Passive paracellular proximal tubular (PT) and intestinal calcium (Ca²⁺) fluxes have been linked to active sodium (re)absorption. Although the epithelial sodium/proton exchanger, NHE3, mediates apical sodium entry at both these sites, its role in Ca²⁺homeostasis remains unclear. We, therefore, set out to determine whether NHE3 is necessary for Ca²⁺(re)absorption from these epithelia by comparing Ca²⁺handling between wild-type and NHE3^−/−mice. Serum Ca²⁺and plasma parathyroid hormone levels were not different between groups. However, NHE3^−/−mice had increased serum 1,25-dihydroxyvitamin D₃. The fractional excretion of Ca²⁺was also elevated in NHE3^−/−mice. Paracellular Ca²⁺flux across confluent monolayers of a PT cell culture model was increased by an osmotic gradient equivalent to that generated by NHE3 across the PT in vivo and by overexpression of NHE3.⁴⁵Ca²⁺uptake after oral gavage and flux studies in Ussing chambers across duodenum of wild-type and NHE3^−/−mice confirmed decreased Ca²⁺absorption in NHE3^−/−mice compared with wild-type mice. Consistent with this, intestinal calbindin-D_9K, claudin-2, and claudin-15 mRNA expression was decreased. Microcomputed tomography analysis revealed a perturbation in bone mineralization. NHE3^−/−mice had both decreased cortical bone mineral density and trabecular bone mass. Our results demonstrate significant alterations of Ca²⁺homeostasis in NHE3^−/−mice and provide a molecular link between Na⁺and Ca²⁺(re)absorption.

Objective: To determine whether treatment with an antiresorptive drug in combination with an antiinflammatory drug reduces periarticular bone and soft tissue adaptations associated with the progression of posttraumatic secondary osteoarthritis (OA).Methods: We used in vivo microfocal computed tomography (micro‐CT) to map bony adaptations and in vivo micro–magnetic resonance imaging (micro‐MRI) to examine joint inflammation in a rat model of surgically induced OA secondary to knee triad injury. We examined the arthroprotective effects of the bisphosphonates alendronate and risedronate and the nonsteroidal antiinflammatory drug (NSAID) meloxicam.Results: Micro‐CT revealed reduced levels of periarticular trabecular bone loss in animals with knee triad injury treated with the bisphosphonate drugs alendronate or risedronate, or the NSAID meloxicam, compared with untreated animals. Alendronate treatment reduced bony osteophyte development. While risedronate as a monotherapy did not positively impact osteophytogenesis, combination therapy with risedronate and meloxicam reduced osteophyte severity somewhat. Micro‐MRI revealed an increased, diffuse water signal in the epiphyses of untreated rats with knee triad injury 8 weeks after surgery, suggestive of a bone marrow lesion–like stimulus. In contrast, meloxicam‐treated rats showed a significant reduction in fluid signal compared with both bisphosphonate‐treated groups 8 weeks after surgery. Histologic analysis qualitatively confirmed the chondroprotective effect of both bisphosphonate treatments, showing fewer degradative changes compared with untreated rats with knee triad injury.Conclusion: Our findings indicate that select combinations of bisphosphonate and NSAID drug therapy in the early stages of secondary OA preserve trabecular bone mass and reduce the impact of osteophytic bony adaptations and bone marrow lesion–like stimulus. Bisphosphonate and NSAID therapy may be an effective disease‐modifying drug regimen if administered early after the initial injury.

Proteins of the bone morphogenetic protein (BMP) family are known to have a role in ocular and skeletal development; however, because of their widespread expression and functional redundancy, less progress has been made identifying the roles of individual BMPs in human disease. We identified seven heterozygous mutations in growth differentiation factor 6 (GDF6), a member of the BMP family, in patients with both ocular and vertebral anomalies, characterized their effects with a SOX9-reporter assay and western analysis, and demonstrated comparable phenotypes in model organisms with reduced Gdf6 function. We observed a spectrum of ocular and skeletal anomalies in morphant zebrafish, the latter encompassing defective tail formation and altered expression of somite markers noggin1 and noggin2. Gdf6^+/− mice exhibited variable ocular phenotypes compatible with phenotypes observed in patients and zebrafish. Key differences evident between patients and animal models included pleiotropic effects, variable expressivity and incomplete penetrance. These data establish the important role of this determinant in ocular and vertebral development, demonstrate the complex genetic inheritance of these phenotypes, and further understanding of BMP function and its contributions to human disease.

One of the major advantages of 3D food printing is the customizability in terms of structure, design, and nutritional content. However, printability of the ingredients and the quality of the 3D printed food products are dependent on several product and printing parameters. In this study, nutrient dense cookies were developed with underutilized ingredients including jackfruit seed powder and finger millet powder as base materials using 3D food printing. The hardness, rheological behavior, and microstructure of 3D printed cookies with different products (e.g., water butter ratio) and printing (e.g., fill density and temperature) parameters were analyzed. The 3D printed cookies were developed by extruding at 27 and 30 °C with fill density values of 50%, 70%, 90%, and 100% and water butter ratios of 3:10 and 6:5. The 3D-printed cookie dough exhibited a more elastic behavior with higher storage modulus values than the loss modulus. The hardness of the baked cookies was influenced by printing temperature, fill density, and water butter ratio of 3D printed cookie dough and their interactions. The closed porosity of 3D printed cookies increased while the open porosity decreased with an increase in fill density. The baking times required were longer for 3D-printed cookies with higher fill density values. Overall, this study shows the importance of considering the specific ingredient and printing parameters to develop high quality 3D-printed cookies.