Comparison of digital and traditional skin wound closure assessment methods in mice.

BACKGROUND: Chronic skin wounds are a common complication of many diseases such as diabetes. Various traditional methods for assessing skin wound closure are used in animal studies, including wound tracing, calliper measurements and histological analysis. However, these methods have poorly defined wound closure or practical limitations. Digital image analysis of wounds is an increasingly popular, accessible alternative, but it is unclear whether digital assessment is consistent with traditional methods. This study aimed to optimise and compare digital wound closure assessment with traditional methods, using a diabetic mouse model. Diabetes was induced in male C57BL/6J mice by high-fat diet feeding combined with low dose (65 mg/kg of body weight) streptozotocin injections. Mice fed normal chow were included as controls. After 18 weeks, four circular full-thickness dorsal skin wounds of 4 mm diameter were created per mouse. The wounds were photographed and measured by callipers. Wound closure rate (WCR) was digitally assessed by two reporters using two methods: wound outline (WCR-O) and re-epithelialisation (WCR-E). Wounded skin tissues were collected at 10-days post-wounding and wound width was measured from haematoxylin and eosin-stained skin tissue. RESULTS: Between reporters, WCR-O was more consistent than WCR-E, and WCR-O correlated with calliper measurements. Histological analysis supported digital assessments, especially WCR-E, when wounds were histologically closed. CONCLUSIONS: WCR-O could replace calliper measurements to measure skin wound closure, but WCR-E assessment requires further refinement. Small animal studies of skin wound healing can greatly benefit from standardised definitions of wound closure and more consistent digital assessment protocols.

Circulating soluble CD163 as a potential biomarker of diabetes complications.

AIMS: To investigate whether soluble CD163 (sCD163) is altered in those with diabetes and various subtypes of complications and non-alcoholic fatty liver disease (NAFLD), and whether it can assess disease complications and severity in people with diabetes. METHODS: Adults with diabetes (n = 101) were recruited and assessed for the presence of any complications (D+Comps). Liver steatosis presence was determined by ultrasound and liver stiffness measurement (LSM) by transient elastography. Liver pathology other than non-alcoholic steatohepatitis (NASH) was excluded. Plasma sCD163 was measured by ELISA. RESULTS: sCD163 was higher in D+Comps (n = 59) compared to D-comps (n = 42) in those with microvascular complications (n = 56; 1.3-fold), including a 1.4-fold increase in chronic kidney disease (CKD) (n = 42). sCD163 correlated positively with HbA1c and urinary albumin-creatinine ratio and negatively with HDL-c in D+Comps. sCD163 was increased 1.7-fold in those with advanced NASH fibrosis (LSM ≥ 10.3 kPa, n = 19) compared to those without (LSM < 10.3 kPa, n = 80). The AUC-ROC-curve was 0.64 for sCD163 to detect CKD and 0.74 to detect advanced NASH fibrosis. CONCLUSIONS: In this study, the elevated circulating sCD163 occurred in people with diabetes who had microvascular complications or advanced NASH fibrosis, suggesting sCD163 may have clinical utility as a biomarker in certain diabetes complications and disease severity in NAFLD.

Alterations of CD163 expression in the complications of diabetes: A systematic review.

AIMS: Diabetes mellitus is a state of chronic low-grade inflammation. Scavenger receptor CD163, expressed on monocyte/macrophage cells with anti-inflammatory functions, has been observed in diabetes complications. This review aimed to systematically survey human studies published until 31st January 2022 for CD163 expression, in particular diabetes complications and additionally to investigate whether CD163 may be implicated as a biomarker of, and mediator in, the progression of diabetes complications. METHODS: A systematic literature search undertaken in Scopus, Embase and Medline established 79 papers of relevance. Data extraction and assessment followed the PRISMA workflow. RESULTS: Based on specific criteria, 11 studies totalling 821 participants were included in this review. CD163 was quantified in various forms including soluble, cell surface, and mRNA measures. This review found that soluble CD163 was upregulated in diabetes complications in various local body fluids and systemically in plasma or serum and therefore implicated in the progression of those complications. CD163+ cells and mRNA were variably expressed across diabetes complications. CONCLUSIONS: CD163 was altered in series of diabetes complications and the circulating sCD163 has potential utility as an inflammation biomarker. The variable expression of CD163 on cell surfaces and its mRNA across different diabetes complications warrants further systematic investigation.