Anti-neurofascin 155 Antibody-positive Neuropathy in a Human Immunodeficiency Virus-infected Patient.

Human immunodeficiency virus (HIV)-associated neuropathy is a common complication of HIV infection and has several clinical subtypes. HIV-associated chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a demyelinating neuropathy whose clinical features are known to differ from those of CIDP in the HIV-uninfected population. We herein report a case of CIDP in an HIV-infected patient who was finally diagnosed with anti-neurofascin 155 (NF155) antibody-positive neuropathy. The clinical features, including clinical findings and therapeutic responses, were typical of paranodal antibody-mediated neuropathy. To our knowledge, this is the first case of anti-NF155 antibody-associated neuropathy in an HIV-infected patient.

Levels of APE1 Repair Gene and CLEC4M in Lung Cancer Patients Receiving Cisplatin Chemotherapy.

This study aimed to detect the levels of apurinic/apyrimidinic endonuclease 1 (APE1) gene expression and C-type lectin domain family 4 member M (CLEC4M) and their association with cisplatin chemotherapy in lung cancer patients. Overall, 105 individuals who attended the Al-Amal National Hospital for Cancer Management, Baghdad, Iraq, were enrolled in the study and divided into three equal groups. The groups included the patients newly diagnosed with lung cancer, cancer patients who received cisplatin, and the healthy control group. All study groups were subjected to the sampling of the venous blood for molecular analysis by real-time polymerase chain reaction (RT-PCR) to detect the APE1 gene and enzyme-linked immunosorbent assay (ELISA) for serological testing to measure the concentration of CLEC4M protein. Significantly, the values of both cancer groups were higher than those reported in the control group. The relative index revealed a significant difference in the mean fold change level of APE1 in the newly diagnosed group (3 fold) and cisplatin therapy patients group (2 fold), compared to the control group (P=0.005). No significant differences were detected between the two cancer groups in terms of fold change mean of expression, demographic characteristics, and cancer histological type. Regarding human CLEC4M protein level, cases receiving cisplatin (139.2±25.9) and newly diagnosed patients (331.0±38.1) had a highly significant difference with the control group (100.3±47.5, P<0.001). There was no significant difference between the concentration level of CLEC4M and all parameters in demographic characteristics and cancer histological type. This was the first study to demonstrate that higher expression levels of new APE1, CLEC4M, and glutathione, especially after chemotherapy, are beneficial as diagnostic and prognostic markers for resistance to platinum chemotherapy in Iraqi lung cancer patients.

Myeloperoxidase Inhibition Reverses Biomarker Profiles Associated With Clinical Outcomes in HFpEF.

BACKGROUND: Systemic microvascular dysfunction and inflammation are postulated to play a pathophysiologic role in heart failure with preserved ejection fraction (HFpEF). OBJECTIVES: This study aimed to identify biomarker profiles associated with clinical outcomes in HFpEF and investigate how inhibition of the neutrophil-derived reactive oxygen species-producing enzyme, myeloperoxidase, affects these biomarkers. METHODS: Using supervised principal component analyses, the investigators assessed the associations between baseline plasma proteomic Olink biomarkers and clinical outcomes in 3 independent observational HFpEF cohorts (n = 86, n = 216, and n = 242). These profiles were then compared with the biomarker profiles discriminating patients treated with active drug vs placebo in SATELLITE (Safety and Tolerability Study of AZD4831 in Patients With Heart Failure), a double-blind randomized 3-month trial evaluating safety and tolerability of the myeloperoxidase inhibitor AZD4831 in HFpEF (n = 41). Pathophysiological pathways were inferred from the biomarker profiles by interrogation of the Ingenuity Knowledge Database. RESULTS: TNF-R1, TRAIL-R2, GDF15, U-PAR, and ADM were the top individual biomarkers associated with heart failure hospitalization or death, and FABP4, HGF, RARRES2, CSTB, and FGF23 were associated with lower functional capacity and poorer quality of life. AZD4831 downregulated many markers (most significantly CDCP1, PRELP, CX3CL1, LIFR, VSIG2). There was remarkable consistency among pathways associated with clinical outcomes in the observational HFpEF cohorts, the top canonical pathways being associated with tumor microenvironments, wound healing signaling, and cardiac hypertrophy signaling. These pathways were predicted to be downregulated in AZD4831 relative to placebo-treated patients. CONCLUSIONS: Biomarker pathways that were most strongly associated with clinical outcomes were also the ones reduced by AZD4831. These results support the further investigation of myeloperoxidase inhibition in HFpEF.

Surfaceome Profiling of Cell Lines and Patient-Derived Xenografts Confirm FGFR4, NCAM1, CD276, and Highlight AGRL2, JAM3, and L1CAM as Surface Targets for Rhabdomyosarcoma.

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children. The prognosis for patients with high-grade and metastatic disease is still very poor, and survivors are burdened with long-lasting side effects. Therefore, more effective and less toxic therapies are needed. Surface proteins are ideal targets for antibody-based therapies, like bispecific antibodies, antibody-drug conjugates, or chimeric antigen receptor (CAR) T-cells. Specific surface targets for RMS are scarce. Here, we performed a surfaceome profiling based on differential centrifugation enrichment of surface/membrane proteins and detection by LC-MS on six fusion-positive (FP) RMS cell lines, five fusion-negative (FN) RMS cell lines, and three RMS patient-derived xenografts (PDXs). A total of 699 proteins were detected in the three RMS groups. Ranking based on expression levels and comparison to expression in normal MRC-5 fibroblasts and myoblasts, followed by statistical analysis, highlighted known RMS targets such as FGFR4, NCAM1, and CD276/B7-H3, and revealed AGRL2, JAM3, MEGF10, GPC4, CADM2, as potential targets for immunotherapies of RMS. L1CAM expression was investigated in RMS tissues, and strong L1CAM expression was observed in more than 80% of alveolar RMS tumors, making it a practicable target for antibody-based therapies of alveolar RMS.

Nectin-4: a Tumor Cell Target and Status of Inhibitor Development.

PURPOSE OF REVIEW: This study aims to gather the current state of the literature about anti-Nectin-4 innovative associations in solid tumors and to investigate underlying resistance mechanisms. RECENT FINDINGS: Antibody-drug conjugate (ADC) targeting Nectin-4 efficacy gained attention and offers a promising association with other antineoplastic drugs especially in urothelial carcinoma. The heterogeneity of Nectin-4 expression across the molecular subtypes was highlighted especially in urothelial cancers. A unique study using preclinical models demonstrated an upregulation of P-gp expression, which may explain the anti-Nectin-4 resistance mechanisms. Further studies are urgently needed to understand anti-Nectin-4 sensitivity and resistance phenomenon. The growing therapeutic associations of enfortumab vedotin offer optimistic opportunities in management and treatment of wide range of solid tumors including rare aggressive malignancies.

Vascular adhesion protein-1 (VAP-1) in vascular inflammatory diseases.

Vascular adhesion protein-1 (VAP-1) also known as amino oxidase copper containing 3 (AOC3) is a pro-inflammatory and versatile molecule with adhesive and enzymatic properties. VAP-1 is a primary amine oxidase belonging to the semicarbazide-sensitive amine oxidase (SSAO) family, which catalyzes the oxidation of primary amines leading to the production of ammonium, formaldehyde, methylglyoxal, and hydrogen peroxide. VAP-1 is mainly expressed by endothelial cells, smooth muscle cells, adipocytes and pericytes. It is involved in a repertoire of biological functions, e.g., immune cell extravasation, angiogenesis, and vascularization. Research into VAP-1 has intensified within the last decade on its role as a novel clinical biomarker and as a potential therapeutic target of vascular inflammatory disorders such as atherosclerosis, stroke, diabetes, neurovascular disorders (e.g., Alzheimer's Disease), hepatic disease (e.g., non-alcoholic steatohepatitis), and skin conditions (e.g., psoriasis). This is the most up-to-date and comprehensive review on VAP-1 focusing on the translational aspects of VAP-1. Compared to recent reviews, our review provides novel insights on VAP-1 and heart failure, stroke and frailty, diabetes, endometriosis, osteoarthritis, COVID-19, conjunctivitis associated systemic lupus erythematosus, hematopoietic stem cells, gliomas, treatment of colorectal cancer with a novel VAP-1 inhibitor (U-V269), promoting recovery of motor functions and habit learning with a novel VAP-1 inhibitor (PXS-4681A), and 68Ga-DOTA-Siglec-9, a labelled peptide of Siglec-9 (a VAP-1 ligand), which appears to be a safe PET tracer for inflammation in rheumatoid arthritis. Finally, we present the emerging role of VAP-1 in pregnancy as a gatekeeper of immune cells, which are critical for spiral arterial remodeling, the deficiency of which could lead to vascular disorders of pregnancy such as preeclampsia. Future research should prioritize clinical trials on VAP-1 small-molecule inhibitors and monoclonal antibodies, thus, maximizing the potential of VAP-1 targeted therapy as well as research into sVAP-1 as a clinical biomarker of diseases and its prognosis.

Advances in Trop2-targeted therapy: Novel agents and opportunities beyond breast cancer.

Trop2 is a transmembrane glycoprotein and calcium signal transducer with limited expression in normal human tissues. It is consistently overexpressed in a variety of malignant tumors and participates in several oncogenic signaling pathways that lead to tumor development, invasion, and metastasis. As a result, Trop2 has become an attractive therapeutic target in cancer treatment. The anti-Trop2 antibody-drug conjugate (Trodelvy™, sacituzumab govitecan) has been approved to treat metastatic triple-negative breast cancer. However, it is still unclear whether the success observed in Trop2-positive breast cancer could be replicated in other tumor types, owing to the differences in the expression levels and functions of Trop2 across cancer types. In this review, we summarize the recent progress on the structures and functions of Trop2 and highlight the potential diagnostic and therapeutic value of Trop2 beyond breast cancer. In addition, the promising novel Trop2-targeted agents in the clinic were discussed, which will likely alter the therapeutic landscape of Trop2-positive tumors in the future.

Activation of HIF-1α/VEGF-A pathway by deferoxamine ameliorates retinal hypoxia in a rat subarachnoid hemorrhage model.

BACKGROUND AND PURPOSE: Subarachnoid hemorrhage (SAH) is associated with sustained vasoconstriction in retinal vessels and vasoconstriction leads to retinal ischemia and hypoxia. Our previous finding also revealed the changes in hypoxia-related elements in the retina after SAH, further lending weight to the hypothesis that retinal vasospasm and hypoxia after SAH. Deferoxamine is a high-affinity iron chelator with reported neuroprotective effects against stroke. Here, we aimed to explore the effects of deferoxamine on retinal hypoxia after SAH. METHODS: SAH was established and deferoxamine was injected intraperitoneally for 3 days in the treatment group. To detect retinal new vessels, platelet endothelial cell adhesion molecule (CD31) was labeled by immunofluorescence and immunohistochemistry. Furthermore, the effects of deferoxamine on the expression of vascular endothelial growth factor A (VEGF-A) and hypoxia-inducible factor-1α (HIF-1α) were revealed by western blot analysis. RESULTS: The immunofluorescence and immunohistochemical staining of CD31 revealed a marked increase in new vessels in the retinal ganglion cell layer after deferoxamine treatment. By western blot analysis, HIF-1α and VEGF-A increased gradually in the first day and then rebounded to a new level on day 7. A deferoxamine-induced increase in HIF-1α/VEGF-A expression was also confirmed by western blot. CONCLUSIONS: Our findings suggest that modulating the application of deferoxamine may offer therapeutic approaches to alleviate retinal complications after SAH.

New emerging targets in advanced urothelial carcinoma: Is it the primetime for personalized medicine?

In recent years the introduction of immunotherapy has importantly changed the treatment landscape of advanced urothelial carcinoma. Several immune checkpoint inhibitors are now the standard of care as maintenance treatment after disease control with platinum-based first-line chemotherapy (avelumab), in subsequent lines (pembrolizumab) or as upfront therapy in platinum-ineligible patients (atezolizumab or pembrolizumab). Moreover, personalized therapy based on tumor molecular features has been developed. Namely, the increasing knowledge of the pathogenesis and molecular pathways underlying cancer development and progression is leading the introduction of target therapies such as the recently approved fibroblastic growth factor receptor (FGFR) inhibitor erdafitinib or the anti-nectin 4 antibody drug-conjugated enfortumab vedotin. Consequently, clinicians face new challenges, such as the choice of the best therapeutic sequence for each patient. The aim of this review is focusing on the emerging treatment options in metastatic urothelial carcinoma and discussing clinical features for choosing therapeutic sequencing.

Management of Dermatologic Events Associated With the Nectin-4-directed Antibody-Drug Conjugate Enfortumab Vedotin.

Enfortumab vedotin is a first-in-class Nectin-4-directed antibody-drug conjugate approved by the US Food and Drug Administration for the treatment of patients with locally advanced or metastatic urothelial cancer (la/mUC) previously treated with a platinum-based chemotherapy and a programmed death receptor-1/programmed death-ligand 1 (PD-1/L1) inhibitor, or patients with la/mUC who are ineligible for cisplatin-based chemotherapy and have previously received one or more prior lines of therapy. Enfortumab vedotin is the only drug to have demonstrated survival benefit versus chemotherapy in a randomized controlled trial in patients with la/mUC previously treated with platinum-based chemotherapy and a PD-1/L1 inhibitor. The development of dermatologic events following the administration of enfortumab vedotin is anticipated given the expression of Nectin-4 in epidermal keratinocytes and skin appendages (eg, sweat glands and hair follicles). There is the potential for rare but severe and possibly fatal cutaneous adverse reactions, including Stevens-Johnson syndrome and toxic epidermal necrosis, as described in the boxed warning of the US prescribing information for enfortumab vedotin. This manuscript describes the presumed pathophysiology and manifestations of dermatologic reactions related to enfortumab vedotin, and presents recommendations for prevention and treatment, to provide oncologists and other healthcare providers with an awareness of these potential adverse events to best anticipate and manage them.

TROP2 Expression Across Molecular Subtypes of Urothelial Carcinoma and Enfortumab Vedotin-resistant Cells.

Sacituzumab govitecan (SG) is an antibody-drug conjugate (ADC) targeting TROP2, which has recently been approved for treatment-refractory metastatic urothelial cancer (UC). However, the variability of TROP2 expression across different bladder cancer (BC) subtypes, as well as after enfortumab vedotin (EV) exposure, remains unknown. Using gene expression data from four clinical cohorts with >1400 patient samples of muscle-invasive BC and a BC tissue microarray, we found that TROP2 mRNA and protein are highly expressed across basal, luminal, and stroma-rich subtypes, but depleted in the neuroendocrine subtype. In addition, TROP2 mRNA levels are correlated with NECTIN4 mRNA but are more highly expressed than NECTIN4 mRNA in patient cohorts and BC cell lines. Moreover, CRISPR/Cas9-mediated knockdown of TROP2 demonstrates that its expression is one factor governing SG sensitivity. After prolonged EV exposure, cells can downregulate NECTIN4, leading to EV resistance, but retain TROP2 expression and remain sensitive to SG, suggesting nonoverlapping resistance mechanisms to these ADCs. While our findings warrant further validation, they have significant implications for biomarker development, patient selection, and treatment sequencing in the clinic as well as clinical trial design and stratification for metastatic BC patients. PATIENT SUMMARY: In this report, we investigated the expression levels of the drug target TROP2 across different molecular subtypes of bladder cancer in multiple patient cohorts and cell lines. We found high levels of TROP2 in most subtypes except in the neuroendocrine subtype. Overall, TROP2 gene expression is higher than NECTIN4 gene expression, and cells resistant to enfortumab vedotin (EV), a NECTIN4-targeting antibody-drug conjugate, remain sensitive to sacituzumab govitecan (SG). Our findings suggest that SG may be effective across most bladder cancer subtypes, including the bladder cancers previously treated with EV.

Downregulation of METTL6 mitigates cell progression, migration, invasion and adhesion in hepatocellular carcinoma by inhibiting cell adhesion molecules.

RNA modifications have attracted increasing interest in recent years because they have been frequently implicated in various human diseases, including cancer, highlighting the importance of dynamic post­transcriptional modifications. Methyltransferase­like 6 (METTL6) is a member of the RNA methyltransferase family that has been identified in many cancers; however, little is known about its specific role or mechanism of action. In the present study, we aimed to study the expression levels and functional role of METTL6 in hepatocellular carcinoma (HCC), and further investigate the relevant pathways. To this end, we systematically conducted bioinformatics analysis of METTL6 in HCC using gene expression data and clinical information from a publicly available dataset. The mRNA expression levels of METTL6 were significantly upregulated in HCC tumor tissues compared to that in adjacent non­tumor tissues and strongly associated with poorer survival outcomes in patients with HCC. CRISPR/Cas9­mediated knockout of METTL6 in HCC cell lines remarkably inhibited colony formation, cell proliferation, cell migration, cell invasion and cell attachment ability. RNA sequencing analysis demonstrated that knockout of METTL6 significantly suppressed the expression of cell adhesion­related genes. However, chromatin immunoprecipitation sequencing results revealed no significant differences in enhancer activities between cells, which suggests that METTL6 may regulate genes of interest post­transcriptionally. In addition, it was demonstrated for the first time that METTL6 was localized in the cytosol as detected by immunofluorescence analysis, which indicates the plausible location of RNA modification mediated by METTL6. Our findings provide further insight into the function of RNA modifications in cancer and suggest a possible role of METTL6 as a therapeutic target in HCC.

Distinct Immune Imprints of Post-Liver Transplantation Hepatitis C Persist Despite Viral Clearance.

Recurrence or de novo infection of hepatitis C virus (HCV) after liver transplantation (LT) has been associated with progressive graft hepatitis that can be improved by treatment with novel direct-acting antivirals. Cases of rejection episodes have been described during and after HCV treatment. The evolution of innate and adaptive immune response during and after cure of HCV LT is unknown. We studied 74 protein biomarkers in the plasma of LT patients receiving antiviral therapy. In addition, deep immune phenotyping of both the myeloid and lymphoid immune cell subsets in peripheral blood mononuclear cells was performed. We found that LT patients with active HCV infection displayed distinct alterations of inflammatory protein biomarkers, such as C-X-Cmotif chemokine 10 (CXCL10), caspase 8, C-C motif chemokine 20 (CCL20), CCL19, interferon γ, CUB domain-containing protein 1 (CDCP1), interleukin (IL)-18R1, CXCL11, CCL3, IL8, IL12B, tumor necrosis factor-beta, CXCL6, osteoprotegerin, IL10, fms-related tyrosine kinase 3 ligand, hepatocyte growth factor, urokinase-type plasminogen activator, neurotrophin-3, CCL4, IL6, tumornecrosis factor receptor superfamily member 9, programmed death ligand 1, IL18, and monocyte chemotactic protein 1, and enrichment of peripheral immune cell subsets unlike patients without HCV infection who received transplants. Interestingly, patients who cleared HCV after LT did not normalize the altered inflammatory milieu nor did the peripheral immune cell subsets normalize to what would be seen in the absence of HCV recurrence. Overall, these data indicate that HCV-specific imprints on inflammatory analytes and immune cell subsets after LT are not completely normalized by therapy-induced HCV elimination. This is in line with the clinical observation that cure of HCV after LT did not trigger rejection episodes in many patients.

An epidermal growth factor motif of developmental endothelial locus 1 protein inhibits efficient angiogenesis in explanted squamous cell carcinoma in vivo

ABSTRACT Background: Cancer gene therapy using a nonviral vector is expected to be repeatable, safe, and inexpensive, and to have long-term effectiveness. Gene therapy using the E3 and C1 (E3C1) domain of developmental endothelial locus-1 (Del1) has been shown to improve prognosis in a mouse transplanted tumor model. Objective: In this study, we examined how this treatment affects angiogenesis in mouse transplanted tumors. Materials and methods: Mouse transplanted tumors (SCCKN human squamous carcinoma cell line) were injected locally with a nonviral plasmid vector encoding E3C1 weekly. Histochemical analysis of the transplanted tumors was then performed to assess the effects of E3C1 on prognosis. Results: All mice in the control group had died or reached an endpoint within 39 days. In contrast, one of ten mice in the E3C1 group had died by day 39, and eight of ten had died or reached an endpoint by day 120 (p < 0.01). Enhanced apoptosis in tumor stroma was seen on histochemical analyses, as was inhibited tumor angiogenesis in E3C1-treated mice. In addition, western blot analysis showed decreases in active Notch and HEY1 proteins. Conclusion: These findings indicate that cancer gene therapy using a nonviral vector encoding E3C1 significantly improved life-span by inhibiting tumor angiogenesis. (REV INVEST CLIN. 2021;73(1):39-51)

An Epidermal Growth Factor Motif of Developmental Endothelial Locus 1 Protein Inhibits Efficient Angiogenesis in Explanted Squamous Cell Carcinoma In Vivo.

BACKGROUND: Cancer gene therapy using a nonviral vector is expected to be repeatable, safe, and inexpensive, and to have longterm effectiveness. Gene therapy using the E3 and C1 (E3C1) domain of developmental endothelial locus-1 (Del1) has been shown to improve prognosis in a mouse transplanted tumor model. OBJECTIVE: In this study, we examined how this treatment affects angiogenesis in mouse transplanted tumors. MATERIALS AND METHODS: Mouse transplanted tumors (SCCKN human squamous carcinoma cell line) were injected locally with a nonviral plasmid vector encoding E3C1 weekly. Histochemical analysis of the transplanted tumors was then performed to assess the effects of E3C1 on prognosis. RESULTS: All mice in the control group had died or reached an endpoint within 39 days. In contrast, one of ten mice in the E3C1 group had died by day 39, and eight of ten had died or reached an endpoint by day 120 (p < 0.01). Enhanced apoptosis in tumor stroma was seen on histochemical analyses, as was inhibited tumor angiogenesis in E3C1-treated mice. In addition, western blot analysis showed decreases in active Notch and HEY1 proteins. CONCLUSION: These findings indicate that cancer gene therapy using a nonviral vector encoding E3C1 significantly improved life-span by inhibiting tumor angiogenesis.

Human Copper-Containing Amine Oxidases in Drug Design and Development.

Two members of the copper-containing amine oxidase family are physiologically important proteins: (1) Diamine oxidase (hDAO; AOC1) with a preference for diamines is involved in degradation of histamine and (2) Vascular adhesion protein-1 (hVAP-1; AOC3) with a preference for monoamines is a multifunctional cell-surface receptor and an enzyme. hVAP-1-targeted inhibitors are designed to treat inflammatory diseases and cancer, whereas the off-target binding of the designed inhibitors to hDAO might result in adverse drug reactions. The X-ray structures for both human enzymes are solved and provide the basis for computer-aided inhibitor design, which has been reported by several research groups. Although the putative off-target effect of hDAO is less studied, computational methods could be easily utilized to avoid the binding of VAP-1-targeted inhibitors to hDAO. The choice of the model organism for preclinical testing of hVAP-1 inhibitors is not either trivial due to species-specific binding properties of designed inhibitors and different repertoire of copper-containing amine oxidase family members in mammalian species. Thus, the facts that should be considered in hVAP-1-targeted inhibitor design are discussed in light of the applied structural bioinformatics and structural biology approaches.

OPCML: A Promising Biomarker and Therapeutic Avenue.

Opioid-binding protein/cell adhesion molecule (OPCML) is expressed in many tissues and localizes to the plasma membrane. It is a putative tumor suppressor that acts on receptor tyrosine kinases (RTKs), influencing cell cycle arrest, apoptosis, and migration. Its expression is silenced epigenetically in cancer, inferring potential diagnostic, prognostic, and therapeutic roles.

Absence of Therapeutic Benefit of the Anti-Inflammatory Protein TSG-6 for Corneal Alkali Injury in a Rat Model.

Purpose: To investigate the therapeutic efficacy of tumor necrosis factor (TNF)-α stimulated gene/protein 6 (TSG-6) in a rat model of corneal alkali injury. Methods: Corneal alkali injury was produced by placing an NaOH-soaked filter paper disk on the central cornea of the right eye of an anesthetized male Lewis (LEW/Crl) rat. Recombinant human TSG-6, or an equal volume of phosphate-buffered saline (PBS), was administered intravenously (IV), by anterior chamber (AC) injection, or as a topical drop. The affected eyes were photographed daily using a dissecting microscope and documented for clinical time course analysis of corneal opacification. Corneal tissue was excised at pre-determined therapeutic endpoints, with subsequent qRT-PCR or histological analyses. Results: The continuous monitoring of corneal alkali injury progression revealed TSG-6 treatments do not show sufficient effectiveness in vivo regardless of IV injection, AC injection, or topical application. Corneal opacification and neovascularization were not diminished, and gene expression was not impacted by these treatments. However, both IV and AC administration of TSG-6 significantly suppressed pro-inflammatory cytokines compared to PBS-treated eyes. Conclusion: We conclude that the therapeutic potential of TSG-6 is insufficient in a rat corneal alkali injury model.

Intra-articular TSG-6 delivery from heparin-based microparticles reduces cartilage damage in a rat model of osteoarthritis.

As a potential treatment for osteoarthritis (OA), we have developed injectable and hydrolytically degradable heparin-based biomaterials with tunable sulfation for the intra-articular delivery of tumor necrosis factor-alpha stimulated gene-6 (TSG-6), a protein known to inhibit plasmin which may degrade extracellular matrix within OA joints. We first assessed the effect of heparin sulfation on TSG-6 anti-plasmin activity and found that while fully sulfated (Hep) and heparin desulfated at only the N position (Hep-N) significantly enhanced TSG-6 bioactivity in vitro, fully desulfated heparin (Hep-) had no effect, indicating that heparin sulfation plays a significant role in modulating TSG-6 bioactivity. Next, TSG-6 loaded, degradable 10 wt% Hep-N microparticles (MPs) were delivered via intra-articular injection into the knee at 1, 7, and 15 days following medial meniscal transection (MMT) injury in a rat model. After 21 days, cartilage thickness, volume, and attenuation were significantly increased with soluble TSG-6, indicating degenerative changes. In contrast, no significant differences were observed with TSG-6 loaded MP treatment, demonstrating that TSG-6 loaded MPs reduced cartilage damage following MMT injury. Ultimately, our results indicate that Hep-N can enhance TSG-6 anti-plasmin activity and that Hep-N-based biomaterials may be an effective method for TSG-6 delivery to treat OA.

Emerging Roles of Tumor Necrosis Factor-Stimulated Gene-6 in the Pathophysiology and Treatment of Atherosclerosis.

Tumor necrosis factor-stimulated gene-6 (TSG-6) is a 35-kDa glycoprotein that has been shown to exert anti-inflammatory effects in experimental models of arthritis, acute myocardial infarction, and acute cerebral infarction. Several lines of evidence have shed light on the pathophysiological roles of TSG-6 in atherosclerosis. TSG-6 suppresses inflammatory responses of endothelial cells, neutrophils, and macrophages as well as macrophage foam cell formation and vascular smooth muscle cell (VSMC) migration and proliferation. Exogenous TSG-6 infusion and endogenous TSG-6 attenuation with a neutralizing antibody for four weeks retards and accelerates, respectively, the development of aortic atherosclerotic lesions in ApoE-deficient mice. TSG-6 also decreases the macrophage/VSMC ratio (a marker of plaque instability) and promotes collagen fibers in atheromatous plaques. In patients with coronary artery disease (CAD), plasma TSG-6 levels are increased and TSG-6 is abundantly expressed in the fibrous cap within coronary atheromatous plaques, indicating that TSG-6 increases to counteract the progression of atherosclerosis and stabilize the plaque. These findings indicate that endogenous TSG-6 enhancement and exogenous TSG-6 replacement treatments are expected to emerge as new lines of therapy against atherosclerosis and related CAD. Therefore, this review provides support for the clinical utility of TSG-6 in the diagnosis and treatment of atherosclerotic cardiovascular diseases.