Tfap2a is a novel gatekeeper of nephron differentiation during kidney development.

Renal functional units known as nephrons undergo patterning events during development that create a segmental array of cellular compartments with discrete physiological identities. Here, from a forward genetic screen using zebrafish, we report the discovery that transcription factor AP-2 alpha (tfap2a) coordinates a gene regulatory network that activates the terminal differentiation program of distal segments in the pronephros. We found that tfap2a acts downstream of Iroquois homeobox 3b (irx3b), a distal lineage transcription factor, to operate a circuit consisting of tfap2b, irx1a and genes encoding solute transporters that dictate the specialized metabolic functions of distal nephron segments. Interestingly, this regulatory node is distinct from other checkpoints of differentiation, such as polarity establishment and ciliogenesis. Thus, our studies reveal insights into the genetic control of differentiation, where tfap2a is essential for regulating a suite of segment transporter traits at the final tier of zebrafish pronephros ontogeny. These findings have relevance for understanding renal birth defects, as well as efforts to recapitulate nephrogenesis in vivo to facilitate drug discovery and regenerative therapies.

Weight Gain in People with HIV: The Role of Demographics, Antiretroviral Therapy, and Lifestyle Factors on Weight.

We explored factors associated with weight gain among people with HIV (PWH) on antiretroviral therapy (ART) at The Ohio State University Wexner Medical Center (OSUWMC). This was a retrospective cohort study of adult PWH on ART for ≥3 months. Patients with CD4+ T cell count <200 cells/mm3, viral load >200 copies/mL, history of malignancy, or pregnancy were excluded. Eight hundred seventy patients met criteria. The primary outcome was percent weight change over the follow-up period (Δ = relative effects). The secondary outcome was the odds of ≥5 kg weight gain over the study period. The effects of concurrent medications, medical comorbidities, ART combinations, and lifestyle behaviors on these outcomes were modeled using mixed effects regression analyses. Over a mean follow-up of 1.86 years, the study population gained a mean percent weight of 2.12% ± 0.21% (p < .001) with the odds of ≥5 kg weight gain of 0.293 (p < .001). Males gained an average of 1.88% ± 0.22% over follow up, while females gained an average of 3.37% ± 0.51% over follow up (p = .008 for the difference). In regression models, combination therapy with tenofovir alafenamide (TAF) and integrase strand transfer inhibitor (INSTI) containing regimens was associated with an increase in weight over the study period (Δ = 2.14% ± 0.45%, p < .001 and Δ = 1.09% ± 0.39%, p = .005, respectively). Increasing age was significantly associated with a decrease in percent weight change over the study period (Δ = -0.68% ± 0.18% per year, p < .001). Self-reported improvement in diet was associated with a decrease in weight change (Δ = -1.99% ± 0.47%, p ≤ .001) and reduced odds of ≥5 kg weight gain (odds ratio = 0.70, 95% confidence interval = 0.50-0.97, p = .03). Factors associated with weight gain include therapy with TAF and INSTI. Diet may play an influential role in attenuating weight gain in PWH.