Interruption of the long non-coding RNA HOTAIR signaling axis ameliorates chemotherapy-induced cachexia in bladder cancer.

BACKGROUND: Cisplatin-based chemotherapy is the first line of treatment for bladder cancer. However, cisplatin induces muscle wasting associated with NF-κB and cancer cachexia. HOTAIR, an oncogenic long non-coding RNA (lncRNA), promotes cancer progression in different cancers. Crosstalk between HOTAIR and NF-κB is documented. Prothymosin α (ProT) plays important roles in cancer progression and inflammation. However, the potential link between HOTAIR, ProT, and cisplatin-induced cancer cachexia remains unexplored. Here, we investigated the contribution of HOTAIR in cisplatin-induced cancer cachexia and dissected the potential signaling cascade involving the epidermal growth factor receptor (EGFR), ProT, NF-κB, and HOTAIR. MATERIALS AND METHODS: Expression of ProT and HOTAIR transcripts and their correlations in tumor tissues of bladder cancer patients and bladder cancer cell lines were determined by RT-qPCR. Next, levels of phospho-EGFR, EGFR, phospho-NF-κB, and NF-κB were examined by immunoblot analysis in human bladder cancer cells treated with cisplatin. Expression of HOTAIR in cisplatin-treated cells was also assessed by RT-qPCR. Pharmacological inhibitors and overexpression and knockdown approaches were exploited to decipher the signaling pathway. The murine C2C12 myoblasts were used as an in vitro muscle atrophy model. The syngeneic murine MBT-2 bladder tumor was used to investigate the role of mouse Hotair in cisplatin-induced cancer cachexia. RESULTS: Expression of ProT and HOTAIR was higher in bladder tumors than in normal adjacent tissues. There were positive correlations between ProT and HOTAIR expression in clinical bladder tumors and bladder cancer cell lines. Cisplatin treatment increased EGFR and NF-κB activation and upregulated ProT and HOTAIR expression in bladder cancer cells. ProT overexpression increased, whereas ProT knockdown decreased, HOTAIR expression. Notably, cisplatin-induced HOTAIR upregulation was abrogated by EGFR inhibitors or ProT knockdown. ProT-induced HOTAIR overexpression was diminished by NF-κB inhibitors. HOTAIR overexpression enhanced, whereas its knockdown reduced, cell proliferation, cachexia-associated pro-inflammatory cytokine expression, and muscle atrophy. Cachexia-associated symptoms were ameliorated in mice bearing Hotair-knockdown bladder tumors undergoing cisplatin treatment. CONCLUSIONS: We demonstrate for the first time a critical role for HOTAIR and identify the involvement of the EGFR-ProT-NF-κB-HOTAIR signaling axis in cisplatin-induced cachexia in bladder cancer and likely other cancers. Our findings also provide therapeutic targets for this disease.

Exposure to lipid mixture induces intracellular lipid droplet formation and impairs mitochondrial functions in astrocytes.

Astrocytes, the predominant glial cells in the central nervous system (CNS), play diverse roles including metabolic support for neurons, provision of neurotrophic factors, facilitation of synaptic neurotransmitter uptake, regulation of ion balance, and involvement in synaptic formation. The accumulation of lipids has been noted in various neurological conditions, yet the response of astrocytes to lipid-rich environments remains unclear. In this study, primary astrocytes isolated from the neonatal rat cortex were exposed to a lipid mixture (LM) comprising cholesterol and various fatty acids to explore their reaction. Our results showed that astrocyte viability remained unchanged following 24 h of 5% or 10% LM treatment. However, exposure to LM for 96 h resulted in reduced cell viability. In addition, LM treatment led to the accumulation of lipid droplets (LDs) in astrocytes, with LD size increasing over prolonged exposure periods. Following 24 h of LM treatment and then 48 h in fresh medium, a significant reduction in intracellular LD size was observed in cultures treated with 5% LM, while no change occurred in cultures exposed to 10% LM. Yet, exposure to 10% LM for 24 h significantly increased the expression of the cholesterol efflux regulatory protein/ATP-binding cassette transporter (ABCA1) gene, responsible for intracellular cholesterol efflux, resulting in reduced cholesterol content within astrocytes. Moreover, LM exposure led to decreased mitochondrial membrane potential (MMP) and increased levels of mature apoptosis-inducing factor (AIF). The smaller LDs were observed to co-localize with microtubule-associated protein 1A/1 B light chain 3 B (LC3) and lysosomal-associated membrane protein-1 (LAMP-1) in LM-treated astrocytes, coinciding with lysosomal acidification. These results indicate that the continuous buildup of LDs in astrocytes residing in lipid-enriched environments may be attributed to disruptions caused by LM in mitochondrial and lysosomal functions. Such disruptions could potentially impede the supportive role of astrocytes in neuronal function.

Erinacine S, a small active component derived from Hericium erinaceus, protects oligodendrocytes and alleviates mood abnormalities in cuprizone-exposed rodents.

Hericium erinaceus mycelium extract (HEM), containing erinacine A (HeA) and erinacine S (HeS), has shown promise in promoting the differentiation of oligodendrocyte precursor cells (OPCs) into mature oligodendrocytes (OLs), crucial for myelin production in the central nervous system (CNS). The main aim of this study was to characterize the protective effects of HEM and its components on OLs and myelin in demyelinating rodents by exposure to cuprizone (CPZ), a copper chelating agent commonly used to induce demyelination in the corpus callosum of the brain. Rats were fed by CPZ-containing diet and simultaneously orally administered HEM, HeA, or HeS on a daily basis for three weeks. We found that HEM and HeS preserved myelin and OLs in the corpus callosum of CPZ-fed rats, along with reduced microglia and astrocyte activation, and downregulated IL-1ß expression. Furthermore, post-treatment with HeS, in mouse models with acute (6 weeks) or chronic (12 weeks) CPZ-induced demyelination demonstrated oral administration during the final 4 weeks (HeS4/6 or HeS4/12) effectively preserved myelin in the corpus callosum. Additionally, HeS4/6 and HeS4/12 inhibited anxious and depressive-like behaviors in CPZ-fed mice. In summary, simultaneous administration of HEM and HeS in rats during short-term CPZ intoxication preserved OLs and myelin. Furthermore, post-administration of HeS not only inhibited demyelination and gliosis but also alleviated anxiety and depression in both acute and chronic CPZ-fed mice. This study presents compelling evidence supporting the potential of HeS as a promising small active compound for protecting OLs and preserving myelin in demyelinating diseases associated with emotional disorders.