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Background: BCL6 co-repressor ( BCOR ) gene variants are involved in oculofaciocardiodental (OFCD) syndrome, acute myeloid leukaemia, renal tumours, and photoreceptor degenerative diseases. Here, we describe a British family with a pathogenic heterozygous variant in the BCOR gene causing congenital nuclear cataract., Methods: Whole-exome sequencing was conducted on an individual affected by X-linked dominant congenital cataract in a three-generation family to establish the underlying genetic basis. Bioinformatics analysis confirmed the variants with damaging pathogenicity scores., Results: A novel likely pathogenic frameshift variant BCOR NM_001123385.1: c.3621del; p.Lys1207AsnfsTer31, was identified and found to co-segregate with the disease in this family., Conclusions: This is apparently the first report of a variant in BCOR causing X-linked dominant congenital cataract which is potentially isolated or presenting with a remarkably mild systemic phenotype. Our findings extend the genetic basis for congenital cataract and add to the phenotypic spectrum of BCOR variants.

Eukaryotic cells tether the nucleoskeleton to the cytoskeleton via a conserved molecular bridge, called the LINC complex. The core of the LINC complex comprises SUN-domain and KASH-domain proteins that directly associate within the nuclear envelope lumen. Intra- and inter-chain disulphide bonds, along with KASH-domain protein interactions, both contribute to the tertiary and quaternary structure of vertebrate SUN-domain proteins. The significance of these bonds and the role of PDIs (protein disulphide isomerases) in LINC complex biology remains unclear. Reducing and non-reducing SDS-PAGE analyses revealed a prevalence of SUN2 homodimers in non-tumorigenic breast epithelia MCF10A cells, but not in the invasive triple-negative breast cancer MDA-MB-231 cell line. Furthermore, super-resolution microscopy revealed SUN2 staining alterations in MCF10A, but not in MDA-MB-231 nuclei, upon reducing agent exposure. While PDIA1 levels were similar in both cell lines, pharmacological inhibition of PDI activity in MDA-MB-231 cells led to SUN-domain protein down-regulation, as well as Nesprin-2 displacement from the nucleus. This inhibition also caused changes in perinuclear cytoskeletal architecture and lamin downregulation, and increased the invasiveness of PDI-inhibited MDA-MB-231 cells in space-restrictive in vitro environments, compared to untreated cells. These results emphasise the key roles of PDIs in regulating LINC complex biology, cellular architecture, biomechanics, and invasion.

(1) Background: The evidence base for the management of spontaneous viral controllers in pregnancy is lacking. We describe the management outcomes of pregnancies in a series of UK women with spontaneous HIV viral control (<100 copies/mL 2 occasions before or after pregnancy off ART). (2) Methods: A multi-centre, retrospective case series (1999-2021) comparing pre- and post-2012 when guidelines departed from zidovudine-monotherapy (ZDVm) as a first-line option. Demographic, virologic, obstetric and neonatal information were anonymised, collated and analysed in SPSS. (3) Results: A total of 49 live births were recorded in 29 women, 35 pre-2012 and 14 post. HIV infection was more commonly diagnosed in first reported pregnancy pre-2012 (15/35) compared to post (2/14), p = 0.10. Pre-2012 pregnancies were predominantly managed with ZDVm (28/35) with pre-labour caesarean section (PLCS) (24/35). Post-2012 4/14 received ZDVm and 10/14 triple ART, p = 0.002. Post-2012 mode of delivery was varied (5 vaginal, 6 PLCS and 3 emergency CS). No intrapartum ZDV infusions were given post-2012 compared to 11/35 deliveries pre-2012. During pregnancy, HIV was detected (> 50 copies/mL) in 14/49 pregnancies (29%) (median 92, range 51-6084). Neonatal ZDV post-exposure prophylaxis was recorded for 45/49 infants. No transmissions were reported. (4) Conclusion: UK practice has been influenced by the change in guidelines, but this has had little impact on CS rates.

Intermediate filaments are critical for cell and tissue homeostasis and for stress responses. Cytoplasmic intermediate filaments form versatile and dynamic assemblies that interconnect cellular organelles, participate in signaling and protect cells and tissues against stress. Here we have focused on their involvement in redox signaling and oxidative stress, which arises in numerous pathophysiological situations. We pay special attention to type III intermediate filaments, mainly vimentin, because it provides a physical interface for redox signaling, stress responses and mechanosensing. Vimentin possesses a single cysteine residue that is a target for multiple oxidants and electrophiles. This conserved residue fine tunes vimentin assembly, response to oxidative stress and crosstalk with other cellular structures. Here we integrate evidence from the intermediate filament and redox biology fields to propose intermediate filaments as redox sentinel networks of the cell. To support this, we appraise how vimentin detects and orchestrates cellular responses to oxidative and electrophilic stress., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

The tardigrade Ramazzottius varieornatus has remarkable resilience to a range of environmental stresses. In this study, we have characterised two members of the small heat shock protein (sHSP) family in R. varieornatus, HSP20-3 and HSP20-6. These are the most highly upregulated sHSPs in response to a 24 h heat shock at 35 0 C of adult tardigrades with HSP20-3 being one of the most highly upregulated gene in the whole transcriptome. Both R. varieornatus sHSPs and the human sHSP, CRYAB (HSPB5), were produced recombinantly for comparative structure-function studies. HSP20-3 exhibited a superior chaperone activity than human CRYAB in a heat-induced protein aggregation assay. Both tardigrade sHSPs also formed larger oligomers than CRYAB as assessed by size exclusion chromatography and transmission electron microscopy of negatively stained samples. Whilst both HSP20-3 and HSP20-6 formed particles that were variable in size and larger than the particles formed by CRYAB, only HSP20-3 formed filament-like structures. The particles and filament-like structures formed by HSP20-3 appear inter-related as the filament-like structures often had particles located at their ends. Sequence analyses identified two unique features; an insertion in the middle region of the N-terminal domain (NTD) and preceding the critical-sequence identified in CRYAB, as well as a repeated QNTN-motif located in the C-terminal domain of HSP20-3. The NTD insertion is expected to affect protein-protein interactions and subunit oligomerisation. Removal of the repeated QNTN-motif abolished HSP20-3 chaperone activity and also affected the assembly of the filament-like structures. We discuss the potential contribution of HSP20-3 to protein condensate formation., Competing Interests: Declaration of Competing interest No competing interests., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)

Recent studies apparently finding deleterious effects of radiation exposure on cataract formation in birds and voles living near Chernobyl represent a major challenge to current radiation protection regulations. This study conducted an integrated assessment of radiation exposure on cataractogenesis using the most advanced technologies available to assess the cataract status of lenses extracted from fish caught at both Chernobyl in Ukraine and Fukushima in Japan. It was hypothesised that these novel data would reveal positive correlations between radiation dose and early indicators of cataract formation. The structure, function and optical properties of lenses were analysed from atomic to millimetre length scales. We measured the short-range order of the lens crystallin proteins using Small Angle X-Ray Scattering (SAXS) at both the SPring-8 and DIAMOND synchrotrons, the profile of the graded refractive index generated by these proteins, the epithelial cell density and organisation and finally the focal length of each lens. The results showed no evidence of a difference between the focal length, the epithelial cell densities, the refractive indices, the interference functions and the short-range order of crystallin proteins (X-ray diffraction patterns) in lens from fish exposed to different radiation doses. It could be argued that animals in the natural environment which developed cataract would be more likely, for example, to suffer predation leading to survivor bias. But the cross-length scale study presented here, by evaluating small scale molecular and cellular changes in the lens (pre-cataract formation) significantly mitigates against this issue., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Jim T. Smith reports financial support was provided by Natural Environment Research Council. Adelaide Lerebours reports financial support was provided by Natural Environment Research Council. Jim T. Smith reports financial support was provided by Science and Technology Funding Council. Adelaide Lerebours reports financial support was provided by Science and Technology Funding Council. Roy Quinlan reports financial support was provided by EU Framework Programme for Research and Innovation Euratom. Alexia Kalligeraki reports financial support was provided by National Eye Research Foundation. Roy Quinlan reports financial support was provided by Fight for Sight. Roy Quinlan reports was provided by Leverhulme Trust. John Girkin, Laura Young reports financial support was provided by Engineering and Physical Sciences Research Council. Jim T. Smith reports a relationship with The Chernobyl Spirit Community Interest Company that includes: board membership and equity or stocks., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: A five generation family has been analysed by whole exome sequencing (WES) for genetic associations with the multimorbidities of congenital cataract (CC), retinitis pigmentosa (RP) and Crohn's disease (CD)., Methods: WES was performed for unaffected and affected individuals within the family pedigree followed by bioinformatic analyses of these data to identify disease-causing variants with damaging pathogenicity scores., Results: A novel pathogenic missense variant in WFS1 : c.1897G>C; p.V633L, a novel pathogenic nonsense variant in RP1 : c.6344T>G; p.L2115* and a predicted pathogenic missense variant in NOD 2: c.2104C>T; p.R702W are reported. The three variants cosegregated with the phenotypic combinations of autosomal dominant CC, RP and CD within individual family members., Conclusions: Here, we report multimorbidity in a family pedigree listed on a CC register, which broadens the spectrum of potential cataract associated genes to include both RP1 and NOD2 ., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY. Published by BMJ.)

Background: BFSP1 (beaded filament structural protein 1) is a plasma membrane, Aquaporin 0 (AQP0/MIP)-associated intermediate filament protein expressed in the eye lens. BFSP1 is myristoylated, a post-translation modification that requires caspase cleavage at D433. Bioinformatic analyses suggested that the sequences 434-452 were α-helical and amphipathic., Methods and Results: By CD spectroscopy, we show that the addition of trifluoroethanol induced a switch from an intrinsically disordered to a more α-helical conformation for the residues 434-467. Recombinantly produced BFSP1 fragments containing this amphipathic helix bind to lens lipid bilayers as determined by surface plasmon resonance (SPR). Lastly, we demonstrate by transient transfection of non-lens MCF7 cells that these same BFSP1 C-terminal sequences localise to plasma membranes and to cytoplasmic vesicles. These can be co-labelled with the vital dye, lysotracker, but other cell compartments, such as the nuclear and mitochondrial membranes, were negative. The N-terminal myristoylation of the amphipathic helix appeared not to change either the lipid affinity or membrane localisation of the BFSP1 polypeptides or fragments we assessed by SPR and transient transfection, but it did appear to enhance its helical content., Conclusions: These data support the conclusion that C-terminal sequences of human BFSP1 distal to the caspase site at G433 have independent membrane binding properties via an adjacent amphipathic helix.

Ionising radiation (IR) is a cause of lipid peroxidation, and epidemiological data have revealed a correlation between exposure to IR and the development of eye lens cataracts. Cataracts remain the leading cause of blindness around the world. The plasma membranes of lens fibre cells are one of the most cholesterolrich membranes in the human body, forming lipid rafts and contributing to the biophysical properties of lens fibre plasma membrane. Liquid chromatography followed by mass spectrometry was used to analyse bovine eye lens lipid membrane fractions after exposure to 5 and 50 Gy and eye lenses taken from wholebody 2 Gy-irradiated mice. Although cholesterol levels do not change significantly, IR dose-dependant formation of the oxysterols 7β-hydroxycholesterol, 7-ketocholesterol and 5, 6-epoxycholesterol in bovine lens nucleus membrane extracts was observed. Whole-body X-ray exposure (2 Gy) of 12-week old mice resulted in an increase in 7β-hydroxycholesterol and 7-ketocholesterol in their eye lenses. Their increase regressed over 24 h in the living lens cortex after IR exposure. This study also demonstrated that the IR-induced fold increase in oxysterols was greater in the mouse lens cortex than the nucleus. Further work is required to elucidate the mechanistic link(s) between oxysterols and IR-induced cataract, but these data evidence for the first time that IR exposure of mice results in oxysterol formation in their eye lenses., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2022 The Authors. Published by Elsevier B.V.)

In the human eye, a transparent cornea and lens combine to form the "refracton" to focus images on the retina. This requires the refracton to have a high refractive index "n," mediated largely by extracellular collagen fibrils in the corneal stroma and the highly concentrated crystallin proteins in the cytoplasm of the lens fiber cells. Transparency is a result of short-range order in the spatial arrangement of corneal collagen fibrils and lens crystallins, generated in part by post-translational modifications (PTMs). However, while corneal collagen is remodeled continuously and replaced, lens crystallins are very long-lived and are not replaced and so accumulate PTMs over a lifetime. Eventually, a tipping point is reached when protein aggregation results in increased light scatter, inevitably leading to the iconic protein condensation-based disease, age-related cataract (ARC). Cataracts account for 50% of vision impairment worldwide, affecting far more people than other well-known protein aggregation-based diseases. However, because accumulation of crystallin PTMs begins before birth and long before ARC presents, we postulate that the lens protein PTMs contribute to a "cataractogenic load" that not only increases with age but also has protective effects on optical function by stabilizing lens crystallins until a tipping point is reached. In this review, we highlight decades of experimental findings that support the potential for PTMs to be protective during normal development. We hypothesize that ARC is preventable by protecting the biochemical and biophysical properties of lens proteins needed to maintain transparency, refraction, and optical function., Competing Interests: Conflict of interest The authors declare that they have no conflicts of interest with the contents of this article., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Genetically determined cataract is both clinically and molecularly highly heterogeneous. Here, we have identified a heterozygous variant in the lens integral membrane protein LIM2, the second most abundant protein in the lens, responsible for congenital sutural/lamellar cataract in a three-generation Japanese family., Methods: Whole exome sequencing (WES) was undertaken in one affected and one unaffected individual from a family with autosomal dominant congenital cataract to establish the underlying genetic basis., Results: A recurrent missense variant LIM2: c.388C>T; p.R130C was identified and found to co-segregate with disease. In addition, one variant COL11A1:c.3788C>T of unknown significance (VUS) was also identified., Conclusions: We report a variant in LIM2 causing an isolated autosomal-dominant congenital sutural/lamellar cataract in a Japanese family. This is the first report of a LIM2 variant in the Japanese population. Hence, we expand the mutation spectrum of LIM2 variants in different ethnic groups.

Background: Lens development is orchestrated by transcription factors. Disease-causing variants in transcription factors and their developmental target genes are associated with congenital cataracts and other eye anomalies., Methods: Using whole exome sequencing, we identified disease-causing variants in two large British families and one isolated case with autosomal dominant congenital cataract. Bioinformatics analysis confirmed these disease-causing mutations as rare or novel variants, with a moderate to damaging pathogenicity score, with testing for segregation within the families using direct Sanger sequencing., Results: Family A had a missense variant (c.184 G>A; p.V62M) in PAX6 and affected individuals presented with nuclear cataract. Family B had a frameshift variant (c.470-477dup; p.A160R*) in PITX3 that was also associated with nuclear cataract. A recurrent missense variant in HSF4 (c.341 T>C; p.L114P) was associated with congenital cataract in a single isolated case., Conclusions: We have therefore identified novel variants in PAX6 and PITX3 that cause autosomal dominant congenital cataract., (© 2021. Crown.)

Background: Congenital cataracts are the most common cause of visual impairment worldwide. Inherited cataract is a clinically and genetically heterogeneous disease. Here we report disease-causing variants in a novel gene, CYP21A2 , causing autosomal dominant posterior polar cataract. Variants in this gene are known to cause autosomal recessive congenital adrenal hyperplasia (CAH)., Methods: Using whole-exome sequencing (WES), we have identified disease-causing sequence variants in two families of British and Irish origin, and in two isolated cases of Asian-Indian and British origin. Bioinformatics analysis confirmed these variants as rare with damaging pathogenicity scores. Segregation was tested within the families using direct Sanger sequencing., Results: A nonsense variant NM&#95;000500.9 c.955 C > T; p.Q319* was identified in CYP21A2 in two families with posterior polar cataract and in an isolated case with unspecified congenital cataract phenotype. This is the same variant previously linked to CAH and identified as Q318* in the literature. We have also identified a rare missense variant NM&#95;000500.9 c.770 T > C; p.M257T in an isolated case with unspecified congenital cataract phenotype., Conclusion: This is the first report of separate sequence variants in CYP21A2 associated with congenital cataract. Our findings extend the genetic basis for congenital cataract and add to the phenotypic spectrum of CYP21A2 variants and particularly the CAH associated Q318* variant. CYP21A2 has a significant role in mineralo- and gluco-corticoid biosynthesis. These findings suggest that CYP21A2 may be important for extra-adrenal biosynthesis of aldosterone and cortisol in the eye lens.

Lens epithelial cell proliferation and differentiation are naturally well regulated and controlled, a characteristic essential for lens structure, symmetry and function. The effect of ionizing radiation on lens epithelial cell proliferation has been demonstrated in previous studies at high acute doses, but the effect of dose and dose rate on proliferation has not yet been considered. In this work, mice received single acute doses of 0.5, 1 and 2 Gy of radiation, at dose rates of 0.063 and 0.3 Gy/min. Eye lenses were isolated postirradiation at 30 min up until 14 days and flat-mounted. Then, cell proliferation rates were determined using biomarker Ki67. As expected, radiation increased cell proliferation 2 and 24 h postirradiation transiently (undetectable 14 days postirradiation) and was dose dependent (changes were very significant at 2 Gy; P = 0.008). A dose-rate effect did not reach significance in this study (P = 0.054). However, dose rate and lens epithelial cell region showed significant interactions (P < 0.001). These observations further our mechanistic understanding of how the lens responds to radiation., (©2022 by Radiation Research Society. All rights of reproduction in any form reserved.)

Recent epidemiological and experimental animal data, as well as reanalyses of data previously accumulated, indicate that the lens of the eye is more radiosensitive than was previously thought. This has resulted in a reduction of the occupational lens dose limit within the European Union countries, Japan and elsewhere. This Commentary introduces the work done by the LDLensRad Consortium contained within this Focus Issue, towards advancement of understanding of the mechanisms of low dose radiation cataract., (©2022 by Radiation Research Society. All rights of reproduction in any form reserved.)

Human lens regeneration and the Bag-in-the-Lens (BIL) surgical treatment for cataract both depend upon lens capsule closure for their success. Our studies suggest that the first three days after surgery are critical to their long-term outcomes. Using a rat model of lens regeneration, we evidenced lens epithelial cell (LEC) proliferation increased some 50 fold in the first day before rapidly declining to rates observed in the germinative zone of the contra-lateral, un-operated lens. Cell multi-layering at the lens equator occurred on days 1 and 2, but then reorganised into two discrete layers by day 3. E- and N-cadherin expression preceded cell polarity being re-established during the first week. Aquaporin 0 (AQP0) was first detected in the elongated cells at the lens equator at day 7. Cells at the capsulotomy site, however, behaved very differently expressing the epithelial mesenchymal transition (EMT) markers fibronectin and alpha-smooth muscle actin (SMA) from day 3 onwards. The physical interaction between the apical surfaces of the anterior and posterior LECs from day 3 after surgery preceded cell elongation. In the human BIL sample fibre cell formation was confirmed by both histological and proteome analyses, but the cellular response is less ordered and variable culminating in Soemmerring's ring (SR) formation and sometimes Elschnig's pearls. This we evidence for lenses from a single patient. No bow region or recognisable epithelial-fibre cell interface (EFI) was evident and consequently the fibre cells were disorganised. We conclude that lens cells require spatial and cellular cues to initiate, sustain and produce an optically functional tissue in addition to capsule integrity and the EFI., (Copyright © 2021. Published by Elsevier Ltd.)

Background: Pregnant women living with HIV infection (PWLWH) have elevated rates of preterm birth (PTB) in which HIV and cART are implicated. PWLWH also have a high prevalence of adverse vaginal microbiota, which associate with genital tract inflammation. The mechanism underlying PTB in PWLWH is unknown. We present the first data in PWLWH on genital-tract matrix-metalloproteinase-9(MMP-9), an important collagenase implicated in labour onset, and tissue inhibitor of metalloproteinases-1(TIMP-1) and explore correlations with local inflammation and vaginal bacteria., Material and Methods: Cervical vaginal fluid (CVF) collected by a soft cup and high vaginal swabs (HVS) were obtained from PWLWH and HIV uninfected pregnant women (HUPW) at three antenatal time points. Maternal characteristics, combination antiretroviral therapy (cART) exposure, and pregnancy outcome were recorded. Concentrations of MMP-9, TIMP-1 and ten cytokines were measured by immunoassays. Vaginal microbiota composition was determined through 16S rRNA amplicon sequencing. MMP-9, TIMP-1 and cytokine concentrations were compared by HIV status, cART, and prematurity and in PWLWH correlations with polymorphonuclear leucocytes, cytokines and bacterial genera were explored., Results: CVF was available for 50 PWLWH (108 samples) and 12 HUPW (20 samples) between gestation weeks 14-38. Thirty-six PWLWH conceived on cART and 14 initiated post-conception. There were five and one PTB outcomes in PWLWH and HUPW respectively. PWLWH had higher mean CVF concentrations of MMP-9 (p<0.001) and TIMP-1 (p=0.035) in the second trimester compared with HUPW with a similar trend in the third trimester. PWLWH also had higher CVF values of cytokines: IL-1β, IL-8, IL-12 and TNF-α in both trimesters compared to HUPW (p ≤ 0.003). In PWLWH, MMP-9 positively correlated with TIMP-1 (r=0.31, p=0.002) and CVF polymorphonuclear leucocytes (r=0.57, p=0.02). Correlations were observed between MMP-9 and three cytokines: IL-1β (r=0.61), IL-8 (r=0.57) and TNF-α (r=0.64), p<0.001, similarly for TIMP-1. Abundance of anaerobic pathobionts correlated with MMP-9: Gardnerella (r=0.44, p<0.001), Atopobium (r=0.33, p=0.005), and Prevotella genera (r=0.39, p<0.001). Conversely proportion of Lactobacillus genera negatively correlated with MMP-9 (rho=-0.46, p<0.001). MMP-9/TIMP-1 ratio increased with gestational age at sampling in PWLWH, but this was no longer significant after adjusting for confounders and no difference by prematurity was observed in this sub-study., Conclusions: Here we show strong correlations of MMP-9 to genital tract inflammation and sub-optimal bacterial genera in PWLWH indicating the ascending genital tract infection pathway may be a contributory mechanism to the high risk of PTB., Competing Interests: PB reports personal fees and shares and stock ownership in ObsEva Pharmaceuticals, personal fees from GlaxoSmithKline that are both outside the submitted work. PB and DM have a patent for microRNA markers to predict cervical shortening and preterm birth issued again outside of the submitted work. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Short, Quinlan, Wang, Preda, Smith, Marchesi, Lee, MacIntyre, Bennett and Taylor.)