Morphometric evaluation of nitric oxide synthase isoforms and their cytokine regulators predict pulmonary dysfunction and survival in systemic sclerosis

The role of lung biopsy for diagnosis and prognosis of interstitial lung disease in systemic sclerosis: a systematic literature review

BACKGROUND

The prognostic and theragnostic role of histopathological subsets in systemic sclerosis interstitial lung disease (SSc-ILD) have been largely neglected due to the paucity of treatment options and the risks associated with surgical lung biopsy. The novel drugs for the treatment of ILDs and the availability of transbronchial cryobiopsy provide a new clinical scenario making lung biopsy more feasible and a pivotal guide for treatment. The aim of our study was to investigate the usefulness of lung biopsy in SSc ILD with a systematic literature review (SLR).

METHODS

PubMed, Embase and Cochrane databases were searched up to June 30, 2023. Search terms included both database-specific controlled vocabulary terms and free-text terms relating to lung biopsy and SSc-ILD diagnostic and prognosis. The SLR was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA). Studies were selected according to the PEO (population, exposure, and outcomes) framework and Quality assessment of diagnostic accuracy studies (QUADAS) were reported.

RESULTS

We selected 14 articles (comprising 364 SSc-ILD patients). The paucity and heterogeneity of the studies prevented a systematic analysis. Diffuse cutaneous SSc was present in 30-100% of cases. Female predominance was observed in all studies (ranging from 64 to 100%). Mean age ranged from 42 to 64 years. Mean FVC was 73.98 (+/-17.3), mean DLCO was 59.49 (+/-16.1). Anti-Scl70 antibodies positivity was detected in 33% of cases (range: 0-69.6). All patients underwent surgical lung biopsies, and multiple lobes were biopsied in a minority of studies (4/14). Poor HRCT-pathologic correlation was reported with HRCT-NSIP showing histopathologic UIP in up to 1/3 of cases. Limited data suggest that SSc-UIP patients may have a worse prognosis and response to immunosuppressive treatment compared to other histopathologic patterns.

CONCLUSIONS

The data from this SLR clearly show the paucity and heterogeneity of the studies reporting lung biopsy in SSc ILD. Moreover, they highlight the need for further research to address whether the lung biopsy can be helpful to refine prognostic prediction and guide therapeutic choices.

Coadministration of 3'5-dimaleamylbenzoic acid and quercetin decrease pulmonary fibrosis in a systemic sclerosis model

Systemic sclerosis (SSc) is an autoimmune disease characterized by microvascular compromise and fibrosis. Pulmonary fibrosis, a prominent pulmonary complication in SSc, results in impaired lung function due to excessive accumulation of extracellular matrix components. This study aimed to investigate the effects of coadministration of 3'5-dimaleamylbenzoic acid (AD) and quercetin (Q) on key events in the development and maintenance of pulmonary fibrosis in a bleomycin (BLM)-induced SSc mouse model. The model was induced in CD1 mice through BLM administration using osmotic mini pumps. Subsequently, mice were treated with AD (6 mg/kg) plus Q (10 mg/kg) and sacrificed at 21 and 28 days post BLM administration. Histopathological analysis was performed by hematoxylin and eosin staining and Masson's trichrome staining. Immunohistochemistry was used to determine the expression of proliferation, proinflammatory, profibrotic and oxidative stress markers. The coadministration of AD and Q during the fibrotic phase of the BLM-induced SSc model led to attenuated histological alterations and pulmonary fibrosis, reflected in the recovery of alveolar spaces (30 %, p < 0.01) and decreased collagen deposits (50 %, p < 0.001). This effect was achieved by decreasing the expression of the proliferative markers cyclin D1 (87 %, p < 0.0001) and PCNA (43 %, p < 0.0001), inflammatory markers COX-2 (71 %, p < 0.0001) and iNOS (84 %, p < 0.0001), profibrotic markers α-SMA (80 %, p < 0.0001) and TGF-β (81 %, p < 0.0001) and the lipid peroxidation marker 4-HNE (43 %, p < 0.01). The antifibrotic effect of this combined therapy is associated with the regulation of proliferation, inflammation and oxidative stress, mechanisms involved in the development and progression of the fibrotic process. Our novel therapeutic strategy is the first approach to propose the use of the combination of prooxidant and antioxidant compounds as a potential strategy for SSc-associated pulmonary fibrosis.

[Alveolar nitric oxide concentration has a potential value in the diagnosis and differential diagnosis of interstitial lung diseases]

OBJECTIVE

To investigate the value of exhaled nitric oxide (eNO) in the diagnosis and differential diagnosis of interstitial lung disease (ILD).

METHODS

This study was conducted among 45 patients with interstitial lung disease, including 18 with connective tissue disease-related ILD (CTD-ILD) and 27 with non-CTD-ILD, with 68 healthy subjects as the control group. According to European Respiratory Association Guidelines, alveolar nitric oxide (CaNO) concentration and fractional exhaled nitric oxide (FeNO) level were measured at the flow rates of 50 and 200 mL/s. The predictive level of CaNO was analyzed using receiver-operating characteristic curve (ROC), and the correlations between CaNO and pulmonary function indicators were examined in the patients with ILD.

RESULTS

CaNO, FeNO50, and FeNO200 levels were significantly higher in patients with ILD than in the healthy controls. Logistic regression analysis showed that lowered levels of CaNO and FeNO200 were risk factors for ILD. ROC curve analysis showed that the area under the curve (AUC) of CaNO combined with FeNO200 was 0.829 (95% CI: 0.752-0.906) for the diagnosis of ILD. In patients with ILD, CaNO levels were negatively correlated with DLCO%pred (r=-0.471, P < 0.05). Subgroup comparison showed a significantly higher CaNO level in CTD-ILD group than in non-CTD-ILD group. The AUC for CaNO to discriminate CTD-ILD from non-CTD-ILD was 0.725 (95% CI: 0.576 to 0.875).

CONCLUSION

CaNO has a potential value in the diagnosis of ILD and differential diagnosis of CTD-ILD.

CB1 R and iNOS are distinct players promoting pulmonary fibrosis in Hermansky-Pudlak syndrome

Hermansky-Pudlak syndrome (HPS) is a rare genetic disorder which, in its most common and severe form, HPS-1, leads to fatal adult-onset pulmonary fibrosis (PF) with no effective treatment. We evaluated the role of the endocannabinoid/CB1 R system and inducible nitric oxide synthase (iNOS) for dual-target therapeutic strategy using human bronchoalveolar lavage fluid (BALF), lung samples from patients with HPS and controls, HPS-PF patient-derived lung fibroblasts, and bleomycin-induced PF in pale ear mice (HPS1ep/ep ). We found overexpression of CB1 R and iNOS in fibrotic lungs of HPSPF patients and bleomycin-infused pale ear mice. The endocannabinoid anandamide was elevated in BALF and negatively correlated with pulmonary function parameters in HPSPF patients and pale ear mice with bleomycin-induced PF. Simultaneous targeting of CB1 R and iNOS by MRI-1867 yielded greater antifibrotic efficacy than inhibiting either target alone by attenuating critical pathologic pathways. Moreover, MRI-1867 treatment abrogated bleomycin-induced increases in lung levels of the profibrotic interleukin-11 via iNOS inhibition and reversed mitochondrial dysfunction via CB1 R inhibition. Dual inhibition of CB1 R and iNOS is an effective antifibrotic strategy for HPSPF.

Cannabinoid CB1 receptor overactivity contributes to the pathogenesis of idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a life-threatening disease without effective treatment, highlighting the need for identifying new targets and treatment modalities. The pathogenesis of IPF is complex, and engaging multiple targets simultaneously might improve therapeutic efficacy. To assess the role of the endocannabinoid/cannabinoid receptor 1 (endocannabinoid/CB1R) system in IPF and its interaction with inducible nitric oxide synthase (iNOS) as dual therapeutic targets, we analyzed lung fibrosis and the status of the endocannabinoid/CB1R system and iNOS in mice with bleomycin-induced pulmonary fibrosis (PF) and in lung tissue and bronchoalveolar lavage fluid (BALF) from patients with IPF, as well as controls. In addition, we investigated the antifibrotic efficacy in the mouse PF model of an orally bioavailable and peripherally restricted CB1R/iNOS hybrid inhibitor. We report that increased activity of the endocannabinoid/CB1R system parallels disease progression in the lungs of patients with idiopathic PF and in mice with bleomycin-induced PF and is associated with increased tissue levels of interferon regulatory factor-5. Furthermore, we demonstrate that simultaneous engagement of the secondary target iNOS by the hybrid CB1R/iNOS inhibitor has greater antifibrotic efficacy than inhibition of CB1R alone. This hybrid antagonist also arrests the progression of established fibrosis in mice, thus making it a viable candidate for future translational studies in IPF.

Cardiovascular-renal complications and the possible role of plasminogen activator inhibitor: a review

Since angiotensin increases the expression of plasminogen activator inhibitor (PAI), mechanisms associated with an actively functioning renin–angiotensin–aldosterone system can be expected to be associated with increased PAI-1 expression. These mechanisms are present not only in common conditions resulting in glomerulosclerosis associated with aging, diabetes or genetic mutations, but also in autoimmune disease (like scleroderma and lupus), radiation injury, cyclosporine toxicity, allograft nephropathy and ureteral obstruction. While the renin–angiotensin–aldosterone system and growth factors, such as transforming growth factor-beta (TGF-β), are almost always part of the process, there are rare experimental observations of PAI-1 expression without their interaction. Here we review the literature on PAI-1 and its role in vascular, fibrotic and oxidative injury as well as work suggesting potential areas of intervention in the pathogenesis of multiple disorders.