Chlamydomonas reinhardtii (red) rich in protoporphyrin ? exerts anti-diabetic effects in liver tissue

The metabolites derived from microalgae have been attributed with various nutritional and medicinal properties. Therefore, our study aimed to investigate the potential beneficial effects of Chlamydomonas reinhardtii (red), a type of microalgae, in individuals with type 2 diabetes mellitus (T2DM). Mice were fed on high-fat diet and injected with a low dose of streptozotocin to induce T2DM. The diabetic mice were orally treated with either 1% sodium carboxymethylcellulose or Chlamydomonas reinhardtii (red) at doses of 1, 2, or 3 g/kg BW/day for a duration of 4 weeks. The liver sections were subjected to hematoxylin and eosin staining as well as oil red staining for the detection of pathological changes and lipid deposition, respectively. Inflammatory factors in serum were quantified using ELISA kits, while commercial kits were employed to assess oxidative stress-related indicators. Gene expression in liver was analysed by RNA-seq. The results revealed that Chlamydomonas reinhardtii (red) significantly ameliorated fasting blood glucose levels, body weight, triglyceride, and low density lipoprotein cholesterin, while also enhancing oral glucose tolerance and insulin sensitivity. In pathological analysis, Chlamydomonas reinhardtii (red) significantly improved lipid deposition and hepatic tissue damage. Furthermore, Chlamydomonas reinhardtii (red) could obviously decreased the protein expression of G-6-Pase and PEPCK, and regulated the SOCS2/JAK2/STAT5 signaling pathway. Transcriptomic analysis indicated that a total of 972 significantly differentially expressed genes in diabetic mice treated with Chlamydomonas reinhardtii (red). KEGG analyses revealed that lipid and atherosclerosis, MAPK signaling pathway, B cell receptor signaling pathway, TNF signaling pathway, NOD-like receptor signaling pathway, Toll-like receptor signaling pathway, PI3K-Akt signaling pathway were involved in Chlamydomonas reinhardtii (red) modulated process. Therefore, the continuous consumption of Chlamydomonas reinhardtii (red) may have anti-T2DM effects through the inhibition of gluconeogenesis, thus offering a promising alternative for T2DM patient. Overall design: The raw image data file acquired from high-throughput RNA sequencing is converted into the raw reads through base calling analysis following image processing. The assessment of the raw read quality was conducted using the FastQC program (version 0.11.8). The Trimmomatic program (version 0.36) was utilized to filter out bad quality data. RNA-seq reads were mapped to the mouse reference sequence GRCm38 through Hisat2 software (version 2.1.0). Calculate the read count for each gene using StringTie, subsequently normalize the reads using the TMM normalization method, and ultimately determine the FPKM values. Differentially expressed genes (DEGs) analysis was conducted using the R software. The P-values were corrected using multiple hypothesis testing. The threshold for the P-value was established by controlling the False Discovery Rate (FDR), with the adjusted P-value being referred to as the q-value. Additionally, the fold change in differential expression was calculated based on the FPKM values.ClusterProfiler was utilized for Gene Ontology (GO) analysis to elucidate the biological functions of DEGs with a fold change (FC) of at least 2 and a P-value less than 0.05, focusing on biological processes, molecular functions, and cellular components. The Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis was performed using the DAVID database (https://davidbioinformatics.nih.gov/) to identify the critical pathways in which DEGs are involved. A P-value < 0.05 was considered statistically significant.