New strategies and perspectives on managing IgA nephropathy.

IgA nephropathy is an inflammatory renal disease characterised by the deposition of IgA in the glomerular mesangium and is the most commonly reported primary glomerulonephritis worldwide. Thirty to forty percent of patients with the disease develop progressive renal function decline, requiring renal replacement therapy within two decades of diagnosis. Despite this, accurate individual risk stratification at diagnosis and predicting treatment response remains a challenge. Furthermore, there are currently no disease specific treatments currently licensed to treat the condition due to long standing challenges in the nature and prevalence of the disease. Despite this, there have been exciting recent advances in the field that may represent paradigm shifts in the way IgA nephropathy is managed in the near future. In this review, we explore the evidence base informing current approaches to management and explore new strategies and future directions in the diagnosis and management of IgA nephropathy

Expression of Toll-like receptor 4, MyD88, TRIF, and interferon-β in each zinc condition.

<p>(A) Expression of Toll-like receptor 4 (TLR4) for each zinc (Zn) condition with/without lipopolysaccharide (LPS). Expression of TLR4 was significantly increased when stimulated by LPS under low and normal Zn conditions. However, TLR4 expression under high Zn conditions was low despite LPS stimulation. (B) Expression of MyD88 at each Zn condition. Expression of MyD88 remained constant at each Zn condition. (C) Expression of TRIF for each Zn condition. Expression of TRIF under low Zn conditions was significantly higher than that in other groups. (D) Expression of interferon-β in each Zn condition. Expression of interferon-β was higher in low Zn condition and lower in high Zn condition. *p<0.05; **p<0.01.</p

Urinary albumin levels for each dietary zinc condition.

<p>Urinary levels of albumin were significantly higher in the low zinc (Zn) diet group and lower in the high Zn diet group on the sixth week. *p<0.05; **p<0.01.</p

Reactivity against lipopolysaccharide.

<p>Lipopolysaccharide (LPS) was nasally administered to some mice in each dietary group, while others received saline as a vehicle control; samples were collected during the sixth week. We calculated the ratio (sixth:fourth week) of each parameter. Although ACR in all groups increased after LPS stimulation, the elevation in the low zinc (Zn) diet group was very high. Serum concentrations of IgA and IgA–IgG immune complexes (ICs) in the low and normal Zn diet groups tended to be higher after LPS stimulation. However, the high Zn diet group maintained low concentrations of serum IgA and IgA–IgG ICs despite LPS stimulation. *p<0.05.</p

Intensity of mesangial IgA and IgG deposition.

<p>The intensity of IgA and IgG deposition was scored on a 1–5 scale based on an average of more than 10 glomeruli. IgA deposition was significantly attenuated in the high zinc (Zn) diet group. IgG deposition in the low Zn diet group was significantly higher than that in the normal and high Zn diet groups. *p<0.05; **p<0.01.</p

Serum concentration of immunoglobulins for each dietary zinc condition.

<p>Dietary zinc intervention altered the serum concentrations of IgA and IgA–IgG immune complexes but not of IgG and IgM. *p<0.05.</p

IgA production by various spleen cells.

<p>(A) IgA production by B cells increased when cocultured with T cells and/or dendritic cells (DCs). (B) Under low zinc (Zn) conditions, IgA production was significantly increased in the presence of DCs. Under high Zn conditions, IgA production by all cell combinations was suppressed. (C) Coculture of untreated B cells with low Zn-treated T cells and/or DCs. IgA production increased in the presence of DCs. (D) Coculture of B cells and DCs with or without lipopolysaccharide (LPS). LPS significantly enhanced IgA production despite the absence of T cells. (E) Coculture of B cells and DCs from gddY or BALB/c mice. A combination of both B cells and DCs from gddY mice yielded the highest production of IgA. **p<0.01; ***p<0.001.</p

Global DNA methylation of <i>Dnmt1</i> and <i>Uhrf1</i> double-knockout, or TKO ESC expressing ectopic Dnmt1.

<p>(<b>A</b>) Genome DNA prepared from <i>Dnmt1</i> and <i>Uhrf1</i> conditional double-knockout ESC expressing either no ectopic Dnmt1 (Double F/F), or full-length Dnmt1 (FL), oocyte-type Dnmt1 (oocyte), Dnmt1(291–1620) (291), or Dnmt1(602–1620) clone #1 (602#1) treated without (-) or with OHT (+) for ten days was immuno-blotted with anti-methylated cytosine antibody (5mC, upper panel) or stained with methylene blue (DNA, lower panel). The amounts of DNA are shown at the left. (<b>B</b>) The genome DNA in panel A and Dnmt1(602–1620) clone #5 (602#5) were fragmented by sonication, and then precipitated with MBD1. The precipitated DNA was quantitated as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0137509#pone.0137509.g001" target="_blank">Fig 1D</a>, averages ± S. D. being shown. ***, p<0.001. (<b>C</b>) Genome DNA prepared from <i>Dnmt1</i> conditional-knockout ESC expressing either no ectopic Dnmt1 (<i>Dnmt1</i>-F/F), Dnmt1(602–1620), Dnmt1(602–1620) with C1229S clones#1 (602-C1229S #1), or clone #11 (602-C1229S #11) treated without (0) or with OHT for four days (4) or ten days (10) was immuno-blotted with anti-methylated cytosine antibody (5mC, upper panel), or stained with methylene blue (DNA, lower panel). The amounts of DNA are shown at the left. (<b>D</b>) Genome DNA prepared from <i>Dnmt1</i> conditional-knockout ESC expressing either no ectopic Dnmt1 (<i>Dnmt1</i>-F/F), or Dnmt1(602–1620) with C1229S clone #1 (602-C1229S #1) or clone #11 (602-C1229S #11) treated without (blue) or with OHT for four days (red) or ten days (green) was fragmented by sonication, and then precipitated with MBD1. The precipitated DNA was quantitated as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0137509#pone.0137509.g001" target="_blank">Fig 1D</a>, averages ± S. D. being shown. (<b>E</b>) Genome DNA prepared from parent ESC (J1), TKO ESC (TKO), TKO ESC expressing full-length Dnmt1 (FL), Dnmt1(291–1620) (291), Dnmt1(602–1620) (602), full-length Dnmt1 and Dnmt3a2-TAP (FL+Dnmt3a2), or (602–1620) and Dnmt3a2-TAP (602+Dnmt3a2) was immuno-blotted with anti-methylated cytosine antibody (5mC, upper panel), or stained with methylene blue (DNA, lower panel). The amounts of DNA are shown at the left. (<b>F</b>) Genome DNA prepared from J1, TKO ESC (TKO), TKO ESC expressing no ectopic Dnmt1 (TKO), or full-length Dnmt1 (FL), Dnmt1(291–1620) (291), Dnmt1(602–1620) (602), full-length Dnmt1 and Dnmt3a2-TAP (FL+Dnmt3a2), or Dnmt1(602–1620) and Dnmt3a2-TAP (602+Dnmt3a2) was fragmented by sonication, precipitated with MBD1, and then analyzed as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0137509#pone.0137509.g001" target="_blank">Fig 1D</a>. The value obtained for TKO was considered as no DNA methylation and subtracted from each measurement. Averages ± S. D. are shown.</p

Localization of Dnmt1 at the replication region in ESC.

<p>ESC (<i>Dnmt1</i>-F/F), and ESC expressing no Dnmt1 (<i>Dnmt1</i>-F/F +OHT), or ectopic full-length Dnmt1 (FL), oocyte-type Dnmt1 (oocyte), Dnmt1(291–1620) (291), Dnmt1(602–1620) (602), or full-length Dnmt1 with the mutation of H168R (PBDm) treated with OHT were labeled with EdU, and detected the EdU (green) and Dnmt1 (red), and the images were merged. White bars indicate 5 μm.</p

DNA methylation analyses of the <i>gag</i> of <i>IAP</i>.

<p>The methylation state of the genome DNA prepared from ESC expressing no Dnmt1 (<i>Dnmt1</i> F/F), or full-length Dnmt1 (FL), oocyte-type Dnmt1 (oocyte), Dnmt1(291–1620) (291), or Dnmt1(602–1620) (602) four or ten days after addition of OHT. The methylation states of the <i>gag</i> of <i>IAP</i> are shown with that of the parent cells before (<i>Dnmt1</i>-F/F) and after the OHT treatment (<i>Dnmt1</i>-F/F+OHT). Each horizontal line indicates the CpGs in one analyzed clone. Each circle indicates one CpG site, methylated (filled circles) or un-methylated (open circles). The percentages of methylation are indicated at the top.</p