HSPA1A Protects Cells from Thermal Stress by Impeding ESCRT-0-Mediated Autophagic Flux in Epidermal Thermoresistance

STAM2 negatively regulates the MyD88-mediated NF-κB signaling pathway in miiuy croaker, Miichthys miiuy

Signal transducing adapter molecule 2 (STAM2), a member of the Signal Transducing Adapter Molecule (STAM) family, is a protein with significant implications in diverse signaling pathways and endocytic membrane trafficking. However, the role of the STAM2, especially in fish, remains largely unknown. In this study, we discovered that STAM2 negatively regulates the NF-κB signaling pathway, and its inhibitory effect is enhanced upon LPS induction. Our study confirmed that STAM2 can enhance the degradation of myeloid differentiation primary-response protein 88 (MyD88), an upstream regulator of NF-κB pathway. Furthermore, the UIM domain of STAM2 is important for the inhibition of MyD88. Mechanistically, STAM2 inhibits the NF-κB signaling pathway by targeting the MyD88 autophagy pathway. In addition, we showed that STAM2 promotes the proliferation of Vibrio harveyi. In summary, our study reveals that STAM2 inhibits NF-κB signaling activation and mediates innate immunity in teleost via the autophagy pathway.

6-Hydroxy-2,2,4-trimethyl-1,2,3,4-tetrahydroquinoline Demonstrates Neuroprotective Properties in Experimental Parkinson's Disease by Enhancing the Antioxidant System, Normalising Chaperone Activity and Suppressing Apoptosis

Parkinson's disease (PD) is a neurodegenerative disease, whereby disturbances within the antioxidant defence system, increased aggregation of proteins, and activation of neuronal apoptosis all have a crucial role in the pathogenesis. In this context, exploring the neuroprotective capabilities of compounds that sustain the effectiveness of cellular defence systems in neurodegenerative disorders is worthwhile. During this study, we assessed how 6-hydroxy-2,2,4-trimethyl-1,2,3,4-tetrahydroquinoline (HTHQ), which has antioxidant properties, affects the functioning of the antioxidant system, the activity of NADPH-generating enzymes and chaperones, and the level of apoptotic processes in rats with rotenone-induced PD. Six groups of animals were formed for our experiment, each with 12 animals. These were: a control group, animals with rotenone-induced PD, rats with PD given HTHQ at a dose of 50 mg/kg, rats with PD given HTHQ at a dose of 25 mg/kg, animals with pathology who were administered a comparison drug rasagiline, and control animals who were administered HTHQ at a dose of 50 mg/kg. The study results indicate that administering HTHQ led to a significant decrease in oxidative stress in PD rats. The enhanced redox status in animal tissues was linked with the recovery of antioxidant enzyme activities and NADPH-generating enzyme function, as well as an upsurge in the mRNA expression levels of antioxidant genes and factors Nrf2 and Foxo1. Administering HTHQ to rats with PD normalized the chaperone-like activity and mRNA levels of heat shock protein 70. Rats treated with the compound displayed lower apoptosis intensity when compared to animals with pathology. Therefore, owing to its antioxidant properties, HTHQ demonstrated a beneficial impact on the antioxidant system, resulting in decreased requirements for chaperone activation and the inhibition of apoptosis processes triggered in PD. HTHQ at a dose of 50 mg/kg had a greater impact on the majority of the examined variables compared to rasagiline.

Selection Signal Analysis Reveals Hainan Yellow Cattle Are Being Selectively Bred for Heat Tolerance

Hainan yellow cattle are indigenous Zebu cattle from southern China known for their tolerance of heat and strong resistance to disease. Generations of adaptation to the tropical environment of southern China and decades of artificial breeding have left identifiable selection signals in their genomic makeup. However, information on the selection signatures of Hainan yellow cattle is scarce. Herein, we compared the genomes of Hainan yellow cattle with those of Zebu, Qinchuan, Nanyang, and Yanbian cattle breeds by the composite likelihood ratio method (CLR), Tajima's D method, and identifying runs of homozygosity (ROHs), each of which may provide evidence of the genes responsible for heat tolerance in Hainan yellow cattle. The results showed that 5210, 1972, and 1290 single nucleotide polymorphisms (SNPs) were screened by the CLR method, Tajima's D method, and ROH method, respectively. A total of 453, 450, and 325 genes, respectively, were identified near these SNPs. These genes were significantly enriched in 65 Gene Ontology (GO) functional terms and 11 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways (corrected p < 0.05). Five genes-Adenosylhomocysteinase-like 2, DnaJ heat shock protein family (Hsp40) member C3, heat shock protein family A (Hsp70) member 1A, CD53 molecule, and zinc finger and BTB domain containing 12-were recognized as candidate genes associated with heat tolerance. After further functional verification of these genes, the research results may benefit the understanding of the genetic mechanism of the heat tolerance in Hainan yellow cattle, which lay the foundation for subsequent studies on heat stress in this breed.

Evaluation of thermodynamic bioeffects of long-pulsed 1064 nm laser in the photothermal lipolysis

OBJECTIVES

To evaluate the lipolysis effect of air cooling assisted long-pulsed 1064 laser for improving local adiposity.

MATERIALS AND METHODS

The second-level (pulse duration of 0.3-60 s) long-pulsed Nd:YAG 1064 nm laser (LP1064 nm) with or without forced-air cooling was used to irradiate ex-vivo subcutaneous adipose tissue (SAT) of pig or human and in-vivo inguinal fat tissue of Sprague Dawley rats. The temperature of skin surface as well as 5 mm deep SAT was monitored by a plug-in probe thermal couple, and the former was confined to 39°C or 42°C during the treatment. Histological analysis of SAT response was evaluated by SAT sections stained with hematoxylin-eosin and oil red O. Ultra-microstructure changes were examined by transmission electron microscopy. A pilot study on human subject utilizing LP1064 nm laser with air cooling was conducted. The changes in gross abdomen circumference and ultrasonic imaging were studied.

RESULTS

Histological examination showed that LP1064 nm laser treatment induced adipocyte injury and hyperthermic lipolysis both in- and ex-vivo. It was also confirmed by clinical practice on patients. By real-time temperature monitoring, we found that in comparison with LP1064 nm laser alone, additional air cooling could increase the temperature difference between epidermis and SAT, promoting heat accumulation deep in fat tissue, as well as providing better protection for epidermis.

CONCLUSION

LP1064 nm laser provided reliable adipose tissue thermolysis when the temperature of skin surface was sustained at 39°C or 42°C for 10 min. Application of air-cooling during the laser treatment achieved better effect and safety of photothermal lipolysis. LP1064 nm laser, as a noninvasive device, has comparable thermal lipolysis effect as other common heat-generating devices.

Effects of heat stress on physiological parameters, biochemical parameters and expression of heat stress protein gene in Lateolabraxmaculatus

With global warming and the increasing frequency of extreme heat, we have to consider the heat tolerance of fish to sudden high temperatures. This study investigated the effects of high temperature (32 °C) on physiology and biochemistry and heat shock proteins (HSPs) gene of spotted sea bass (Lateolabrax maculatus). The spotted sea bass (14.7 ± 1.54 g) temporarily cultured at 26 °C was directly transferred to the 32 °C high temperature group, and the gill morphology, liver antioxidant activity, respiratory metabolism related enzyme activity and the expression of five HSP70 family members genes were measured at 3, 6, 9, 12, 24, 48, 72, and 96 h. The results showed that 32 °C had damage effect on gill tissue and antioxidant system, and the damage degree increased with high temperature. Respiratory rate and malondialdehyde increased gradually with the continuous heat stress. Superoxide dismutase and total antioxidant capacity increased briefly and then decreased continuously. Succinate dehydrogenase decreased to the lowest value at 24 h and then continued to increase. Lactate dehydrogenase decreased continuously; the expression of HSP70 increased rapidly and then decreased. These results indicated that the antioxidant system and HSP70 were activated under heat stress condition and provided protection to the body, but with the continuous high temperature, the protective effect was limited, and the fish body was irreversibly damaged. It is necessary to pay close attention to the temperature change in the production practice of spotted sea bass to reduce the influence caused by high temperature.

Photothermal lipolysis accelerates ECM production via macrophage-derived ALOX15-mediated p38 MAPK activation in fibroblasts

Skin and subcutaneous tissue tightening is usually treated by noninvasive photothermal treatment for medical esthetics purpose, while the underlying mechanism remains to be elucidated. Here, we hypothesized that adipocyte injury, as a stimulator, may regulate extracellular matrix (ECM) production by increasing ALOX15 in macrophages, which could lead to fibroblast activation. In this study, we show that lipolysis was induced by laser heating (45°C for 15 min) in patients and rats, and adipocyte thermal injury stimulates the ECM production in fibroblasts by ALOX15 that was increased in cocultured macrophages. These phenomena were evidenced by the ALOX15 knockdown. In addition, ALOX15 metabolite 12(S)-HETE activated p38 MAPK signaling pathway that mediated the production of ECM in fibroblast. In summary, the results of this study demonstrate that the mechanisms of adipose photothermal injury-induced skin and/or subcutaneous tissue tightening may have clinical relevance for noninvasive or minimally invasive photothermal therapeutics.

Microanatomy of the metabolic associated fatty liver disease (MAFLD) by single-cell transcriptomics

BACKGROUND

Metabolic-associated fatty liver disease (MAFLD) is a major cause of liver disease worldwide and comprises non-alcoholic fatty liver (NAFL) and non-alcoholic steatohepatitis (NASH). Due to the high prevalence and poor prognosis of NASH, it is critical to identify and treat patients at risk. However, the aetiology and mechanisms remain largely unknown, warranting further analysis.

METHODS

We first identified differential genes in NASH by single-cell analysis of the GSE129516 dataset and conducted expression profiling data analysis of the GSE184019 dataset from the Gene Expression Omnibus (GEO) database. Then single-cell trajectory reconstruction and analysis, immune gene score, cellular communication, key gene screening, functional enrichment analysis, and immune microenvironment analysis were carried out. Finally, cell experiments were performed to verify the role of key genes in NASH.

RESULTS

We conducted transcriptome profiling of 30,038 single cells, including hepatocytes and non-hepatocytes from normal and steatosis adult mouse livers. Comparative analysis of hepatocytes and non-hepatocytes revealed pronounced heterogeneity as non-hepatocytes acted as major cell-communication hubs. The results showed that Hspa1b, Tfrc, Hmox1 and Map4k4 could effectively distinguish NASH tissues from normal samples. The results of scRNA-seq and qPCR indicated that the expression levels of hub genes in NASH were significantly higher than in normal cells or tissues. Further immune infiltration analysis showed significant differences in M2 macrophage distribution between healthy and metabolic-associated fatty liver samples.

CONCLUSIONS

Our results suggest that Hspa1b, Tfrc, Hmox1 and Map4k4 have huge prospects as diagnostic and prognostic biomarkers for NASH and may be potential therapeutic targets for NASH.

Astrocytic circadian clock control of energy expenditure by transcriptional stress responses in the ventromedial hypothalamus

Hypothalamic circuits compute systemic information to control metabolism. Astrocytes residing within the hypothalamus directly sense nutrients and hormones, integrating metabolic information, and modulating neuronal responses. Nevertheless, the role of the astrocytic circadian clock on the control of energy balance remains unclear. We used mice with a targeted ablation of the core-clock gene Bmal1 within Gfap-expressing astrocytes to gain insight on the role played by this transcription factor in astrocytes. While this mutation does not substantially affect the phenotype in mice fed normo-caloric diet, under high-fat diet we unmasked a thermogenic phenotype consisting of increased energy expenditure, and catabolism in brown adipose and overall metabolic improvement consisting of better glycemia control, and body composition. Transcriptomic analysis in the ventromedial hypothalamus revealed an enhanced response to moderate cellular stress, including ER-stress response, unfolded protein response and autophagy. We identified Xbp1 and Atf1 as two key transcription factors enhancing cellular stress responses. Therefore, we unveiled a previously unknown role of the astrocytic circadian clock modulating energy balance through the regulation of cellular stress responses within the VMH.

Bidirectional regulation of structural damage on autophagy in the C. elegans epidermis

A variety of disturbances such as starvation, organelle damage, heat stress, hypoxia and pathogen infection can influence the autophagic process. However, how the macroautophagy/autophagy machinery is regulated intrinsically by structural damage of the cell remains largely unknown. In this work, we utilized the C. elegans epidermis as the model to address this question. Our results showed that structural damage by mechanical wounding exerted proximal inhibitory effect and distant promotional effect on autophagy within the same epidermal cell. By disrupting individual mechanical supporting structures, we found that only damage of the basal extracellular matrix or the underlying muscle cells activated a distinct autophagic response in the epidermis. On the contrary, structural disruption of the epidermal cells at the apical side inhibited autophagy activation caused by different stress factors. Mechanistic studies showed that the basal promotional effect of structural damage on epidermal autophagy was mediated by a mechanotransduction pathway going through the basal hemidesmosome receptor and LET-363/MTOR, while the apical inhibitory effect was mostly carried out by activation of calcium signaling. Elevated autophagy in the epidermis played a detrimental rather than a beneficial role on cell survival against structural damage. The results obtained from these studies will not only help us better understand the pathogenesis of structural damage- and autophagy-related diseases, but also provide insight into more generic rules of autophagy regulation by the structural and mechanical properties of cells across species.Abbreviations : ATG: autophagy related; BLI-1: BLIstered cuticle 1; CeHDs: C. elegans hemidesmosomes; COL-19: COLlagen 19; DPY-7: DumPY 7; ECM: extracellular matrix; EPG-5: ectopic PGL granules 5; GFP: green fluorescent protein; GIT-1: GIT1 (mammalian G protein-coupled receptor kinase InTeractor 1) homolog; GTL-2: Gon-Two Like 2 (TRP subfamily); HIS-58, HIStone 58; IFB-1: Intermediate Filament, B 1; LET: LEThal; LGG-1: LC3, GABARAP and GATE-16 family 1; MTOR: mechanistic target of rapamycin; MTORC1: MTOR complex 1; MUP-4: MUscle Positioning 4; NLP-29: Neuropeptide-Like Protein 29; PAT: Paralyzed Arrest at Two-fold; PIX-1: PIX (PAK (p21-activated kinase) Interacting eXchange factor) homolog 1; RFP: red fluorescent protein; RNAi: RNA interference; SQST-1: SeQueSTosome related 1; UNC: UNCoordinated; UV: ultraviolet; VAB-10: variable ABnormal morphology 10; WT: wild type.

The endosomal sorting complex required for transport repairs the membrane to delay cell death

The endosomal sorting complex required for transport (ESCRT) machinery plays a key role in the repair of damaged plasma membranes with puncta form and removes pores from the plasma membrane in regulated cell death, apoptosis, necroptosis, pyroptosis, ferroptosis, and autophagy. ESCRT-I overexpression and ESCRT-III-associated charged multivesicular body protein (CHMP) 4B participate in apoptosis, and the ESCRT-1 protein TSG 101 maintains low levels of ALIX and ALG-2 and prevents predisposition to apoptosis. The ESCRT-III components CHMP2A and CHMP4B are recruited to broken membrane bubble sites with the requirement of extracellular Ca2+, remove membrane vesicles from cells, and delay the time required for active MLKL to mediate necroptosis, thus preserving cell survival. CHMP4B disturbed pyroptosis by recruiting around the plasma membrane neck to remove the GSDMD pores and preserve plasma membrane integrity depending on Ca2+ influx. The accumulation of the ESCRT-III subunits CHMP5 and CHMP6 in the plasma membrane is increased by the classical ferroptosis activators erastin-1 and ras-selective lethal small molecule 3 (RSL3) upon cytosolic calcium influx and repairs the ferroptotic plasma membrane. ESCRT-III- and VPS4-induced macroautophagy, ESCRT-0-initiated microautophagy. ESCRT-I, ESCRT-II, ESCRT-III, ALIX, and VPS4A are recruited to damaged lysosomes and precede lysophagy, indicating that ESCRT is a potential target to overcome drug resistance during tumor therapy.

HSP70 Ameliorates Septic Lung Injury via Inhibition of Apoptosis by Interacting with KANK2

Acute lung injury is the most common type of organ damage with high incidence and mortality in sepsis, which is a poorly understood syndrome of disordered inflammation. The aims of this study are to explore whether heat shock protein 70 (HSP70), as a molecular chaperone, attenuates the septic lung injury, and to understand the underlying mechanisms. In our study, treatment with HSP70 ameliorated the survival rate, dysfunction of lung, inflammation, and apoptosis in cecal ligation and puncture (CLP)-treated mice as well as in LPS-treated human alveolar epithelial cells. Furthermore, HSP70 interacted with KANK2, leading to reversed cell viability and reduced apoptosis-inducing factor (AIF) and apoptosis. Additionally, knockdown of KANK2 in epithelial cells and deletion of hsp70.1 gene in CLP mice aggravated apoptosis and tissue damage, suggesting that interaction of KANK2 and HSP70 is critical for protecting lung injury induced by sepsis. HSP70 plays an important role in protection of acute lung injury caused by sepsis through interaction with KANK2 to reduce AIF release and apoptotic cell. HSP70 is a novel potential therapeutic approach for attenuation of septic lung injury.

Keratinocyte and Fibroblast Wound Healing In Vitro Is Repressed by Non-Optimal Conditions but the Reparative Potential Can Be Improved by Water-Filtered Infrared A

It is a general goal to improve wound healing, especially of chronic wounds. As light therapy has gained increasing attention, the positive influence on healing progression of water-filtered infrared A (wIRA), a special form of thermal radiation, has been investigated and compared to the detrimental effects of UV-B irradiation on wound closure in vitro. Models of keratinocyte and fibroblast scratches help to elucidate effects on epithelial and dermal healing. This study further used the simulation of non-optimal settings such as S. aureus infection, chronic inflammation, and anti-inflammatory conditions to determine how these affect scratch wound progression and whether wIRA treatment can improve healing. Gene expression analysis for cytokines (IL1A, IL6, CXCL8), growth (TGFB1, PDGFC) and transcription factors (NFKB1, TP53), heat shock proteins (HSP90AA1, HSPA1A, HSPD1), keratinocyte desmogleins (DSG1, DSG3), and fibroblast collagen (COL1A1, COL3A1) was performed. Keratinocyte and fibroblast wound healing under non-optimal conditions was found to be distinctly reduced in vitro. wIRA treatment could counteract the inflammatory response in infected keratinocytes as well as under chronic inflammatory conditions by decreasing pro-inflammatory cytokine gene expression and improve wound healing. In contrast, in the anti-inflammatory setting, wIRA radiation could re-initiate the acute inflammatory response necessary after injury to stimulate the regenerative processes and advance scratch closure.