Low-intensity pulsed ultrasound inhibits adipogenic differentiation via HDAC1 signalling in rat visceral preadipocytes

Therapeutic Effects of Different Ultrasound Intensity Stimulation on Brown Adipose Tissue for the Treatment of Type 2 Diabetes

Type 2 diabetes (T2D) is a persistent illness that has a high incidence rate. Still, there is no conclusive evidence on effectively improving blood sugar levels in patients through physical therapy. This study examined the regulatory effects of different intensities of low-intensity pulsed ultrasound (LIPUS) on T2D by stimulating brown adipose tissue (BAT). Eight-week-old C57BL/6J mice were divided into six groups (n = 10 per group): Control sham (C-Sham), Control-LIPUS (C-LIPUS), T2D-sham (T2D-Sham), T2D groups treated with LIPUS at spatial average-temporal-average intensity (Isata) of 60mW/cm² (T2D-L-60), 80mW/cm² (T2D-L-80), and 100mW/cm² (T2D-L-100). T2D models were induced by intraperitoneal injection of 40 mg/kg streptozotocin (STZ) three times after 12 wks of high-fat diet (HFD). The T2D-LIPUS group received LIPUS stimulation for 20 minutes per day for 6 weeks. The LIPUS stimulation had a duty cycle of 20%, a frequency of 1 MHz, and Isata of 60mW/cm², 80mW/cm², 100mW/cm². Subsequently, glucose tolerance tests (GTT) and insulin tolerance tests (ITT) were performed, and body fat content in mice was analyzed using nuclear magnetic resonance (NMR). Metabolic changes were monitored using metabolic cages. The results indicated that 80mW/cm² intensity level significantly improved glucose tolerance, insulin sensitivity, and metabolic function after LIPUS exposure. Significant reductions in body fat content and enhanced thermogenesis were observed, highlighting the potential of LIPUS in T2D management. This provides the basis for the dose study of LIPUS in the treatment of T2D.

Low-intensity Pulsed Ultrasound Stimulation of the Intestine Improves Insulin Resistance in Type 2 Diabetes

OBJECTIVE

Ultrasound stimulation of internal organs and peripheral nerves has demonstrated promising potential in regulating blood glucose metabolism. This study aims to assess the effectiveness of low-intensity pulsed ultrasound stimulation (LIPUS) on intestine in improving insulin resistance with type 2 diabetes mellitus (T2DM).

METHODS

C57BL/6J mice, both normal and T2DM, were randomly divided into three groups: Control, T2D-sham, and T2D-LIPUS. The T2D-LIPUS group received LIPUS stimulation in the intestine. The parameters were as follows: 1 MHz frequency, 1.0 kHz pulse repetition frequency (PRF), 20% duty cycle, 100 mW/cm² intensity spatial average temporal average (ISATA), for 20 minutes per session, five days per week, over four weeks.

RESULTS

Blood glucose analysis indicated that mice in the T2D-LIPUS group displayed significantly lower area under the curve (AUC) of glucose tolerance tests (GTT) and insulin tolerance tests (ITT) (p < 0.001), HOMA-IR (p < 0.001), and fasting serum insulin levels (p < 0.01) compared to the T2D-sham group. LIPUS treatment effectively lowered serum levels of IL-1β (p < 0.001) and TNF-α (p < 0.01) along with mRNA expression levels of IL-1β (p < 0.01) and IL-18 (p < 0.001) in the intestines of T2DM mice. Additionally, Western blot analysis revealed a reduction in the protein levels of NLRP3, caspase-1, and GSDMD-N in the intestinal tissues of mice treated with LIPUS.

CONCLUSION

These findings suggest that LIPUS can reduce inflammation and cellular apoptosis, while improving insulin resistance by inhibiting the NLRP3/Caspase-1/GSDMD signaling pathway. This research introduces a novel, non-pharmacological approach for managing T2DM.

Acoustic modulation of mechanosensitive genes and adipocyte differentiation

Eukaryotic cells are equipped with multiple mechanosensory systems and perceive a wide range of mechanical stimuli from the environment. However, cell-level responses to audible range of acoustic waves, which transmit feeble yet highly frequent physical perturbations, remain largely unexplored. Here, we established a direct sound emission system with a vibrational transducer, and acoustic waves at frequency 440 Hz, 14 kHz, and white noise were transmitted to the murine C2C12 myoblasts at 100 Pa intensity. After 2 and 24 h sound emission, 42 and 145 differentially expressed genes, respectively, were identified using RNA-sequencing. Both cell- and sound-related factors important for inducing gene responses were further investigated. The activation of prostaglandin-endoperoxide synthase 2/cyclooxygenase-2 (Ptgs2/Cox-2), a high and immediate sound-responding gene, is dependent on focal adhesion kinase activation and mediates sound-triggered gene responses by activating prostaglandin E2 synthesis. Adipocyte cells exhibited prominently high sound responses, and their differentiation was significantly suppressed by continuous or periodic acoustic stimulation. Collectively, these findings redefine acoustic waves as cellular stimulators and provide new avenues for applying acoustic techniques in biosciences.

Low-intensity pulsed ultrasound improves metabolic dysregulation in obese mice by suppressing inflammation and extracellular matrix remodeling

Chronic inflammation in white adipose tissue is crucial in obesity and related metabolic disorders. Low-intensity pulsed ultrasound (LIPUS) is renowned for its anti-inflammatory effects as a non-invasive treatment, yet its precise role in obesity has been uncertain. Our study investigates the therapeutic effect of LIPUS and its underlying mechanism on obesity in mice, thereby offering a novel approach for non-invasive treatment of obesity and associated metabolic disorders for human. Male C57BL/6J mice aged 10 weeks were fed a high-fat diet (HFD) for 8 weeks to establish obesity model, then underwent 8 weeks of LIPUS (frequency: 1.0 MHz, duty cycle: 20 %, Isata: 58-61 mW/cm2, 20 min per day) stimulation of the epididymal white adipose tissue. Fat and lean mass were measured using nuclear magnetic resonance (NMR), while energy homeostasis was evaluated using metabolic cages. Insulin resistance was assessed using glucose tolerance tests (GTT) and insulin tolerance tests (ITT). Regulatory mechanisms were explored using RNA sequencing. Results showed that LIPUS significantly reduced obesity markers in obese mice, including body and adipose tissue weight, and improved insulin resistance, without affecting food intake. RNA sequencing showed 250 up-regulated and 351 down-regulated genes between HFD-LIPUS group and HFD-Sham group, suggesting anti-inflammatory action. Quantitative PCR confirmed reduced pro-inflammatory gene expression and macrophage infiltration in eWAT. Gene set enrichment analysis showed decreased NF-κB signaling and extracellular matrix-receptor interactions in LIPUS-treated mice. Thus, LIPUS effectively mitigates metabolic dysregulation in HFD-induced obesity through inflammation suppression and extracellular matrix remodeling, which provides a potential physical therapy for metabolic syndrome in clinic.

Jingle Cell Rock: Steering Cellular Activity With Low-Intensity Pulsed Ultrasound (LIPUS) to Engineer Functional Tissues in Regenerative Medicine

Acoustic manipulation or perturbation of biological soft matter has emerged as a promising clinical treatment for a number of applications within regenerative medicine, ranging from bone fracture repair to neuromodulation. The potential of ultrasound (US) endures in imparting mechanical stimuli that are able to trigger a cascade of molecular signals within unscathed cells. Particularly, low-intensity pulsed ultrasound (LIPUS) has been associated with bio-effects such as activation of specific cellular pathways and alteration of cell morphology and gene expression, the extent of which can be modulated by fine tuning of LIPUS parameters including intensity, frequency and exposure time. Although the molecular mechanisms underlying LIPUS are not yet fully elucidated, a number of studies clearly define the modulation of specific ultrasonic parameters as a means to guide the differentiation of a specific set of stem cells towards adult and fully differentiated cell types. Herein, we outline the applications of LIPUS in regenerative medicine and the in vivo and in vitro studies that have confirmed the unbounded clinical potential of this platform. We highlight the latest developments aimed at investigating the physical and biological mechanisms of action of LIPUS, outlining the most recent efforts in using this technology to aid tissue engineering strategies for repairing tissue or modelling specific diseases. Ultimately, we detail tissue-specific applications harnessing LIPUS stimuli, offering insights over the engineering of new constructs and therapeutic modalities. Overall, we aim to lay the foundation for a deeper understanding of the mechanisms governing LIPUS-based therapy, to inform the development of safer and more effective tissue regeneration strategies in the field of regenerative medicine.

Dynamic changes in extracellular vesicle-associated miRNAs elicited by ultrasound in inflammatory bowel disease patients

Blood-based biomarkers that reliably indicate disease activity in the intestinal tract are an important unmet need in the management of patients with IBD. Extracellular vesicles (EVs) are cell-derived membranous microparticles, which reflect the cellular and functional state of their site of site of origin. As ultrasound waves may lead to molecular shifts of EV contents, we hypothesized that application of ultrasound waves on inflamed intestinal tissue in IBD may amplify the inflammation-specific molecular shifts in EVs like altered EV-miRNA expression, which in turn can be detected in the peripheral blood. 26 patients with IBD were included in the prospective clinical study. Serum samples were collected before and 30 min after diagnostic transabdominal ultrasound. Differential miRNA expression was analyzed by sequencing. Candidate inducible EV-miRNAs were functionally assessed in vitro by transfection of miRNA mimics and qPCR of predicted target genes. Serum EV-miRNA concentration at baseline correlated with disease severity, as determined by clinical activity scores and sonographic findings. Three miRNAs (miR-942-5p, mir-5588, mir-3195) were significantly induced by sonography. Among the significantly regulated EV-miRNAs, miR-942-5p was strongly induced in higher grade intestinal inflammation and correlated with clinical activity in Crohn's disease. Prediction of target regulation and transfection of miRNA mimics inferred a role of this EV-miRNA in regulating barrier function in inflammation. Induction of mir-5588 and mir-3195 did not correlate with inflammation grade. This proof-of-concept trial highlights the principle of induced molecular shifts in EVs from inflamed tissue through transabdominal ultrasound. These inducible EVs and their molecular cargo like miRNA could become novel biomarkers for intestinal inflammation in IBD.

Inhibition Effect of Adipogenesis and Lipogenesis via Activation of AMPK in Preadipocytes Treated with Canavalia gladiata Extract

The aim of this study was to investigate the effect of Canavalia gladiata extract (CGE) on the regulation of AMP-activated protein kinase (AMPK) in 3T3-L1 preadipocytes and evaluate the adipogenesis and lipogenesis mechanisms. In 3T3-L1 preadipocytes, lipid accumulation and differentiation were suppressed by 1.1, 1.3, and 1.4 times under the CGE treatment at 0.25, 0.5, and 1.0 mg/mL, respectively. The expression of the main genes involved in the inhibition of adipogenesis was evaluated at the mRNA level via a transcription-polymerase chain reaction. The extract at 1.0 mg/mL increased the mRNA expressions of AMPK and carnitine palmitoyl transferase-1 (CPT-1) by 1.9 and 1.2 times, respectively, while it decreased the expression of sterol regulatory element binding proteins-1c (SREBP-1c), peroxisome proliferator activated receptor-γ (PPAR-γ), CCAAT enhancer binding protein-α (C/EBP-α), and fatty acid synthase (FAS) by 1.1, 1.2, 1.8, and 1.5 times, respectively, indicating inhibition of the adipogenesis and lipogenesis potential of CGE. Gallic acid (4.02 mg/g) was identified as the main component of the CGE via LC-MS/MS and HPLC analysis. The results of this study suggested that CGE can be utilized as an anti-obesity food additive or medication by activating the AMPK-induced regulation and suppressing adipogenesis transcription factors.

Low-intensity pulsed ultrasound prevents prolonged hypoxia-induced cardiac fibrosis through HIF-1α/DNMT3a pathway via a TRAAK-dependent manner

Hypoxia-induced cardiac fibrosis is an important pathological process in cardiovascular disorders. This study aimed to determine whether low-intensity pulsed ultrasound (LIPUS), a novel and safe apparatus, could alleviate hypoxia-induced cardiac fibrosis, and to elucidate the underlying mechanisms. Hypoxia (1% O2 ) and transverse aortic constriction (TAC) were performed on neonatal rat cardiac fibroblasts and mice to induce cardiac fibrosis, respectively. LIPUS irradiation was applied for 20 minutes every 6 hours for a total of 2 times in vitro, and every 2 days from 1 week before surgery to 4 weeks after surgery in vivo. We found that LIPUS dose-dependently attenuated hypoxia-induced cardiac fibroblast phenotypic conversion in vitro, and ameliorated TAC-induced cardiac fibrosis in vivo. Hypoxia significantly upregulated the nuclear protein expression of hypoxia-inducible factor-1α (HIF-1α) and DNA methyltransferase 3a (DNMT3a). LIPUS pre-treatment reversed the elevated expression of HIF-1α, and DNMT3a. Further experiments revealed that HIF-1α stabilizer dimethyloxalylglycine (DMOG) hindered the anti-fibrotic effect of LIPUS, and hampered LIPUS-mediated downregulation of DNMT3a. DNMT3a small interfering RNA (siRNA) prevented hypoxia-induced cardiac fibrosis. Results also showed that the mechanosensitive protein-TWIK-related arachidonic acid-activated K+ channel (TRAAK) messenger RNA (mRNA) expression was downregulated in hypoxia-induced cardiac fibroblasts, and TAC-induced hearts. TRAAK siRNA impeded LIPUS-mediated anti-fibrotic effect and downregulation of HIF-1α and DNMT3a. Above results indicated that LIPUS could prevent prolonged hypoxia-induced cardiac fibrosis through TRAAK-mediated HIF-1α/DNMT3a signalling pathway.

Low-intensity pulsed ultrasound ameliorates angiotensin II-induced cardiac fibrosis by alleviating inflammation via a caveolin-1-dependent pathway

OBJECTIVES

Cardiac hypertrophy and fibrosis are major pathological manifestations observed in left ventricular remodeling induced by angiotensin II (AngII). Low-intensity pulsed ultrasound (LIPUS) has been reported to ameliorate cardiac dysfunction and myocardial fibrosis in myocardial infarction (MI) through mechano-transduction and its downstream pathways. In this study, we aimed to investigate whether LIPUS could exert a protective effect by ameliorating AngII-induced cardiac hypertrophy and fibrosis and if so, to further elucidate the underlying molecular mechanisms.

METHODS

We used AngII to mimic animal and cell culture models of cardiac hypertrophy and fibrosis. LIPUS irradiation was applied in vivo for 20 min every 2 d from one week before mini-pump implantation to four weeks after mini-pump implantation, and in vitro for 20 min on each of two occasions 6 h apart. Cardiac hypertrophy and fibrosis levels were then evaluated by echocardiographic, histopathological, and molecular biological methods.

RESULTS

Our results showed that LIPUS could ameliorate left ventricular remodeling in vivo and cardiac fibrosis in vitro by reducing AngII-induced release of inflammatory cytokines, but the protective effects on cardiac hypertrophy were limited in vitro. Given that LIPUS increased the expression of caveolin-1 in response to mechanical stimulation, we inhibited caveolin-1 activity with pyrazolopyrimidine 2 (pp2) in vivo and in vitro. LIPUS-induced downregulation of inflammation was reversed and the anti-fibrotic effects of LIPUS were absent.

CONCLUSIONS

These results indicated that LIPUS could ameliorate AngII-induced cardiac fibrosis by alleviating inflammation via a caveolin-1-dependent pathway, providing new insights for the development of novel therapeutic apparatus in clinical practice.

Multi-Omics Approaches and Radiation on Lipid Metabolism in Toothed Whales

Lipid synthesis pathways of toothed whales have evolved since their movement from the terrestrial to marine environment. The synthesis and function of these endogenous lipids and affecting factors are still little understood. In this review, we focused on different omics approaches and techniques to investigate lipid metabolism and radiation impacts on lipids in toothed whales. The selected literature was screened, and capacities, possibilities, and future approaches for identifying unusual lipid synthesis pathways by omics were evaluated. Omics approaches were categorized into the four major disciplines: lipidomics, transcriptomics, genomics, and proteomics. Genomics and transcriptomics can together identify genes related to unique lipid synthesis. As lipids interact with proteins in the animal body, lipidomics, and proteomics can correlate by creating lipid-binding proteome maps to elucidate metabolism pathways. In lipidomics studies, recent mass spectroscopic methods can address lipid profiles; however, the determination of structures of lipids are challenging. As an environmental stress, the acoustic radiation has a significant effect on the alteration of lipid profiles. Radiation studies in different omics approaches revealed the necessity of multi-omics applications. This review concluded that a combination of many of the omics areas may elucidate the metabolism of lipids and possible hazards on lipids in toothed whales by radiation.

Review on experimental study and clinical application of low-intensity pulsed ultrasound in inflammation

Low-intensity pulsed ultrasound (LIPUS), as physical therapy, is widely used in both research and clinical settings. It induces multiple bioeffects, such as alleviating pain, promoting tissue repair, and shortening disease duration. LIPUS can also mediate inflammation. This paper reviews the application of LIPUS in inflammation and discusses the underlying mechanism. In basic experiments, LIPUS can regulate inflammatory responses at the cellular level by affecting some signaling pathways. In a clinical trial, LIPUS has been shown to alleviate inflammatory responses efficiently. As a cheap, safe, and convenient physical method, LIPUS is promising as anti-inflammatory therapy.