The Involvement of Collagen Triple Helix Repeat Containing 1 in Muscular Dystrophies

Apolipoprotein E4 (APOE4) genotype is the strongest genetic risk factor for late-onset Alzheimer disease and confers a proinflammatory, neurotoxic phenotype to microglia. Here, we tested the hypothesis that bone marrow cell APOE genotype modulates pathological progression in experimental Alzheimer disease. We performed bone marrow transplants (BMT) from green fluorescent protein–expressing human APOE3/3 or APOE4/4 donor mice into lethally irradiated 5-month-old APPswe/PS1ΔE9 mice. Eight months later, APOE4/4 BMT–recipient APPswe/PS1ΔE9 mice had significantly impaired spatial working memory and increased detergent-soluble and plaque Aβ compared with APOE3/3 BMT–recipient APPswe/PS1ΔE9 mice. BMT-derived microglia engraftment was significantly reduced in APOE4/4 recipients, who also had correspondingly less cerebral apoE. Gene expression analysis in cerebral cortex of APOE3/3 BMT recipients showed reduced expression of tumor necrosis factor-α and macrophage migration inhibitory factor (both neurotoxic cytokines) and elevated immunomodulatory IL-10 expression in APOE3/3 recipients compared with those that received APOE4/4 bone marrow. This was not due to detectable APOE-specific differences in expression of microglial major histocompatibility complex class II, C-C chemokine receptor (CCR) type 1, CCR2, CX3C chemokine receptor 1 (CX3CR1), or C5a anaphylatoxin chemotactic receptor (C5aR). Together, these findings suggest that BMT-derived APOE3-expressing cells are superior to those that express APOE4 in their ability to mitigate the behavioral and neuropathological changes in experimental Alzheimer disease.Humans uniquely have three different apolipoprotein E (APOE) alleles (ɛ2, ɛ3, and ɛ4). APOE4 is the single greatest genetic risk factor for late-onset Alzheimer disease (AD), and there is a gene dosage effect.¹ However, genetic association does not inform function/pathogenesis. Multiple mechanisms have been postulated that predominantly focus on production, metabolism, or clearance of amyloid-β (Aβ) and that are variably supported by multiple observations, including: i) APOE genotype is strongly related to Aβ levels in brain and cerebrospinal fluid of AD patients^2,3; ii) modulation of apolipoprotein E (apoE) protein levels in brain results in alterations of Aβ burden^4,5; iii) Aβ degradation is at least partially apoE dependent^6,7; and iv) Aβ clearance is differentially modulated by apoE isoforms, with APOE4 mice exhibiting reduced central and peripheral Aβ clearance compared with APOE3 mice.^8–10 Aβ degradation and clearance is at least partially dependent on microglia, the innate immune effector cells of the brain. Microglia have migratory and phagocytic capacity, are increased in the vicinity of Aβ plaques, and phagocytose Aβ.^11–13 APOE genotype modulates central nervous system innate immune function in culture,¹⁴ including astrocyte and microglia elaboration of cytokines and chemokines,^15,16 microglia production of reactive oxygen species,¹⁷ microglia-mediated paracrine neurotoxicity,¹⁸ microglia migration,¹⁹ and other functions.²⁰ However, the specific contribution of microglial APOE genotype to AD pathophysiology in vivo is largely unknown.To address this critical question and to test a potential therapeutic application, we used the fact that bone marrow transplantation (BMT) results in the gradual replacement of endogenous (host) microglia (to the near exclusion of other cell types) with microglia derived from donor marrow, in both wild-type mice and transgenic mouse models of AD.^21–24 We used targeted-replacement (TR) APOE mice homozygous for either the APOE3 or APOE4 gene inserted into the mouse APOE regulatory elements^25,26 that coexpressed green fluorescent protein (GFP). We transplanted whole bone marrow (BM) isolated from TR APOE3/3;GFP or TR APOE4/4;GFP mice into lethally irradiated APPswe/PS1ΔE9 mice to determine the specific role of microglial APOE genotype in the pathological progression of AD.     

Amyloid beta and the longest-lived rodent: the naked mole-rat as a model for natural protection from Alzheimer's disease

Amyloid beta (Aβ) is implicated in Alzheimer's disease (AD) as an integral component of both neural toxicity and plaque formation. Brains of the longest-lived rodents, naked mole-rats (NMRs) approximately 32 years of age, had levels of Aβ similar to those of the 3xTg-AD mouse model of AD. Interestingly, there was no evidence of extracellular plaques, nor was there an age-related increase in Aβ levels in the individuals examined (2–20+ years). The NMR Aβ peptide showed greater homology to the human sequence than to the mouse sequence, differing by only 1 amino acid from the former. This subtle difference led to interspecies differences in aggregation propensity but not neurotoxicity; NMR Aβ was less prone to aggregation than human Aβ. Nevertheless, both NMR and human Aβ were equally toxic to mouse hippocampal neurons, suggesting that Aβ neurotoxicity and aggregation properties were not coupled. Understanding how NMRs acquire and tolerate high levels of Aβ with no plaque formation could provide useful insights into AD, and may elucidate protective mechanisms that delay AD progression.     

Studying host genetic background effects on multimorbidity of intestinal cancer development,type 2 diabetes and obesity in response to oral bacterial infection and high‐fat diet using the collaborative cross (CC) lines

BackgroundMultimorbidity of intestinal cancer (IC), type 2 diabetes (T2D) and obesity is a complex set of diseases, affected by environmental and genetic risk factors. High‐fat diet (HFD) and oral bacterial infection play important roles in the etiology of these diseases through inflammation and various biological mechanisms.MethodsTo study the complexity of this multimorbidity, we used the collaborative cross (CC) mouse genetics reference population. We aimed to study the multimorbidity of IC, T2D, and obesity using CC lines, measuring their responses to HFD and oral bacterial infection. The study used 63 mice of both sexes generated from two CC lines (IL557 and IL711). For 12 weeks, experimental mice were maintained on specific dietary regimes combined with co‐infection with oral bacteria Porphyromonas gingivalis and Fusobacterium nucleatum, while control groups were not infected. Body weight (BW) and results of a intraperitoneal glucose tolerance test (IPGTT) were recorded at the end of 12 weeks, after which length and size of the intestines were assessed for polyp counts.ResultsPolyp counts ranged between 2 and 10 per CC line. The combination of HFD and infection significantly reduced (P < .01) the colon polyp size of IL557 females to 2.5 cm², compared to the other groups. Comparing BW gain, IL557 males on HFD gained 18 g, while the females gained 10 g under the same conditions and showed the highest area under curve (AUC) values of 40 000‐45 000 (min mg/dL) in the IPGTT.ConclusionThe results show that mice from different genetic backgrounds respond differently to a high fat diet and oral infection in terms of polyp development and glucose tolerance, and this effect is gender related.     

Immunoglobulin-Mediated Neuro-Cognitive Impairment: New Data and a Comprehensive Review

Excessive influx of immunoglobulin (IgG) into the brain has been reported to induce central nervous system (CNS) dysfunction. Depressed patients may exhibit immune activation manifested by elevated inflammatory markers and pro-inflammatory cytokines. The brain and especially the limbic system contain high concentrations of high affinity Fc receptors. We reviewed the literature on this phenomena and present data on the behavioral effects of pooled normal IgG on the brain. Many disease states are associated with depression and we examined whether this may be linked to high IgG influx. Female Balb/C mice were injected intra-cerbroventricularly with human immunoglobulin whole molecule, or human IgG F(ab′)₂ or Fc fragments. Control mice were injected with saline. The four groups were subjected to behavioral (staircase, forced swimming test, and elevated plus maze) and cognitive tests (passive avoidance test). IgG-injected mice exhibited depression-like behavior as reflected by significantly higher immobility time in the forced swimming test (p?<?0.05) and hyperactive behavior as reflected by higher number of stairs climbed in the staircase test compared to controls (p?<?0.01). Fc-fragments-injected mice showed hyperactive behavior as reflected by both higher number of stairs climbed and rearing events in the staircase test compared to controls. The results indicate that high levels of normal IgG in the cerebrospinal fluid can cause hyperactivity and depression-like behavior. The mechanism involved in these CNS manifestations include possibly Fc receptor binding.     

Functionalized PLGA-doped zirconium oxide ceramics for bone tissue regeneration

Bone tissue engineering is an alternative approach to bone grafts. In our study we aim to develop a composite scaffold for bone regeneration made of doped zirconium oxide (ZrO₂) conjugated with poly(lactic-co-glycolic acid) (PLGA) particles for the delivery of growth factors. In this composite, the PLGA microspheres are designed to release a crucial growth factor for bone formation, bone morphogenetic protein-2 (BMP2). We found that by changing the polymer’s molecular weight and composition, we could control microsphere loading, release and size. The BMP2 released from PLGA microspheres retained its biological activity and increased osteoblastic marker expression in human mesenchymal stem cells (hMSCs). Uncapped PLGA microspheres were conjugated to ZrO₂ scaffolds using carbodiimide chemistry, and the composite scaffold was shown to support hMSCs growth. We also demonstrated that human umbilical vein endothelial cells (HUVECs) can be co-cultured with hMSCs on the ZrO₂ scaffold for future vascularization of the scaffold. The ZrO₂ composite scaffold could serve as a bone substitute for bone grafting applications with the added ability of releasing different growth factors needed for bone regeneration.     

Chronic Pain and Premature Aging – The Moderating Role of Physical Exercise

Chronic pain induces a multitude of harmful effects; recently it has been suggested that chronic pain is also associated with premature aging, manifested in shortened telomere length (TL). However, evidence for this hypothesis is scarce and inconsistent. The aim was twofold: 1) Investigate whether chronic pain is associated with premature aging, and 2) Determine whether physical exercise (PE) moderates this association if it exists. Participants were 116 male subjects, with (n = 67) and without chronic pain (n = 49). Blood samples for TL analysis were collected and participants were interviewed and completed questionnaires. As a part of the cohort, we included people with physical disability; this variable was controlled in the analysis. The TL of individuals with chronic pain was significantly shorter than that of pain-free individuals. Regression analysis revealed a significant moderating effect of PE on chronic pain and TL, above and beyond the effects of disability, age, and weight. Whereas chronic pain was associated with shorter telomeres in participants who did not exercise, this association was nonsignificant among participants who did exercise. The results suggest that chronic pain is associated with premature ageing; however, PE may mitigate this association and may protect individuals against the harmful effects of chronic pain.PerspectiveThe study suggests that it is important to monitor signs of premature ageing among chronic pain patients as they are at risk. However, chronic pain patients may benefit from regular PE in this respect as it may moderate premature ageing.     

Menstrual Cycle Effects on Psychological Symptoms in Women With PTSD

The menstrual cycle has been implicated as a sex‐specific biological process influencing psychological symptoms across a variety of disorders. Limited research exists regarding the role of the menstrual cycle in psychological symptoms among women with posttraumatic stress disorder (PTSD). The current study examined the severity of a broad range of psychological symptoms in both the early follicular (Days 2–6) and midluteal (6–10 days postlutenizing hormone surge) phases of the menstrual cycle in a sample of trauma‐exposed women with and without PTSD (N = 49). In the sample overall, total psychological symptoms (d = 0.63), as well as depression (d = 0.81) and phobic anxiety (d = 0.81) symptoms, specifically, were increased in the early follicular compared to midluteal phase. The impact of menstrual cycle phase on phobic anxiety was modified by a significant PTSD × Menstrual Phase interaction (d = 0.63). Women with PTSD reported more severe phobic anxiety during the early follicular versus midluteal phase, whereas phobic anxiety did not differ across the menstrual cycle in women without PTSD. Thus, the menstrual cycle appears to impact fear‐related symptoms in women with PTSD. The clinical implications of the findings and future research directions are discussed.     

Mid-term results of a physiotherapist-led Ponseti service for the management of non-idiopathic and idiopathic clubfoot

BackgroundThe Ponseti method is the preferred treatment for idiopathic clubfoot. Although popularised by orthopaedic surgeons it has expanded to physiotherapists and other health practitioners. This study reviews the results of a physiotherapist-led Ponseti service for idiopathic and non-idiopathic clubfeet and compares these results with those reported by other groups.MethodA prospective cohort of clubfeet (2005–2012) with a minimum 2-year follow-up after correction was reviewed. Physiotherapists treated 91 children—41 patients (69 feet) had non-idiopathic deformities and 50 children (77 feet) were idiopathic. Objective outcomes were evaluated and compared to results from other groups managing similar patient cohorts.ResultsThe mean follow-up was 4.6 years (range 2–8.3 years) for both groups. The non-idiopathic group required a median of 7 casts to correct the clubfoot deformity with an 83 % tenotomy rate compared to a median of 5 casts for the idiopathic group with a 63 % tenotomy rate. Initial correction was achieved in 96 % of non-idiopathic feet and in 100 % of idiopathic feet. Recurrence requiring additional treatment was higher in the non-idiopathic group with 40 % of patients (36 % of feet) sustaining a relapse as opposed to 8 % (6 % feet) in the idiopathic group. Surgery was required in 26 % of relapsed non-idiopathic feet and 6 % of idiopathic.ConclusionsAlthough Ponseti treatment was not as successful in non-idiopathic feet as in idiopathic feet, deformity correction was achieved and maintained in the mid-term for the majority of feet. These results compare favourably to other specialist orthopaedic-based services for Ponseti management of non-idiopathic clubfeet.

Level of evidence

Prognostic Level III.     

A cell-based multifactorial approach to angiogenesis

We here propose an alternative cell therapy approach to induce angiogenesis. We prepared small organ fragments whose geometry allows preservation of the natural epithelial/mesenchymal interactions and ensures appropriate diffusion of nutrients and gases to all cells. Fragments derived from lung are shown to behave as fairly independent units, to undergo a marked upregulation of angiogenic factors and to continue to function for several weeks in vitro in serum-free media. When implanted into hosts, they transcribe a similar array of angiogenic factors that specifically induce the formation of a potent vascular network. The angiogenic induction capacity of these fragments was also tested in a mouse and rat model of limb ischemia. We report that such fragments, when implanted in the vicinity of the ischaemic area, induce an angiogenic response which can rescue the ischaemia-induced damage. The approach presented differs from single factor application, gene therapy and other cell therapy methods in that it exploits the complex behaviour of autologous cells in their near to normal environment in order to achieve secretion of a whole range of angiogenic stimuli continuously and in an apparently coordinated fashion.