Lathosterolosis (LS) is a defect of cholesterol biosynthesis due to the deficiency of the enzyme sterol-C5-desaturase. Only two patients have been described to date, both presenting with multiple malformations, mental retardation, and liver involvement. In addition in one of them pathological examination revealed mucolipidosis-like inclusions on optic microscopy analysis, and peculiar lysosomal lamellar bodies on electron microscopy analysis. This study is focused on a better characterization of the clinical phenotype of LS. We describe a further case in a fetus, sibling of the first patient reported, presenting with neural tube defect, craniofacial and limb anomalies, and prenatal liver involvement. The fetal phenotype suggests the possible occurrence of significant intrafamilial variability in LS, and expands the phenotypic spectrum of the disease. Histological examination of autopsy samples from the fetus and skin fibroblasts from the living sibling suggested that the mucolipidosis-like picture previously reported is not a constant feature of LS, being possibly associated with the most severe biochemical defects, but confirmed the ultrastructural finding of lamellar inclusions. The LS phenotype appears to be characterized by the distinctive association of a recognizable pattern of congenital anomalies, involving axial and appendicular skeleton, liver, central nervous and urogenital systems, and lysosomal storage. This condition partially overlaps with other defects of sterol metabolism, suggesting intriguing pathogenic links among these conditions.

The requirement for correct dosage of the transcription factor Pax6 during corneal growth and development was investigated using the Pax6-overexpressing (PAX77) transgenic mouse. Transgenics had a microcornea phenotype due to failure of postnatal growth, associated with reduction in the number of cells layers in the corneal epithelium. Cell cycle progression was monitored using bromodeoxyuridine, p63, cyclin E, and phosphohistone-3 labeling: proliferation rates were higher in PAX77 ؉ than wild-type, without a concomitant increase in apoptosis. Hence, failure of proliferation did not underlie microcornea. PAX77 ؉ corneal epithelia had reduced levels of cytokeratin-12, and exhibited severe wound healing delay that, in contrast to Pax6 ؉/؊ mice, could not be modulated by exogenous growth factors. PAX77 ؉ lenses showed partial failure of lens fiber differentiation. The data demonstrate that anterior eye development is very sensitive to Pax6 dosage. Although there are similarities between the eye phenotype of Pax6 heterozygotes and overexpressing mice, there are also striking differences.

Brachytelephalangic chondrodysplasia punctata (CDPX1, OMIM: #302950) is a rare congenital skeletal dysplasia caused by arylsulfatase E deficiency (OMIM: #300180). Although the symptoms are usually mild, severe spinal cord compression by dysplastic vertebras may develop. We report four new cases with severe cervical spinal canal narrowing documented by radiography, magnetic resonance imaging (MRI), and autopsy. In all, nine cases of CDPX1 with severe cervical spinal cord compression have now been described. Because these cases account for a large proportion of all reported CDPX1 cases, we believe that an antenatal suspicion of CDPX1 should lead to genetic counseling and to investigations for spinal cord compression. After birth, this complication must be routinely anticipated, and we suggest spinal MRI in all CDPX1 infants. Unless spinal cord compression is confidently ruled out, we recommend that these newborns receive the same care as trauma patients suspected of craniocervical junction disruption.

ObjectivesNerve growth factor (NGF) has emerged as a key driver of pain in osteoarthritis (OA) and antibodies to NGF are potent analgesics in human disease. Here, we validate a novel vaccine strategy to generate anti-NGF antibodies for reversal of pain behaviour in a surgical model of OA.MethodsVirus-like particles were derived from the cucumber mosaic virus (CuMV) and coupled to expressed recombinant NGF to create the vaccine. 10-week-old male mice underwent partial meniscectomy to induce OA or sham-surgery. Spontaneous pain behaviour was measured by Linton incapacitance and OA severity was quantified using OARSI histological scoring. Mice (experimental and a sentinel cohort) were inoculated with CuMVttNGF (Vax) or CuMVttctrl (Mock) either before surgery or once pain was established. Efficacy of anti-NGF from the plasma of sentinel vaccinated mice was measured in vitro using a neurite outgrowth assay in PC12 cells.ResultsAnti-NGF titres were readily detectable in the vaccinated but not mock vaccinated mice. Regular boosting with fresh vaccine was required to maintain anti-NGF titres as measured in the sentinel cohort. Both prophylactic and therapeutic vaccination demonstrated a reversal of pain behaviour by incapacitance testing, and a meta-analysis of the two studies showing analgesia at peak anti-NGF titres was highly statistically significant. Serum anti-NGF was able to inhibit neurite outgrowth equivalent to around 150 ug/mL of recombinant monoclonal antibody.ConclusionsThis study demonstrates therapeutic efficacy of a novel NGF vaccine strategy that reversibly alleviates spontaneous pain behaviour in surgically induced murine OA.

Mechanical forces are known to drive cellular signalling programmes in cartilage development, health, and disease. Proteins of the primary cilium, implicated in mechanoregulation, control cartilage formation during skeletal development, but their role in post-natal cartilage is unknown. Ift88fl/fl and AggrecanCreERT2 mice were crossed to create a cartilage specific inducible knockout mouse AggrecanCreERT2;Ift88fl/fl. Tibial articular cartilage thickness was assessed, through adolescence and adulthood, by histomorphometry and integrity by OARSI score. In situ cell biology was investigated by immunohistochemistry (IHC) and qPCR of micro-dissected cartilage. OA was induced by destabilisation of the medial meniscus (DMM). Some mice were provided with exercise wheels in their cage. Deletion of IFT88 resulted in a reduction in medial articular cartilage thickness (atrophy) during adolescence from 102.57μm, 95% CI [94.30, 119.80] in control (Ift88fl/fl) to 87.36μm 95% CI [81.35, 90.97] in AggrecanCreERT2;Ift88fl/fl by 8-weeks p<0.01, and adulthood (104.00μm, 95% CI [100.30, 110.50] in Ift88fl/fl to 89.42μm 95% CI [84.00, 93.49] in AggrecanCreERT2;Ift88fl/fl, 34-weeks, p<0.0001) through a reduction in calcified cartilage. Thinning in adulthood was associated with spontaneous cartilage degradation. Following DMM, AggrecanCreERT2;Ift88fl/fl mice had increased OA (OARSI scores at 12 weeks Ift88fl/fl = 22.08 +/− 9.30, and AggrecanCreERT2;Ift88fl/fl = 29.83 +/− 7.69). Atrophy was not associated with aggrecanase-mediated destruction or chondrocyte hypertrophy. Ift88 expression positively correlated with Tcf7l2 and connective tissue growth factor. Cartilage thickness was restored in AggrecanCreERT2;Ift88fl/fl by voluntary wheel exercise. Our results demonstrate that ciliary IFT88 regulates cartilage thickness and is chondroprotective, potentially through modulating mechanotransduction pathways in articular chondrocytes.