The role of thrombospondins in wound healing, ischemia, and the foreign body reaction

Thrombospondin (TSP) 1 and TSP2 have been implicated in the regulation of several processes during tissue repair. Due to their matricellular nature, these proteins are thought to modulate cell-matrix interactions through a variety of mechanisms specific to the spatio-temporal context of their expression. Most notably, TSP1 and TSP2 appear to play distinct, non-overlapping roles in the healing of skin wounds. In contrast, both proteins have been implicated as regulators of ischemia-induced angiogenesis. Moreover, TSP2 has been shown to be a critical regulator of angiogenesis in the foreign body response (FBR). In this review, we discuss the role of TSPs in tissue repair and examine the mechanistic data regarding the ability of the thrombospondins to modulate cell-matrix interactions in this context

Thrombospondins in the heart: potential functions in cardiac remodeling

Cardiac remodeling after myocardial injury involves inflammation, angiogenesis, left ventricular hypertrophy and matrix remodeling. Thrombospondins (TSPs) belong to the group of matricellular proteins, which are non-structural extracellular matrix proteins that modulate cell–matrix interactions and cell function in injured tissues or tumors. They interact with different matrix and membrane-bound proteins due to their diverse functional domains. That the expression of TSPs strongly increases during cardiac stress or injury indicates an important role for them during cardiac remodeling. Recently, the protective properties of TSP expression against heart failure have been acknowledged. The current review will focus on the biological role of TSPs in the ischemic and hypertensive heart, and will describe the functional consequences of TSP polymorphisms in cardiac disease

The balsam bark weevil, Pissodes striatulus (Coleoptera: Curculionidae): life history and occurrence in southern British Columbia

Subalpine fir (Abies lasiocarpa (Pinaceae)) forests in British Columbia (B.C.) are increasingly climate-stressed and vulnerable to pest damage. Following a drought in southern B.C., the balsam bark weevil, Pissodes striatulus (Coleoptera: Curculionidae), was observed attacking and killing mature subalpine fir trees. This study documents P. striatulus as a tree-killing insect, often associated with western balsam bark beetle (Coleoptera: Curculionidae), which is considered the most destructive insect pest of subalpine fir. In B.C., this weevil displays a one-year life history, overwintering as late-instar larvae in the bark and as newly emerged or older adults in the duff at the base of attacked trees. Attacked trees are difficult to identify until the tree becomes chlorotic and dies. Larvae may excavate diagnostic chip cocoons in the sapwood before pupating, but most complete their development in the phloem where their galleries quickly become obscured by woodborer activity and other insects. Pissodes striatulus was found at 71% of sites surveyed, and 19% of trees sampled were killed by the weevil acting as the primary invader. The weevil uses downed trees, slash, and susceptible live trees, is long lived, and can switch from primary to secondary attacker, demonstrating its capacity to adapt to available and changing conditions

Activation of non-canonical WNT signaling in human visceral adipose tissue contributes to local and systemic inflammation

Abstract The accumulation of visceral adiposity is strongly associated with systemic inflammation and increased cardiometabolic risk. WNT5A, a non-canonical WNT ligand, has been shown to promote adipose tissue inflammation and insulin resistance in animal studies. Among other non-canonical pathways, WNT5A activates planar cell polarity (PCP) signaling. The current study investigated the potential contribution of non-canonical WNT5A/PCP signaling to visceral adipose tissue (VAT) inflammation and associated metabolic dysfunction in individuals with obesity. VAT and subcutaneous adipose tissue (SAT) samples obtained from subjects undergoing bariatric surgery were analyzed by qRT-PCR for expression of WNT/PCP genes. In vitro experiments were conducted with preadipocytes isolated from VAT and SAT biopsies. The expression of 23 out of 33 PCP genes was enriched in VAT compared to SAT. Strong positive expression correlations of individual PCP genes were observed in VAT. WNT5A expression in VAT, but not in SAT, correlated with indexes of JNK signaling activity, IL6, waist-to-hip ratio and hsCRP. In vitro, WNT5A promoted the expression of IL6 in human preadipocytes. In conclusion, elevated non-canonical WNT5A signaling in VAT contributes to the exacerbated IL-6 production in this depot and the low-grade systemic inflammation typically associated with visceral adiposity