worker over the period 2006-2017, compared to all other occupations. RESULTS: Suicide rates for chefs was significantly higher than for persons in non-hospitality occupations [incidence rate ratio (IRR), 3.93; 95% CI 2.53-5.79; P < 0.001]. The interaction between occupation and sex was examined with follow-up testing. Suicide rates for female chefs were significantly higher than for females in non-hospitality occupations (IRR, 3.93; 95% CI 2.60-5.94). Suicide rates for male chefs were also significantly higher than males in non-hospitality occupations (IRR, 1.38; 95% CI 1.14-1.67). Compared with non-hospitality occupations, hospitality workers who died by suicide had significantly greater odds of being female (OR 0.63, 95% CI 0.50-0.79), residing in residential Socio-Economic Indexes for Areas (SEIFA) classified as most disadvantaged (OR 1.62, 95% CI 1.19-2.20), and being born outside of Australia (OR 1.74, 95% CI 1.34-2.25). CONCLUSION: Results indicate the need for targeted prevention of suicide by Australian hospitality workers. Overall, results suggest that specific hospitality occupations present a higher risk of suicidal behaviour than other non-hospitality occupations.


Subject(s)
Suicide , Australia/epidemiology , Female , Humans , Male , Occupations , Risk Factors , Suicidal Ideation
7.
World Neurosurg ; 160: e335-e343, 2022 04.
Article in English | MEDLINE | ID: mdl-35032715

ABSTRACT

BACKGROUND: Sleep-wake disorders (SWDs) are associated with multiple systemic pathologies; however, the clinical risk that such disorders carry for spinal surgery patients is not well understood. In the present population-based study, we comprehensively evaluated the significance of sleep-related risk factors on instrumented spinal surgery outcomes. METHODS: National Inpatient Sample data for the hospitalization of patients who had undergone elective instrumented spine surgery from 2008 to 2014 were analyzed using national estimates. The cohorts were defined as those admissions with or without a coexisting SWD diagnosis identified by International Classification of Diseases, ninth revision, codes. Postoperative complications, mortality rate, length of stay, discharge status, and the total cost of admission were compared between the groups using bivariate and multivariate analyses. RESULTS: A coexisting SWD was present in 234,640 of 2,171,167 instrumented spinal surgery hospitalizations (10.8%). Multivariate binary logistic regression accounting for these variables confirmed that a SWD is a significant risk factor for postoperative complications (odds ratio [OR], 1.160; 95% confidence interval [CI], 1.140-1.179; P < 0.0001), length of stay greater than the 75th percentile (OR, 1.303; 95% CI, 1.288-1.320; P < 0.0001), nonroutine discharge (OR, 1.147; 95% CI, 1.131-1.163; P < 0.0001), and death (OR, 1.533; 95% CI, 1.131-2.078; P < 0.01), but not for total charges greater than the 75th percentile (OR, 0.975; 95% CI, 0.962-0.989; P < 0.001). CONCLUSIONS: SWDs confer an increased risk of morbidity and mortality for elective instrumented spine surgery. Understanding the specific contributions of SWDs to postoperative morbidity and mortality will help physicians implement prophylactic measures to reduce complications and improve postoperative patient recovery.


Subject(s)
Spinal Fusion , Spine , Elective Surgical Procedures , Humans , Length of Stay , Neurosurgical Procedures , Postoperative Complications/epidemiology , Sleep
8.
Front Microbiol ; 12: 721004, 2021.
Article in English | MEDLINE | ID: mdl-34512600

ABSTRACT

Circadian rhythms, referring to 24-h daily oscillations in biological and physiological processes, can significantly regulate host immunity to pathogens, as well as commensals, resulting in altered susceptibility to disease development. Furthermore, vaccination responses to microbes have also shown time-of-day-dependent changes in the magnitude of protective immune responses elicited in the host. Thus, understanding host circadian rhythm effects on both gut bacteria and viruses during infection is important to minimize adverse effects on health and identify optimal times for therapeutic administration to maximize therapeutic success. In this review, we summarize the circadian modulations of gut bacteria, viruses and their interactions, both in health and during infection. We also discuss the importance of chronotherapy (i.e., time-specific therapy) as a plausible therapeutic administration strategy to enhance beneficial therapeutic responses.

9.
J Control Release ; 338: 295-306, 2021 10 10.
Article in English | MEDLINE | ID: mdl-34416322

ABSTRACT

The long-term success of endovascular intervention has long been overshadowed by vessel re-occlusion, also known as restenosis. Mainstream anti-restenotic devices, such as drug-eluting stent (DES) and drug-coated balloon (DCB), were recently shown with suboptimal performances and life-threatening complications, thereby underpinning the urgent need for alternative strategies with enhanced efficacy and safety profile. In our current study, we engineered a multimodal nanocluster formed by self-assembly of unimolecular nanoparticles and surface coated with platelet membrane, specifically tailored for precision drug delivery in endovascular applications. More specifically, it incorporates the combined merits of platelet membrane coating (lesion targetability and biocompatibility), reactive oxygen species (ROS)-detonable "cluster-bomb" chemistry (to trigger the large-to-small size transition at the target site, thereby achieving longer circulation time and higher tissue penetration), and sustained drug release. Using RVX-208 (an emerging anti-restenotic drug under clinical trials) as the model payload, we demonstrated the superior performances of our nanocluster over conventional poly(lactic-co-glycolic acid) (PLGA) nanoparticle. In cultured vascular smooth muscle cell (VSMC), the drug-loaded nanocluster induced effective inhibition of proliferation and protective gene expression (e.g., APOA-I) with a significantly reduced dosage of RVX-208 (1 µM). In a rat model of balloon angioplasty, intravenous injection of Cy5.5-tagged nanocluster led to greater lesion targetability, improved biodistribution, and deeper penetration into injured vessel walls featuring enriched ROS. Moreover, in contrast to either free drug solution or drug-loaded PLGA nanoparticle formulation, a single injection with the drug-loaded nanocluster (10 mg/kg of RVX-208) was sufficient to substantially mitigate restenosis. Additionally, this nanocluster also demonstrated biocompatibility according to in vitro cytotoxicity assay and in vivo histological and tissue qPCR analysis. Overall, our multimodal nanocluster offers improved targetability, tissue penetration, and ROS-responsive release over conventional nanoparticles, therefore making it a highly promising platform for development of next-generation endovascular therapies.


Subject(s)
Coronary Restenosis , Drug-Eluting Stents , Animals , Biomimetics , Coated Materials, Biocompatible , Rats , Reactive Oxygen Species , Tissue Distribution
11.
FASEB J ; 35(1): e21092, 2021 01.
Article in English | MEDLINE | ID: mdl-33378124

ABSTRACT

Myosin 18Aα is a myosin 2-like protein containing unique N- and C-terminal protein interaction domains that co-assembles with myosin 2. One protein known to bind to myosin 18Aα is ß-Pix, a guanine nucleotide exchange factor (GEF) for Rac1 and Cdc42 that has been shown to promote dendritic spine maturation by activating the assembly of actin and myosin filaments in spines. Here, we show that myosin 18A⍺ concentrates in the spines of cerebellar Purkinje neurons via co-assembly with myosin 2 and through an actin binding site in its N-terminal extension. miRNA-mediated knockdown of myosin 18A⍺ results in a significant defect in spine maturation that is rescued by an RNAi-immune version of myosin 18A⍺. Importantly, ß-Pix co-localizes with myosin 18A⍺ in spines, and its spine localization is lost upon myosin 18A⍺ knockdown or when its myosin 18A⍺ binding site is deleted. Finally, we show that the spines of myosin 18A⍺ knockdown Purkinje neurons contain significantly less F-actin and myosin 2. Together, these data argue that mixed filaments of myosin 2 and myosin 18A⍺ form a complex with ß-Pix in Purkinje neuron spines that promotes spine maturation by enhancing the assembly of actin and myosin filaments downstream of ß-Pix's GEF activity.


Subject(s)
Dendritic Spines/metabolism , Myosins/metabolism , Purkinje Cells/metabolism , Rho Guanine Nucleotide Exchange Factors/metabolism , Animals , Dendritic Spines/genetics , Gene Deletion , Mice , Myosin Type II/genetics , Myosin Type II/metabolism , Myosins/genetics , Rho Guanine Nucleotide Exchange Factors/genetics
12.
Klin Monbl Augenheilkd ; 238(5): 609-615, 2021 May.
Article in German | MEDLINE | ID: mdl-31416097

ABSTRACT

Retrobulbar haematoma (RBH) is a rare complication that may affect vision after a trauma or a surgical procedure. The diagnosis must be made promptly, as only early surgical intervention can adequately prevent irreversible visual impairment. Because of the bony orbital walls, there is hardly any room for the increasing intraorbital volume due to the retrobulbar haemorrhage. This leads to an increase in intraorbital pressure and subsequently to compression of the optic nerve. Symptoms include disorders in ocular motility, ophthalmoplegia, diplopia, conjunctival chemosis, subconjunctival haemorrhage, proptosis, increased intraocular pressure, deterioration in visual acuity, decreased direct pupillary reflex, and a relative afferent pupillary defect. If the cause is traumatic or iatrogenic, prompt lateral canthotomy with cantholysis is the treatment of choice, and successfully lowers pressure in most cases. It can be performed in the emergency room by an ophthalmologist and may even be indicated without previous imaging. As the reconstruction of cantholysis is generally uncomplicated, we recommend performing the procedure when RBH is suspected. If canthotomy with cantholysis does not lead to adequate improvement, surgical orbital decompression must be performed. Supportive treatment should always include systemic steroids.


Subject(s)
Retrobulbar Hemorrhage , Decompression, Surgical , Hematoma/diagnosis , Hematoma/etiology , Hematoma/surgery , Humans , Retrobulbar Hemorrhage/diagnosis , Retrobulbar Hemorrhage/etiology , Retrobulbar Hemorrhage/surgery , Vision Disorders/diagnosis , Vision Disorders/etiology , Visual Acuity
14.
J Stroke Cerebrovasc Dis ; 29(9): 105018, 2020 Sep.
Article in English | MEDLINE | ID: mdl-32807433

ABSTRACT

INTRODUCTION: Recent clinical comparisons of M1 and M2 segment endovascular thrombectomy have reached incongruous results in rates of complication and functional outcomes. This study aims to clarify the controversy surrounding this rapidly advancing technique through literature review and meta-analysis. METHODS: A Pubmed search was performed (January 2015-September 2019) using the following keywords: "M2 AND ("stroke" OR "occlusion") AND ("thrombectomy" OR "endovascular")". Safety and clinical outcomes were compared between segments via weighted Student's t-test, Chi-square and odds ratio while study heterogeneity was analyzed using Cochran Q and I2 tests. RESULTS: Pubmed identified 208 articles and eleven studies were included after full-text analysis, comprising 2,548 M1 and 758 M2 mechanical thrombectomy segment cases. Baseline National Institutes of Health Stroke Scale scores were comparatively lower in patients experiencing an M2 occlusion (16 ± 1.25 vs 13.6 ± 0.96, p < 0.01). Patients who underwent M2 mechanical thrombectomy were more likely to experience both good clinical outcomes (modified Rankin Scale 0-2) (48.6% vs 43.5% respectively, OR 1.24; CI 1.05-1.47, p = 0.01) and excellent clinical outcomes (modified Rankin Scale 0-1) (34.7% vs. 26.5%%, OR 1.6; CI 1.28-1.99, p < 0.01) at 90 days compared to M1 mechanical thrombectomy. Neither recanalization rates (75.3% vs 72.8%, OR 0.92, CI 0.75-1.13, p = 0.44) nor symptomatic intracranial hemorrhage rates (5.6% vs 4.9%, OR 0.92; CI 0.61-1.39, p= 0.7) were significantly different between M1 and M2 cohorts. Mortality was less frequent in the M2 cohort compared to M1 (16.3% vs 20.7%, OR 0.73; CI 0.57-0.94, p = 0.01). M1 and M2 cohorts did not differ in symptom onset-to-puncture (238.1 ± 46.7 vs 239.8 ± 43.9 min respectively, p=0.488) nor symptom onset-to recanalization times (318.7 ± 46.6 vs 317.7 ± 71.1 min respectively, p = 0.772), though mean operative duration was shorter in the M2 cohort (61.8 ± 25.5 vs 54.6 ± 24 min, p < 0.01). CONCLUSIONS: Patients who underwent M2 mechanical thrombectomy had a higher prevalence of good and excellent clinical outcomes compared to the M1 mechanical thrombectomy cohorts. Additionally, our data suggest lower mortality rates in the M2 cohort and symptomatic intracranial hemorrhage rates that are similar to the M1 cohort. Therefore, M2 segment thrombectomy likely does not pose a significantly elevated operative risk and may have a positive impact on patient outcomes.


Subject(s)
Endovascular Procedures/adverse effects , Infarction, Middle Cerebral Artery/therapy , Thrombectomy/adverse effects , Aged , Disability Evaluation , Endovascular Procedures/mortality , Female , Humans , Infarction, Middle Cerebral Artery/diagnosis , Infarction, Middle Cerebral Artery/mortality , Infarction, Middle Cerebral Artery/physiopathology , Male , Recovery of Function , Risk Assessment , Risk Factors , Thrombectomy/mortality , Time Factors , Treatment Outcome
15.
Cureus ; 12(4): e7694, 2020 Apr 16.
Article in English | MEDLINE | ID: mdl-32431973

ABSTRACT

We present our experience following a unique case of coincident intracranial hemorrhage and comminuted fractures of both the squamous temporal bone and zygomaticofrontal orbit. Surgical techniques and outcome for this presentation have yet to be sufficiently described. A 55-year-old male presented following trauma with Glasgow Coma Scale score of 7. Radiographic evaluation revealed comminuted fractures of the squamous temporal bone with extension into the lateral orbit, along with zygomatic process fracture extending 2.5 cm medially into the orbital roof. Zygomaticofrontal orbital roof fragments reached superiorly into the middle cranial fossa and inferiorly into the orbit. Surgical intervention was deemed necessary to address underlying epidural hematoma, subarachnoid hemorrhage, correction of cranial bone defects, and decompression of the optic nerve and other intraorbital nerves. A frontotemporal approach was employed. Repair of temporal and orbital fractures was accomplished using a combination of wire mesh screws and titanium miniplates. Postoperative imaging demonstrated bony approximation and successful evacuation of traumatic hemorrhage. The patient remains functionally and neurologically intact apart from a sluggishly responsive left eye presumed to result from a left optic nerve or ciliary ganglion lesion. Although rapid reconstruction of complex cranial-orbital trauma and hematoma evacuation can permit acceptable gross functional neurological outcome following massive trauma, orbital fracture and subsequent hemorrhagic processes may be the nidus of neurological sequelae in this complex traumatic constellation. Thus, alterations in surgical approach and reconstruction are appropriate in order to maximize neurological function while supporting restoration of cosmetic space.

16.
PLoS One ; 15(4): e0227496, 2020.
Article in English | MEDLINE | ID: mdl-32267864

ABSTRACT

Atlantic salmon migrate to sea following completion of a developmental process known as smolting, which establishes a seawater (SW) tolerant phenotype. Smolting is stimulated by exposure to long photoperiod or continuous light (LL) following a period of exposure to short photoperiod (SP), and this leads to major changes in gill ion exchange and osmoregulatory function. Here, we performed an RNAseq experiment to discover novel genes involved in photoperiod-dependent remodeling of the gill. This revealed a novel cohort of genes whose expression rises dramatically in fish transferred to LL following SP exposure, but not in control fish maintained continuously on LL or on SP. A follow-up experiment revealed that the SP-history dependence of LL induction of gene expression varies considerably between genes. Some genes were inducible by LL exposure after only 2 weeks exposure to SP, while others required 8 weeks prior SP exposure for maximum responsiveness to LL. Since subsequent SW growth performance is also markedly improved following 8 weeks SP exposure, these photoperiodic history-dependent genes may be useful predictive markers for full smolt development.


Subject(s)
Gene Expression Regulation, Developmental , Photoperiod , Salmo salar/physiology , Salt Tolerance/genetics , Seawater/adverse effects , Animal Migration/physiology , Animals , Gills/growth & development , Life Cycle Stages/physiology , Norway , RNA-Seq , Time Factors
17.
J Invasive Cardiol ; 31(7): E170-E176, 2019 Jul.
Article in English | MEDLINE | ID: mdl-31257210

ABSTRACT

OBJECTIVE: Arterial access from the wrist for cardiac catheterization is increasingly being used. Right heart catheterization (RHC) is an integral part of many of these procedures. Reliable venous access from the arm allows avoidance of femoral or jugular venous access for RHC. It is uncertain if ultrasound guidance offers a benefit for venous access of the arm for RHC. This study sought to assess the efficacy of ultrasound-guided venous access of the arm (UGVAA) for RHC. METHODS: A retrospective study was performed on consecutive patients undergoing RHC at a single institution between August 2015 and July 2016. Baseline data, procedural information, and success rates of UGVAA and RHC were assessed. RESULTS: A total of 266 consecutive RHC procedures were identified, of which 253 (95.1%) were performed via arm venous access; of these, a pre-existing intravenous catheter was used in 3 cases, UGVAA was used in 241 cases, and UGVAA was probably used but not documented in 9 cases. There was 100% success of venous cannulation and sheath placement in these 253 patients. RHC via the arm vein was successful in 248 patients (98.0%) and failed in 5 patients (2.0%). Mean procedure time for RHC via arm access was 5.7 minutes. The femoral approach was used in 12 patients (4.5%). A jugular approach was used in 1 patient (0.4%). All patients had concomitant left heart catheterization via transradial access. CONCLUSIONS: UGVAA is a highly efficacious and safe technique, with a success rate of 98% for RHC in our consecutive series of 253 patients. UGVAA may allow for near-universal use of arm veins for RHC.


Subject(s)
Cardiac Catheterization/methods , Catheterization, Central Venous/methods , Heart Diseases/diagnosis , Ultrasonography/methods , Aged , Female , Follow-Up Studies , Humans , Jugular Veins , Male , Retrospective Studies , Time Factors
18.
Cerebellum ; 18(3): 406-421, 2019 Jun.
Article in English | MEDLINE | ID: mdl-30729383

ABSTRACT

While mixed primary cerebellar cultures prepared from embryonic tissue have proven valuable for dissecting structure-function relationships in cerebellar Purkinje neurons (PNs), this technique is technically challenging and often yields few cells. Recently, mouse embryonic stem cells (mESCs) have been successfully differentiated into PNs, although the published methods are very challenging as well. The focus of this study was to simplify the differentiation of mESCs into PNs. Using a recently described neural differentiation media, we generate monolayers of neural progenitor cells from mESCs and differentiate them into PN precursors using specific extrinsic factors. These PN precursors are then differentiated into mature PNs by co-culturing them with granule neuron (GN) precursors also derived from neural progenitors using different extrinsic factors. The morphology of mESC-derived PNs is indistinguishable from PNs grown in primary culture in terms of gross morphology, spine length, and spine density. Furthermore, mESC-derived PNs express Calbindin D28K, IP3R1, IRBIT, PLCß4, PSD93, and myosin IIB-B2, all of which are either PN-specific or highly expressed in PNs. Moreover, we show that mESC-derived PNs form synapses with GN-like cells as in primary culture, express proteins driven by the PN-specific promoter Pcp2/L7, and exhibit the defect in spine ER inheritance seen in PNs isolated from dilute-lethal (myosin Va-null) mice when expressing a Pcp2/L7-driven miRNA directed against myosin Va. Finally, we define a novel extracellular matrix formulation that reproducibly yields monolayer cultures conducive for high-resolution imaging. Our improved method for differentiating mESCs into PNs should facilitate the dissection of molecular mechanisms and disease phenotypes in PNs.


Subject(s)
Cell Differentiation/physiology , Mouse Embryonic Stem Cells/cytology , Neural Stem Cells/cytology , Purkinje Cells/cytology , Animals , Cell Culture Techniques , Mice , Mice, Inbred C57BL
19.
J Funct Biomater ; 9(4)2018 Oct 12.
Article in English | MEDLINE | ID: mdl-30322006

ABSTRACT

Complex open musculoskeletal wounds are a leading cause of morbidity worldwide, partially due to a high risk of bacterial contamination. Local delivery systems may be used as adjunctive therapies to prevent infection, but they may be nondegradable, possess inadequate wound coverage, or migrate from the wound site. To address this issue, a thermo-responsive, injectable chitosan paste was fabricated by incorporating beta-glycerophosphate. The efficacy of thermo-paste as an adjunctive infection prevention tool was evaluated in terms of cytocompatibility, degradation, antibacterial, injectability, and inflammation properties. In vitro studies demonstrated thermo-paste may be loaded with amikacin and vancomycin and release inhibitory levels for at least 3 days. Further, approximately 60% of thermo-paste was enzymatically degraded within 7 days in vitro. The viability of cells exposed to thermo-paste exceeded ISO 10993-5 standards with approximately 73% relative viability of a control chitosan sponge. The ejection force of thermo-paste, approximately 20 N, was lower than previously studied paste formulations and within relevant clinical ejection force ranges. An in vivo murine biocompatibility study demonstrated that thermo-paste induced minimal inflammation after implantation for 7 days, similar to previously developed chitosan pastes. Results from these preliminary preclinical studies indicate that thermo-paste shows promise for further development as an antibiotic delivery system for infection prevention.

20.
Cytoskeleton (Hoboken) ; 75(9): 395-409, 2018 09.
Article in English | MEDLINE | ID: mdl-29979496

ABSTRACT

The actin-based motor myosin Va transports numerous cargos, including the smooth endoplasmic reticulum (SER) in cerebellar Purkinje neurons (PNs) and melanosomes in melanocytes. Identifying proteins that interact with this myosin is key to understanding its cellular functions. Toward that end, we used recombineering to insert via homologous recombination a tandem affinity purification (TAP) tag composed of the immunoglobulin G-binding domain of protein A, a tobacco etch virus cleavage site, and a FLAG tag into the mouse MYO5A locus immediately after the initiation codon. Importantly, we provide evidence that the TAP-tagged version of myosin Va (TAP-MyoVa) functions normally in terms of SER transport in PNs and melanosome positioning in melanocytes. Given this and other evidence that TAP-MyoVa is fully functional, we purified it together with associated proteins directly from juvenile mouse cerebella and subjected the samples to mass spectroscopic analyses. As expected, known myosin Va-binding partners like dynein light chain were identified. Importantly, numerous novel interacting proteins were also tentatively identified, including guanine nucleotide-binding protein G(o) subunit alpha (Gnao1), a biomarker for schizophrenia. Consistently, an antibody to Gnao1 immunoprecipitates myosin Va, and Gnao1's localization to PN dendritic spines depends on myosin Va. The mouse model created here should facilitate the identification of novel myosin Va-binding partners, which in turn should advance our understanding of the roles played by this important myosin in vivo.


Subject(s)
Cerebellum/physiology , Mice, Transgenic/metabolism , Myosin Type V/metabolism , Animals , Mice
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