Therapeutic Effects of FK506 on IgA Nephropathy Rat

Deciphering roles of protein post-translational modifications in IgA nephropathy progression and potential therapy

Immunoglobulin A nephropathy (IgAN), one type of glomerulonephritis, displays the accumulation of glycosylated IgA in the mesangium. Studies have demonstrated that both genetics and epigenetics play a pivotal role in the occurrence and progression of IgAN. Post-translational modification (PTM) has been revealed to critically participate in IgAN development and progression because PTM dysregulation results in impaired degradation of proteins that regulate IgAN pathogenesis. A growing number of studies identify that PTMs, including sialylation, o-glycosylation, galactosylation, phosphorylation, ubiquitination and deubiquitination, modulate the initiation and progression of IgAN. Hence, in this review, we discuss the functions and mechanisms of PTMs in regulation of IgAN. Moreover, we outline numerous compounds that govern PTMs and attenuate IgAN progression. Targeting PTMs might be a useful strategy to ameliorate IgAN.

Short-term use of ceftriaxone sodium leads to intestinal barrier disruption and ultrastructural changes of kidney in SD rats

OBJECTIVE

Antibiotic treatments are known to disturb gut microbiota, but their effects on the mucosal barrier and extraintestinal diseases are rarely discussed. The aim of this study was to evaluate and visualize the impact of antibiotics on colonic mucus and the microbial community, and to assess whether intestinal dysbacteriosis is involved in the pathogenesis and progression of extraintestinal diseases in vivo.

MATERIALS AND METHODS

Twenty-one SD rats were randomly assigned into three groups followed by different experimental treatments. The albumin-creatinine ratio, urinary protein and occult blood semi-quantified test were tested. Fecal samples were collected at different time points (0,4, and 12 weeks) for 16S rRNA gene sequencing. Colon and kidney specimens were examined using light microscopy and transmission electron microscopy (TEM) to identify morphological changes.

RESULTS

Ceftriaxone intervention for one week did not cause any symptoms of diarrhea or weight loss, but the alpha and beta diversities of gut microbiota decreased quickly and significantly, a lower Firmicutes/Bacteroidetes (F/B) ratio was observed. At week 12, although the alpha and beta diversities increased to a level similar to that of the control (CON) group, LEfSe analysis indicated that the microbial community composition still differed significantly in each group. In addition, KEGG metabolic prediction revealed different metabolic functions in each group. TEM examination of colon revealed that dramatic morphological changes were observed in the ceftriaxone (Cef) group, wherein microvilli were misaligned and shortened significantly and morphologically intact bacteria were seen on the epithelial cell surface. TEM examination of kidneys from the Cef group showed characteristic glomerular changes in the form of widely irregularly thickened glomerular basement membrane (GBM) and foot process fusion or effacement; mild thickening of the GBM and foot process fusion was detected when ceftriaxone and Resatorvid (TAK242, an inhibitor of TLR4 signaling) are used together in the ceftriaxone + TAK242 (TAK) group.

CONCLUSIONS

Short-term use of ceftriaxone induced dynamic changes of gut microbiota and lead to intestinal barrier disruption and ultrastructural changes of kidneys in the SD rats. Moreover, interference with the TLR4-dependent signaling pathway can alleviate the damage to the intestinal barrier and kidney.

Efficacy and safety of tacrolimus-based treatment for non-rapidly progressive IgA nephropathy

In this study, we aimed to evaluate the efficacy and safety of tacrolimus-based treatment for immunoglobulin A nephropathy (IgAN). We retrospectively reviewed 127 adult patients with primary IgAN with 24 h urine total protein quantity (24 h UTP) ≥ 1 g and serum creatinine ≤3 mg/dL. All patients were divided into tacrolimus (TAC) and control (non-TAC) groups according to the treatment strategy. Proteinuria remission, remission rate, and adverse events were compared between the two groups. Among the 127 patients, 61 received TAC-based treatment and 66 received non-TAC treatment. TAC group exhibited a more rapid decline in proteinuria than the non-TAC group at 3, 9, and 12 months (p = 0.049, 0.001, and 0.018, respectively). Remission rates at 1, 3, 6, 9, and 12 months were 41.0, 68.9, 80.3, 90.2, and 88.5%, respectively, in the TAC group. These rates were higher than those in the control group at 3, 9, and 12 months (p = 0.030, 0.008, and 0.026, respectively). Complete remission rates at 1, 3, 6, 9, and 12 months were 6.56, 19.7, 37.7, 54.1, and 62.3%, respectively, in the TAC group. These rates were higher than those in the control group at 9 and 12 months (p = 0.013 and 0.008, respectively). The estimated mean time to complete remission was significantly shorter in the TAC group than in the control group (p = 0.028). TAC did not increase the incidence of adverse events. In conclusion, TAC accelerated proteinuria remission in patients with non-rapidly progressive IgAN with no increased risk of adverse events. Further prospective randomized controlled trials are necessary to validate our findings.

Long noncoding RNA FGD5-AS1 alleviates childhood IgA nephropathy by targeting PTEN-mediated JNK/c-Jun signaling pathway via miR-196b-5p

This paper studied lncRNA FGD5 antisense RNA 1 (FGD5-AS1)-associated mechanisms in immunoglobulin A nephropathy (IgAN). FGD5-AS1, miR-196b-5p, and PTEN in the serum of children with IgAN were assessed. MES-13 cells were stimulated by p-IgA1 to construct an in vitro model of IgAN. After plasmid intervention, cell proliferation, cell cycle, apoptosis, and inflammatory response were correspondingly evaluated. An IgAN mouse model was established to define FGD5-AS1/miR-196b-5p/PTEN axis-mediated alternations of 24-h proteinuria, blood urea nitrogen, serum creatinine, glomerular IgA deposition, renal fibrosis, and glycogen content in renal tissue. The changes in JNK/c-Jun pathway activation in the cell model were also tested. Our results discovered that FGD5-AS1 and PTEN were down-regulated and miR-196b-5p was up-regulated in children with IgAN. Overexpression of FGD5-AS1 or silencing of miR-196b-5p impeded the proliferation and inflammatory response and induced apoptosis of p-IgA1-stimulated MES-13 cells, and improved pathological conditions in IgAN mice. Inhibition of PTEN rescued the therapeutic effects of overexpression of FGD5-AS1 or inhibition of miR-196b-5p on IgAN. FGD5-AS1/miR-196b-5p/PTEN axis inhibited the activation of the JNK/c-Jun pathway. Taken together, FGD5-AS1 attenuates IgAN by targeting PTEN-mediated JNK/c-Jun signaling via miR-196b-5p. Therefore, FGD5-AS1 may be a new therapeutic target for IgAN.

Canonical transient receptor potential channels and their modulators: biology, pharmacology and therapeutic potentials

Canonical transient receptor potential channels (TRPCs) are nonselective, high calcium permeability cationic channels. The TRPCs family includes TRPC1, TRPC2, TRPC3, TRPC4, TRPC5, TRPC6, and TRPC7. These channels are widely expressed in the cardiovascular and nervous systems and exist in many other human tissues and cell types, playing several crucial roles in the human physiological and pathological processes. Hence, the emergence of TRPCs modulators can help investigate these channels’ applications in health and disease. It is worth noting that the TRPCs subfamilies have structural and functional similarities, which presents a significant difficulty in screening and discovering of TRPCs modulators. In the past few years, only a limited number of selective modulators of TRPCs were detected; thus, additional research on more potent and more selective TRPCs modulators is needed. The present review focuses on the striking desired therapeutic effects of TRPCs modulators, which provides intel on the structural modification of TRPCs modulators and further pharmacological research. Importantly, TRPCs modulators can significantly facilitate future studies of TRPCs and TRPCs related diseases.