Statistical/design methods

Inhibition of Adipocyte Necroptosis Alleviates Fat Necrosis and Fibrosis After Grafting in a Murine Model

BACKGROUND

Because of the delicate structure of the adipose tissue, fat necrosis accounts for 43.7% of all complications after autologous fat grafting; however, its regulation remains unclear.

OBJECTIVES

The purpose of this study was to examine the role of necroptosis in fat graft remodeling after grafting.

METHODS

Clinical fat graft necrosis samples were collected, and the expression levels of the necroptosis marker phosphorylated(p)-MLKL were analyzed. Transcriptome analysis was performed on fat grafts before and 1 week after transplantation in C57BL/6 mouse fat grafting models. Additionally, the in vivo effects of RIPK1 inhibitor Nec-1s or RIPK3 inhibitor GSK'872 on the fat grafting complications, including fat necrosis and fibrosis, were investigated.

RESULTS

Necroptosis markers were observed and associated with higher occurrence of fibrosis in clinical fat graft necrosis samples compared to normal fat tissue. Amplification and RNA-Seq were conducted on RNA isolated from fat grafts before and after grafting. MLKL, RIPK1, and RIPK3's expression levels were significantly upregulated in comparison to controls. Higher expression levels of necroptotic RNAs were associated with higher levels of DAMPs, including Cxcl2, HMGB1, S100a8, S100a9, Nlrp3, and IL33, and activated proinflammatory signaling pathways, including the TNF, NF-kappa B, and chemokine signaling pathways. Necroptotic inhibitor Nec-1s and GSK'872 robustly suppressed the p-MLKL expression level and significantly inhibited necroptotic cell death, especially in adipocytes. Moreover, administration of Nec-1s and GSK'872 significantly alleviated fat necrosis and subsequent fibrosis in fat grafts.

CONCLUSIONS

Collectively, our study findings highlight the potential therapeutic applications of necroptosis inhibitors in preventing fat necrosis and fibrosis after grafting.

LEVEL OF EVIDENCE: 4

High allergen exposure as a risk factor for asthma and allergic disease

The association between pet ownership in childhood and subsequent asthma and sensitization is very controversial. Intriguing, but contradictory, reports have caused considerable uncertainty in parents who wish to avoid asthma and allergic disease in their children. This article argues that high allergen exposure is a risk factor for asthma and allergic disease. It describes dispersal of pet allergens in society and critically assesses epidemiological studies regarding how early exposure to pet allergens affects subsequent immunoglobulin E-sensitization and allergic diseases. Additionally, this article evaluates the effects of allergen exposure in already sensitized subjects with asthma. Cat and dog allergens are ubiquitous in society and may induce sensitization and allergic symptoms in predisposed individuals, regardless of pet ownership. This, in combination with selection mechanisms for pet ownership in families with a history of allergic diseases, makes it difficult to study associations between early exposure to pets and subsequent allergic disease. Nevertheless, exposure to pet allergens worsens asthma in already sensitized children. Thus, it is clear that clinicians should advise sensitized asthmatics that avoidance of exposure to indoor allergens is an important element in the treatment of allergic disease.

Prevalence of respiratory symptoms in school children and salivary IgA--an epidemiological study in a rural area of Northrhine-Westphalia, Germany

An elevated frequency of wheezing was found in school children in a rural area of Northrhine-Westphalia, Germany (Duhme and Keil, Institut für Epidemiologie und Sozialmedizin, Universität Münster, Münster, Germany 1997). In this study the prevalence of wheezing was reinvestigated by including main influencing factors. A cross-sectional survey was performed in all school children visiting school classes 1, 2 and 7, 8 (n = 1161). Two corresponding questionnaires were used: a parental questionnaire and a questionnaire for self-completion by the children aged 12-15. The latter included the ISAAC video questionnaire. The levels of immunoglobulins A, G and M were determined in 995 saliva samples. Testing of lung function (whole body plethysmography before and after physical exercise) was performed in children with and without parent-reported wheezing in the last 12 months (n = 377). Response rate (questionnaire: 93%) and participation rates (saliva samples: 86%, lung function tests: 93%) were high. Our study confirmed higher prevalence of asthmatic symptoms in children aged 6-8 in Ochtrup (13.2%) compared to children of the same age in Muenster (8.5% (Duhme et al., Eur. Respir. J. 11, 840-847, 1998)). However, in the age group 12-15 years the prevalence was significantly lower in Ochtrup (9.8%), when compared to the former investigation and in comparison to Muenster (former survey: 17.9%; Muenster: 13.1%). Prevalence of wheezing was consistently higher in families with atopic disease. Additionally, history of respiratory disease, premature birth and presence of pets during 1st year of life showed a positive association with prevalence of wheezing. Mean salivary IgA levels were 61.4 (SD (standard deviation) 35.1, median: 53.7) mg/l in children aged 6-8 years and 83.4 (SD 39.0, median: 76.3) mg/l in children aged 12-15 years. No significant association between salivary immunoglobulins and wheezing was detected.