Obesity Attenuates Ventilator-Induced Lung Injury by Modulating the STAT3-SOCS3 Pathway

Polysaccharides from Dendrobium officinale improve obesity-induced insulin resistance through the gut microbiota and the SOCS3-mediated insulin receptor substrate-1 signaling pathway

BACKGROUND

Obesity induces insulin resistance and chronic inflammation, impacting human health. The relationship between obesity, gut microbiota, and regulatory mechanisms has been studied extensively. Dendrobium officinale polysaccharide (DOP), a traditional Chinese herbal medicine, potentially reduces insulin resistance. However, the mechanism through which DOP affects gut microbiota and alleviates obesity-induced insulin resistance in rats requires further investigation.

RESULTS

The current study aimed to assess the impact of DOP on gut microbiota and insulin resistance in rats on a high-fat diet. The results revealed that DOP effectively reduced blood lipids, glucose disorders, oxidative stress, and inflammatory infiltration in the liver of obese Sprague Dawley rats. This was achieved by downregulating SOCS3 expression and upregulating insulin receptor substrate-1 (IRS-1) by regulating the JAK/STAT/SOCS3 signaling pathway. Notably, DOP intervention enhanced the abundance of beneficial gut microbiota and reduced harmful microbiota. Correlation analysis demonstrated significant associations among intestinal microbiota, SOCS3-mediated IRS-1 expression, and inflammatory factors.

CONCLUSION

Dendrobium officinale polysaccharide regulated the gut microbiota, enhanced IRS-1 expression, and mitigated liver injury and insulin resistance due to a high-fat diet. These findings depict the potential anti-insulin resistance properties of DOP and offer further evidence for addressing obesity and its complications. © 2023 Society of Chemical Industry.

Progress in the relationship between mechanical ventilation parameters and ventilator-related complications during perioperative anesthesia

BACKGROUND

Mechanical ventilation, as an important respiratory support, plays an important role in general anesthesia and it is the cornerstone of intraoperative management of surgical patients. Different from spontaneous respiration, intraoperative mechanical ventilation can lead to postoperative lung injury, and its impact on surgical mortality cannot be ignored. Postoperative lung injury increases hospital stay and is related to preoperative conditions, anesthesia time, and intraoperative ventilation settings.

METHOD

Through reading literature and research reports, the relationship between perioperative input parameters and output parameters related to mechanical ventilation and ventilator-related complications was reviewed, providing reference for the subsequent setting of input parameters of mechanical ventilation and new ventilation strategies.

RESULTS

The parameters of inspiratory pressure rise time and inspiratory time can change the gas distribution, gas flow rate and airway pressure into the lungs, but there are few clinical studies on them. It can be used as a prospective intervention to study the effect of specific protective ventilation strategies on pulmonary complications after perioperative anesthesia.

CONCLUSION

There are many factors affecting lung function after perioperative mechanical ventilation. Due to the difference of human body, the ventilation parameters suitable for each patient are different, and the deviation of each ventilation parameter can lead to postoperative pulmonary complications. Inspiratory pressure rise time and inspiratory time will be used as the new ventilation strategy.

Adipocyte dysfunction promotes lung inflammation and aberrant repair: a potential target of COPD

Background

Obesity and chronic obstructive pulmonary disease (COPD) are prevailing worldwide, bringing a heavy medical burden. Clinical and pathophysiological relationship between obesity and COPD is paradoxical and elusive. We aim to explore their inherent associations from clinical, genetic, and animal levels.

Methods

We performed literature review and cohort analysis of patients with COPD to compare lung function, symptom, and prognosis among different weight groups. After retrieving datasets of obesity and COPD in Gene Expression Omnibus (GEO) database, we carried out differentially expressed gene analysis, functional enrichment, protein-protein interactions network, and weighted gene co-expression network analysis. Then, we acquired paraffin-embedded lung tissues of fatty acid-binding protein 4-Cre-BMPR2fl/fl conditional knockout (CKO) mice that were characterized by adipocyte-specific knockout of bone morphogenetic protein receptor 2 (BMPR2) for staining and analysis.

Results

Our cohort study reports the effect of obesity on COPD is inconsistent with previous clinical studies. Lung function of overweight group was statistically superior to that of other groups. We also found that the inflammatory factors were significantly increased hub genes, and cytokine-associated pathways were enriched in white adipose tissue of patients with obesity. Similarly, injury repair-associated genes and pathways were further enhanced in the small airways of patients with COPD. CKO mice spontaneously developed lung injury, emphysema, and pulmonary vascular remodeling, along with increased infiltration of macrophages. BMPR2-defiecient adipocytes had dysregulated expression of adipocytokines.

Conclusion

Inflammation and abnormal repair might be potential mechanisms of the pathological association between obesity and COPD. BMPR2-associated adipocyte dysfunction promoted lung inflammation and aberrant repair, in which adipocytokines might play a role and thus could be a promising therapeutic target.

Obesity Paradox in Lung Diseases: What Explains It?

BACKGROUND

Obesity is a globally increasing health problem that impacts multiple organ systems and a potentially modifiable risk factor for many diseases. Obesity has a significant impact on lung function and is strongly linked to the pathophysiology that contributes to lung diseases. On the other hand, reports have emerged that obesity is associated with a better prognosis than for normal weight individuals in some lung diseases, including pneumonia, acute lung injury/acute respiratory distress syndrome, chronic obstructive pulmonary disease, and lung cancer. The lesser mortality and better prognosis in patients with obesity is known as obesity paradox. While obesity paradox is both recognized and disputed in epidemiological studies, recent research has suggested possible mechanisms.

SUMMARY

In this review, we attempted to explain and summarize these factors and mechanisms, including immune response, pulmonary fibrosis, lung function, microbiota, fat and muscle reserves, which are significantly altered by obesity and may contribute to the obesity paradox in lung diseases. We also discuss contrary literature that attributes the "obesity paradox" to confounding.

KEY MESSAGES

The review will illustrate the possible role of obesity in the prognosis or course of lung diseases, leading to a better understanding of the obesity paradox and provide hints for further basic and clinical research in lung diseases.

SOCS3 Silencing Promotes Activation of Vocal Fold Fibroblasts via JAK2/STAT3 Signaling Pathway

Suppressor of cytokine signaling 3 (SOCS3) is a negative regulatory protein that has been identified as a key inhibitory regulator of JAK/STAT signaling pathway. However, the mutual regulatory relationship between SOCS3 and JAK2/STAT3 signaling pathway after vocal fold injury remains unclear. In this study, we used small interfering RNA (siRNA) to investigate the mechanism of SOCS3 regulating of fibroblasts through JAK2/STAT3 signaling pathway after vocal fold injury. Our data shows that SOCS3 silencing promotes the transformation of normal vocal fold fibroblasts (VFFs) into an fibrotic phenotype and activates the JAK2/STAT3 signaling pathway. JAK2 silencing significantly inhibits the increase in type I collagen and α-smooth muscle actin (α-SMA) secretion in VFFs induced by TGF-β but has no significant effect on normal VFFs. The silencing of SOCS3 and JAK2 reverses the fibrotic phenotype of VFFs induced by SOCS3 silencing. Therefore, we suggest that SOCS3 can affect the activation of vocal fold fibroblasts by regulating the JAK2/STAT3 signaling pathway after vocal fold injury. It provides a new insight for promoting the repair of vocal fold injury and preventing the formation of fibrosis.

The Wnt/β-catenin pathway regulates inflammation and apoptosis in ventilator-induced lung injury

Ventilator-induced lung injury (VILI) may be caused by incorrect mechanical ventilation (MV), and its progression is mainly related to inflammatory reaction, apoptosis, and oxidative stress. The Wnt/β-catenin pathway can modulate inflammation and apoptosis; however, its role in VILI is unknown. This research aims to explore the role of the Wnt/β-catenin pathway in VILI. VILI models were established using rats and type II alveolar epithelial (ATII) cells. Glycogen synthase kinase 3β (GSK-3β), β-catenin, and cyclin D1 were determined using western blotting and immunofluorescence. Apoptosis of lung tissues was evaluated using TUNEL, flow cytometry, Bax, and Bcl2 protein. Interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) were detected via enzyme-linked immunosorbent assay (ELISA). Lung pathological injury was evaluated through hematoxylin and eosin (H&E) staining. Lung permeability was evaluated by the ratio of dry to wet weight of lung tissue and the total protein level of bronchoalveolar lavage fluid (BALF). The results showed that GSK-3β expression was enhanced and β-catenin expression was diminished in lung tissue under MV. SB216763 increased β-catenin and cyclin D1 expression by inhibiting GSK-3β expression and inhibited the inflammatory response and apoptosis of lung, alleviated pulmonary edema and lung tissue permeability, and significantly mitigated lung injury. However, inhibition of β-catenin expression by MSAB attenuated the anti-inflammatory and antiapoptotic effects of SB216763 in VILI. Overall, the present study demonstrates that the Wnt/β-catenin pathway activation in MV may play an anti-inflammatory and antiapoptotic role, thereby alleviating lung injury and delaying VILI progression, which may be a key point of intervention in VILI.

Relationship between miR-338-3p and Clinicopathological Parameters, Prognosis, and STAT3 mRNA Expression in Nasopharyngeal Carcinoma

Objective

To investigate the expression of miR-338-3p in nasopharyngeal carcinoma (NPC) and its relationship with STAT3 mRNA expression as well as their relationship with clinical pathological parameters and prognosis of patients.

Methods

From September 2016 to September 2018, 71 patients with NPC were selected as the NPC group, and 71 samples of NPC tissues were collected during the operation. A total of 23 patients who underwent biopsy due to chronic nasopharyngitis were selected as the control group and 23 nasopharyngeal mucosal tissues were collected. The expressions of miR-338-3p and STAT3 mRNA in nasopharyngeal tissue of two groups were detected by real-time quantitative PCR, and the relationship between the two was analyzed. To collect clinical data of NPC patients and analyze the relationship between the expressions of miR-338-3p and STAT3 in NPC tissues and clinical pathological parameters of the patients, we followed up the patients with nasopharyngeal carcinoma for three years to observe the relationship between miR-338-3p, STAT3, and the prognosis of the patients.

Results

The relative expression levels of miR-338-3p in nasopharyngeal tissues of the NPC group and the control group were 0.39 ± 0.05 and 1.01 ± 0.09, respectively (P < 0.05). The relative expression levels of STAT3 mRNA in nasopharyngeal tissues of the NPC group and the control group were 3.82 ± 0.21 and 1.04 ± 0.11, respectively (P > 0.05). miR-338-3p was negatively correlated with the relative expression of STAT3 mRNA in nasopharyngeal carcinoma (r = 0.038, P > 0.05). The expression of miR-338-3p was related to the age of the patient, clinical TNM stage, T stage, and distant metastasis (all P < 0.05). STAT3 expression was correlated with clinical TNM stage, T stage, and distant metastasis in our patient (P < 0.05). The expressions of miR-338-3p and STAT3 in nasopharyngeal carcinoma tissues from different gender, histological type, N stage, M stage, and degree of differentiation showed no statistical differences (P > 0.05). The survival rate of the group with low miR-338-3p expression was significantly lower than that of the group with high miR-338-3p expression (P > 0.05). The survival rate of patients with the high STAT3 expression group was significantly lower than that of patients with the low STAT3 expression group (P > 0.05).

Conclusion

There is a negative correlation between the low expression of miR-338-3p and the high expression of STAT3 in NPC, which are all related to the TNM stage, T stage, and prognosis of the patient.