Single-cell RNA sequencing of equine mesenchymal stromal cells from primary donor-matched tissue sources reveals functional heterogeneity in immune modulation and cell motility.

BACKGROUND: The efficacy of mesenchymal stromal cell (MSC) therapy is thought to depend on the intrinsic heterogeneity of MSC cultures isolated from different tissue sources as well as individual MSCs isolated from the same tissue source, neither of which is well understood. To study this, we used MSC cultures isolated from horses. The horse is recognized as a physiologically relevant large animal model appropriate for translational MSC studies. Moreover, due to its large size the horse allows for the simultaneous collection of adequate samples from multiple tissues of the same animal, and thus, for the unique collection of donor matched MSC cultures from different sources. The latter is much more challenging in mice and humans due to body size and ethical constraints, respectively. METHODS: In the present study, we performed single-cell RNA sequencing (scRNA-seq) on primary equine MSCs that were collected from three donor-matched tissue sources; adipose tissue (AT), bone marrow (BM), and peripheral blood (PB). Based on transcriptional differences detected with scRNA-seq, we performed functional experiments to examine motility and immune regulatory function in distinct MSC populations. RESULTS: We observed both inter- and intra-source heterogeneity across the three sources of equine MSCs. Functional experiments demonstrated that transcriptional differences correspond with phenotypic variance in cellular motility and immune regulatory function. Specifically, we found that (i) differential expression of junctional adhesion molecule 2 (JAM2) between MSC cultures from the three donor-matched tissue sources translated into altered cell motility of BM-derived MSCs when RNA interference was used to knock down this gene, and (ii) differences in C-X-C motif chemokine ligand 6 (CXCL6) expression in clonal MSC lines derived from the same tissue source correlated with the chemoattractive capacity of PB-derived MSCs. CONCLUSIONS: Ultimately, these findings will enhance our understanding of MSC heterogeneity and will lead to improvements in the therapeutic potential of MSCs, accelerating the transition from bench to bedside.

Secreted sphingomyelins modulate low mammary cancer incidence observed in certain mammals.

Determining mechanisms that naturally protect species from developing cancer is critical in order to prevent and treat cancer. Here, we describe a novel cancer-suppressing mechanism, via the secretion of bioactive factors by mammary cells, that is present in domesticated mammals with a low mammary cancer incidence. Specifically, these bioactive factors induced triple-negative breast cancer cell (TNBC) death in vitro and reduced tumorigenicity in a xenograft TNBC mouse model in vivo. RNA deep sequencing showed significant downregulation of genes associated with breast cancer progression in secretome-cultured TNBC cells. Further in-depth multi-omics analysis identified sphingomyelins as key secreted factors, and their role was confirmed via inhibition of the sphingomyelin signaling pathway. We speculate that secreted sphingomyelins in the mammary gland of mammals with a naturally low incidence of mammary cancer mediate the elimination of cancer cells. This study contributes to the growing list of protective mechanisms identified in cancer-proof species.

Primary orbital extraskeletal osteosarcoma.

The authors describe a case of orbital extraskeletal osteosarcoma. A 78-year-old man with a history of rheumatoid arthritis on long-term corticosteroids had a left medial canthal basal cell carcinoma excision followed by adjuvant radiotherapy. Twelve months later, he re-presented with a large rapidly-growing calcified mass involving his left medial canthus and orbit. An incisional biopsy demonstrated an infiltrate of atypical cells exhibiting mitotic activity with a rosette arrangement around partially calcified necrotic tissue. The patient underwent orbital exenteration and a partial maxillectomy. Histopathology demonstrated an extraskeletal osteosarcoma. It is extremely rare for this tumor to occur in the orbit. Immunosuppression and adjuvant radiotherapy were possible predisposing factors in the development of this tumor. Extraskeletal osteosarcoma (ESOS) is a malignant tumour that produces osteoid. It develops in soft tissue without continuity to bone or periosteum. It is rare and comprises fewer than 5% of all osteosarcomas. Extraskeletal osteosarcoma primarily affects patients above 50 years of age and has a poor prognosis. In this report, we describe the clinical, radiologic, and pathologic records of a rare case of primary ESOS of the orbit.

Multifocal malignant optic glioma of adulthood presenting as acute anterior optic neuropathy.

We report a 63-year-old, previously healthy female patient with glioblastoma multiforme of the optic nerve and chiasm presenting as acute anterior optic neuropathy. She presented with a 3-week history of progressively increasing headaches, retrobulbar pain, rapidly progressive visual loss in the right eye and blurred vision in the left eye. Early clinical examination revealed right optic disc swelling and she was initially diagnosed with demyelinating optic neuritis. Her clinical course deteriorated with total visual loss in the right eye and progressive visual loss in the left eye despite treatment with intravenous (IV) methylprednisone and IV immunoglobulins. MRI revealed enhancement of the right optic nerve and optic chiasm, with multiple periventricular hyperintense foci. Six weeks later, the patient presented with left facial palsy and left hemiparesis. Follow-up MRI showed multiple enhancing lesions in addition to the previous lesions involving right lentiform and right thalamic nucleus, right cerebral peduncle, right temporal and parietal lobes. Although the optic nerve biopsy was inconclusive, the brain biopsy revealed glioblastoma multiforme. This report demonstrated that malignant glioma of adulthood may be multicentric and may mimic optic neuritis clinically, which might help explain the difficulties in diagnosis.

Infectious endophthalmitis: clinical features, management and visual outcomes.

AIM: To identify the clinical features and outcomes of infectious endophthalmitis in New Zealand. METHODS: A retrospective review was performed on all patients presenting at Auckland Public Hospital with presumed infectious endophthalmitis between 1996 and 2004. RESULTS: One hundred and six patients were diagnosed with infectious endophthalmitis over the 9-year study period. More than half the infections occurred in the perioperative setting (58.5%), with the next most common group being patients with a history of ocular trauma (18.9%). Endogenous endophthalmitis accounted for 16.0% of the cases while a small percentage arose from other causes. The mean interval between the onset of symptoms and presentation was 4.2 +/- 7.9 days. There was no significant difference in outcomes between clinical settings (P = 0.616) or between gram-positive, gram-negative and fungal infections (P = 0.090). Evisceration/enucleation was more likely in Pacific peoples and those with poor presenting visual acuity. CONCLUSIONS: The most common clinical scenario for patients presenting with presumed infectious endophthalmitis in this series was in the perioperative setting. We did not find that the prognosis was influenced by the microbiological isolate or clinical setting. However, those patients presenting with poor acuities typically had the worst outcomes. Pacific ethnicity was also associated with increased rate of complications.

Long-term microstructural changes following epikeratophakia: in vivo confocal microscopy study.

The unilateral epikeratophakic eye of a 20-year-old woman with a history of congenital cataracts was examined using laser scanning in vivo confocal microscopy 17 years after transplantation. In vivo confocal microscopy demonstrated a reduced keratocyte density in the grafted lenticule and the host stroma, with unusual elongated and tortuous hyperreflective branching structures in the anterior stroma of the host cornea. The sub-basal nerve plexus was present in the lenticule, although with a reduced nerve density. The appearance of the host endothelium was similar to that observed in Fuchs endothelial dystrophy. Dramatic microstructural changes were observed in almost all layers of the cornea 17 years after epikeratophakia. Although no longer performed as routine practice, in vivo confocal microscopy examination of epikeratophakia has provided fascinating insight into the potential corneal adaptations at a cellular level.

Citation analysis of the most influential authors and ophthalmology journals in the field of cataract and corneal refractive surgery 2000-2004.

PURPOSE: To identify the most published authors on the topics of 'cataract' and 'LASIK', the journals in which they publish, and the citation patterns of the most-cited articles by these authors over a 5-year publication period. METHODS: Science Citation Index Expanded (SCI) was used to identify the 30 most-published authors in 'cataract' and 'laser in situ keratomileusis' (LASIK) (2000-2004 inclusive). SCI was subsequently used to analyse the recorded articles for each author in terms of source journal, the most commonly cited articles and citation source. RESULTS: Of the 30 most-published authors in the fields of cataract and LASIK, the USA was the most well-represented source country, accounting for 33%; 20% were from Australia, and 17% from Austria. Germany and Japan each contributed 7%. Eighty per cent of the publications produced by these 30 authors (2000-2004) were in 10 journals, of which the Journal of Cataract and Refractive Surgery (JCRS) published more than one-third. Of the three most-cited articles for each author, the greatest number were published in JCRS (35.6%). The citation count of the articles had a weak correlation to the journal impact factor of the source journal; however, the self-citation rate of these articles did not. CONCLUSIONS: The USA and Australia together were the source of more than half of the most-published authors on cataract and LASIK and the majority of articles published by the 30 most prolific authors were published in only 10 journals. The impact factors of the publication journals preferred by these authors are influenced by the article citation counts, not vice versa.

Teaching of ophthalmology in undergraduate curricula: a survey of Australasian and Asian medical schools.

BACKGROUND: Despite established international guidelines on preferred teaching components for ophthalmology in undergraduate curricula, with increasingly less specialty-based undergraduate teaching within curricula, teaching of core ophthalmology knowledge and skills may become marginalized. This survey aims to evaluate the current state of undergraduate ophthalmology teaching in Australasia and proximate Asian medical schools. METHODS: A questionnaire was developed to determine the content and extent of ophthalmology teaching in the undergraduate medical curriculum. The questionnaire was sent to 25 medical schools throughout Australasia and Asia. RESULTS: Nineteen of the 25 questionnaires were returned (76% response rate). Ophthalmology teaching programmes ranged from 2 to 20 days: five (26%) medical schools having one ophthalmology attachment; six schools (32%) two attachments; and the remainder three or more. Only seven of the schools taught all 13 ophthalmology topics recommended in current curriculum guidelines. Ocular examination (100%), lens and cataract (95%) and ocular manifestations of systemic disease (95%) were the most commonly taught topics, with intraocular tumours only covered by 10 schools (53%). Students in 14 schools (74%) attended ophthalmology operating theatre, but only two schools (11%) offered attendance at optometry clinics. Ten schools (53%) required a pass in ophthalmology to complete the academic year. CONCLUSION: Ophthalmology may increasingly be a small, or even absent, component of undergraduate medical curricula. Despite established international ophthalmology curriculum guidelines, this survey highlights significant lack of uniformity in their implementation.