The impact of the cytoplasmic ubiquitin ligase TNFAIP3 gene variation on transcription factor NF-κB activation in acute kidney injury.

Nuclear factor κB (NF-κB) activation is a deleterious molecular mechanism that drives acute kidney injury (AKI) and manifests in transplanted kidneys as delayed graft function. The TNFAIP3 gene encodes A20, a cytoplasmic ubiquitin ligase and a master negative regulator of the NF- κB signaling pathway. Common population-specific TNFAIP3 coding variants that reduce A20's enzyme function and increase NF- κB activation have been linked to heightened protective immunity and autoimmune disease, but have not been investigated in AKI. Here, we functionally identified a series of unique human TNFAIP3 coding variants linked to the autoimmune genome-wide association studies single nucleotide polymorphisms of F127C; namely F127C;R22Q, F127C;G281E, F127C;W448C and F127C;N449K that reduce A20's anti-inflammatory function in an NF- κB reporter assay. To investigate the impact of TNFAIP3 hypomorphic coding variants in AKI we tested a mouse Tnfaip3 hypomorph in a model of ischemia reperfusion injury (IRI). The mouse Tnfaip3 coding variant I325N increases NF- κB activation without overt inflammatory disease, providing an immune boost as I325N mice exhibit enhanced innate immunity to a bacterial challenge. Surprisingly, despite exhibiting increased intra-kidney NF- κB activation with inflammation in IRI, the kidney of I325N mice was protected. The I325N variant influenced the outcome of IRI by changing the dynamic expression of multiple cytoprotective mechanisms, particularly by increasing NF- κB-dependent anti-apoptotic factors BCL-2, BCL-XL, c-FLIP and A20, altering the active redox state of the kidney with a reduction of superoxide levels and the enzyme super oxide dismutase-1, and enhancing cellular protective mechanisms including increased Foxp3+ T cells. Thus, TNFAIP3 gene variants represent a kidney and population-specific molecular factor that can dictate the course of IRI.

Impacts of paediatric chronic pain on parents: A qualitative study.

BACKGROUND: Paediatric chronic pain adversely impacts the child's functioning, health-related quality of life and development. However, there is a need for a holistic assessment of parental impacts of caring for a child with chronic pain. This qualitative study aimed to investigate the possible psychosocial, functional and work impacts of caring for a child with chronic pain on parents, including any positive effects of the experience. METHODS: Ten parents (eight mothers and two fathers), whose child attended the Sydney Children's Hospital Interdisciplinary Chronic and Complex Pain Clinic, participated in semi-structured interviews exploring the impact of caring for a child with chronic pain. Interviews were audio-recorded, transcribed, coded (with good inter-coder agreement) and analysed using thematic analysis. RESULTS: The parental experience of caring for a child with chronic pain was encapsulated by four overarching themes: (1) 'the constant and all-consuming nature of pain' - parents described the unpredictable, yet constant nature of chronic pain, contributing to wide-reaching impacts in various areas of their life; (2) 'dealing with uncertainty' - their experience was commonly characterized by a sense of uncertainty, stress, hopelessness and fear; (3) 'importance of support and self-care' - strong support networks and prioritizing self-care were crucial in alleviating the negative effects of paediatric chronic pain; and (4) 'a revitalized and optimistic view on life and relationships' - some parents identified unique and positive effects, such as stronger relationships, personal growth and a reformed view on life. CONCLUSIONS: This study provided rich data on the various impacts of caring for a child with chronic pain, highlighting the need for the development of holistic, family-centred interventions addressing both child and parental functioning.

Caregiver Burden Associated With Pediatric Chronic Pain: A Retrospective Study Using the Pediatric Electronic Persistent Pain Outcomes Collaboration Database.

OBJECTIVES: This retrospective, cross-sectional study investigated the nature and extent of burden experienced by caregivers of children and adolescents with chronic pain, and factors associated with increased caregiver burden. METHODS: The Pediatric Electronic Persistent Pain Outcomes Collaboration database provided prospectively collected data from 1929 families attending 9 pediatric chronic pain services across Australia and New Zealand. Data included demographic information, responses to child pain and functioning measures, caregiver work impairment, and psychosocial functioning. RESULTS: Caregivers of children with chronic pain reported work impairment associated with their child's pain (mean: 15% ± SD 25 absenteeism; 38% ± SD 29 productivity lost), significantly worse than published international population norms (large-scale community survey data), most other caregiver samples of adults and children with other chronic conditions, and adult samples with various pain conditions. Caregivers reported considerable burden in multiple psychosocial functioning domains, particularly leisure functioning, pain-related catastrophizing, and adverse parenting behaviors (with greater pain-related avoidance). Caregiver psychosocial burden was significantly associated with child psychosocial functioning (ß = -0.308, P < 0.01), school absenteeism (ß = 0.161, P < 0.01), physical disability (ß = 0.096, P < 0.05), and pain duration (ß = 0.084, P < 0.05), but not pain intensity. Caregiver work productivity loss was significantly associated with school absenteeism (ß = 0.290, P < 0.01), child physical disability (ß = 0.148, P < 0.01), child health care utilization (ß = 0.118, P < 0.05), and worst pain intensity (ß = 0.101, P < 0.05). DISCUSSION: These results highlight the significant and varied impacts experienced by caregivers of children with chronic pain. This work is novel in reporting significant work impairment and confirms psychosocial burden in a larger sample than previous studies.

Repurposing of metformin and colchicine reveals differential modulation of acute and chronic kidney injury.

Acute kidney injury (AKI) is a major health problem affecting millions of patients globally. There is no effective treatment for AKI and new therapies are urgently needed. Novel drug development, testing and progression to clinical trials is overwhelmingly expensive. Drug repurposing is a more cost-effective measure. We identified 2 commonly used drugs (colchicine and metformin) that alter inflammatory cell function and signalling pathways characteristic of AKI, and tested them in models of acute and chronic kidney injury to assess therapeutic benefit. We assessed the renoprotective effects of colchicine or metformin in C57BL/6 mice challenged with renal ischemia reperfusion injury (IRI), treated before or after injury. All animals underwent analysis of renal function and biomolecular phenotyping at 24 h, 48 h and 4 weeks after injury. Murine renal tubular epithelial cells were studied in response to in vitro mimics of IRI. Pre-emptive treatment with colchicine or metformin protected against AKI, with lower serum creatinine, improved histological changes and decreased TUNEL staining. Pro-inflammatory cytokine profile and multiple markers of oxidative stress were not substantially different between groups. Metformin augmented expression of multiple autophagic proteins which was reversed by the addition of hydroxychloroquine. Colchicine led to an increase in inflammatory cells within the renal parenchyma. Chronic exposure after acute injury to either therapeutic agent in the context of reduced renal mass did not mitigate the development of fibrosis, with colchicine significantly worsening an ischemic phenotype. These data indicate that colchicine and metformin affect acute and chronic kidney injury differently. This has significant implications for potential drug repurposing, as baseline renal disease must be considered when selecting medication.

Mice deficient in both pituitary adenylyl cyclase-activating polypeptide and vasoactive intestinal peptide survive, but display growth retardation and sex-dependent early death.

Pituitary adenylyl cyclase-activating polypeptide (PACAP) and vasoactive intestinal peptide (VIP) are two closely related neuropeptides exhibiting overlapping activities which have actions on almost every organ system of the body. To determine if these peptides exert essential but redundant functions, we interbred VIP- and PACAP-deficient mice to obtain VIP/PACAP double knockout (DKO) mice. DKO mice had normal birth weights and survived to weaning, but exhibited a dramatic postnatal growth rate reduction. Analyses at postnatal day 16 indicated that all organs examined except the brain were reduced in mass by 40-70% compared to mixed background controls, with the thymus and spleen most profoundly affected. Brain size was also significantly reduced, but by only 10%. The reduced growth rate of DKO mice was associated with reduced serum concentrations of insulin-like growth hormone-1 (IGF-1), but unchanged levels of growth hormone. Despite the normal survival of DKO mice up to the weaning stage, many subsequently experienced early sudden death, with only 48% of females and 82% of males surviving past 6 months. The results indicate that a significant percentage of mice deficient in both VIP and PACAP survive to adulthood, but their growth rate is profoundly affected, and that females in particular exhibit high rate of mortality after about 3 months of age.

PA-GOSUB: a searchable database of model organism protein sequences with their predicted Gene Ontology molecular function and subcellular localization.

PA-GOSUB (Proteome Analyst: Gene Ontology Molecular Function and Subcellular Localization) is a publicly available, web-based, searchable and downloadable database that contains the sequences, predicted GO molecular functions and predicted subcellular localizations of more than 107,000 proteins from 10 model organisms (and growing), covering the major kingdoms and phyla for which annotated proteomes exist (http://www.cs.ualberta.ca/~bioinfo/PA/GOSUB). The PA-GOSUB database effectively expands the coverage of subcellular localization and GO function annotations by a significant factor (already over five for subcellular localization, compared with Swiss-Prot v42.7), and more model organisms are being added to PA-GOSUB as their sequenced proteomes become available. PA-GOSUB can be used in three main ways. First, a researcher can browse the pre-computed PA-GOSUB annotations on a per-organism and per-protein basis using annotation-based and text-based filters. Second, a user can perform BLAST searches against the PA-GOSUB database and use the annotations from the homologs as simple predictors for the new sequences. Third, the whole of PA-GOSUB can be downloaded in either FASTA or comma-separated values (CSV) formats.

Impairment of axotomy-induced pituitary adenylyl cyclase-activating peptide gene expression in T helper 2 lymphocyte-deficient mice.

CD4+ (T helper) lymphocytes appear to play important roles in neuron survival and regeneration after injury, although their functions in regulating gene expression in injured neurons are unknown. Mice with targeted mutations in the STAT4 and STAT6 genes are deficient in T helper (Th)1 and Th2 responses, respectively, and have been used to determine the relative importance of T helper subsets in a variety of inflammatory processes. As pituitary adenylyl cyclase-activating peptide mRNA is normally strongly induced in facial motor neurons after axotomy, we examined this induction in Th1 and Th2 lymphocyte-deficient and control Balb/C wild-type mice. As previously reported, pituitary adenylyl cyclase-activating peptide gene expression was strongly induced in ipsilateral but not contralateral motor neurons in the facial motor nucleus of wild-type mice. The mean number of hybridizing motor neurons in STAT4-deficient mice did not differ from that in wild-type mice, whereas the number in STAT6 mice was reduced by more than 50%. The results indicate that STAT6 plays a key role in the upregulation of pituitary adenylyl cyclase-activating peptide gene expression in facial motor neurons after injury, possibly through its role in regulating T helper cell differentiation to the type 2 phenotype.

Cancer therapy related complications in the liver, pancreas, and biliary system: an imaging perspective.

UNLABELLED: Awareness of cancer therapy-induced toxicities is important for all clinicians treating patients with cancer. Cancer therapy has evolved to include classic cytotoxic agents in addition to newer options such as targeted agents and catheter-directed chemoembolisation. Several adverse affects can result from the wide array of treatments including effects on the liver, pancreas, and biliary system that can be visualised on imaging. These complications include sinusoidal obstruction syndrome, fatty liver, pseudocirrhosis, acute hepatitis, pancreatitis, pancreatic atrophy, cholecystitis, biliary sclerosis, and biliary stasis. Many of these toxicities are manageable and reversible with supportive therapies and/or cessation of cancer therapy. The objective of this review is to discuss the imaging findings associated with cancer therapy-induced toxicity of the liver, biliary system, and pancreas. TEACHING POINTS: • Cancer therapy can have adverse effects on the hepatobiliary system and pancreas. • Cancer therapy-induced toxicities can be visualised on imaging. • Knowledge of imaging changes associated with cancer therapy complications can improve treatment.