Incontinentia pigmenti revisited. A novel nonsense mutation of the IKBKG gene

Aim: To describe and evaluate the clinical and molecular findings of patients with incontinentia pigmenti (IP) in Greece. Methods: We examined 12 female patients, initially aged 2 weeks to 7 months with clinical diagnosis of IP. Standard tests were performed including skin biopsies and ocular, dental and neurologic examinations. Molecular analysis was carried out on 8 out of 12 cases. Results: The initial clinical examination was stage 1 (vesicular lesions), stage 2 (verrucous lesions) or stage 3 (hyperpigmented linear lesions of the trunk/limbs). At the final clinical examination, 10 of our patients had typical vesicular, verrucous or mixed hyper‐hypopigmented skin lesions which had persisted from the neonatal period; seven had delayed dentition or conical teeth; two had developmental delay; one had microcephaly and strabismus and two had scarring alopecia. In seven patients, deletion of exons 4–10 of the IKBKG gene was found. In one patient, skewed X‐inactivation was demonstrated and a novel mutation p.Gln332X was found. The mothers’ DNA analyses were all normal. Conclusion: In our sample, all the cases were sporadic and the diagnosis of IP was based mainly on clinical features and confirmed with skin histology. Molecular analysis was used to find the mutations, in some cases to confirm diagnosis and to identify the carriers, which are crucial for prenatal and preimplantation diagnosis.     

Replication of Theiler's virus requires NF-kappa B-activation: higher viral replication and spreading in astrocytes from susceptible mice

To investigate viral replication and cell-cell spreading in astrocytes, recombinant Theiler's murine encephalomyelitis virus (TMEV) expressing green fluorescent protein (GFP) during the replication was generated. GFP and TMEV proteins were processed correctly in infected cells and production of viral proteins could be tracked by fluorescent microscopy. Viral replication of both wild-type TMEV and GFP-TMEV was dependent on the activation of NF-kappaB and partially MAP kinase, based on chemical inhibition studies. Viral replication was significantly reduced in primary astrocytes from NF-kappaB1 (p105)-deficient mice compared with that from wild-type control mice, whereas cytokine production was enhanced. These results suggest an association of canonical NF-kappaB subunits in viral replication, but not cytokine production. Viral replication was also suppressed in both IKKalpha and IKKbeta-deficient mouse embryonic fibroblasts (MEFs), compared with that in wild-type MEF. However, the inhibition was significantly greater in IKKbeta-deficient MEF, suggesting that IKKbeta plays a stronger role in supporting viral replication. Interestingly, viral replication and spreading in primary astrocytes from susceptible SJL/J mice were several-fold higher than those in astrocytes from resistant C57BL/6 mice, suggesting that higher viral replication levels in astrocytes may also contribute to the viral persistence in the central nervous system (CNS) of susceptible SJL/J mice. A relatively higher level of activated NF-kappaB was found in the nuclei of virus-infected SJL astrocytes compared with C57BL/6 astrocytes suggest that the NF-kappaB activation level affects on viral replication.     

Omega-3 fatty acids are protective in hepatic ischemia reperfusion injury in the absence of GPR120 signaling

BackgroundA single dose of IV fish oil (FO) before hepatic ischemia reperfusion injury (HIRI) increases hepatocyte proliferation and reduces necrosis in wild type (WT) mice. It has been suggested that the GPR120 receptor on Kupffer cells mediates FO's ability to reduce HIRI. The purpose of this study was to determine whether GPR120 is required for FO to reduce HIRI.MethodsSixty-four (n = 8/group) adult male WT (C57BL/6) and GPR120 knockout (KO) mice received IV FO (1 g/kg) or saline 1 h prior to HIRI or sham operation. Mice were euthanized 24 h postoperatively for analysis of hepatic histology, NFκB activity, and serum alanine transaminase (ALT) levels.ResultsFO pretreated livers had less necrosis after HIRI than saline pretreated livers in both WT (mean ± SEM 25.9 ± 7.3% less, P = 0.007) and KO (36.6 ± 7.3% less, P < 0.0001) mice. There was no significant difference in percent necrosis between WT-FO and KO-FO groups. Sham groups demonstrated minimal necrosis (0–1.9%). Mean [95% CI] ALT after HIRI was significantly higher (P = 0.04) in WT-Saline mice (1604 U/L [751–3427]) compared to WT-FO (321 U/L [150–686]) but was not significantly higher in KO-Saline mice compared to KO-FO. There were no differences in ALT between WT-FO and KO-FO mice who underwent HIRI or between groups who underwent sham surgery. There were no differences in NFκB or IKKβ activation among groups as measured by Western blot analysis.ConclusionsIV FO pretreatment was able to reduce HIRI in GPR120 KO mice, suggesting the hepatoprotective effects of FO are not mediated by GPR120 alone.     

Porcine reproductive and respiratory syndrome virus NADC30‐like strain accelerates Streptococcus suis serotype 2 infection in vivo and in vitro

Porcine reproductive and respiratory syndrome (PRRS), an economically significant pandemic disease, commonly results in increased impact of bacterial infections, including those by Streptococcus suis (S. suis). In recent years, PRRS virus (PRRSV) NADC30‐like strain has emerged in different regions of China, and coinfected with S. suis and PRRSV has also gradually increased in clinical performance. However, the mechanisms involved in host innate responses towards S. suis and their implications of coinfection with NADC30‐like strain remain unknown. Therefore, the pathogenicity of NADC30‐like strain and S. suis serotype 2 (SS2) coinfection in vivo and in vitro was investigated in this study. The results showed that NADC30‐like increased the invasion and proliferation of SS2 in blood and tissues, resulting in more severe pneumonia, myocarditis, and peritonitisas well as higher mortality rate in pigs. In vitro, NADC30‐like strain increased the invasion and survival of SS2 in porcine alveolar macrophages (PAM) cells, causing more drastic expression of inflammatory cytokines and activation of NF‐ĸB signalling. These results pave the way for understanding the interaction of S. suis with the swine immune system and their modulation in a viral coinfection.     

Implantation auditive du tronc cérébral chez l’enfant. À propos de trois cas

Aim of the studyTo present three pediatric cases of auditory brainstem implantation (ABI) and review literature data concerning this topic.PatientsThe first two children had a neurofibromatosis type II with bilateral sensorineural deafness; in both cases, the implant was inserted during the surgical removal of a vestibular schwannoma; the third patient had profound deafness due to bilateral cochlear nerve insufficiency associated with inner ear malformation.ResultsTwo postoperative complications were observed: patient 1 had a persistent fever which required the replacement of the fat graft used to seal the translabyrinthine approach; patient 3 had a CSF leakage requiring additional surgery and lumbar external drainage. In our three patients, the numbers of active electrodes were 6/22 (Cochlear ABI 24M ABI), 11/12 (Medel Opus II ABI) and 11/12 (implant Medel), respectively. Due to additional major surgical procedures and to disappointing functional results of the ABI, patient 1 stopped wearing her implant 18 months after implantation. Nine months after surgery, patient 2 achieved open-set speech recognition and was very satisfied with the implant. Six months after implantation, patient 3 (cochlear nerve deficiency), who was 3.5 years-old at the time, clearly reacted to some environmental sounds but was not yet able to achieve speech recognition.ConclusionsABI has now entered the list of treatments that can be proposed in pediatric profound sensorineural deafness. Its major risks of complications are CSF leakage and non-auditory side effects. Its outcomes are worse and less predictable than cochlear implants. Thus, its indications must remain restricted to cases meeting the following conditions: absence of alternative option to restore hearing, patients and parents high level of motivation and realistic expectations.     

Synaptotagmin‐11 inhibits cytokine secretion and phagocytosis in microglia

Cytokine secretion and phagocytosis are key functions of activated microglia. However, the molecular mechanisms underlying their regulation in microglia remain largely unknown. Here, we report that synaptotagmin‐11 (Syt11), a non‐Ca²⁺‐binding Syt implicated in Parkinson disease and schizophrenia, inhibits cytokine secretion and phagocytosis in microglia. We found Syt11 expression in microglia in brain slices and primary microglia. Interestingly, Syt11‐knockdown (KD) increased cytokine secretion and NO release in primary microglia both in the absence and presence of lipopolysaccharide. NF‐κB was activated in untreated KD microglia together with enhanced synthesis of IL‐6, TNF‐α, IL‐1β, and iNOS. When the release capacity was assessed by the ratio of extracellular to intracellular levels, only the IL‐6 and TNF‐α secretion capacity was increased in Syt11‐KD cells, suggesting that Syt11 specifically regulates conventional secretion. Consistently, Syt11 localized to the trans‐Golgi network and recycling endosomes. In addition, Syt11 was recruited to phagosomes and its deficiency enhanced microglial phagocytosis. All the KD phenotypes were rescued by expression of an shRNA‐resistant Syt11, while overexpression of Syt11 suppressed cytokine secretion and phagocytosis. Importantly, Syt11 also inhibited microglial phagocytosis of α‐synuclein fibrils, supporting its association with Parkinson disease. Taken together, we propose that Syt11 suppresses microglial activation under both physiological and pathological conditions through the inhibition of cytokine secretion and phagocytosis.