Hyaluronan, platelets, and monocytes: a novel pro-inflammatory triad

Dynamic changes of peripheral inflammatory markers link with disease severity and predict short-term poor outcome of myasthenia gravis

The relationship between peripheral inflammatory markers, their dynamic changes, and the disease severity of myasthenia gravis (MG) is still not fully understood. Besides, the possibility of using it to predict the short-term poor outcome of MG patients have not been demonstrated. This study aims to investigate the relationship between peripheral inflammatory markers and their dynamic changes with Myasthenia Gravis Foundation of America (MGFA) classification (primary outcome) and predict the short-term poor outcome (secondary outcome) in MG patients. The study retrospectively enrolled 154 MG patients from June 2016 to December 2021. The logistic regression was used to investigate the relationship of inflammatory markers with MGFA classification and determine the factors for model construction presented in a nomogram. Finally, net reclassification improvement (NRI) and integrated discrimination improvement (IDI) were utilized to evaluate the incremental capacity. Logistic regression revealed significant associations between neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), aggregate index of systemic inflammation (AISI) and MGFA classification (p = 0.013, p = 0.032, p = 0.017, respectively). Incorporating dynamic changes of inflammatory markers into multivariable models improved their discriminatory capacity of disease severity, with significant improvements observed for NLR, systemic immune-inflammation index (SII) and AISI in NRI and IDI. Additionally, AISI was statistically associated with short-term poor outcome and a prediction model incorporating dynamic changes of inflammatory markers was constructed with the area under curve (AUC) of 0.953, presented in a nomograph. The inflammatory markers demonstrate significant associations with disease severity and AISI could be regarded as a possible and easily available predictive biomarker for short-term poor outcome in MG patients.

The systemic inflammation markers as possible indices for predicting respiratory failure and outcome in patients with myasthenia gravis

OBJECTIVE

This study aimed to explore the relationship between systemic inflammation markers and clinical activity, respiratory failure, and prognosis in patients with myasthenia gravis (MG).

METHODS

One hundred and seventeen MG patients and 120 controls were enrolled in this study. Differences in the four immune-related markers of two groups based on blood cell counts: neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR), lymphocyte to monocyte ratio (LMR), and systemic immune-inflammation index (SII) were measured. The stability of the associations between systemic inflammation markers and respiratory failure in MG patients was confirmed by adjusted logistic regression analysis. Moreover, Kaplan-Meier curve and multivariate COX regression models were applied to assess the factors affecting the outcome of MG.

RESULTS

NLR, PLR, and SII were higher in MG patients than those in controls and were positively associated with MGFA classification, but not LMR. Adjusted logistic regression analysis showed that PLR was an independent predictor of MG with respiratory failure. The ROC curve demonstrated that PLR showed good sensitivity and specificity for the diagnosis of MG with respiratory failure. Kaplan-Meier curve showed that GMG, positive AchR-Ab, respiratory failure, high NLR, PLR, SII, and IVIg exposure correlated with the risk for poor outcomes in MG patients. The multivariate COX regression models indicated that GMG and high SII was a risk factor for poor outcome of MG.

INTERPRETATION

The systemic inflammation markers expressed abnormally in MG patients, in which PLR may be an independent predictor of respiratory failure, and high SII and GMG were predictive risk factors for poor outcomes in MG patients.

Preliminary study of the gene expression of sulfation and degradation enzymes for chondroitin sulfate in glycerol-treated C2C12 myoblast cells

In this study, we induced chemical damage of C2C12 myoblasts that had differentiated into myotubes with glycerol, and four sulfation enzymes for chondroitin sulfate (CS) [carbohydrate sulfotransferase (Chst) 12, Chst15 and Chst3 and uronyl 2-O-sulfotransferase (UST)] and two CS degradation enzymes [hyaluronidase (Hyal) 1 and Hyal2] were examined for changes in gene expression. Treatment of myoblasts with 5% glycerol significantly increased the expression levels of the sulfation enzymes Chst12 and Chst15 and the degradation enzymes Hyal1 and Hyal2. However, the expression levels of the other two genes (Chst3 and Ust) showed no change. Differences in the expression levels of these enzymes may help to understand the difference in responsiveness of myoblasts to glycerol after muscle injury in vivo or in vitro.

Hyaluronan in skin wound healing: therapeutic applications

Hyaluronan is a vital constituent in effective skin wound healing. This polysaccharide is ubiquitous throughout the human body and has functional significance for tissue repair and remodelling. The importance of hyaluronan in the proliferative phase of healing is diverse, impacting on cell migration, proliferation, modification of the inflammatory response and on angiogenesis. As such, it holds therapeutic potential for a variety of clinical applications that range from facilitating effective wound healing to burns management and scarring. This overview of the multifaceted roles of hyaluronan considers its current applications to clinical practice in plastic surgery as well as the latest advances in research.

Worsen depression after viscosupplementation treatment for geriatric people with knee osteoarthritis?

Background/objective: Knee osteoarthritis (OA) in older people may result in psychological impairment, including anxiety and depression. This study investigates the effect of intraarticular hyaluronic acid injection (IAHA) on geriatric patients with OA. Method: A total of 102 geriatric patients with knee OA undergoing IAHA were prospectively enrolled in this study. Geriatric Depression Scale (GDS), State-Trait Anxiety Inventory (STAI), Western Ontario and McMaster University Osteoarthritis Index (WOMAC) and the International Knee Documentation Committee Subjective Knee Evaluation Form (IKDC), and Visual Analogue Scale (VAS) for pain were recorded. All outcomes were measured at baseline before injection and during two, four, and six month follow-ups. Results: IAHA had a significant short-term effect, relieving pain at the two month follow-up, but the effect was weaker at the four month follow-up. Both IKDC and WOMAC scores were significantly improved at the two month follow-up. Viscosupplementation did not improve STAI. GDS exhibited significant deterioration at the four month follow-up. Conclusions: Although IAHA for the treatment of OA provided short-term efficiency, it had no effects on anxiety and increased depression of geriatric people. Health education should be provided with caution before viscosupplementation treatment to manage expectations of the efficacy of treatment for geriatric OA patients.

Are Platelets Cells? And if Yes, are They Immune Cells?

Small fragments circulating in the blood were formally identified by the end of the nineteenth century, and it was suggested that they assisted coagulation via interactions with vessel endothelia. Wright, at the beginning of the twentieth century, identified their bone-marrow origin. For long, platelets have been considered sticky assistants of hemostasis and pollutants of blood or tissue samples; they were just cell fragments. As such, however, they were acknowledged as immunizing (to specific HPA and HLA markers): the platelet’s dark face. The enlightened face showed that besides hemostasis, platelets contained factors involved in healing. As early as 1930s, platelets entered the arsenal of medicines were transfused, and were soon manipulated to become a kind of glue to repair damaged tissues. Some gladly categorized platelets as cells but they were certainly not fully licensed as such for cell physiologists. Actually, platelets possess almost every characteristic of cells, apart from being capable of organizing their genes: they have neither a nucleus nor genes. This view prevailed until it became evident that platelets play a role in homeostasis and interact with cells other than with vascular endothelial cells; then began the era of physiological and also pathological inflammation. Platelets have now entered the field of immunity as inflammatory cells. Does assistance to immune cells itself suffice to license a cell as an “immune cell”? Platelets prove capable of sensing different types of signals and organizing an appropriate response. Many cells can do that. However, platelets can use a complete signalosome (apart from the last transcription step, though it is likely that this step can be circumvented by retrotranscribing RNA messages). The question has also arisen as to whether platelets can present antigen via their abundantly expressed MHC class I molecules. In combination, these properties argue in favor of allowing platelets the title of immune cells.

[Connective tissue and inflammation]

The author summarizes the structure of the connective tissues, the increasing motion of the constituents, which determine the role in establishing the structure and function of that. The structure and function of the connective tissue are related to each other in the resting as well as inflammatory states. It is emphasized that cellular events in the connective tissue are part of the defence of the organism, the localisation of the damage and, if possible, the maintenance of restitutio ad integrum. The organism responds to damage with inflammation, the non specific immune response, as well as specific, adaptive immunity. These processes are located in the connective tissue. Sterile and pathogenic inflammation are relatively similar processes, but inevitable differences are present, too. Sialic acids and glycoproteins containing sialic acids have important roles, and the role of Siglecs is also highlighted. Also, similarities and differences in damages caused by pathogens and sterile agents are briefly summarized. In addition, the roles of adhesion molecules linked to each other, and the whole event of inflammatory processes are presented. When considering practical consequences it is stressed that the structure (building up) of the organism and the defending function of inflammation both have fundamental importance. Inflammation has a crucial role in maintaining the integrity and the unimpaired somato-psychological state of the organism. Thus, inflammation serves as a tool of organism identical with the natural immune response, inseparably connected with the specific, adaptive immune response. The main events of the inflammatory processes take place in the connective tissue.

The way of self-defence of the organism: inflammation

The acute and chronic constitutional reactions of the organism elicited by sterile causes and pathogenic structures threatening the soundness of the organism are surveyed by the author. It is emphasized that depending on causes which can be very different, there are various syndromes occurring in the clinical practice. On the basis of multitudiness of pathogenic factors and individual differences, the infammatory reactions are clinically, pathologically and pathobiochemically can be hugely variable. The acute inflammatory response may be sterile. It is often difficult to recognize in these processes whether the inflammation is harmful or beneficial for the organism as a whole. It is possible that the inflammatory response itself is the defending resource of the individual. The non-sterile acute inflammation is evoked by pathogenic microorganisms. The variety of clinical syndromes are explained by the high diversity of pathogenic microbes, the individualities of the defending organisms, and the natural and adaptive immunity of the organism which may be intact or possibly defective. In the latter case the inflammation itself is the disease, as a consequence of a pathological process conducted by the cortico-hypothalamo-adernal axis. The acute inflammation is a defending, preventing and repairing process, constituting an important part of the natural innate immune response. It is inseparable from the natural innate immune response, which is in close cooperation with the adaptive, specific immune response with mutual effects on each of the other. The conductor and the response reactions of the two immune responses are also the same. There are alterations in serum proteins/glycoproteins synthesized mostly by the hepatocytes. Because the concentration of almost all proteins/glycoproteins may change, the use of the discriminative term “acute phase reactant” is hardly relevant. For example, the HDL molecule is a negative “acute phase reactant”. On the gound of clinical, pathological and biochemical caracteristics, the chronic sterile inflammation is a very different entity. It has been established that atherosclerosis is one of the ab origine chronic inflammatory syndrome. It is a long-lasting pathological entity progressing, rather than resolving with different celerity, namely a unique vasculitis syndrome. We are speaking about risk factors instead of causes, which constitute larger or smaller groups to elicite the preventing reaction of the host. The propagations and final outcomes are quite different from that of the acute process. The disadvantages or benefits for the organism are scarcely predictable, albeit the chronic process may have roles in its prolonged nature. Orv. Hetil., 2013, 154, 1247–1255.

A RHAMM mimetic peptide blocks hyaluronan signaling and reduces inflammation and fibrogenesis in excisional skin wounds

Hyaluronan is activated by fragmentation and controls inflammation and fibroplasia during wound repair and diseases (eg, cancer). Hyaluronan-binding peptides were identified that modify fibrogenesis during skin wound repair. Peptides were selected from 7- to 15mer phage display libraries by panning with hyaluronan-Sepharose beads and assayed for their ability to block fibroblast migration in response to hyaluronan oligosaccharides (10 kDa). A 15mer peptide (P15-1), with homology to receptor for hyaluronan mediated motility (RHAMM) hyaluronan binding sequences, was the most effective inhibitor. P15-1 bound to 10-kDa hyaluronan with an affinity of K(d) = 10(-7) and appeared to specifically mimic RHAMM since it significantly reduced binding of hyaluronan oligosaccharides to recombinant RHAMM but not to recombinant CD44 or TLR2,4, and altered wound repair in wild-type but not RHAMM(-/-) mice. One topical application of P15-1 to full-thickness excisional rat wounds significantly reduced wound macrophage number, fibroblast number, and blood vessel density compared to scrambled, negative control peptides. Wound collagen 1, transforming growth factor β-1, and α-smooth muscle actin were reduced, whereas tenascin C was increased, suggesting that P15-1 promoted a form of scarless healing. Signaling/microarray analyses showed that P15-1 blocks RHAMM-regulated focal adhesion kinase pathways in fibroblasts. These results identify a new class of reagents that attenuate proinflammatory, fibrotic repair by blocking hyaluronan oligosaccharide signaling.

Sensing sterile injury: opportunities for pharmacological control

Sterile injury can trigger an acute inflammatory response, which might be responsible for the pathogenesis of several diseases, including rheumatoid arthritis, lung fibrosis and acute liver failure. A key event for the pathogenesis of these diseases is the recruitment of leukocytes to necrotic areas. Much is known about the mechanisms of recruitment to sites of infection. However, only now is it becoming clear how leukocytes, especially neutrophils, are recruited to areas of tissue damage and necrosis in the absence of infection. Here, we review and discuss mechanisms responsible for sensing and driving the influx of leukocytes, specifically neutrophils, into sites of sterile injury. This knowledge clearly opens new opportunities for therapeutic intervention.

Increased HAS2-driven hyaluronic acid synthesis in shar-pei dogs with hereditary cutaneous hyaluronosis (mucinosis)

The Chinese shar-pei dog is known for its distinctive feature of wrinkled and thickened skin, defined as primary or hereditary cutaneous mucinosis. In a recent report, we identified the mucinous material deposited in the shar-pei skin as the polysaccharide hyaluronan (HA). In the present work, the molecular and cellular mechanisms underlying this phenotype have been identified in dermal fibroblasts isolated from shar-pei dogs. The production of HA, which appeared to be mainly associated with cell membrane protrusions and also intracellular, was higher in shar-pei fibroblasts than in control cells. The HA accumulation is related to a higher mRNA expression of the isoform HAS2 of the HA-synthesizing enzyme family, hyaluronan synthases (HAS). The higher expression of HAS2 in shar-pei fibroblasts was confirmed at the protein level. The other HAS isoenzymes, HAS1 and HAS3, and the HA-degrading enzymes, Hyal1 and Hyal2, were not differentially expressed in shar-pei fibroblasts compared with cells from control dogs. Fibroblasts from shar-pei dogs and from control dogs are morphologically different as observed by transmission electron microscopy. Scanning electron microscopy revealed a large number of cellular protrusions with associated globular deposits. Electron microscopy after labelling with biotinylated HA-binding protein confirmed an increased HA content in shar-pei fibroblasts, which could be localized in several subcellular structures. The authors propose the name hereditary cutaneous hyaluronosis (HCH) for affected dogs, because it better defines the cutaneous mucinosis of shar-pei dogs.

Genetic variation in hyaluronan metabolism loci is associated with plasma plasminogen activator inhibitor-1 concentration

Elevated plasma plasminogen activator inhibitor-1 (PAI-1) concentration is associated with cardiovascular disease risk. PAI-1 is the primary inhibitor of fibrinolysis within both the circulation and the arterial wall, playing roles in both atherosclerosis and thrombosis. To define the heritable component, subjects within the population-based SHARE (Study of Health Assessment and Risk in Ethnic groups) and SHARE-AP (Study of Health Assessment and Risk Evaluation in Aboriginal Peoples) studies, composed of Canadians of South Asian (n = 298), Chinese (n = 284), European (n = 227), and Aboriginal (n = 284) descent, were genotyped using the gene-centric Illumina HumanCVD BeadChip. After imputation, more than 150,000 single nucleotide polymorphisms (SNPs) in more than 2000 loci were tested for association with plasma PAI-1 concentration. Marginal association was observed with the PAI-1 locus itself (SERPINE1; P < .05). However, 5 loci (HABP2, HSPA1A, HYAL1, MBTPS1, TARP) were associated with PAI-1 concentration at a P < 1 × 10(-5) threshold. The protein products of 2 of these loci, hyaluronan binding protein 2 (HABP2) and hyaluronoglucosaminidase 1 (HYAL1), play key roles in hyaluronan metabolism, providing genetic evidence to link these pathways.

[Hyaluronan in inflammation, auto-immunity and cardio-vascular diseases]

Hyaluronan (H) is an ubiquitous high-molecular size glycosaminoglycan involved in many physiological functions. Evidences are numerous implying H in various pathological pathways, such as inflammation, cancer cardio-vascular diseases. CD44 is the principal membrane cell receptor of H. In inflammation, H has size-specific different biological activities. The high molecular weight H are anti-angiogenic, anti-inflammatory and immunosuppressive. Smaller H oligomers are angiogenic, inflammatory and immuno-stimulatory. H is strongly involved in the recruitment of leucocytes at the site of inflammation (role of CD44). Data giving evidence for a role of H in allergic pathways and auto-immunity are scarce. H is implicated in pathogenetic process leading to atherosclerosis.

Anti-inflammatory actions of serine protease inhibitors containing the Kunitz domain

INTRODUCTION

Protease inhibitors, including the Kunitz, Kazal, serpin and mucus families, play important roles in inhibiting protease activities during homeostasis, inflammation, tissue injury, and cancer progression. Interestingly, in addition to their anti-protease activity, protease inhibitors also often possess other intrinsic properties that contribute to termination of the inflammatory process, including modulation of cytokine expression, signal transduction and tissue remodeling. In this review we have tried to summarize recent findings on the Kunitz family of serine proteinase inhibitors and their implications in health and disease.

MATERIALS AND METHODS

A systematic search was performed in the electronic databases PubMed and ScienceDirect up to October 2009. We tried to limit the review to anti-inflammatory actions and actions not related to protease inhibition.

RESULTS AND CONCLUSION

Recent studies have demonstrated that the Kunitz inhibitors are not only protease inhibitors, but can also prevent inflammation and tissue injury and subsequently promote tissue remodeling.