Influence of calcineurin inhibitors and genetic polymorphism of transporters on enterohepatic circulation and exposure of mycophenolic acid in Chinese adult renal allograft recipients

Aim: Study the influence of calcineurin inhibitors (CNI) and genetic polymorphisms of transporters on enterohepatic circulation (EHC) of mycophenolic acid (MPA) in Chinese adult renal allograft recipients and estimate the effect of various covariates on prediction performance of MPA AUC0-12h. Method: MPA concentrations of 125 Chinese patients were collected 0-12 hours after administration. Genotypes of transporters were determined in 64 patients. The influence of type of CNI and genetic polymorphisms on MPA exposure was studied. Shapley additive explanations method was used to study the impact of sampling times and covariates related to EHC on AUC0-12h. Extreme gradient boosting (XGboost) machine learning-based model was established to predict AUC0-12h. Results: Dn-AUC6-12h was significantly lower in patients co-administered with CsA (P<0.05). When co-administered with TAC, for SLCO1B1 T521C or ABCC C-24T, patients with wild-type genotype had significantly higher dn-AUC6-12h (P <0.05). Patients with SLCO1B3 334T/699G alleles had significantly lower dn-AUC6-12h than homozygotes (P=0.004). No significant difference was found in CsA subgroup. For estimating AUC0-12h, C0h, C2h, C8h, type of CNI, transporters genotypes and the difference between C0h and C2h were retained in the final model, which had good prediction performance (r2=0.9739). Conclusion: Patients co-administered with CsA had lower MPA EHC than those who received TAC. MPA EHC is affected by ABCC2 C-24T, SLCO1B3 T334G/G699A, and SLCO1B1 T521C genotypes in patients treated with TAC. Type of CNI and genetic polymorphisms of transporters can improve prediction performance of MPA AUC0-12h estimating model, developed using XGboost machine learning method.

Penicillium Arizonense as a Novel Producer Strain for Mycophenolic Acid and Expression Analysis of Biosynthesizing Gene Clusters

A novel potent mycophenolic acid (MPA) producer strain of the genus Penicillium was isolated from refrigerated Mozzarella cheese and identified as P. arizonenseHEWt1. The molecular mechanism of MPA production by this new isolate was our main target. To achieve this objective, we first isolated three MPA overproducer mutants by exposing the wild type to different doses of gamma-rays, and the fermentation conditions for the highest production of MPA by both the wild type and mutants were optimized. Then, orthologs of MPA gene clusters in P. brevicompactum were cloned and predicted from the genome of P. arizonense. Sequencing and bioinformatic analysis proved the presence of a cluster containing five putative genes in the P. arizonense HEWt1 genome ortholog to the MPA cluster, mpaA, mpaC, mpaF, mpaG, and mpaH. All predicted genes displayed 96-97% similarity with the related hypothetical protein of P. arizonense. The genes, mpaG, mpaC, and mpaF. represented 69%, 82%, 84%, respectively, similarity with their orthologous genes in P. brevicompactum, whereas mpaG and mpaA represented 75% and 79%, respectively, similarity to their orthologous genes in P. roqueforti. Gene expression analysis through quantitative rPCR indicated an increase in the transcription value of all annotated genes in the three mutants over the wild type. A highly significant increase in the gene expression of mpaC, mpaF, and mpaH was observed, with 8.4561±1.02, 5.6569±0.87, and 4.6268±0.18-fold increases, respectively, in P. arizonense-MT1 compared with wild-type. These results confirmed the potential participation of these genes in MPA biosynthesis and are the first report regarding the molecular mechanism of MPA production by P. arizonense.

Antibody Response to mRNA Vaccines against SARS-CoV-2 with Chronic Kidney Disease, Hemodialysis, and after Kidney Transplantation

Most trials on mRNA vaccines against SARS-CoV-2 did not include patients with chronic kidney disease (CKD), hemodialysis (HD) patients, or kidney transplant recipients (KTR). However, those patients have a higher risk for a severe course of COVID-19 disease and mortality. Available literature has demonstrated a reduced efficacy of mRNA vaccines in HD patients and KTR, while data on CKD patients is scarce. Additionally, factors associated with non-response are poorly understood and not well characterized. We assessed antibody (AB) response (n = 582, 160 CKD patients, 206 patients on HD, 216 KTR) after the administration of two doses of a mRNA-vaccine with either BNT162b2 or mRNA-1273. AB measurements were carried out after a median of 91 days after first vaccinations, demonstrating non-response in 12.5% of CKD patients, 12.1% of HD patients, and 50% of KTR. AB titers were significantly higher in CKD patients than in HD patients or KTR. Factors associated with non-response were treated with rituximab in CKD patients, the use of calcineurin inhibitors in HD patients and older age, and the use of BNT162b2, mycophenolic acid, or glucocorticoids and lower hemoglobin levels in KTR. This study contributes to the understanding of the extent and conditions that predispose for non-response in patients with impaired kidney function.

Research on Crystal Structure and Fungicidal Activity of the Amide Derivatives Based on the Natural Products Sinapic Acid and Mycophenolic Acid

Structural optimization based on natural products is an important and effective way to discover new green pesticides. Here, two series of amide derivatives based on sinapic acid and mycophenolic acid were designed in combination with the fungicidal natural product piperlongumine and synthesized by preparing the carboxylic acid into acyl chloride and then reacting with the corresponding aromatic amines, respectively. The resulting structures were successively characterized by 1H NMR, 13 C NMR, and HRMS. The crystal structures of molecules I-4 and II-5 were analyzed for structure validation. The in vitro inhibitory activity indicated that most of the target products exhibited fungicidal activity equivalent to or even better than fluopyram against Physalospora piricola. The in vivo fungicidal activity demonstrated that the compounds I-5 and II-4 displayed almost the same preventative activity as carbendazim and fluopyram at 200 μg mL−1. The TEM observation revealed that the fungicidal activity of the target molecules against Physalospora piricola may be due to the influence on the mitochondria in the cell structure. These results will provide valuable theoretical guidance for developing the new green fungicides.