Enzymatic and Non-enzymatic Collagen Cross-Links and Fracture Occurrence in Type 1 Diabetes Patients.

Increased fracture risk in type 1 diabetes (T1D) patients is not fully captured by bone mineral density (BMD) by DXA. Advanced glycation end-products (AGEs) have been implicated in the increased fracture risk in T1D, yet recent publications question this. To test the hypothesis that enzymatic collagen cross-links rather than AGEs correlate with fracture incidence in T1D, we analyzed iliac crest biopsies from sex-matched, fracturing T1D patients (N = 5; T1DFx), 6 non-fracturing T1D patients (T1DNoFx), and 6 healthy subjects, by Raman microspectroscopy as a function of tissue age (based on double fluorescent labels), in intracortical and trabecular bone, to determine pyridinoline (Pyd), ε-N-Carboxymethyl-L-lysine, and pentosidine (PEN)). There were no differences in the clinical characteristics between the T1DFx and T1DNoFx groups. At trabecular forming surfaces, T1DFx patients had higher PEN and Pyd content compared to T1DNoFx ones. Previous studies have shown that elevated PEN does not necessarily correlate with fracture incidence in postmenopausal, long-term T1D patients. On the other hand, the elevated Pyd content in the T1DFx patients would be consistent with published studies showing a significant correlation between elevated trivalent enzymatic collagen cross-links and fracture occurrence independent of BMD. Collagen fibers with high Pyd content are more brittle. Thus, a plausible suggestion is that it is the enzymatic collagen cross-links that either by themselves or in combination with the adverse effects of increased AGE accumulation that result in fragility fracture in T1D.

A Magnetic Actuator Device for Fully Automated Blinking in Total Bidirectional Eyelid Paralysis: First Proof of Concept in a Human Participant.

Purpose: Currently, no solution exists to restore natural eyelid kinematics for patients with complete eyelid paralysis due to loss of function of both the levator palpebrae superioris and orbicularis oculi. These rare cases are prone to complications of chronic exposure keratopathy which may lead to corneal blindness. We hypothesized that magnetic force could be used to fully automate eyelid movement in these cases through the use of eyelid-attached magnets and a spectacle-mounted magnet driven by a programmable motor (motorized magnetic levator prosthesis [MMLP]). Methods: To test this hypothesis and establish proof of concept, we performed a finite element analysis (FEA) for a prototype MMLP to check the eyelid-opening force generated by the device and verified the results with experimental measurements in a volunteer with total bidirectional eyelid paralysis. The subject was then fitted with a prototype to check the performance of the device and its success. Results: With MMLP, eye opening was restored to near normal, and blinking was fully automated in close synchrony with the motor-driven polarity reversal, with full closure on the blink. The device was well tolerated, and the participant was pleased with the comfort and performance. Conclusions: FEA simulation results conformed to the experimentally observed trend, further supporting the proof of concept and design parameters. This is the first viable approach in human patients with proof of concept for complete reanimation of a bidirectionally paretic eyelid. Further study is warranted to refine the prototype and determine the feasibility and safety of prolonged use. Translational Relevance: This is first proof of concept for our device for total bidirectional eyelid paralysis.

The prophylactic value of TNF-α inhibitors against retinal cell apoptosis and optic nerve axon loss after corneal surgery or trauma.

BACKGROUND AND PURPOSE: Late secondary glaucoma is an often-severe complication after acute events like anterior segment surgery, trauma and infection. TNF-α is a major mediator that is rapidly upregulated, diffusing also to the retina and causes apoptosis of the ganglion cells and degeneration of their optic nerve axons (mediating steps to glaucomatous damage). Anti-TNF-α antibodies are in animals very effective in protecting the retinal cells and the optic nerve-and might therefore be useful prophylactically against secondary glaucoma in future such patients. Here we evaluate (1) toxicity and (2) efficacy of two TNF-α inhibitors (adalimumab and infliximab), in rabbits by subconjunctival administration. METHODS: For drug toxicity, animals with normal, unburned corneas were injected with adalimumab (0.4, 4, or 40 mg), or infliximab (1, 10, or 100 mg). For drug efficacy, other animals were subjected to alkali burn before such injection, or steroids (for control). The rabbits were evaluated clinically with slit lamp and photography, electroretinography, optical coherence tomography, and intraocular pressure manometry. A sub-set of eyes were stained ex vivo after 3 days for retinal cell apoptosis (TUNEL). In other experiments the optic nerves were evaluated by paraphenylenediamine staining after 50 or 90 days. Loss of retinal cells and optic nerve degeneration were quantified. RESULTS: Subconjunctival administration of 0.4 mg or 4.0 mg adalimumab were well tolerated, whereas 40.0 mg was toxic to the retina. 1, 10, or 100 mg infliximab were also well tolerated. Analysis of the optic nerve axons after 50 days confirmed the safety of 4.0 mg adalimumab and of 100 mg infliximab. For efficacy, 4.0 mg adalimumab subconjunctivally in 0.08 mL provided practically full protection against retinal cell apoptosis 3 days following alkali burn, and infliximab 100 mg only slightly less. At 90 days following burn injury, control optic nerves showed about 50% axon loss as compared to 8% in the adalimumab treatment group. CONCLUSIONS: Subconjunctival injection of 4.0 mg adalimumab in rabbits shows no eye toxicity and provides excellent neuroprotection, both short (3 days) and long-term (90 days). Our total. accumulated data from several of our studies, combined with the present paper, suggest that corneal injuries, including surgery, might benefit from routine administration of anti-TNF-α biologics to reduce inflammation and future secondary glaucoma.

An Adjustable Magnetic Levator Prosthesis for Customizable Eyelid Reanimation in Severe Blepharoptosis II: Randomized Evaluation of Angular Translation.

Purpose: Examine the effect of force modulation via angular translation of a static magnetic field for customizable treatment of severe blepharoptosis. Methods: Prototype adjustable-force magnetic levator prostheses (aMLP) consisted of a spectacle-mounted magnet in rotatable housing and small eyelid-attached magnets embedded in a biocompatible polymer. Interpalpebral fissure (IPF) of 17 participants with severe blepharoptosis was continuously measured for one minute at five spectacle magnet angles, with order randomized and participant and data analyst masked. The hypothesis that angular position affected opening IPF (o-IPF), minimum blink IPF (m-IPF), and comfort ratings (1-10) was tested. Results: The aMLP improved o-IPF from 4.5 mm without the device to 6.2 mm on the lowest force setting (P < 0.001) and 7.1 mm on the highest setting (P < 0.001) and allowed for complete volitional blink regardless of setting (average m-IPF 0.4 mm and no change with aMLP; P = 0.76). Spontaneous blink without the device (2.0 mm) was affected on the highest force setting (m-IPF 3.9 mm; P < 0.001) but only marginally so on the lowest setting (3.0 mm; P = 0.06). Comfort (7.6/10) did not vary with the angle (P > 0.36). Profile analysis found substantial individual responses to angle (P < 0.001), confirming the value of customization. Conclusions: Angular translation provided adjustable force, which had a statistically and clinically meaningful impact on eye opening and the completeness of the spontaneous blink. This quantitative evidence supports continued use of the angular translation mechanism for force adjustment in the customizable magnetic correction of severe blepharoptosis. Translational Relevance: Evidence for the benefit of customizable magnetic force via angular translation in a larger sample of participants than reported previously.

Peripheral monocytes and neutrophils promote photoreceptor cell death in an experimental retinal detachment model.

Photoreceptor cell death and immune cell infiltration are two major events that contribute to retinal degeneration. However, the relationship between these two events has not been well delineated, primarily because of an inadequate understanding of the immunological processes involved in photoreceptor degeneration, especially that of peripheral leukocytes that infiltrate the subretinal space and retinal tissues. In this work, we characterized the role of leukocyte infiltration within the detached retina. We observed that CD45+ CD11b+ Ly6G+ neutrophils and CD45+ CD11b+ Ly6G- Ly6C+ monocytes are the predominant peripheral immune cell populations that infiltrate the retinal and subretinal space after detachment. Selective depletion of monocytes or neutrophils using cell-specific targeting is neuroprotective for photoreceptors. These results indicate that peripheral innate immune cells contribute to photoreceptor degeneration, and targeting these immune cell populations could be therapeutic during retinal detachment.

Clinical Report: Clinician Feedback on the Magnetic Levator Prosthesis.

SIGNIFICANCE: Stakeholder engagement has been identified by national health organizations as a crucial step to successful translation of new health care treatments. In this clinical report, clinician-stakeholder feedback is presented for the magnetic levator prosthesis (MLP), a promising noninvasive spectacle device that restores eyelid motility with magnetic force. PURPOSE: This study aimed to evaluate MLP clinical need and translational barriers. METHODS: Ten vision rehabilitation optometrists who attended an educational presentation on the MLP and participated in a hands-on workshop in the fitting of a patient were invited to complete an anonymous online survey. Ten multiple-choice items gathered data on estimated patient need, current approaches, main barriers to MLP, temporary versus chronic use, cost barriers, and need for insurance coverage. Open fields allowed for additional comments. RESULTS: Nine of 10 specialists completed the survey. Of those, seven answered that they could potentially see at least 1 to 5 patients for ptosis management within a year. The most common ptosis management options reported were the ptosis crutch, taping the eyelid open, and oxymetazoline drops, all with six responses each. Seven clinicians indicated that cost was a main concern. If cost to patient was not a barrier, all indicated they would be at least somewhat likely to try the MLP (1) for temporary management of ptosis, (2) as a pre-surgical trial, and (3) for long-term management of ptosis, with more selecting extremely likely and very likely than somewhat likely. Main comments were expressing enthusiasm for the technology and that it would be more appealing for patients if covered by insurance. CONCLUSIONS: This clinical report suggests that the main barriers to clinical success of the MLP may be cost and insurance coverage, appearance of the device, and self-application. Possible solutions are cost-benefit analysis research, engineering efforts to reduce spectacle magnet size and improve the ease of eyelid magnet application.

CSF1R inhibition is not specific to innate immune cells but also affects T-helper cell differentiation independently of microglia depletion.

Colony-stimulating factor 1 receptor (CSF1R) inhibition has been proposed as a specific method for microglia depletion. However, recent work revealed that in addition to microglia, CSF1R inhibition also affects other innate immune cells, such as peripheral monocytes and tissue-resident macrophages of the lung, liver, spleen, and peritoneum. Here, we show that this effect is not restricted to innate immune cells only but extends to the adaptive immune compartment. CSF1R inhibition alters the transcriptional profile of bone marrow cells that control T helper cell activation. In vivo or ex vivo inhibition of CSF1R profoundly changes the transcriptional profile of CD4+ cells and suppresses Th1 and Th2 differentiation in directionally stimulated and unstimulated cells and independently of microglia depletion. Given that T cells also contribute in CNS pathology, these effects may have practical implications in the interpretation of relevant experimental data.

Sustained Inhibition of VEGF and TNF-α Achieves Multi-Ocular Protection and Prevents Formation of Blood Vessels after Severe Ocular Trauma.

PURPOSE: This study aimed to develop a clinically feasible and practical therapy for multi-ocular protection following ocular injury by using a thermosensitive drug delivery system (DDS) for sustained delivery of TNF-α and VEGF inhibitors to the eye. METHODS: A thermosensitive, biodegradable hydrogel DDS (PLGA-PEG-PLGA triblock polymer) loaded with 0.7 mg of adalimumab and 1.4 mg of aflibercept was injected subconjunctivally into Dutch-belted pigmented rabbits after corneal alkali injury. Control rabbits received 2 mg of IgG-loaded DDS or 1.4 mg of aflibercept-loaded DDS. Animals were followed for 3 months and assessed for tolerability and prevention of corneal neovascularization (NV), improvement of corneal re-epithelialization, inhibition of retinal ganglion cell (RGC) and optic nerve axon loss, and inhibition of immune cell infiltration into the cornea. Drug-release kinetics was assessed in vivo using an aqueous humor protein analysis. RESULTS: A single subconjunctival administration of dual anti-TNF-α/anti-VEGF DDS achieved a sustained 3-month delivery of antibodies to the anterior chamber, iris, ciliary body, and retina. Administration after corneal alkali burn suppressed CD45+ immune cell infiltration into the cornea, completely inhibited cornea NV for 3 months, accelerated corneal re-epithelialization and wound healing, and prevented RGC and optic nerve axon loss at 3 months. In contrast, anti-VEGF alone or IgG DDS treatment led to persistent corneal epithelial defect (combined: <1%; anti-VEGF: 15%; IgG: 10%, of cornea area), increased infiltration of CD45+ immune cells into the cornea (combined: 28 ± 20; anti-VEGF: 730 ± 178; anti-IgG: 360 ± 186, cells/section), and significant loss of RGCs (combined: 2.7%; anti-VEGF: 63%; IgG: 45%) and optic nerve axons at 3 months. The aqueous humor protein analysis showed first-order release kinetics without adverse effects at the injection site. CONCLUSIONS: Concomitant inhibition of TNF-α and VEGF prevents corneal neovascularization and ameliorates subsequent irreversible damage to the retina and optic nerve after severe ocular injury. A single subconjunctival administration of this therapy, using a biodegradable, slow-release thermosensitive DDS, achieved the sustained elution of therapeutic levels of antibodies to all ocular tissues for 3 months. This therapeutic approach has the potential to dramatically improve the outcomes of severe ocular injuries in patients and improve the therapeutic outcomes in patients with retinal vascular diseases.

Opposing Roles of Blood-Borne Monocytes and Tissue-Resident Macrophages in Limbal Stem Cell Damage after Ocular Injury.

Limbal stem cell (LSC) deficiency is a frequent and severe complication after chemical injury to the eye. Previous studies have assumed this is mediated directly by the caustic agent. Here we show that LSC damage occurs through immune cell mediators, even without direct injury to LSCs. In particular, pH elevation in the anterior chamber (AC) causes acute uveal stress, the release of inflammatory cytokines at the basal limbal tissue, and subsequent LSC damage and death. Peripheral C-C chemokine receptor type 2 positive/CX3C motif chemokine receptor 1 negative (CCR2+ CX3CR1-) monocytes are the key mediators of LSC damage through the upregulation of tumor necrosis factor-alpha (TNF-α) at the limbus. In contrast to peripherally derived monocytes, CX3CR1+ CCR2- tissue-resident macrophages have a protective role, and their depletion prior to injury exacerbates LSC loss and increases LSC vulnerability to TNF-α-mediated apoptosis independently of CCR2+ cell infiltration into the tissue. Consistently, repopulation of the tissue by new resident macrophages not only restores the protective M2-like phenotype of macrophages but also suppresses LSC loss after exposure to inflammatory signals. These findings may have clinical implications in patients with LSC loss after chemical burns or due to other inflammatory conditions.

An Adjustable Magnetic Levator Prosthesis for Customizable Eyelid Re-Animation in Severe Blepharoptosis: Design and Proof-of-Concept.

Purpose: Blepharoptosis is a common oculoplastic condition causing incomplete opening of the upper eyelid. Surgical approaches, the mainstay for correction, often fail to improve blink function. The purpose of this study was to develop a nonsurgical treatment option for severe ptosis that allows blink re-animation. Methods: Magnetic force required to perform blink re-animation was characterized by evaluation of eye-opening and closing using inter-palpebral fissure (IPF) outcomes with various combinations of eyelid array and box magnets. Optimal size of the spectacle magnet that achieved forces required for optimal blink dynamics was selected using simulation. The adjustable magnetic levator prosthesis (aMLP) included an eyelid array magnet and an adjustable rotating spectacle magnet that allowed change in the magnetic direction, thus changing the net magnetic interactive force between the magnets. The clinical feasibility of aMLP in improving eye opening without limiting eye closing was evaluated in patients with ptosis through a proof-of-concept study using IPF and comfort outcomes. Results: Optimal eye opening and closing was achieved by a magnet-array combination providing 45 grams of surface force (gF) in the tested ptosis population. The aMLP was able to modulate eye opening and closing with change in rotation of the spectacle magnet in two patients with ptotis. The best fitting of an aMLP improved IPF opening without limiting eye closing and with good comfort reported. Conclusions: Preliminary results suggest that the an aMLP can correct ptosis without adversely affecting blink function. Further evaluation in a larger patient population is warranted. Translational Relevance: A nonsurgical, proof of concept, adjustable magnetic treatment option for blink re-animation in patients with severe ptosis is presented.

Bone intrinsic material and compositional properties in postmenopausal women diagnosed with long-term Type-1 diabetes.

The incidence of diabetes mellitus and the associated complications are growing worldwide, affecting the patients' quality of life and exerting a considerable burden on health systems. Yet, the increase in fracture risk in type 1 diabetes (T1D) patients is not fully captured by bone mineral density (BMD), leading to the hypothesis that alterations in bone quality are responsible for the increased risk. Material/compositional properties are important aspects of bone quality, yet information on human bone material/compositional properties in T1D is rather sparse. The purpose of the present study is to measure both the intrinsic material behaviour by nanoindentation, and material compositional properties by Raman spectroscopy as a function of tissue age and microanatomical location (cement lines) in bone tissue from iliac crest biopsies from postmenopausal women diagnosed with long-term T1D (N = 8), and appropriate sex-, age-, BMD- and clinically-matched controls (postmenopausal women; N = 5). The results suggest elevation of advanced glycation endproducts (AGE) content in the T1D and show significant differences in mineral maturity / crystallinity (MMC) and glycosaminoglycan (GAG) content between the T1D and control groups. Furthermore, both hardness and modulus by nanoindentation are greater in T1D. These data suggest a significant deterioration of material strength properties (toughness) and compositional properties in T1D compared with controls.

Comparative In Vitro Activity of New Lipoglycopeptides and Vancomycin Against Ocular Staphylococci and Their Toxicity on the Human Corneal Epithelium.

PURPOSE: The purpose of this study was to assess the potential of new lipoglycopeptides as novel topical therapies for improved treatment of recalcitrant ocular infections. We evaluated the in vitro antimicrobial activity of oritavancin, dalbavancin, and telavancin compared with vancomycin (VAN) against a large collection of ocular staphylococcal isolates and their cytotoxicity on human corneal epithelial cells (HCECs). METHODS: Antimicrobial susceptibility testing was performed by broth microdilution against 223 Staphylococcus spp. clinical isolates. Time-kill kinetics were determined for methicillin-resistant strains of Staphylococcus aureus (MRSA) (n = 2) and Staphylococcus epidermidis (MRSE) (n = 1). In vitro cytotoxicity assays were performed with AlamarBlue and live/dead staining on HCECs. RESULTS: All new lipoglycopeptides showed strong in vitro potency against ocular staphylococci, including multidrug-resistant MRSA strains, with dalbavancin showing a slightly higher potency overall [minimum inhibitory concentration (MIC) 90 0.06 µg/mL] compared with telavancin and oritavancin (MIC 90 0.12 µg/mL), whereas VAN had the lowest potency (MIC 90 2 µg/mL). Oritavancin exerted rapid bactericidal activity within 1 h for MRSA and 2 h for MRSE. All other drugs were bactericidal within 24 h. At a concentration commonly used for topical preparations (25 mg/mL), cytotoxicity was observed for VAN after 5 min of incubation, whereas reduction in HCEC viability was not seen for telavancin and was less affected by oritavancin and dalbavancin. Cytotoxicity at 25 mg/mL was seen for all drugs at 30 and 60 min but was significantly reduced or undetected for lower concentrations. CONCLUSIONS: Our study demonstrates that new lipoglycopeptides have substantially better in vitro antimicrobial activity against ocular staphylococcal isolates compared with VAN, with a similar or improved toxicity profile on HCECs.

Incidence and risk factors for glaucoma development and progression after corneal transplantation.

OBJECTIVE: To assess the cumulative incidence and risk factors for glaucoma development and progression within 1-2 years following corneal transplant surgery. DESIGN: Retrospective cohort study. METHODS: Patients undergoing penetrating keratoplasty (PK), deep anterior lamellar keratoplasty (DALK), Descemet stripping endothelial keratoplasty (DSEK), Descemet membrane endothelial keratoplasty (DMEK), Boston keratoprosthesis type I (KPro) implantation, or endothelial keratoplasty (DSEK or DMEK) under previous PK (EK under previous PK) at one academic institution with at least 1 year of follow-up were included. Primary outcome measures were cumulative incidence of glaucoma development and progression after corneal transplant, in patients without and with preoperative glaucoma, respectively. Risk factors for glaucoma development and progression were also assessed. RESULTS: Four hundred and thirty-one eyes of 431 patients undergoing PK (113), DALK (17), DSEK (71), DMEK (168), KPro (35) and EK under previous PK (27) with a mean follow-up of 22.9 months were analyzed. The 1-year cumulative incidence for glaucoma development and progression was 28.0% and 17.8% in patients without and with preoperative glaucoma, respectively. In a Cox proportional hazards analysis, DSEK surgery, KPro implantation, average intraocular pressure (IOP) through follow-up and postoperative IOP spikes of ≥30 mmHg were each independently associated with glaucoma development or progression (p < 0.04 for all). CONCLUSIONS: A significant proportion of patients developed glaucoma or exhibited glaucoma progression within 1 year after corneal transplantation. Patient selection for DSEK may partly explain the higher risk for glaucoma in these patients. Postoperative IOP spikes should be minimized and may indicate the need for co-management with a glaucoma specialist.

Vitamin C epigenetically controls osteogenesis and bone mineralization.

Vitamin C deficiency disrupts the integrity of connective tissues including bone. For decades this function has been primarily attributed to Vitamin C as a cofactor for collagen maturation. Here, we demonstrate that Vitamin C epigenetically orchestrates osteogenic differentiation and function by modulating chromatin accessibility and priming transcriptional activity. Vitamin C regulates histone demethylation (H3K9me3 and H3K27me3) and promotes TET-mediated 5hmC DNA hydroxymethylation at promoters, enhancers and super-enhancers near bone-specific genes. This epigenetic circuit licenses osteoblastogenesis by permitting the expression of all major pro-osteogenic genes. Osteogenic cell differentiation is strictly and continuously dependent on Vitamin C, whereas Vitamin C is dispensable for adipogenesis. Importantly, deletion of 5hmC-writers, Tet1 and Tet2, in Vitamin C-sufficient murine bone causes severe skeletal defects which mimic bone phenotypes of Vitamin C-insufficient Gulo knockout mice, a model of Vitamin C deficiency and scurvy. Thus, Vitamin C's epigenetic functions are central to osteoblastogenesis and bone formation and may be leveraged to prevent common bone-degenerating conditions.

Feasibility of Magnetic Levator Prosthesis Frame Customization Using Craniofacial Scans and 3-D Printing.

Purpose: To determine the feasibility of a custom frame generation approach for nonsurgical management of severe blepharoptosis with the magnetic levator prosthesis (MLP). Methods: Participants (n = 8) with severe blepharoptosis (obscuring the visual axis) in one or both eyes who had previously been using a non-custom MLP had a craniofacial scan with a smartphone app to generate a custom MLP frame. A magnetic adhesive was attached to the affected eyelid. The custom MLP frame held a cylindrical magnet near the eyebrow above the affected eyelid, suspending it in the magnetic field while still allowing blinking. The spectacle magnet could be rotated manually, providing adjustable force via angular translation of the magnetic field. Fitting success and comfort were recorded, and interpalpebral fissure (IPF) was measured from video frames after 20 minutes in-office and one-week at-home use. Preference was documented, custom versus non-custom. Results: Overall, 88% of patients (7/8) were successfully fitted with a median 9/10 comfort (interquartile 7-10) and median ptosis improvement of 2.3 mm (1.3-5.0); P = 0.01). Exact binomial testing suggested, with 80% power, that the true population success rate was significantly greater than 45% (P = 0.05). Five participants took the custom MLP home for one week, with only one case of mild conjunctival redness which resolved without treatment. Highest to lowest force modulation resulted in a marginally significant median IPF adjustment of 1.5 mm (0.8 to 2.7; P = 0.06). All preferred the custom frame. Conclusions: The three-dimensional custom MLP frame generation approach using a smartphone app-based craniofacial scan is a feasible approach for clinical deployment of the MLP. Translational Relevance: First demonstration of customized frame generation for the MLP.

Bone Matrix Mineralization and Response to Burosumab in Adult Patients With X-Linked Hypophosphatemia: Results From the Phase 3, Single-Arm International Trial.

X-linked hypophosphatemia (XLH) is characterized by excess fibroblast growth factor 23 (FGF23) secretion, renal phosphate wasting, and low 1,25(OH)2 D3 . Adult patients present with osteomalacia, hypomineralized periosteocytic lesions, bone fragility, and pain. Burosumab is a fully human monoclonal FGF23 antibody approved for XLH treatment. UX023-CL304 was an open-label, phase 3 study investigating the effects of burosumab on osteomalacia in adults with XLH, who remained untreated at least 2 years prior enrollment. Here, we present the effect of burosumab on bone material properties. We analyzed transiliac bone biopsy samples from 11 individuals before and after 48 weeks of subcutaneous burosumab treatment (1.0 mg/kg administered every 4 weeks). We used quantitative backscattered electron imaging (qBEI) and Fourier transform infrared imaging (FTIRI) to assess bone mineralization density distribution (BMDD), mineralized bone volume, properties of the organic matrix, and size of periosteocytic lesions. The outcomes were compared with reference values from healthy adults and with four XLH patients either untreated or treated by conventional therapy. Prior to burosumab, the average mineralization in cancellous bone was lower than in healthy reference. CaLow, the fraction of lowly mineralized matrix, and CaHigh, the fraction of highly mineralized matrix, were both elevated resulting in a broad heterogeneity in mineralization (CaWidth). Burosumab resulted in a decrease of CaHigh toward normal range, whereas CaLow and CaWidth remained elevated. The mineralized bone volume was notably increased (+35.9%). The size of the periosteocytic lesions was variable but lower than in untreated XLH patients. FTIRI indicated decreased enzymatic collagen crosslink ratio heterogeneity. In summary, matrix mineralization in XLH is very heterogeneous. Highly mineralized regions represent old bone packets, probably protected from osteoclastic resorption by osteoid seams. The concomitant decrease of highly mineralized matrix, persistence of lowly mineralized matrix, and increase in mineralized bone volume after burosumab suggest a boost in mineralization of preexisting unmineralized or very lowly mineralized matrix, providing a potential explanation for previously observed improved osteomalacia. © 2022 American Society for Bone and Mineral Research (ASBMR).

Treatment of postmenopausal osteoporosis patients with teriparatide for 24 months reverts forming bone quality indices to premenopausal healthy control values.

Postmenopausal osteoporosis (PMOP) therapies are frequently evaluated by bone mineral density (BMD) gains against patients receiving placebo (calcium and vitamin D supplementation, a mild bone turnover-suppressing intervention), which is not equivalent to either healthy or treatment-naive PMOP. The aim of the present observational study was to assess the effects of TPTD treatment in PMOP (20 µg, once daily) at 6 (TPTD 6m; n = 28, age 65 ± 7.3 years), and 24 (TPTD 24m; n = 32, age 67.4 ± 6.15 years) months on bone quality indices at actively forming trabecular surfaces (with fluorescent double labels). Data from the TPTD-treated PMOP patients were compared with those in healthy adult premenopausal women (HC; n = 62, age 40.5 ± 10.6 years), and PMOP receiving placebo (PMOP-PLC; n = 94, age 70.6 ± 4.5 years). Iliac crest biopsies were analyzed by Raman microspectroscopy at three distinct tissue ages: mid-distance between the second label and the bone surface, mid-distance between the two labels, and 1 µm behind the first label. Mineral to matrix ratio (MM), mineral maturity/crystallinity (MMC), tissue water (TW), glycosaminoglycan (GAGs), and pyridinoline (Pyd) content were determined. Outcomes were compared by ANCOVA with subject age and tissue age as covariates, and health status as a fixed factor, followed by Sidak's post-hoc testing (significance assigned to p < 0.05). Both TPTD groups increased MM compared to PMOP-PLC. While TPTD 6m had values similar to HC, TPTD 24m had higher values compared to either HC or TPTD 6m. Both TPTD groups had lower MMC values compared to PMOP-PLC and similar to HC. TPTD 6m patients had higher TW content compared to HC, while TPTD 24m had values similar to HC and lower than either PMOP-PLC or TPTD 6m. Both TPTD groups had lower GAG content compared to HC group, while TPTD 6m had higher values compared to PMOP-PLC. Finally, TPTD 6m patients had higher Pyd content compared to HC and lower compared to PMOP-PLC, while TPTD 24m had lower values compared to PMOP-PLC and TPTD 6m, and similar to HC group. The results of the present study indicate that effects of TPTD on forming trabecular bone quality indices depend on treatment duration. At the recommended length of 24 m, TPTD restores bone mineral and organic matrix quality indices (MMC, TW, Pyd content) to premenopausal healthy (HC) levels.

Circulating inflammatory monocytes oppose microglia and contribute to cone cell death in retinitis pigmentosa.

Retinitis pigmentosa (RP) is an intractable inherited disease that primarily affects the rods through gene mutations followed by secondary cone degeneration. This cone-related dysfunction can lead to impairment of daily life activities, and ultimately blindness in patients with RP. Paradoxically, microglial neuroinflammation contributes to both protection against and progression of RP, but it is unclear which population(s) - tissue-resident microglia and/or peripheral monocyte-derived macrophages (mφ) - are implicated in the progression of the disease. Here we show that circulating blood inflammatory monocytes (IMo) are key effector cells that mediate cone cell death in RP. Attenuation of IMo and peripherally engrafted mφ by Ccl2 deficiency or immune modulation via intravenous nano-particle treatment suppressed cone cell death in rd10 mice, an animal model of RP. In contrast, the depletion of resident microglia by a colony-stimulating factor 1 receptor inhibitor exacerbated cone cell death in the same model. In human patients with RP, IMo was increased and correlated with disease progression. These results suggest that peripheral IMo is a potential target to delay cone cell death and prevent blindness in RP.

A One-Step Electrochemical Aptasensor Based on Signal Amplification of Metallo Nanoenzyme Particles for Vascular Endothelial Growth Factor.

In this study, a one-step electrochemical aptasensor was developed to detect the biomarker vascular endothelial growth factor (VEGF), an important protein in the pathogenesis of many retinal diseases, including age-related macular degeneration, diabetic retinopathy, retinopathy of prematurity, and retinal vein occlusion. The aptamer has a good affinity and can rapidly identify and capture VEGF based on its unique structure. We designed a VEGF aptasensor based on the aptamer recognition and complex metallo nanoenzyme particles as an electron exchange center and bridge between capture DNA and electrode. The aptamers maintained the hairpin structure to avoid nonspecific surface adsorption and expose the capture sequence outwards when the target was inexistent. Conversely, the aptamers opened the hairpin structure to release space to accomplish binding between VEGF and DNA, resulting in increased impedance. The performance of the electrochemical aptasensor is detected by electrochemical impedance spectroscopy (EIS). The limit of detection by EIS was as low as 8.2 pg ml-1, and the linear range was 10 pg ml-1-1 µg ml-1. The electrochemical aptasensor also showed high specificity and reproducibility.