Probes for INS

Introduction Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive and lethal disease of unknown aetiology. In France, it ranks among the most frequent interstitial pathologies and affects 6 out of 8 people per 100,000 each year. IPF is characterized by dysregulated healing mechanisms that leads to the accumulation of large amounts of collagen in the lung tissue that disrupts the alveolar architecture. Nintedanib and Pirfenidone are the only currently available treatments even though they are only able to slow down the disease without being curative. In this context, inhibiting HSPB5, a low molecular weight heat shock protein known to be involved in the development of fibrosis, could constitute a potential therapeutic target. Our aim consist to explore how NCI-41356 (a chemical inhibitor of HSPB5) can limit the development of pulmonary fibrosis. Methods In vivo, fibrosis was assessed in mice injected intratracheally (i.t.) with Bleomycin (BLM) and treated with NaCl or NCI-41356 (3 times i.t. or 3 times a week i.v.). Fibrosis was evaluated by collagen quantification (Sircol, Sirius Red staining), Immunofluorescence, TGF-β gene expression (RNAscope). In vitro, TGF-β1 signaling was evaluated in epithelial cells treated by TGF-β1 with or without NCI-41356 (Western Blot, Immunofluorescence, Proximity ligation assay). Results In vivo, NCI-41356 reduced the accumulation of collagen, the expression of TGF-β1 and several pro-fibrotic markers (PAI-1, α-SMA). In vitro, NCI-41356 decreased the interaction between HSPB5 and SMAD4 explaining NCI-41356 anti-fibrotic properties. Conclusion In this study, we determined that inhibition of HSPB5/SMAD4 could limit IPF in mice. NCI-41356 modulates SMAD4 nuclear translocation thus limiting TGF-β1 signaling and synthesis of collagen and pro-fibrotic markers. Further investigations with human fibrotic lung tissues are needed to determine if these results can be transposed in human.

In addition to the traditional activation of resident receptors by release of local mediators, new evidence favors the existence of exosomes in cell-to-cell communication that mediates delivery of specific cargo to modulate recipient cell function. We report that mast cell exosomes are an additional source of pro-fibrotic substances and constitute a unique pathway for the generation of excess collagen.We use primary human lung fibroblasts (HLFs) to demonstrate the uptake of labeled exosomes isolated from the human mast cell line HMC-1 (MC-EXOs), previously shown to contain protein cargo in common with human mast cell exosomes.The MC-EXO uptake by HLF is to the cytosol and increases both proline hydroxylation in HLF lysate and secreted collagen, within 24 h, which is sustained over 72 h, the same time required for transforming growth factor-β (TGF-β) to activate collagen synthesis in the HLFs. Unlike TGF-β, MC-EXO uptake does not induce fibrillar gene activation or invoke the Smad-nuclear transcription pathway. We show that MC-EXO uptake and TGF-β have an additive effect on collagen synthesis in HLF and postulate that MC-EXO uptake by HLFs is a contributing factor to excess collagen synthesis and represents a unique paradigm for understanding fibrosis.It is known that, in the lungs, mast cells are more activated and increase in number with inflammation, injury and viral infection associated with fibrosis. With the reported increased incidence of post-COVID-pulmonary fibrosis (PCPF), data from patients with severe COVID-19 are presented that show an increase in the mast cell number in lung parenchyma, the site of PCPF. Our findings provide a rationale for targeting multiple fibrogenic pathways in the management of lung fibrosis and the use of mast cell exosomes as a biomarker for the prognostic and diagnostic management of evolving fibrotic lung disease.

Epithelial-mesenchymal transition is a hallmark of uterine carcinosarcoma (UCS). Here, we used shotgun proteomics analysis to identify biomarkers associated with blebbistatin-mediated epithelial-mesenchymal transition in UCS, and found up-regulation of nucleobindin-2 (NUCB2) in endometrial carcinoma (Em Ca) cells. Expression of N-cadherin, Snail, Slug, and ZEB1 was reduced in NUCB2 knockout Em Ca cells, whereas ZEB1, Twist1, and vimentin were up-regulated in NUCB2-overexpressing Em Ca cells. NUCB2 knockout reduced cell proliferation and migration, whereas NUCB2 overexpression had the opposite effect. Treatment of Em Ca cells with transforming growth factor (TGF)-β1 dramatically altered morphology toward a fibroblastic appearance; concomitantly, expression of NUCB2 and ZEB1 increased. The NUCB2 promoter was also activated by transfection of Smad2. In UCS tissues, NUCB2 expression was significantly higher in sarcomatous compared with carcinomatous components; this was consistent with increased TGF-β1 mRNA expression in stromal and sarcomatous components compared with carcinomatous components. In addition, NUCB2 score correlated positively with ZEB1 and vimentin scores, whereas ZEB1 score correlated positively with Slug and vimentin scores and inversely with the E-cadherin score. We therefore suggest that TGF-β-dependent up-regulation of NUCB2 and ZEB1 contributes to the phenotypic characteristics of sarcomatous components in UCS.

Pulmonary hypertension (PH) can occur as a complication of schistosomiasis. In humans, schistosomiasis-PH persists despite antihelminthic therapy and parasite eradication. We hypothesized that persistent disease arises as a consequence of exposure repetition.Following intraperitoneal sensitization, mice were experimentally exposed to Schistosoma eggs by intravenous injection, either once or three times repeatedly. The phenotype was characterized by right heart catheterization and tissue analysis.Following intraperitoneal sensitization, a single intravenous Schistosoma egg exposure resulted in a PH phenotype that peaked at 7-14 days, followed by spontaneous resolution. Three sequential exposures resulted in a persistent PH phenotype. Inflammatory cytokines were not significantly different between mice exposed to one or three egg doses, but there was an increase in perivascular fibrosis in those who received three egg doses. Significant perivascular fibrosis was also observed in autopsy specimens from patients who died of this condition.Repeatedly exposing mice to schistosomiasis causes a persistent PH phenotype, accompanied by perivascular fibrosis. Perivascular fibrosis may contribute to the persistent schistosomiasis-PH observed in humans with this disease.

Collagens in the extracellular matrix (ECM) provide a physical barrier to tumor immune infiltration, while also acting as a ligand for immune inhibitory receptors. Transforming growth factor-β (TGF-β) is a key contributor to shaping the ECM by stimulating the production and remodeling of collagens. TGF-β-activation signatures and collagen-rich environments have both been associated with T-cell exclusion and lack of responses to immunotherapy. Here we describe the effect of targeting collagens that signal through the inhibitory leukocyte-associated immunoglobulin-like receptor-1 (LAIR-1) in combination with blockade of TGF-β and programmed cell death ligand 1 (PD-L1). This approach remodeled the tumor collagenous matrix, enhanced tumor infiltration and activation of CD8+ T cells, and repolarized suppressive macrophage populations resulting in high cure rates and long-term tumor-specific protection across murine models of colon and mammary carcinoma. The results highlight the advantage of direct targeting of ECM components in combination with immune checkpoint blockade therapy.

The number of deaths has been increased due to COVID-19 infections and uncertain neurological complications associated with the central nervous system. Post-infections and neurological manifestations in neuronal tissues caused by COVID-19 are still unknown and there is a need to explore how brainstorming promoted congenital impairment, dementia, and Alzheimer's disease. SARS-CoV-2 neuro-invasion studies in vivo are still rare, despite the fact that other beta-coronaviruses have shown similar properties. Neural (olfactory or vagal) and hematogenous (crossing the blood-brain barrier) pathways have been hypothesized in light of new evidence showing the existence of SARS-CoV-2 host cell entry receptors into the specific components of human nerve and vascular tissue. Spike proteins are the primary key and structural component of the COVID-19 that promotes the infection into brain cells. Neurological manifestations and serious neurodegeneration occur through the binding of spike proteins to ACE2 receptor. The emerging evidence reported that, due to the high rate in the immediate wake of viral infection, the olfactory bulb, thalamus, and brain stem are intensely infected through a trans-synaptic transfer of the virus. It also instructs the release of chemokines, cytokines, and inflammatory signals immensely to the blood-brain barrier and infects the astrocytes, which causes neuroinflammation and neuron death; and this induction of excessive inflammation and immune response developed in more neurodegeneration complications. The present review revealed the pathophysiological effects, molecular, and cellular mechanisms of possible entry routes into the brain, pathogenicity of autoantibodies and emerging immunotherapies against COVID-19.

Spike-based COVID-19 vaccines induce potent neutralizing antibodies but their efficacy against SARS-CoV-2 variants decreases. OVX033 is a recombinant protein composed of the full-length nucleocapsid (N) protein of SARS-CoV-2 genetically fused to oligoDOM , a self-assembling domain which improves antigen immunogenicity. OVX033 including N as an antigenic target is proposed as new vaccine candidate providing broad-spectrum protection against sarbecoviruses. OVX033 demonstrated its ability to trigger cross-reactive T cell responses and cross-protection against three variants of SARS-CoV-2 (B.1 Europe, Delta B.1.617.2, and Omicron B.1.1.529) in a hamster challenge model, as evidenced by lower weight loss, lower lung viral loads, and reduced lung histopathological lesions.

While rare, coronary stent infections present with significant mortality-with most infections and further complications occurring within months of percutaneous coronary intervention (PCI). Here, we discuss a post-COVID-19 patient who presented approximately one year after PCI for declotting of an arteriovenous graft (AVG). Upon admission, the patient was found to be bacteremic with multilobar pneumonia and an infection of the AVG. Empiric antibiotics were started, and blood cultures were subsequently positive for MRSA. Removal of the AVG was unsuccessful, and two days after admission, the patient passed. Autopsy revealed a perivascular abscess in the RCA near the origin of the stent with a ground section of the RCA with stent revealing abundant calcific atherosclerosis and marked necrosis of the artery wall. The cause of death was determined to be sepsis complicating coronary artery disease and chronic renal failure.