Brain-derived neurotrophic factor released from blood platelets prevents dendritic atrophy of lesioned adult central nervous system neurons

In humans and other primates, blood platelets contain high concentrations of brain-derived neurotrophic factor due to the expression of the BDNF gene in megakaryocytes. By contrast, mice, typically used to investigate the impact of CNS lesions, have no demonstrable levels of brain-derived neurotrophic factor in platelets, and their megakaryocytes do not transcribe significant levels of the Bdnf gene. Here, we explore potential contributions of platelet brain-derived neurotrophic factor with two well-established CNS lesion models, using ‘humanized’ mice engineered to express the Bdnf gene under the control of a megakaryocyte-specific promoter. Retinal explants prepared from mice containing brain-derived neurotrophic factor in platelets were labelled using DiOlistics and the dendritic integrity of retinal ganglion cells assessed after 3 days by Sholl analysis. The results were compared with retinas of wild-type animals and with wild-type explants supplemented with saturating concentrations of brain-derived neurotrophic factor or the tropomyosin kinase B antibody agonist, ZEB85. An optic nerve crush was also performed, and the dendrites of retinal ganglion cells similarly assessed 7-day post-injury, comparing the results of mice containing brain-derived neurotrophic factor in platelets with wild-type animals. In mice engineered to contain brain-derived neurotrophic factor in platelets, the mean serum brain-derived neurotrophic factor levels were 25.74 ± 11.36 ng/mL for homozygous and 17.02 ± 6.44 ng/mL for heterozygous mice, close to those determined in primates. Retinal explants from these animals showed robust preservation of dendrite complexity, similar to that seen with wild-type explants incubated with medium supplemented with brain-derived neurotrophic factor or the tropomyosin receptor kinase B antibody agonist, ZEB85. The Sholl areas under curve were 1811 ± 258, 1776 ± 435 and 1763 ± 256 versus 1406 ± 315 in the wild-type control group (P ≤ 0.001). Retinal ganglion cell survival based on cell counts was similar in all four groups, showing ∼15% loss. A robust neuroprotective effect was also observed following optic nerve crush when assessing the dendrites of the retinal ganglion cells in the transgenic mouse, with Sholl area under the curve significantly higher compared to wild-type (2667 ± 690 and 1921 ± 392, P = 0.026), with no significant difference in the contralateral eye controls. Repeat experiments found no difference in cell survival, with both showing ∼50% loss. These results indicate that platelet brain-derived neurotrophic factor has a strong neuroprotective effect on the dendrite complexity of retinal ganglion cells in both an ex vivo and in vivo model, suggesting that platelet brain-derived neurotrophic factor is likely to be a significant neuroprotective factor in primates

Novel monoclonal antibodies against mouse C1q: characterisation and development of a quantitative ELISA for mouse C1q

Recent studies have identified roles for complement in synaptic pruning, both physiological during development and pathological in Alzheimer’s disease (AD). These reports suggest that C1q initiates complement activation on synapses and C3 fragments then tag them for removal by microglia. There is an urgent need to characterise these processes in rodent AD models; this requires the development of reagents and methods for detection and quantification of rodent C1q in fluids and pathological tissues. These will enable better evaluation of the role of C1q in disease and its value as disease biomarker. We describe the generation in C1q-deficient mice of novel monoclonal antibodies against mouse and rat C1q that enabled development of a sensitive, specific, and quantitative ELISA for mouse and rat C1q capable of measuring C1q in biological fluids and tissue extracts. Serum C1q levels were measured in wild-type (WT), C1q knockout (KO), C3 KO, C7 KO, Crry KO, and 3xTg and APPNL-G-F AD model mice through ageing. C1q levels significantly decreased in WT, APPNL-G-F, and C7 KO mice with ageing. C1q levels were reduced in APPNL-G-F compared to WT at all ages and in 3xTg at 12 months; C3 KO and C7 KO, but not Crry KO mice, also demonstrated significantly lower C1q levels compared to matched WT. In brain homogenates, C1q levels increased with age in both WT and APPNL-G-F mice. This robust and adaptable assay for quantification of mouse and rat C1q provides a vital tool for investigating the expression of C1q in rodent models of AD and other complement-driven pathologies

Nicotinamide provides neuroprotection in glaucoma by protecting against mitochondrial and metabolic dysfunction.

Nicotinamide adenine dinucleotide (NAD) is a REDOX cofactor and metabolite essential for neuronal survival. Glaucoma is a common neurodegenerative disease in which neuronal levels of NAD decline. We assess the effects of nicotinamide (a precursor to NAD) on retinal ganglion cells (the affected neuron in glaucoma) in normal physiological conditions and across a range of glaucoma relevant insults including mitochondrial stress and axon degenerative insults. We demonstrate retinal ganglion cell somal, axonal, and dendritic neuroprotection by nicotinamide in rodent models which represent isolated ocular hypertensive, axon degenerative, and mitochondrial degenerative insults. We performed metabolomics enriched for small molecular weight metabolites for the retina, optic nerve, and superior colliculus which demonstrates that ocular hypertension induces widespread metabolic disruption, including consistent changes to α-ketoglutaric acid, creatine/creatinine, homocysteine, and glycerophosphocholine. This metabolic disruption is prevented by nicotinamide. Nicotinamide provides further neuroprotective effects by increasing oxidative phosphorylation, buffering and preventing metabolic stress, and increasing mitochondrial size and motility whilst simultaneously dampening action potential firing frequency. These data support continued determination of the utility of long-term nicotinamide treatment as a neuroprotective therapy for human glaucoma

The role of innate immune activation in experimental glaucoma

Glaucoma is the leading cause of irreversible blindness worldwide. It is characterised by progressive degeneration and loss of retinal ganglion cells (RGCs) and their axons. Increasing amount of evidence indicates that neuroinflammation plays a role in glaucoma and other neurodegenerative diseases, however, its contribution in disease pathophysiology is not clear. Targeting components of the immune system, particularly the complement system, has been proposed as a potential treatment strategy for glaucoma. This thesis investigates the effect of systemic innate immune activation on RGC degeneration, in a rat experimental glaucoma model. Ocular hypertension (OHT) is one of the main risk factors for glaucoma, so this thesis uses a model of induced OHT to mimic glaucoma, and systemic lipopolysaccharide (LPS) administration to induce innate immune activation. Morphological analysis of RGC dendrites and functional assessment of the retina, showed that OHT induced dendritic atrophy and functional deficits in the retina. However, innate immune activation did not further exacerbate RGC degeneration in this model and was associated with protection of RGC dendrites, while intravitreal inhibition of the classical pathway of the complement system did not have a significant effect on the progress of RGC degeneration. In addition, microglial activation was observed in OHT eyes and interestingly in contralateral normotensive (NT) eyes. Overall, this thesis demonstrates the need for further research to understand the multifaceted role of immune activation in glaucoma and other neurodegenerative diseases. It also warrants for caution in the use of NT contralateral eyes as controls in ophthalmic research

Crohn’s Disease of the Vulva: a Case Report

Crohn’s disease is a multi-systemic chronic inflammatory disease that can affect various organs besides the gastrointestinal tract such as joints, uvea, and the skin. Vulvar Crohn’s disease is a rare entity occurring with vulvar lesions that show typical Crohn’s disease granulomatous inflammation but are not contiguous with the gastrointestinal involvement. Vulvar Crohn’s disease can be easily confused with other granulomatous diseases and awareness that such involvement may precede gastrointestinal symptoms must be raised. Few cases of vulvar Crohn’s disease have been reported in the literature to date. Here, we report a case of a 43-year-old woman with a 6-month history of a vulvar lesion; the patient was diagnosed with Crohn’s disease of the large bowel just over a year ago

Uterine angiolipoleiomyoma. A case report and systematic literature review

Uterine angiolipoleiomyomas are rare, benign mixed mesenchymal lesions. A manifestation in the gynecological region is quite uncommon, with few cases described in the literature so far. We present an interesting case of a 59-year-old woman diagnosed with uterine angiolipoleiomyoma, and the results of the conducted systematic review of the literature. The patient presented with a pelvic mass masquerading as a leiomyoma on the ultrasound and postmenopausal vaginal bleeding. At laparotomy, a large uterus was noticed and the histopathology set the diagnosis of angiolipoleiomyoma. Immunohistochemistry revealed negativity for Melan-A and HMB-45 melanoma-specific antibodies and positivity for Van Gieson and orcein histochemical stains. We systematically reviewed the literature. The eligible articles were those written in English, excluding animal studies and studies reporting angiolipoleiomyomas in other regions beside the uterus. The present case is one of the 10 cases of uterine angiolipoleiomyoma reported in the literature. In 8 out of 11 (72.7%) cases, uterine angiolipoleiomyomas arose from the corpus of the uterus, while in 2 (18.1%) cases they were located at the cervix, and in one case (9%) angiolipoleiomyoma was located in the broad ligament. Concerning symptoms, four of the patients (36.4%) presented with abdominal and pelvic pain, two (18.1%) with postmenopausal vaginal bleeding, one with menometrorrhagia (9%), and one with uterine prolapse and cystocele (9%). Immunohistochemical staining of uterine angiolipoleiomyomas was positive for SMA in 4 patients (36.4%), positive for desmin in 3 cases (27.3%), positive for anti-S-100 protein antibody in 2 patients (18.1%), while in one case (9%) immunopositivity was observed for CD31. Only our case (9%) was also tested for CD34, Van Gieson and orcein, the first of these being negative and the other two positive (at the blood vessels in a specialized pattern). Three of the patients (27.3%) were also tested for HMB-45 and all three were immunonegative. In order to establish the diagnosis of uterine angiolipoleiomyomas, ultrasonography and additional MRI may help the preoperative prediction of a benign mass. Immunohistochemistry will show strong positivity of alpha-smooth muscle actin and desmin. Complete abdominal hysterectomy is the preferable treatment

Uterine angiolipoleiomyoma. A case report and systematic literature review

Uterine angiolipoleiomyomas are rare, benign mixed mesenchymal lesions. A manifestation in the gynecological region is quite uncommon, with few cases described in the literature so far. We present an interesting case of a 59-year-old woman diagnosed with uterine angiolipoleiomyoma, and the results of the conducted systematic review of the literature. The patient presented with a pelvic mass masquerading as a leiomyoma on the ultrasound and postmenopausal vaginal bleeding. At laparotomy, a large uterus was noticed and the histopathology set the diagnosis of angiolipoleiomyoma. Immunohistochemistry revealed negativity for Melan-A and HMB-45 melanoma-specific antibodies and positivity for Van Gieson and orcein histochemical stains. We systematically reviewed the literature. The eligible articles were those written in English, excluding animal studies and studies reporting angiolipoleiomyomas in other regions beside the uterus. The present case is one of the 10 cases of uterine angiolipoleiomyoma reported in the literature. In 8 out of 11 (72.7%) cases, uterine angiolipoleiomyomas arose from the corpus of the uterus, while in 2 (18.1%) cases they were located at the cervix, and in one case (9%) angiolipoleiomyoma was located in the broad ligament. Concerning symptoms, four of the patients (36.4%) presented with abdominal and pelvic pain, two (18.1%) with postmenopausal vaginal bleeding, one with menometrorrhagia (9%), and one with uterine prolapse and cystocele (9%). Immunohistochemical staining of uterine angiolipoleiomyomas was positive for SMA in 4 patients (36.4%), positive for desmin in 3 cases (27.3%), positive for anti-S-100 protein antibody in 2 patients (18.1%), while in one case (9%) immunopositivity was observed for CD31. Only our case (9%) was also tested for CD34, Van Gieson and orcein, the first of these being negative and the other two positive (at the blood vessels in a specialized pattern). Three of the patients (27.3%) were also tested for HMB-45 and all three were immunonegative. In order to establish the diagnosis of uterine angiolipoleiomyomas, ultrasonography and additional MRI may help the preoperative prediction of a benign mass. Immunohistochemistry will show strong positivity of alpha-smooth muscle actin and desmin. Complete abdominal hysterectomy is the preferable treatment