Anti-inflammatory Effect of Low-Intensity Ultrasound in Septic Rats

Effects of Low-Intensity Pulsed Ultrasound on the Regulation of Free Fatty Acid Release in 3T3-L1 Cells

OBJECTIVES

To investigate the effects of low-intensity pulsed ultrasound (LIPUS) on the proliferation, differentiation, and tumor necrosis factor-α (TNF-α)-induced lipolysis of 3T3-L1 cells, and to explore the feasibility of regulating the release of free fatty acids (FFA) to prevent lipotoxicity.

METHODS

Different intensities (30, 60, 90, and 120 mW/cm2) of LIPUS were applied to 3T3-L1 preadipocytes for different durations (5, 10, 15, 20, 25, and 30 minutes). Appropriate parameters for subsequent experiments were selected by assessing cell viability. The effect of LIPUS on the proliferation and differentiation of 3T3-L1 cells was evaluated by microscope observation, flow cytometry, and lipid content determination. After treated with LIPUS and TNF-α (50 ng/mL), the degree of lipolysis was assessed by measuring the extracellular FFA content. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the mRNA expression of relevant genes.

RESULTS

Different parameters of LIPUS significantly enhance the viability of 3T3-L1 cells (P < .05), with 20 minutes and 30 mW/cm2 as the most suitable settings. After LIPUS treatment, 3T3-L1 cell proliferation accelerated, apoptosis rate and G1 phase cell proportion decreased, the content of lipid droplets and TG was increased in differentiated cells, while FFA release decreased (P < .05). The expression of PCNA, PPARγ, C/EBPα, Perilipin A mRNA increased, and the expression of TNF-α, ATGL, HSL mRNA decreased (P < .05).

CONCLUSIONS

LIPUS could promote the proliferation and differentiation of 3T3-L1 cells and inhibit TNF-α-induced lipolysis, indicating its potential as a therapy for mitigating lipotoxicity caused by decompensated adipocytes.

Low-intensity pulsed ultrasound activated the anti-tumor immunity by irradiating the spleen of mice in 4 T-1 breast cancer

Tumor immunotherapy is booming around the world. However, strategies to activate the immune system and alleviate the immunosuppression still need to be refined. Here, we demonstrate for the first time that low-intensity pulsed ultrasound (LIPUS, spatial average time average intensity (Isata) is 200 mW/cm2, frequency is 0.3 MHz, repetition frequency is 1 kHz, and duty cycle is 20%) triggers the immune system and further reverses the immunosuppressive state in the mouse models of breast cancer by irradiating the spleen of mice. LIPUS inhibited tumor growth and extended survival in mice with 4 T-1 tumors. Further studies had previously shown that LIPUS enhanced the activation of CD4+ and CD8+ T cells in the spleen and led to significant changes in cytokines, as well as induced upregulation of mRNA levels involved in multiple immune regulatory pathways in the spleen. In addition, LIPUS promoted tumor-infiltrating lymphocyte accumulation and CD8+ T cell activation and improved the dynamics of cytokines/chemokines in the tumor microenvironment, resulting in a reversal of the immunosuppressive state of the tumor microenvironment. These results suggest a novel approach to activate the immune response by irradiating the spleen with LIPUS.

Comparative analysis of noise and music exposure on inflammatory responses on lipopolysaccharide-induced septic rats

OBJECTIVE

Environmental factors such as noise and music can significantly impact physiological responses, including inflammation. This study explored how environmental factors like noise and music affect lipopolysaccharide (LPS)-induced inflammation, with a focus on systemic and organ-specific responses.

MATERIALS AND METHODS

24 Wistar rats were divided into four groups (n = 6 per group): Control group, LPS group, noise-exposed group, and music-exposed group. All rats, except for the Control group, received 10 mg/kg LPS intraperitoneally. The rats in the noise-exposed group were exposed to 95 dB noise, and the music-exposed group listened to Mozart's K. 448 music (65-75 dB) for 1 h daily over 7 days. An enzyme-linked immunosorbent assay was utilized to detect the levels of inflammatory cytokines, including tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β), in serum and tissues (lung, liver, and kidney). Western blot examined the phosphorylation levels of nuclear factor-κB (NF-κB) p65 in organ tissues.

RESULTS

Compared with the Control group, LPS-induced sepsis rats displayed a significant increase in the levels of TNF-α and IL-1β in serum, lung, liver, and kidney tissues, as well as a remarkable elevation in the p-NF-κB p65 protein expression in lung, liver, and kidney tissues. Noise exposure further amplified these inflammatory markers, while music exposure reduced them in LPS-induced sepsis rats.

CONCLUSION

Noise exposure exacerbates inflammation by activating the NF-κB pathway, leading to the up-regulation of inflammatory markers during sepsis. On the contrary, music exposure inhibits NF-κB signaling, indicating a potential therapeutic effect in reducing inflammation.