Mitochondrial dysfunction is a crucial event in acute kidney injury (AKI), leading to a metabolic shift toward glycolysis and increased lactate production. Lactylation, a posttranslational modification derived from lactate, plays a significant role in various cellular processes, yet its implications in AKI remain underexplored. Here, a marked increase in lactate levels and pan‐Kla levels are observed in kidney tissue from AKI patients and mice, with pronounced lactylation activity in injured proximal tubular cells identified by single‐cell RNA sequencing. The lactylation of aldehyde dehydrogenase 2 (ALDH2) is identified at lysine 52 (K52la), revealing that ALDH2 lactylation exacerbates tubular injury and mitochondrial dysfunction. Conversely, the ALDH2 K52R mutation alleviates these injuries in HK‐2 cells and adeno‐associated virus‐infected kidney tissues in mice. Furthermore, ALDH2 lactylation can be modulated by upregulating SIRT3 in vivo and in vitro, which reduces ALDH2 lactylation, mitigating tubular injury and mitochondrial dysfunction. Mechanistically, immunoprecipitation‐mass spectrometry analysis demonstrates an interaction between ALDH2 and prohibitin 2 (PHB2), a crucial mitophagy receptor. ALDH2 lactylation promotes the ubiquitination‐proteasomal degradation of PHB2 to inhibit mitophagy and worsen mitochondrial dysfunction. These findings highlight the critical role of endogenous lactate in AKI and propose ALDH2 lactylation as a potential therapeutic target.

The use of single-cell combinatorial indexing sequencing via droplet microfluidics presents an attractive approach for balancing cost, scalability, robustness and accessibility. However, existing methods often require tailored protocols for individual modalities, limiting their automation potential and clinical applicability. To address this, we introduce UDA-seq, a universal workflow that integrates a post-indexing step to enhance throughput and systematically adapt existing droplet-based single-cell multimodal methods. UDA-seq was benchmarked across various tissue and cell types, enabling several common multimodal analyses, including single-cell co-assay of RNA and VDJ, RNA and chromatin, and RNA and CRISPR perturbation. Notably, UDA-seq facilitated the efficient generation of over 100,000 high-quality single-cell datasets from three dozen frozen clinical biopsy specimens within a single-channel droplet microfluidics experiment. Downstream analysis demonstrated the robustness of this approach in identifying rare cell subpopulations associated with clinical phenotypes and exploring the vulnerability of cancer cells.

Hyponatremia (serum sodium concentration < 135 mmol/L) is the most common electrolyte abnormality and is a predictor of the mortality of hospitalized patients in Western countries. However, hyponatremia data are lacking in Asian countries. Here we evaluate the epidemiology and mortality of hyponatremia in general medical hospitalized patients in China. This is a cohort study of 154,378 adults who were hospitalized between 2008 and 2012 at a teaching hospital in Beijing. We identified hospital patients with hyponatremia and calculated the prevalence and in-hospital mortality of hyponatremia. We also conducted a comprehensive retrospective review of the medical records of patients who had severe hyponatremia (serum sodium <120 mmol/L) during hospitalization in 2012. The overall prevalence of hyponatremia at some point during hospitalization was 17.5% (26,990 patients), but only 0.26% (394 patients) of cases were identified with the diagnostic code of hyponatremia. Hyponatremia was more common in patients with infectious disease, cancer, or cardiovascular disease as the primary reason for hospitalization based on discharge diagnosis, with prevalences of 33.0, 25.9 and 24.9%, respectively. The in-hospital mortality was 0.48% amongst patients without hyponatremia compared to 3.57 and 20.23% in patients with serum sodium levels of 130–134 and <120 mmol/L, resulting in multivariable adjusted odds ratios (ORs) of 4.8 (95% CI 4.3–5.4) and 32.9 (95% CI 25.2–42.3), respectively. The mortality risk increased with increasing severity of hyponatremia in all diagnostic groups. After the multivariate adjustment, only the Charlson Comorbidity Index and age were independently associated with death risk (OR 1.36, 95% CI 1.14–1.64 and OR 1.04, 95% CI 1.00–1.09, respectively) in the patients with severe hyponatremia. Hyponatremia is highly prevalent among Chinese hospitalized patients and is associated with increased in-hospital mortality risk. Physicians should raise awareness to improve the prognosis of hyponatremia.

Aim: To retrospectively investigate the features of renal involvements in patients with primary Sjögren's syndrome (pSS) with biopsy results.Methods: A total of 2096 pSS inpatients at Peking Union Medical College Hospital in China from 2005 to 2015 were identified. Patients with biopsy‐proven renal involvement (SS‐renal) and matched controls (SS‐only) were recruited. The clinical and pathologic features as well as treatments and outcomes were systematically analyzed.Results: One hundred and three pSS nephritis (inpatients had biopsy‐proven renal involvement. Tubulointerstitial 53, 51.5%) was the prominent pathologic pattern with glomerulonephritis (GN) present in 50 (48.5%) of the renal lesions. The patterns of GN lesions included membranous nephropathy (37, 35.9%), mesangial proliferative glomerulonephritis (six, 5.8%) or immunoglobulin A nephropathy (three, 2.9%), minimal change disease (four, 3.9%) and focal segmental glomerulosclerosis (three, 2.9%). Compared to SS‐only patients, SS‐renal patients had fewer dry eyes and positive objective xerostomia (P < 0.05). They presented with a significantly lower incidence of interstitial lung disease (ILD), leukocytopenia and elevated immunoglobulin G levels (P < 0.05). They received a larger initial dosage of corticosteroid and had a higher mortality rate (P < 0.05).Conclusion: This Chinese SS‐renal population with biopsy results has diverse pathologic patterns and distinct clinical features. They are characterized with prominent renal‐associated and mild SS‐associated features. They received more vigorous treatment but had poorer prognosis.

Aim: To evaluate the effects of sodium-glucose co-transporter 2 (SGLT2) inhibition on renal function and albuminuria in patients with type 2 diabetes. Methods: We conducted systematic searches of PubMed, Embase and Cochrane Central Register of Controlled Trials up to June 2016 and included randomized controlled trials of SGLT2 inhibitors in adult type 2 diabetic patients reporting estimated glomerular filtration rate (eGFR) and/or urine albumin/creatinine ratio (ACR) changes. Data were synthesized using the random-effects model. Results: Forty-seven studies with 22,843 participants were included. SGLT2 inhibition was not associated with a significant change in eGFR in general (weighted mean difference (WMD), −0.33 ml/min per 1.73 m², 95% CI [−0.90 to 0.23]) or in patients with chronic kidney disease (CKD) (WMD −0.78 ml/min per 1.73 m², 95% CI [−2.52 to 0.97]). SGLT2 inhibition was associated with eGFR reduction in short-term trials (WMD −0.98 ml/min per 1.73 m², 95% CI [−1.42 to −0.54]), and with eGFR preservation in long-term trials (WMD 2.01 ml/min per 1.73 m², 95% CI [0.86 to 3.16]). Urine ACR reduction after SGLT2 inhibition was not statistically significant in type 2 diabetic patients in general (WMD −7.24 mg/g, 95% CI [−15.54 to 1.06]), but was significant in patients with CKD (WMD −107.35 mg/g, 95% CI [−192.53 to −22.18]). Conclusions: SGLT2 inhibition was not associated with significant changes in eGFR in patients with type 2 diabetes, likely resulting from a mixture of an initial reduction of eGFR and long-term renal function preservation. SGLT2 inhibition was associated with statistically significant albuminuria reduction in type 2 diabetic patients with CKD.