Introduction. The long-term goal of our studies is to determine if, and to what extent, a multi-mineral product (Aquamin) could have beneficial impact on individuals with ulcerative colitis (UC). As a step toward achieving that goal, we carried out a 180-day biomarker trial in patients with UC in remission or at the mild stage. Approach. A total of 28 subjects were included in the study. Each was randomized to receive either Aquamin for 180 days or placebo for the first 90 days. At day-90, placebo subjects crossed over to Aquamin for the final 90 days. At days-0, -90 and -180, serum samples were assessed for alkaline phosphatase (ALP), intestine-specific ALP (ALPI), C-reactive protein (CRP) and for biomarkers of bone turnover (osteocalcin, TRAP5b and bone-specific ALP [e.g., BALP]). Stool specimens were assessed for fecal calprotectin at the same time points and colon biopsies were examined histologically. Each subject underwent DEXA scanning (day-0 and -180 only). In addition, a mass spectrometry-based proteomic assessment was performed using colon biopsy specimens obtained at each time point. Results. Subjects receiving Aquamin for the complete 180-day period (a total of 12) demonstrated improvement in all biomarkers; this was not seen in the placebo group (16 subjects). Subjects who received Aquamin for 90-days were intermediary in their responses. Subjects receiving Aquamin for 180-days also demonstrated increases in bone mineral density (BMD) and bone mineral content (BMC) resulting in a statistically-significant increase in the hip strength index over the period of treatment. This was accompanied by increases in osteocalcin and TRAP5b and by a decrease in BALP. The proteomic screen demonstrated up-regulation of multiple gut barrier proteins, cell surface transporter molecules and certain proteins with anti-inflammatory potential in response to Aquamin. Aquamin treatment also led to down-regulation of several proteins associated with the pro-inflammatory state. Conclusion. These findings suggest the potential value of multi-mineral intervention (Aquamin) as a low-cost, non-toxic adjuvant therapy for mild UC or for individuals with UC in remission. ### Competing Interest Statement The authors have declared no competing interest. ### Clinical Trial NCT03869905 ### Funding Statement This investigator-initiated trial was supported through discretionary funds (JV) provided by Marigot Inc. as a gift to the University of Michigan, as well as the University of Michigan Pandemic Research Recovery (PRR) funding awarded to MA, and funding from the American Society for Investigative Pathology (ASIP) Summer Research Opportunity Program in Pathology (SROPP) to MA. None of these entities played any role in or had any influence on the research activities (i.e., study design, recruitment, data collection, data interpretation, or data dissemination). This study also utilized services at the University of Michigan supported by NIH funding (UM1TR004404 to the Michigan Institute for Clinical and Health Research). ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The interventional study was conducted with FDA approval of Aquamin as an Investigational New Drug (IND#141600) and with oversight by the Institutional Review Board at the University of Michigan Medical School (IRBMED). I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes - All data produced in the present study are available upon reasonable request to the authors - All data produced in the present work are contained in the manuscript - All generated proteomic data will be made publicly available in an online repository following the manuscript's publication.

Control of inflammation is critical for the treatment of nonhealing wounds, but a delicate balance exists between early inflammation that is essential for normal tissue repair and the pathologic inflammation that can occur later in the repair process. This necessitates the development of novel therapies that can target inflammation at the appropriate time during repair. Here, we found that SIRT3 is essential for normal healing and regulates inflammation in wound macrophages after injury. Under prediabetic conditions, SIRT3 was decreased in wound macrophages and resulted in dysregulated inflammation. In addition, we found that FABP4 regulates SIRT3 in human blood monocytes, and inhibition of FABP4 in wound macrophages decreases inflammatory cytokine expression, making FABP4 a viable target for the regulation of excess inflammation and wound repair in diabetes. Using a series of ex vivo and in vivo studies with genetically engineered mouse models and diabetic human monocytes, we showed that FABP4 expression is epigenetically upregulated in diabetic wound macrophages and, in turn, diminishes SIRT3 expression, thereby promoting inflammation. These findings have significant implications for controlling inflammation and promoting tissue repair in diabetic wounds.

Macrophage plasticity is critical for normal tissue repair to ensure transition from the inflammatory to the proliferative phase of healing. We examined macrophages isolated from wounds of patients afflicted with diabetes and of healthy controls and found differential expression of the methyltransferase Setdb2. Myeloid-specific deletion of Setdb2 impaired the transition of macrophages from an inflammatory phenotype to a reparative one in normal wound healing. Mechanistically, Setdb2 trimethylated histone 3 at NF-κB binding sites on inflammatory cytokine gene promoters to suppress transcription. Setdb2 expression in wound macrophages was regulated by interferon (IFN) β, and under diabetic conditions, this IFNβ-Setdb2 axis was impaired, leading to a persistent inflammatory macrophage phenotype in diabetic wounds. Setdb2 regulated the expression of xanthine oxidase and thereby the uric acid (UA) pathway of purine catabolism in macrophages, and pharmacologic targeting of Setdb2 or the UA pathway improved healing. Thus, Setdb2 regulates macrophage plasticity during normal and pathologic wound repair and is a target for therapeutic manipulation.

Abstract Epigenetic regulation of macrophages can alter their function and impact tissue inflammation and wound repair. Unregulated inflammation at the wound level in inflammatory diseases like type 2 diabetes (T2D) leads to significant morbidity and mortality. Recent work by our group and others has shown that chromatin-modifying enzymes influence inflammatory gene expression in macrophages and other immune cells. Here we show that Setdb2, a histone methyltransferase, is induced in macrophages during the inflammatory phase of wound healing. Specifically, Setdb2 repressed expression of NF-κB-induced inflammatory genes, including IL-1B. This coincided with occupancy by Setdb2 at the IL-1B promoter, which in the absence of Setdb2 displayed diminished trimethylation of histone 3 lysine 9 (H3K9me3) in bone marrow derived macrophages (BMDM). Mice with the inability to upregulate setdb2 in their macrophages (Setdb2f/fLyz2cre+) demonstrated impaired healing during the inflammatory phase of wound healing. This corresponded with decreased H3K9me3 at the promoter of IL-1B and other inflammatory genes in macrophages isolated from the wounds of these animals. Further, LPS was able to upregulate setdb2 expression in BMDM and hence TLR4 signaling may play a role in regulation of inflammation in wound tissue. This suggests that a Setdb2-mediated alteration of NF-κB pathways represents an important mechanism for successful wound healing.

Kimball, Andrew MD; Schaller, Matthew PhD; Joshi, Amrita PhD; Allen, Ron PhD; Bonikowski, Anna MD; Henke, Peter K. MD, FACS; Kunkel, Steven PhD; Gallagher, Katherine MD, FACS Author Information

Background: Wound healing in chronic diseases, such as type 2 diabetes (T2D), is impaired due to dysregulated inflammation. Innate immune cells, particularly macrophages, play a significant role in regulated inflammation following tissue injury. After injury, CCR2+ monocytes are recruited to the peripheral wound. This recruitment is mediated in part by the CCR2 ligand, CCL2. Thus, we hypothesized that the CCL2/CCR2 interaction is vital for normal wound healing and appropriate inflammation, and that this signaling cascade is impaired in T2D. Methods: CCR2 -/- mice and littermate controls underwent 4mm hindlimb wounds, and wound closure was compared daily. Wound macrophages (CD3-CD19-NK1.1-CD11b+ cells) were analyzed on day 3 by flow cytometry for intracellular cytokine production. Adoptive transfer was performed using blood CD11b+ cells from WT C57BL/6 or CCR2 -/- mice isolated by magnetic sorting and transferred into CCR2 -/- mice via tail vein injection. Mice were then wounded and wound closure was compared between the two groups. C57BL/6 mice were maintained on normal or high fat diet for 12-14 weeks, wounds were created, and CD11b+ cells were isolated from wounds on day 2. ELISA for CCL2 was performed. Results: CCR2 -/- mice showed significantly impaired wound healing on days 2-7 compared with littermate controls. Macrophages isolated on day 3 from wounds of CCR2 -/- mice expressed significantly less inflammatory cytokines (IL-1β, TNF-α) by qPCR. Flow cytometry analysis revealed less Ly6C hi macrophages in the wounds, as well as macrophages that made significantly less IL-1β, NOS2, and TNF-α. When adoptive transfer was performed, wound healing was restored to normal in the mice that received WT compared to those that received CCR2 -/- CD11b+ cells (P< 0.01). Since CCR2 is important for normal wound inflammation, and we have previously shown that inflammation is impaired in the diet-induced obese (DIO) mice, we examined CCL2 in DIO wounds. CCL2 was significantly decreased in DIO wound macrophages on day 2. Conclusion: Appropriate CCR2/CCL2 interaction plays a crucial role in macrophage recruitment and regulated inflammation in normal wound healing. Impairment in CCR2/CCL2 signaling may be responsible, in part, for delayed early inflammation in T2D.

Macrophages are critical for the initiation and resolution of the inflammatory phase of wound repair. In diabetes, macrophages display a prolonged inflammatory phenotype in late wound healing. Mixed-lineage leukemia-1 (MLL1) has been shown to direct gene expression by regulating nuclear factor-κB (NF-κB)–mediated inflammatory gene transcription. Thus, we hypothesized that MLL1 influences macrophage-mediated inflammation in wound repair. We used a myeloid-specific Mll1 knockout (Mll1f/fLyz2Cre+) to determine the function of MLL1 in wound healing. Mll1f/fLyz2Cre+ mice display delayed wound healing and decreased wound macrophage inflammatory cytokine production compared with control animals. Furthermore, wound macrophages from Mll1f/fLyz2Cre+ mice demonstrated decreased histone H3 lysine 4 trimethylation (H3K4me3) (activation mark) at NF-κB binding sites on inflammatory gene promoters. Of note, early wound macrophages from prediabetic mice displayed similarly decreased MLL1, H3K4me3 at inflammatory gene promoters, and inflammatory cytokines compared with controls. Late wound macrophages from prediabetic mice demonstrated an increase in MLL1, H3K4me3 at inflammatory gene promoters, and inflammatory cytokines. Prediabetic macrophages treated with an MLL1 inhibitor demonstrated reduced inflammation. Finally, monocytes from patients with type 2 diabetes had increased Mll1 compared with control subjects without diabetes. These results define an important role for MLL1 in regulating macrophage-mediated inflammation in wound repair and identify a potential target for the treatment of chronic inflammation in diabetic wounds.

SummaryDeep-vein thrombosis (DVT) resolves via a sterile inflammatory response. Defining the inflammatory response of DVT may allow for new therapies that do not involve anticoagulation. Previously, we have shown that Toll-like receptor 9 (Tlr9) gene deleted mice had impaired venous thrombosis (VT) resolution. Here, we further characterise the role of Tlr9 signalling and sterile inflammation in chronic VT and vein wall responses. First, we found a human precedent exists with Tlr9 + cells present in chronic post thrombotic intraluminal tissue. Second, in a stasis VT mouse model, endogenous danger signal mediators of uric acid, HMGB-1, and neutrophil extracellular traps marker of citrullinated histone-3 (and extracellular DNA) were greater in Tlr9-/- thrombi as compared with wild-type (WT), corresponding with larger VT at 8 and 21 days. Fewer M1 type (CCR2+) monocyte/macrophages (MØ) were present in Tlr9-/- thrombi than WT controls at 8 days, suggesting an impaired inflammatory cell influx. Using bone marrow-derived monocyte (BMMØ) cell culture, we found decreased fibrinolytic gene expression with exposure to several endogenous danger signals. Next, adoptive transfer of cultured Tlr9+/+ BMMØ to Tlr9-/- mice normalised VT resolution at 8 days. Lastly, although the VT size was larger at 21 days in Tlr9-/- mice and correlated with decreased endothelial antigen markers, no difference in fibrosis was found. These data suggest that Tlr9 signalling in MØ is critical for later VT resolution, is associated with necrosis clearance, but does not affect later vein wall fibrosis. These findings provide insight into the Tlr9 MØ mechanisms of sterile inflammation in this disease process.

Toll-like receptor (TLR) activation has been implicated in acetaminophen (APAP)-induced hepatotoxicity. Herein, we hypothesize that TLR3 activation significantly contributed to APAP-induced liver injury. In fasted wildtype (WT) mice, APAP caused significant cellular necrosis, edema, and inflammation in the liver, and the de novo expression and activation of TLR3 was found to be necessary for APAP-induced liver failure. Specifically, liver tissues from similarly fasted TLR3-deficient (tlr3(-/-) ) mice exhibited significantly less histological and biochemical evidence of injury after APAP challenge. Similar protective effects were observed in WT mice in which TLR3 was targeted through immunoneutralization at 3 h post-APAP challenge. Among three important death ligands (i.e. TNFα, TRAIL, and FASL) known to promote hepatocyte death after APAP challenge, TNFα was the only ligand that was significantly reduced in APAP-challenged tlr3(-/-) mice compared with APAP-challenged WT controls. In vivo studies demonstrated that TLR3 activation contributed to TNFα production in the liver presumably via F4/80(+) and CD11c(+) immune cells. In vitro studies indicated that there was cooperation between TNFα and TLR3 in the activation of JNK signaling in isolated and cultured liver epithelial cells (i.e. nMuLi). Moreover, TLR3 activation enhanced the expression of phosphorylated JNK in APAP injured livers. Thus, the current study demonstrates that TLR3 activation contributes to APAP-induced hepatotoxicity.

C57BL/6 mice were maintained for up to 18 months on high-fat and low-fat diets with or without a multi-mineral supplement derived from the skeletal remains of the red marine algae Lithothamnion calcareum. Numerous grossly observable liver masses were visible in animals on the "western-style" high-fat diet sacrificed at 12 and 18 months. The majority of the masses were in male mice (20 out of 100 males versus 3 out of 100 females; p = 0.0002). There were more liver masses in animals on the high-fat diet than on the low-fat diet (15 out of 50 on high-fat versus 5 out of 50 on low-fat; p = 0.0254). The multi-mineral supplement reduced the number of liver masses in mice on both diets (3 out of 25 male mice in the low-fat diet group without the supplement versus 1 out of 25 mice with supplement; 12 of 25 male mice in the high-fat diet group without the supplement versus 3 of 25 mice with supplement [p = 0.0129]). Histological evaluation revealed a total of 17 neoplastic lesions (9 adenomas and 8 hepatocellular carcinomas), and 18 pre-neoplastic lesions. Out of eight hepatocellular carcinomas, seven were found in unsupplemented diet groups. Steatosis was widely observed in livers with and without grossly observable masses, but the multi-mineral supplement had no effect on the incidence of steatosis or its severity. Taken together, these findings suggest that a multi-mineral-rich natural product can protect mice against neoplastic and pre-neoplastic proliferative liver lesions that may develop in the face of steatosis.