Connective tissue growth factor, matrix regulation, and diabetic kidney disease

The Effectiveness of Treating Osgood-Schlatter Disease (OSD) with Leukocyte-Rich Platelet-Rich Plasma (LR-PRP) Depending on the Duration of the Disease

Background: Osgood-Schlatter disease (OSD) occurs mainly in physically active adolescents, causing significant physical activity restrictions. The aim of this study is to compare the effectiveness of treating OSD with leukocyte-rich platelet-rich plasma (LR-PRP) depending on the duration of the disease and to attempt to develop an alternative treatment method to the currently used conservative therapy. Methods: Treatment efficacy was evaluated using the VAS, Tegner, Lysholm, and KOOS scales. Subject satisfaction, return to sports activity, potential adverse effects, and X-ray evaluation were likewise used to assess the success of the procedure. Results: Analysis across all scales showed statistically significant treatment effectiveness with LR-PRP in both groups of patients. When comparing the two groups, significantly better treatment outcomes were achieved in the acute phase of OSD. Treatment satisfaction in the acute OSD group was 95%, compared to 64% in the chronic group. The MCID value after LR-PRP injection in acute OSD compared to chronic OSD reached 100% vs. 81% on the VAS scale, 95.5% vs. 55% on the Tegner scale, 95% vs. 47% on the Lysholm scale and 91% vs. 27% on the KOOS scale. No adverse effects were recorded in either group. Conclusions: The high efficacy of LR-PRP treatment in patients with acute OSD, in correlation with high safety, as well as rapid and lasting results, can be an effective and beneficial alternative to conservative treatment. This single procedure seems particularly justified in a group of young professional athletes, where absence from training can lead to serious consequences.

Age-related downregulation of CCN2 is regulated by cell size in a YAP/TAZ-dependent manner in human dermal fibroblasts: impact on dermal aging

CCN2, a member of the CCN family of matricellular proteins, is a key mediator and biomarker of tissue fibrosis. We previously reported that CCN2 is significantly reduced in aged human dermis, which contributes to dermal aging through the downregulation of collagen production, the major structural protein in the skin. In this study, we investigated the underlying mechanisms of the age-related downregulation of CCN2 in human skin dermal fibroblasts. Dermal fibroblasts isolation and laser-capture microdissection‒coupled RT-PCR from human skin confirmed that age-related reduction of CCN2 expression is regulated by epigenetics. Mechanistic investigation revealed that age-related reduction of CCN2 is regulated by impaired dermal fibroblast spreading/cell size, which is a prominent feature of aged dermal fibroblasts in vivo. Gain-of-function and loss-of-function analysis confirmed that age-related downregulation of CCN2 is regulated by YAP/TAZ in response to reduced cell size. We further confirmed that restoration of dermal fibroblast size rapidly reversed the downregulation of CCN2 in a YAP/TAZ-dependent manner. Finally, we confirmed that reduced YAP/TAZ nuclear staining is accompanied by loss of CCN2 in aged human skin in vivo. Our data reveal a mechanism by which age-related reduction in fibroblast spreading/size drives YAP/TAZ-dependent downregulation of CCN2 expression, which in turn contributes to loss of collagen in aged human skin.

Cellular crosstalk of glomerular endothelial cells and podocytes in diabetic kidney disease

Diabetic kidney disease (DKD) is a serious microvascular complication of diabetes and is the leading cause of end-stage renal disease (ESRD). Persistent proteinuria is an important feature of DKD, which is caused by the destruction of the glomerular filtration barrier (GFB). Glomerular endothelial cells (GECs) and podocytes are important components of the GFB, and their damage can be observed in the early stages of DKD. Recently, studies have found that crosstalk between cells directly affects DKD progression, which has prospective research significance. However, the pathways involved are complex and largely unexplored. Here, we review the literature on cellular crosstalk of GECs and podocytes in the context of DKD, and highlight specific gaps in the field to propose future research directions. Elucidating the intricates of such complex processes will help to further understand the pathogenesis of DKD and develop better prevention and treatment options.

Hypoxia-inducible factors and diabetes

Hypoxia can be defined as a relative deficiency in the amount of oxygen reaching the tissues. Hypoxia-inducible factors (HIFs) are critical regulators of the mammalian response to hypoxia. In normal circumstances, HIF-1α protein turnover is rapid, and hyperglycemia further destabilizes the protein. In addition to their role in diabetes pathogenesis, HIFs are implicated in development of the microvascular and macrovascular complications of diabetes. Improving glucose control in people with diabetes increases HIF-1α protein and has wide-ranging benefits, some of which are at least partially mediated by HIF-1α. Nevertheless, most strategies to improve diabetes or its complications via regulation of HIF-1α have not currently proven to be clinically useful. The intersection of HIF biology with diabetes is a complex area in which many further questions remain, especially regarding the well-conducted studies clearly describing discrepant effects of different methods of increasing HIF-1α, even within the same tissues. This Review presents a brief overview of HIFs; discusses the range of evidence implicating HIFs in β cell dysfunction, diabetes pathogenesis, and diabetes complications; and examines the differing outcomes of HIF-targeting approaches in these conditions.

CTGF mediates high-glucose induced epithelial-mesenchymal transition through activation of β-catenin in podocytes

OBJECTIVE

It is known that connective tissue growth factor (CTGF) and β-catenin are involved in DN; however, the underlying molecular mechanisms remain unknown. Here we hypothesized that podocytes undergo epithelial-mesenchymal transition (EMT) in high-glucose condition and CTGF mediates high-glucose induced EMT by activating β-catenin in podocytes.

METHODS

The differentiated podocytes were cultured and divided into three groups: the normal glucose group (5 mmol/L glucose), the high-glucose group (30 mmol/L glucose), and the osmotic control group (5 mmol/L glucose supplemented with 25 mmol/L mannitol). The morphology of cultured podocytes was observed under phase contrast microscopy. To study the relevant markers of EMT, as well as CTGF and β-catenin, the mRNA and protein expressions were analyzed by real-time PCR and western blotting, respectively. In addition, the effects of inhibition CTGF by anti-CTGF antibody on high-glucose-induced EMT and β-catenin expression in podocytes were studied.

RESULTS

High glucose not only induced phenotypic transition of podocytes but also increased the expression of CTGF and β-catenin. Under high-glucose condition, podocytes underwent EMT, which were demonstrated by downregulation of nephrin and upregulation of desmin. Moreover, high-glucose-induced EMT and β-catenin overexpression in podocytes were attenuated by anti-CTGF antibody.

CONCLUSION

CTGF and β-catenin are involved in the EMT of podocytes in diabetes. CTGF mediates high-glucose induced EMT through activation of β-catenin in podocytes. CTGF inhibition may protect podocytes from EMT in diabetes.

From molecular signatures to predictive biomarkers: modeling disease pathophysiology and drug mechanism of action

Omics profiling significantly expanded the molecular landscape describing clinical phenotypes. Association analysis resulted in first diagnostic and prognostic biomarker signatures entering clinical utility. However, utilizing Omics for deepening our understanding of disease pathophysiology, and further including specific interference with drug mechanism of action on a molecular process level still sees limited added value in the clinical setting. We exemplify a computational workflow for expanding from statistics-based association analysis toward deriving molecular pathway and process models for characterizing phenotypes and drug mechanism of action. Interference analysis on the molecular model level allows identification of predictive biomarker candidates for testing drug response. We discuss this strategy on diabetic nephropathy (DN), a complex clinical phenotype triggered by diabetes and presenting with renal as well as cardiovascular endpoints. A molecular pathway map indicates involvement of multiple molecular mechanisms, and selected biomarker candidates reported as associated with disease progression are identified for specific molecular processes. Selective interference of drug mechanism of action and disease-associated processes is identified for drug classes in clinical use, in turn providing precision medicine hypotheses utilizing predictive biomarkers.

New insight into the molecular drug target of diabetic nephropathy

Diabetic nephropathy (DN) lowered quality of life and shortened life expectancy amongst those affected. Evidence indicates interaction between advanced glycation end products (AGEs), activated protein kinase C (PKC) and angiotensin II exacerbate the progression of DN. Inhibitors of angiotensin-converting enzyme (ACEIs), renin angiotensin aldosterone system (RAAS), AGEs, and PKC have been tested for slowing down the progression of DN. The exact molecular drug targets that lead to the amelioration of renal injury in DN are not well understood. This review summarizes the potential therapeutic targets, based on putative mechanism in the progression of the disease.